Define in Humans With Compensated CHF and Renal Dysfunction, the Modulating Action of Chronic AT1 Receptor Blockade in Addition to ACE Inhibition on Cardiorenal and Humoral Function
Phase: PHASE1
Conditions: Cardiorenal Syndrome (CRS)
Sponsor: Mayo Clinic

 
 
Define in Humans With Compensated CHF and 
Renal Dysfunction, the Modulating Action of 
Chronic AT1 Receptor Blockade in Addition to 
ACE Inhibition on Cardiorenal and Humoral 
Function   
 
 
 NCT01678794 
 
 
9/17/2015 

1
1R01 HL084155-01A2 Specific Aims 2:   Define in humans with compensated CHF and renal 
dysfunction, the modulating action of chronic AT1 receptor blockade in addition to ACE inhibition on 
cardiorenal and humoral function 
Horng H Chen, John A Schirger, Paul McKie, Kent Bailey and John C Burnett  - IRB approved 9/17/2015
ABSTRACT 
The broad objective of this protocol is to advance our understanding of the pathophysiological mechanisms of 
human Cardiorenal Syndrome (CRS) with a specific emphasis upon the biological interaction between 
diuretic therapy, the renin-angiotensin-aldosterone-system (RAAS) and cyclic 3′-5′-guanosine 
monophosphate (cGMP) pathway.   
Chronic heart failure (CHF) as a result of left ventricular systolic dysfunction is a clinical syndrome with high 
mortality and morbidity.  Renal dysfunction is a common and progressive complication of CHF and despite 
growing recognition of the frequent presentation of combined cardiac and renal dysfunction, or "Cardiorenal 
Syndrome (CRS)", its underlying pathophysiology is not well understood, with a lack of consensus as to its 
appropriate management.  The CRS can be classified into 2 broad categories: 1) patients with compensated 
CHF and impaired renal function; and 2) patients with decompensated CHF and worsening renal function. 
Studies have established that renal dysfunction is one of the most important prognostic indicators in patients 
with CHF, suggesting that it is a manifestation of and/or exacerbating factor for left ventricular dysfunction. In 
hospitalized patients with decompensated CHF, worsening renal function is even more important than baseline 
renal function for predicting adverse outcomes. 
Diuretics are effective and necessary to relieve congestion in CHF, and some studies have reported that in 
CHF patients with congestion, diuretic therapy may have favorable neurohumoral and hemodynamic effects. 
In contrast, recent reports have suggested potential deleterious consequence of chronic diuretic therapy on the 
progression of CHF, specifically furosemide that is the most widely used diuretic in CHF. Others and we have 
reported that in compensated CHF patients, furosemide therapy has deleterious neurohumoral and renal 
hemodynamic effects such as renal vasoconstriction and activation of the RAAS.  More importantly we 
demonstrated that angiotensin II receptor (AT1) blockade prevented the detrimental renal effects of diuretics in 
these compensated CHF patients.  In decompensated CHF patients who present with the combination of 
worsening renal function, volume overload, and diuretic refractoriness, the management of cardiorenal 
dysfunction is extremely challenging, and effective therapies are lacking.
The main objective of this study is to translate the findings of the applicant’s study in experimental CHF to 
human CHF and determine the modulating actions of chronic AT1 receptor blockade in addition to ACE 
inhibitor, beta-blocker and furosemide on cardiorenal and humoral function in humans with compensated CHF 
and renal dysfunction.  Preliminary studies completed by the applicant in experimental CHF have shown 
improvement in left ventricular function and enhanced renal function with AT1 receptor blockade.  Furthermore, 
the applicant also completed a study in human compensated CHF demonstrating that acute AT1 blockade 
prevented the detrimental renal effects of furosemide therapy. 
Hypothesis: Chronic AT1 receptor blockade in subjects with compensated CHF and renal dysfunction will 
improve renal function with increased sodium excretion, glomerular filtration rate and effective renal plasma 
flow and renal function reserve as compared to the response of placebo-treated subjects. 
This will be a double-blinded placebo controlled study design. Subjects will be randomized to the Chronic 
AT1 receptor blockade or to the placebo group. We will compare the effect of 12 weeks of Chronic AT1 
receptor blockade with Candesartan (n=38) or placebo (n=38) on cardiorenal and humoral in subjects with 
compensated CHF and renal dysfunction 

 
2
 
BACKGROUND AND SIGNIFICANCE 
 
Chronic heart failure (CHF) secondary to left ventricular systolic dysfunction is a clinical syndrome with 
significant mortality and morbidity despite recent advances in the understanding of the pathophysiology and 
treatment.  The latest figures from the American Heart Association reports a prevalence of 5 million with 
incidence of 550,000 cases, annual mortality of 52,000 and a total cost of 28 billion dollars in healthcare 
expense per year in the US. 
 
 Cardiorenal Syndrome  
Renal dysfunction is a common and progressive complication of CHF and despite growing recognition of the 
frequent presentation of combined cardiac and renal dysfunction, or "Cardiorenal Syndrome (CRS)", its 
underlying pathophysiology is not well understood, with a lack of consensus as to its appropriate management.  
The CRS can be classified into 2 broad categories: 1) patients with compensated CHF and impaired renal 
function; and 2) patients with decompensated CHF and worsening renal function.   
 
Recent studies have established the prognostic importance of renal function in both patients with compensated 
and decompensated CHF.  A multivariate analysis of the patients in the second prospective randomized study 
of Ibopamine on mortality and efficacy (PRIME) by Hillege et al1 demonstrated that estimated glomerular 
filtration rate (GFR) is the most powerful predictor of mortality, exceeding functional status and ejection fraction 
(EF).  Furthermore, a retrospective analysis of the studies in left ventricular dysfunction (SOLVD) treatment 
trial and SOLVD prevention trial by Dries et al2 confirmed that estimated GFR as an important determinant of 
survival.  Importantly, Dries et al demonstrated that a mild reduction of estimated GFR had an impact on 
survival even in patients who were asymptomatic. In patients who are hospitalized with decompensated CHF, 
worsening renal function is also associated with worse outcome as reported by Gottlieb et al3 and Smith et al4 
in 2 separate studies. In both studies, an increase in plasma creatinine of 0.2-0.3 mg/dL predicated a worse 
outcome.  Various studies have estimated that 25-30% of patients hospitalized for decompensated CHF has 
worsening of renal function leading to prolonged hospitalization increased morbidity and mortality.5-7 The acute 
decompensated heart failure national registry (ADHERE) database enrolled 160,000 non-selected patients 
admitted to the 281 participating hospitals for acute decompensated heart failure.  In this database, more than 
70% of the patients have moderate renal dysfunction as defined by estimated GFR of less than 50 ml/min m2.  
Using the classification and regression tree analysis on the ADHERE database, inpatient mortality risk can be 
estimated by measuring serum creatinine, blood urea nitrogen (BUN) and systolic blood pressure.  It has been 
determined that patients with BUN > 43 mg/dL, systolic blood pressure of < 115 mmHg and serum creatinine of 
> 2.75 mg/dL had a 10 fold increase in inpatient mortality.8 
 
Pathophysiology of Cardiorenal Syndrome 
The underlying pathophysiology of cardiorenal syndrome is not well understood; it is most likely multifactorial 
and complex.  Decreased renal perfusion can lead to renal insufficiency; this may be caused by decreased 
cardiac output and neurohumoral mediated vasoconstriction by the renin-angiotensin-aldosterone system 
(RAAS).9 Recent evidence suggests that both the natriuretic peptide (NP) and nitric oxide (NO) cyclic GMP 
pathways are impaired in CRS and may contribute to the renal dysfunction.10,11 Renal cGMP generation, which 
is calculated as follows: [urine cGMP X urine flow] – [plasma cGMP X GFR}, is a marker of renal 
responsiveness to the NP and NO.12 Furthermore, studies have proposed the assessment of renal functional 
reserve (RFR), that is, the glomerular vasodilatory response to amino acid infusion (AA), as an index of the 
intrarenal balance between vasocontricting hormones such as angiotensin II and vasodilators such as the NPs 
and NO.13,14 Under normal conditions, AA induces a decrease of renal vascular resistances and a consequent 
increase of GFR.  On the other hand, attenuated RFR has been observed in experimental models of renal 
damage and humans with hypertension, diabetes, and glomerulonephritis.15 Volpe et al demonstrated 
elegantly that in human asymptomatic left ventricular dysfunction, RFR is attenuated despite preserved 
baseline GFR, suggesting that RFR may be an early indicator of renal hemodynamic disruption.16   RFR has 
also been described as an indicator of the workload per nephron and may be useful to assess the progression 
renal dysfunction.  To date, no studies have assessed the RFR in patients with compensated CHF and renal 
dysfunction. 
 

 
3
Another cause of renal dysfunction in CHF may be due to elevated venous pressure.  This was elegantly 
demonstrated in a study by Firth et.al17 who showed that as central venous pressure increased, GFR 
decreased despite the fact that cardiac output and mean arterial blood pressure was maintained.  GFR 
improved when venous pressure returned to normal. We have recently completed a prospective study to 
assess the neurohumoral and renal hemodynamic profile in hospitalized patients with decompensated CHF 
associated with the development of CRS. (see Preliminary studies).  Our findings suggest that indeed the 
combination of pronounced activation of RAAS with decreased renal perfusion pressure (estimated by mean 
arterial pressure minus central venous pressure) and a relative deficiency of the NPs predisposes to the 
development of CRS. 
 
Among heart failure patients, several clinical features are more common in those who develop worsening renal 
function: On average, they are older and have a greater prevalence of prior heart failure, renal dysfunction, 
diabetes, and hypertension.  Furthermore, a study by Butler et al 5 demonstrated that the use of calcium 
channel blockers and higher loop diuretics doses was associated with higher risk of developing worsening 
renal failure in patients hospitalized with acute decompensated CHF.   
 
Treatment of Patients with Cardiorenal Syndrome 
The role of diuretics, especially furosemide in the management of patients with decompensated CHF and 
cardiorenal syndrome remains controversial.  Studies have suggested that aggressive diuresis with high 
diuretic doses have been associated with worsening renal function and increased mortality.  However it is 
unclear if diuretics are causally related to increased renal dysfunction and mortality risk.19 It is likely that 
diuretic resistance and concomitant worsening renal dysfunction necessitate high doses of diuretics, which are 
a marker rather than a mechanism for poor outcomes.  
 
Gaps in our Knowledge 
The cardiorenal syndrome represents an ominous and frequent development in the natural history of chronic 
heart failure, yet our understanding of the underlying mechanisms remains rudimentary, and we lack effective 
therapies. A working group on cardio-renal connections in heart failure convened by the National Heart, Lung 
and Blood Institute in August 2004 stated in the executive summary that “It is clear that our current 
understanding of cardio-renal connections is inadequate to explain many of the clinical observations 
in heart failure or to direct its therapy. Further investigation is required to elucidate the pathways by 
which integration of the cardiovascular and renal systems effectively maintains volume regulation in 
order to develop effective therapies.” 20 
 
Diuretics Therapy and the RAAS in CHF  
Diuretics are effective in relieving symptoms and edema in CHF.  The 4 main classes of diuretics are loop, 
thiazide, potassium sparing and carbonic anhydrase.21 Loop diuretics used for CHF include furosemide and 
torasemide.22 Recent studies have suggested that torasemide has anti-aldosterone actions and may be safer 
than furosemide23-25.  However furosemide is used most widely in both the outpatient therapy of CHF patients 
and in patients hospitalized for acute decompensated CHF.22 As such, we will focus on furosemide for this 
application.  While thiazide diuretics have been shown in randomized controlled studies to reduce morbidity 
and mortality in patients with hypertension26, furosemide has not been shown to improve outcome in CHF.  
Recent preclinical studies and retrospective clinical studies have questioned the safety of furosemide use in 
CHF.  McCurley et al demonstrated in a porcine model of CHF that furosemide use resulted in acceleration of 
both contractile and metabolic features of CHF, including left ventricular systolic dysfunction, elevated 
aldosterone and altered calcium handling27.  A retrospective analysis of the studies of left ventricular 
dysfunction (SOLVD) database reported that the use of potassium sparing diuretic was associated with 
improved outcome as compared to non-potassium sparing diuretics.28 We have also demonstrated in a canine 
model of mild/compensated CHF that chronic furosemide therapy resulted in activation of RAAS and the 
development of renal resistance to exogenous NPs. (see Preliminary studies) 
 
In the congested patient with LV systolic dysfunction, furosemide is extremely effective in relieving symptoms, 
reducing intracardiac pressures, and improving cardiac performance. In non-congested patients, administration 
of furosemide may result in disparate vascular and hemodynamic effects.  In an elegant study by Ikram et al29, 
they assess the effects of acute furosemide in congested patients with LV systolic dysfunction and 
subsequently assess the effects of chronic furosemide in the same patients when they are non-congested.  

 
4
They reported that in congested patients, administration of furosemide resulted in diuresis and improved 
hemodynamics in the absence of major changes in the RAAS.  However, in non-congested patients, the 
diuretic and hemodynamic responses to furosemide declined whereas the RAAS was activated. Francis et al 30 
observed that the administration of intravenous furosemide to patients with CHF on chronic diuretic therapy 
resulted in an increase in left ventricular filling pressures, a fall in the stroke volume index, and deterioration in 
pump function. We have also reported recently that the administration of oral furosemide in compensated CHF 
patients have detrimental renal vascular and neurohumoral effects.31 (See Preliminary studies) More 
importantly, we demonstrated that acute AT1 receptor blockade prevented the detrimental renal hemodynamic 
effects with suppression of aldosterone. Previous studies have also established beneficial renal hemodynamic 
and excretory function of AT1 receptor blockade in experimental models of CHF.32 Vople et al demonstrated 
that 6 weeks of AT1 blockade improve renal functional reserve in patients with mild CHF.16 It is now known that 
inhibition of ACE by ACE-inhibitors is neither uniform nor sustained, angiotensin II and aldosterone levels may 
rise again despite chronic ACE-inhibitor therapy.33 We have preliminary result suggesting that in patients with 
compensated CHF on ACE inhibitor therapy and diuretics, plasma angiotensin II levels are still elevated.34 
(See Preliminary studies)  Thus, it is possible that noxious effects of diuretics on the RAAS may hence persist 
despite ACE-inhibitor therapy and may affect prognosis adversely.  To date, the renal effects of AT1 blockade 
in patient with compensated CHF in addition to ACE inhibition has not been assessed.  
 
Gaps in our knowledge 
The renal effect of AT1 blockade in compensated patient who is already on ACE-inhibitors and beta-blockers 
remains undefined. 
 
Significance 
Our proposed studies will advance our knowledge of the integrated cardiorenal and humoral physiology in 
patients with cardiorenal syndrome.   Strategies that improve renal function in human cardiorenal syndrome 
may favorably affect clinical outcomes in this group of CHF patients, who have high morbidity and mortality and 
no proven effective therapy. 
 
PRELIMINARY STUDIES 
To understand the biological interaction between furosemide therapy, RAAS and cGMP pathway, the applicant 
has completed both laboratory-based studies in canine models of experimental compensated CHF and Overt 
CHF with cardiorenal syndrome and more importantly Clinical Research Unit (CRU) based patient orientated 
research studies and case control human studies, which are the basis for this application.  
 
Laboratory-Based Disease Oriented Studies 
Chronic Angiotensin II (AT1) receptor blockade improved renal function and enhanced renal cGMP 
production by endogenous natriuretic peptides and nitric oxide with in experimental overt CHF with 
cardiorenal syndrome65 
A hallmark of overt/severe CHF is an attenuated renal cGMP production by endogenous natriuretic peptides 
(NP) and nitric oxide (NO), which may contribute to decline in renal function.  Previous studies have 
demonstrated that Angiotensin II activate PDE V resulting in increased cGMP degradation. We therefore 
hypothesized that chronic AT1 receptor blockade would restore the renal cGMP by endogenous NPs and NO 
as assessed by urinary cGMP, with improved sodium excretion.   We determined the cardiorenal actions of 
chronic AT1 blockade (Valsartan, Novartis, 320 mg daily for 10 days, n=5) in a canine model rapid ventricular 
pacing induced overt CHF (245 bpm for 10 days) as compared to a non-treated group (n=5).  After 10 days of 
chronic AT1 receptor antagonism, urinary sodium excretion increased (UNaV) (12.4±3.3 vs 2.7±1.3 
uEq/min,p<0.05) in association with a marked increase in urinary cGMP excretion (UcGMPV) (1558±200 vs 
UcGMPV
0
1000
2000
*
              Placebo     AT1 Blocker
pmol/min
UNaV
0
10
20
         Placebo              AT1 Blocker
*
Eq/min
CO
0
1
2
3
4
       Placebo             AT1 Blocker
*
l/min
Figure 1.  Urinary cGMP 
excretion, sodium 
excretion and cardiac-
output. Open bar- 
placebo and shaded bar -
AT1 blocker. * p<0.05 

 
5
139±65 pmol/min, p<0.05) as compared to the non-treated group. (Figure 1)The natriuretic response to AT1 
receptor antagonism was localized to the inner medullary collecting duct, a nephron site rich in natriuretic 
peptide receptors, as distal tubular fractional sodium reabsorption decreased in the AT1 blocker group vs non-
treated group (97.6±0.3 vs 98.9±0.5 %, p<0.05). These renal responses occurred in the absence of any 
changes in plasma NPs or cGMP. Chronic AT1 also resulted in marked decreases in cardiac filling pressures 
(RAP: 3.4±1.1 vs 10.4±1.6 mmHg, p<0.05 and PCWP: 15.4±1.9 vs 25.6±3.1 mmHg, p<0.05) and increased 
cardiac output (CO) (2.90.4 vs 1.90.2 l/min, p<0.05). (Figure 1)   We conclude that chronic AT1 receptor 
antagonism in experimental overt CHF enhances the renal cGMP production, the common secondary 
messenger for the NPs and NO resulting in improved renal tubular function and sodium excretion. This study 
provides insight into renal and humoral pathophysiological actions of angiotensin II and the AT1 receptor in 
CHF and mechanisms by which AT1 receptor antagonism may mediate beneficial therapeutic properties. 
 
Angiotensin II AT1 receptor blockade prevents the detrimental renal actions of acute diuretic therapy in 
human heart failure in compensated human CHF which are mediated via the renin-angiotensin 
aldosterone system 31 
To better understand the effects of renin-angiotensin aldosterone system (RAAS) on renal function in human 
heart failure, we defined the renal hemodynamic and humoral actions acute AT1 blockade (Losartan, 50 mg 
orally) vs placebo in combination with Furosemide in 10 NYHA II-III CHF patients in a double-blind placebo 
controlled cross-over study.  Furosemide with placebo resulted in increased sodium excretion (212±66 to 425± 
82 Eq/min, p<0.05) associated with reductions in both renal blood flow (307±30 to 246±23 ml/min, p<0.05) 
and glomerular filtration rate (76±8 to 63±6 ml/min, P<0.05). (Figure 3)  However, after 4 hrs, there was a 
significant reduction in sodium excretion as compared to baseline (212±66 to 104±21 Eq/min, p<0.05).  In 
contrast, Lasix with Losartan resulted in a similar increase in sodium excretion without reductions in renal 
blood flow and glomerular filtration rate.  Furthermore, after 4 hrs, sodium excretion was greater as compared 
to the placebo group.  Plasma aldosterone decreased only in the losartan group.  This study suggests that the 
RAAS via AT1 receptors may be involved in the detrimental renal effects of diuretics in CHF.  Therefore, 
antagonizing the RAAS in CHF patients on diuretics may improve renal function, which is an important 
predictor of survival in human CHF.  
 
RESEARCH DESIGN AND METHODS  
 
Objectives 
The main objective of this study is to translate the findings of the applicant’s study in experimental CHF to 
human CHF and determine the modulating actions of chronic AT1 receptor blockade in addition to ACE 
inhibitor, beta-blocker and furosemide on cardiorenal and humoral function in humans with compensated CHF 
and renal dysfunction.  Preliminary studies completed by the applicant in experimental CHF have shown 
improvement in left ventricular function and enhanced renal function with AT1 receptor blockade. (see 
Preliminary studies)  Furthermore, the applicant also completed a study in human compensated CHF 
demonstrating that acute AT1 blockade prevented the detrimental renal effects of furosemide therapy. (see 
Preliminary studies) 
 
 Hypotheses 
 
1. Chronic AT1 receptor blockade in subjects with compensated CHF and renal dysfunction will improve renal 
function with increased sodium excretion, glomerular filtration rate and effective renal plasma flow as 
compared to the response of placebo-treated subjects. 
 
2. Chronic AT1 receptor blockade in subjects with compensated CHF and renal dysfunction will improve 
humoral function with suppression of the aldosterone and increase renal cGMP generation as compared to 
placebo. 
 
3. Chronic AT1 receptor blockade in subjects with compensated CHF and renal dysfunction will improve left 
ventricular systolic and diastolic function and filling pressures as compared to placebo as evident by: 
▪ 
Improvement in ejection fraction 

 
6
▪ 
Decrease in filling pressures with a decrease in the ratio of early mitral diastolic Doppler flow 
velocity (E) to tissue Doppler velocity (e’) of the mitral annulus (E/e’)  
▪ 
Improved indices of diastolic function with an increase in the e’ velocity (faster relaxation) 
▪ 
Improvement in clinical status as measured by 6-min walk and MLWHFQ 
 Study design  
 
This will be a double-blinded placebo controlled study design. Subjects will be randomized to the Chronic 
AT1 receptor blockade or to the placebo group. We will compare the effect of 12 weeks of Chronic AT1 
receptor blockade with Candesartan (n=38) or placebo (n=38) on cardiorenal and humoral in subjects with 
compensated CHF and renal dysfunction 
 
Specific methods  
 
i) Study population 
 
76 Subjects with compensated CHF with renal dysfunction  
 
Inclusion Criteria: 
▪ 
Left ventricular ejection fraction of equal or less than 40% assessed by echocardiography, nuclear scan, 
MRI or left ventriculogram within the past 48 months.   
▪ 
Stable New York Heart Association (NYHA) class II and III symptoms as defined by: no change in NYHA 
symptoms over the past 3 months, on stable doses of ACE inhibitor, beta blocker, digoxin and furosemide 
over the last 4 weeks and no episode of decompensated CHF over the past 6 months. 
▪ 
Calculated creatinine clearance of less than 90 ml/min and greater than 20 ml/min, using the MDRD 
formula assessed within the past 48 months and a confirmatory calculated creatinine clearance equal or 
less than 80 ml/min and greater than 20 ml/min at the time of enrollment.   
Subjects who are already taking AT1 receptor blocker will be excluded.  Aldosterone antagonist, antiarrhythmic 
medications and other vasodilators will be allowed; however, all cardiac medications must be at stable doses 4 
weeks prior to initial testing visit.  Subjects taking nonsteroidal anti-inflammatory drugs (NSAIDs) except aspirin 
will not be able to increase their medication dose for the duration of the study.  Subjects will be excluded if they 
have had a prior diagnosis of intrinsic renal disease, including renal artery stenosis of > 50%, or if they meet 
any one of the exclusion criteria listed below. 
 
Exclusion criteria specification 
 
▪ 
Prior diagnosis of intrinsic renal diseases including renal artery stenosis of > 50% 
▪ 
Peritoneal or hemodialysis within 90 days or anticipation that dialysis or ultrafiltration of any form will be 
required during the study period  
▪ 
Hospitalization for decompensated CHF during the past 6 months 
▪ 
Subjects that are taking AT1 receptor blockers 
▪ 
Myocardial infarction within 6 months of screening 
▪ 
Unstable angina within  6 months of screening, or any evidence of myocardial ischemia 
▪ 
Significant valvular stenosis, hypertrophic, restrictive or obstructive cardiomyopathy, constrictive 
pericarditis, primary pulmonary hypertension, or biopsy proven active myocarditis 
▪ 
Severe congenital heart diseases 
▪ 
Sustained ventricular tachycardia or ventricular fibrillation within 14 days of screening 
▪ 
Second or third degree heart block without a permanent cardiac pacemaker 
▪ 
Stroke within 3 months of screening, or other evidence of significantly compromised CNS perfusion 
▪ 
ALT >1.5 times the upper limit of normal 
▪ 
Serum sodium of  < 125 mEq/dL or > 160 mEq/dL 
▪ 
Serum potassium of < 3.5 mEq/dL or > 5.7 mEq/dL 
▪ 
Serum digoxin level of > 2.0 ng/ml 
▪ 
Hemoglobin < 9 gm/dl 
▪ 
Other acute or chronic medical conditions or laboratory abnormality which may increase the risks 
associated with study participation or may interfere with interpretation of the data 
▪ 
Received an investigational drug within 1 month prior to dosing 

 
7
▪ 
Patients with an allergy to iodine. 
▪ 
Female subject who is pregnant or breastfeeding 
▪ 
In the opinion of the investigator, is unlikely to comply with the study protocol or is unsuitable for any 
reasons 
 
ii) Study protocol 
After enrollment into the study, diet instructions will be given by a dietician about a no added salt diet, 2-3 gm 
salt/day and 0.75 gm protein/Kg/day diet which will be maintained throughout the study period. Baseline 
chemistry, ALT and complete blood count will be obtained and subjects taking NSAIDs except for aspirin will 
not increase their dose until the end of the study. A urine pregnancy test will be performed, if necessary. 
 
Twenty-four hour urine collection will be obtained one day prior to the active renal clearance study day for 
assessment of sodium excretion, creatinine clearance and microalbuminuria. . Sulfa containing medications 
and Probenecid will be withdrawn for 72 hours prior to the active renal clearance study days. Patients will be 
instructed to avoid strenuous physical activity and to abstain from smoking and alcohol-containing drinks three 
days prior to active renal clearance study day.  
 
After the three-week stabilization period subjects will fast overnight and be admitted to the CRU on the morning 
of the active study day where they will undergo a 6 min walk. Their first urine void after admitting will be 
collected for protein analysis and urine pregnancy test (if necessary).. They will complete the Minnesota Living 
with Heart Failure Questionnaire (MLHFQ) during their stay. Their usual morning dose of medications (except 
diabetic medications) will be taken at 07:00 upon admission.  The subjects will be placed in the supine position 
for 1 hour. During the first 15 minutes, two standard intravenous (IV) catheters will be placed (one in each 
arm). One catheter will be used for infusion and the other (in the contralateral arm) for blood sampling.  
Subjects will be asked to drink 5 mL/Kg of water initially and then drink the amount equal to the urine output 
every 30 minutes to ensure sufficient urinary flow. A priming dose of Iothalamate (0.0053 mL/Kg) to measure 
glomerular filtration rate (GFR) will be infused, followed by a constant rate IV sustaining dose (calculated 
according to estimated kidney function) of Iothalamate to achieve steady-state plasma concentrations of 15 to 
20 mg/L.  The subjects will be asked to empty their bladder spontaneously every thirty minutes. 
 
After an equilibration period of 45 minutes, urine and blood samples are collected at 30-minute intervals for 3 
periods to determine the baseline GFR and urinary sodium excretion (UNaV). Blood pressure will be measured 
at 20-minute intervals by using automatic blood pressure cuff, and heart rate will be continuously monitored. 
Urinary samples for determination of volume, sodium, potassium, Iothalmate, and PAH, will be obtained at the 
end of each clearance period.  Venous blood samples for Iothalmate, PAH and sodium will be obtained at the 
middle of each clearance period. During the first clearance, venous blood samples for renin, aldosterone, 
angiotensin II, ACE, ACE 2, angiotensin 1-7, ANP, BNP, Bradykinin, NO, DNA, protein and cGMP will be 
obtained and urine samples for cGMP will also be obtained. BUN will also be run. Echocardiography will be 
performed after these baseline clearances as described. 
 
At the completion of the baseline assessments, subjects will be randomized to Candesartan or placebo group. 
The randomization schedule will be provided by the Division of Biostatistics, implemented by the Mayo 
Pharmacy and administered by the CRU staff. The investigators and the CRU staff will not be aware of the 
randomization arm the subject is assigned to.   
 
Subjects will receive the first dose of study drug in the CRU.  Subjects will be started at 4 mg once a day.  
Thereafter, both blood pressure and heart rate (by electrocardiography) will continue to be monitored for the 
next 4 hours. If the patients develop symptomatic hypotension as defined by systolic blood pressure of =< 85 
mmHg, with lightheadedness, dizziness or visual symptoms after the first dose of the medication in the CRU, 
the patient will be excluded from the rest of the study.  The dose will be doubled every 14-18 days as tolerated 
to a goal of 16 mg a day or highest dose tolerated.  Patients will get blood draw 7-10 days after each dose 
increase to measure plasma creatinine and potassium until target dose is achieved. If there should be a 
potassium result <3.5 or >6.0,  subjects will need to have labs redrawn the same day.Thereafter, subjects will 
get blood draws every 4 weeks (+/- 3 days). If distance indicates, blood draws will be arranged at the 
participants local clinic. Subjects will also have access to a 24-hour phone number should they have any 
questions or develop any side effects. They will be instructed to measure their blood pressure weekly and 

 
8
record it, along with heart rate and weight. They will also receive a weekly phone call to review status. During 
the study, if patient develops symptomatic hypotension as defined above or an increase of plasma creatinine of 
> 0.3 mg/dL or hyperkalemia > 5.7 meq/ml, the dose will be reduced by 50%.  If those parameters persist, the 
dose will be decreased further by 50%.  At the discretion of the investigator, the medication can be 
discontinued. 
   
At the end of the twelve-week study period (+ 7 days), subjects will be admitted to the CRU again.  A 6-min 
walk, MLHFQ, echocardiography, renal clearance, humoral determination and renal functional reserve will be 
performed in the same manner as the baseline study.  Subjects will also perform a 24-hour urine collection the 
day prior to their return visit for determination of sodium excretion, creatinine clearance and microalbuminuria.  
Subjects will be dismissed after the renal clearance study.  
 
iii) Sample size and statistical analysis 
The sample size calculation and statistical analysis have been designed in collaboration with the Division of Biostatistics, 
(Kent Bailey, Ph.D and David Hodge, MSc). 
 
The primary analysis for this study will be a comparison of the parameters of interest between the AT1 
receptor blockade group and placebo. This analysis will be completed using a two-sample t-test comparing the 
change from baseline to the latest time point available. In addition to this primary analysis, if complete or near 
complete data is available, a secondary analysis will be completed using all data from baseline to the latest 
available time point. The groups will be compared in this analysis using a 2 factor repeated measures analysis 
of variance. Values will be expressed as the mean + SE. A statistically significant difference will be considered 
to be present when p<0.05.  
 
Sample size calculation: Preliminary data were obtained from the applicant’s previous study.  These data were 
used to estimate the standard deviation of the change in each parameter in the treated group.  It was assumed 
that the standard deviation in the untreated group would be only ½ of that in the treated group, since the 
treated group is composed of responders and non-responders, while the untreated group response data is 
largely due to biological and measurement variability between 2 occasions, with little or no actual signal.  In 
light of this argument, allocation will be unequal in order to optimize the precision of the group comparison.  
Specifically, there will be 2 treated subjects per 1 placebo subject.  Preliminary data for this analysis is 
provided below.  
 
Change from 
Baseline in AT1 
group 
Change from 
Baseline in 
Placebo group 
 N 
GFR ml/min 
-20.67±15.97 
1.13±12.18 
 6 
Na excretion 
mEq/min 
-11.89±27.27 
-10.78±20.08 
 6 
ANG II pg/ml 
29.32±107 
11.98±43.67 
 6 
Renin ng/ml/hr 
4.9±6.5 
3.9±4.4 
 6 
 
 
So based on this preliminary data, the study will have 90% power to detect the following differences using 38 
patients in the AT1 receptor blocker group, and 38 in the placebo group. 
 
 
Detectable change 
N/group   
GFR ml/min 
15 
38 and 38 
Na excretion mEq/min 
25.4 
38 and 38 
ANG II pg/ml 
100 
38 and 38 
Reninng/ml/hr 
6.1 
38 and 38 
 
Data Handling  
The study coordinator will enter data into a Microsoft Excel spreadsheet. In addition to cardiorenal and humoral 
data mentioned above, 6 min walk, MLWHFQ scores and clinical data including cardiovascular risk factors, 
medications, clinical events, laboratory data and physical exam will be collected.  Data will be stored on a 

 
9
secure site on the Mayo Clinic computer server to ensure all safety protocols established by the clinic are in 
place.  This will also provide adequate backup of the data.  Printouts of the computer information will be made 
and stored in the cardiovascular office for data backup.  At the conclusion of the study, Dr Kent Bailey and Mr. 
David Hodge, Division of Biostatistics using methods as described above, will analyze the data. Analysis will 
be completed using SAS Proprietary Software Release 8.2 (1999-2000 SAS Institute, Inc., Cary, NC). 
Guidelines established by the Department for the handling and storage of research data will be followed.  
Standardized systems have been developed to ensure that patient confidentiality is maintained. Each member 
of the department has undergone training in these systems at the time of their initial and ongoing employment 
training.  They include username/password access to data and programs; the ability to log access; patient data 
displayed by numeric id not patient name; the use of numeric identifications on all patient listings and summary 
reports of statistical analyses.  All data sets and computer programs are logged within the Division of 
Biostatistics with respect to Institutional Review Board authorization, principal and secondary investigators, 
lead statistician, team statisticians, and accounting information. Working data are maintained on a single large 
file server (over 350 GB of user space) which serves the entire Section.  Inactive data files are moved to 
archival storage under the control of an automated system, itself controlled by a DBMS based request system 
which ensures that all data movement is appropriately logged and commented.  The archival storage is hosted 
on the institutional mainframe computer.  The use of the mainframe ensures several high-level support 
functions for the archive system, e.g. storage of media in separate fire zones and regular copying of data to 
new media.  All active data and programs are maintained on a central password-protected (UNIX) system 
accessible to the members of the Division of Biostatistics.  An audit trail of file access is available if necessary. 
Active data files are backed-up nightly and are available for retrieval at any time.  
 
Recruitment of subjects 
Subjects meeting the inclusion criteria of the study will be recruited at the Mayo Clinic from the Heart Failure 
Clinic, Community Internal Medicine, General Internal Medicine, and past participants of Dr. Chen’s studies. 
The Mayo Clinic Life Science System (MCLSS) will aid recruitment for all the protocols. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Currently we have approximately 80 patients who would qualify for Specific Aims 1 
and 2.  Hence using a conservative estimate of 20% recruitment success, we project a recruitment of 16 
patients for Aims 1 and 2 in 6 months, hence we will complete Specific Aims 1 and 2 in the 5 years as stated 
below. 
 
Recruitment will be limited to men and women aged 18 years and above.  Female participants must be 
postmenopausal or have been surgically sterilized or have a negative pregnancy test and must agree to use a 
reliable double barrier method of contraception until study completion.  A double barrier method of 
contraception is considered to be a combination of TWO of the following: birth control pill/implants/injections, 
intrauterine devices, spermicide, diaphragm or condoms.    
 
Upon identification of a subject, the study will be explained in detail, the consent form reviewed, questions 
answered and the consent form signed.  Protocol procedures will then begin to be scheduled.  Subjects will 
receive a reimbursement of $400 for participation in the study. 
 

 
10 
Assessment of systolic and diastolic function by echocardiography 
 
Transthoracic echocardiography will be performed by the certified sonographer of the Mayo Clinic 
Echocardiography Laboratory. The Principal investigator, Horng Chen MD, who has level III echocardiography 
certification, will review all studies in a blinded fashion.  Echocardiographic images will be obtained from 
standard acoustic windows according to the recommendations of the American Society of Echocardiography.  
Assessment of pulmonary artery pressure: In the subcostal window, imaging of the inferior vena cava and 
hepatic veins will be performed and used to estimate RA diastolic pressures.  Pulmonary artery pressure will 
be calculated from the tricuspid regurgitation velocity and the estimated RA diastolic pressure. 
Ventricular structure: Ventricular volumes (Systolic and Diastolic) will be assessed by Biplane Simpsons 
(method of discs) analysis of LV volume obtained from two orthogonal cuts of the LV (apical 4 and 2 chamber). 
Systolic function. Ejection fraction (EF)  will be calculated from the M-mode measurements and from the 
volumes as calculated from the Biplane Simpsons analysis using the formula: EF (%) = 100 * (Diastolic 
Volume – Systolic Volume)/ Diastolic Volume 
Assessment of LV diastolic function and LV filling pressures.  Pulsed wave Doppler examination of mitral 
(before and with Valsalva maneuver) and pulmonary venous inflow as well as Doppler tissue imaging of the 
mitral annulus will be performed.  
 
Analytic methods 
Both plasma and urine concentration of Iothalmate will be determined by the Mayo Core Renal lab. Glomerular 
filtration rate (GFR) will be calculated using Iothalmate clearance using the following equation:  
 
GFR (ml / min)  =     U   x   V              
 
                         P                                                           
 
[Where:    U = urine concentration; P = plasma concentration; V = urine flow (mL/ min)] 
Plasma and urine will be analyzed for sodium with the Beckman ion-selective analyzer.  Urine creatinine will be 
measured by the Mayo Core Renal Laboratory.  Renal cGMP generation, will calculated as follows: {[urine 
cGMP * urine flow] – [plasma cGMP* GFR]}.  Venous blood for hormone analysis will be collected in heparin 
and EDTA tubes and immediately placed on ice.  After centrifugation at 2,500 rpm at 4C, the plasma will be 
decanted and stored at -80C until analysis. Urine for cGMP radioimmunoassays will also be collected on ice as 
previously described.31,67 Specific radioimmunoassays include renin, aldosterone, angiotensin II, angiotensin 1-
7 ANP, BNP, Bradykinin, NO and cGMP will be carried out in the co-investigator Dr Burnett’s laboratory, 
utilizing well established methodologies in the laboratory.68 ACE and ACE 2 will be measured by high-
performance liquid chromatography with electrochemical detection. 
 
Potential risk and protection against risk 
 
E. Human Subjects Research 
 
This Human Subjects Research meets the definition of a clinical trial. 
 
 
Human subject involvement and characteristic 
The specific subject population is described in the Specific Methods for each protocol.  The inclusion and 
exclusion criteria are listed in the Specific Methods.   These protocols will not involve special classes of 
subjects, such as fetus, neonates, pregnant women, children, prisoners, institutionalized individuals, or others 
who may be considered vulnerable populations.  
 
Source of materials  
Plasma samples, urine samples echocardiographic data and clinical data will be used entirely for research 
purposes. Patient identifiers will not be released outside of Mayo and any publications will exclude any kind of 
patient identifiers that could be correlated with the specific patient.  
 
Potential risks and Protection against risk 
 

 
11 
The overall risk for participation in this protocol is small and the main concern is that the addition of 
Candesartan (AT 1 blocker) and or increasing the ACE inhibitor dose would result in hypotension, 
hyperkalemia, and increased plasma creatinine.  However, we demonstrated that acute AT1 receptor blockade 
prevented the detrimental renal hemodynamic effects of furosemide with suppression of aldosterone. Previous 
studies have also established beneficial renal hemodynamic and excretory function of AT1 receptor blockade 
in experimental models of CHF. Vople et al demonstrated that 6 weeks of AT1 blockade improve renal 
functional reserve in patients with mild CHF.  Furthmore, the Val-HeFT and Charm studies have demonstrated 
that AT1 blockage can be added on safely in patient with stable CHF. 
 
  
To protect the patients against the risk of hypotension, hyperkalemia, and increased plasma creatinine, the 
following measure are incorporated in the protocol: 
 
 
• 
We will only include patients with compensated stable CHF as defined by; a) no change in NYHA 
symptoms over the past 3 months; b) on stable doses of ACE inhibitor, beta blocker, digoxin and 
furosemide over the past 4 weeks; c) no episode of decompensated CHF over the past 6 months.  
Theis will minimize their risk of fluid retention and congestion. 
• 
We will exclude patients with prior diagnosis of intrinsic renal diseases including renal artery stenosis of 
> 50%  
• 
We will exclude patients with Serum potassium of > 5.7 mEq/dL 
• 
The protocol for Specific Aims 2 will be initiated in the CRU under close monitoring.  Subjects will 
receive their first dose of study drug in the CRU.  Thereafter, both blood pressure and heart rate will 
continue to be monitored for the next 4 hours. If the patients develop symptomatic hypotension as 
defined by systolic blood pressure of =< 85 mmHg, with lightheadedness, dizziness or visual symptoms 
after the first dose of the medication in the CRU, the patient will be excluded form the rest of the study.   
• 
Patients will have blood drawn to measure plasma creatinine and potassium 7-10 days after every dose 
increase until target dose is achieved. Thereafter, subjects will get blood draws every 4 weeks.  If there 
should be a potassium result <3.5 or >6.0,  subjects will need to have labs redrawn the same day. 
• 
Subjects will also have access to a 24-hour phone number should they have any questions or develop 
any side effects.  
• 
They will be instructed to measure their blood pressure weekly and record it, along with heart rate and 
weight.  
• 
They will also receive a weekly phone call to review status.  
• 
During the study, if patient develops symptomatic hypotension as defined above or an increased of 
plasma creatinine of > 0.3 mg/dL or hyperkalemia > 5.7 meq/ml, the dose will be reduced by 50%.  If 
those parameters persist, the dose will be decreased further by 50%.  At the discretion of the 
investigator, the medication can be discontinued 
 
The following stopping rule will be applied to ensure patient safety 
If the patients develop symptomatic hypotension as defined by systolic blood pressure of =< 85 mmHg, with 
lightheadedness, dizziness or visual symptoms after the first dose of the medication in the CRU, the patient will 
be excluded from the rest of the study.  During the study, if patient develops symptomatic hypotension as 
defined above or an increase in plasma creatinine of > 0.3 mg/dL or hyperkalemia > 5.7 meq/ml, the dose will 
be reduced by 50%.  If those parameters persist, the dose will be decreased further by 50%.  If those 
parameters persist, the subject will be withdrawn from the study 
 
Other potential minor risk includes: 
 
The risks of blood drawing include bleeding at the puncture site, bruising and pain. These risks occur in a very 
small portion of the population. We will exclude patients with hemoglobin of < 9 g/dl. The blood draw amount 
for this study is 200 mLs.     
 
This protocol may be hazardous to an unborn child.  There is no medical information to determine whether 
there are significant risks to a fetus carried by a mother who is participating in this study.  Therefore, female 

 
12 
participants must be postmenopausal or have been surgically sterilized or have a negative pregnancy test and 
must agree to use a reliable double barrier method of contraception until study completion.  A double barrier 
method of contraception is considered to be a combination of TWO of the following: birth control 
pill/implants/injections, intrauterine devices, spermicide, diaphragm or condoms.    
 
Iothalamate contains a small amount of iodine and for persons allergic to iodine, this could pose a higher risk 
for an allergic reaction. To date in more than 5,000 patients, there have been only rare allergic reactions (one 
or two) when the solution has been used for this type of test. The amount of the material injected for this test 
will be approximately the same as used in a similar kidney function test performed on a routine basis 
(Approximately 250 test per month) in the Renal Function Laboratory. However, patients with a history of an 
allergic reaction to iodine should not participate in this study.  
 
Adequacy of protection against risks 
 
Recruitment and informed consent 
Subjects will be recruited at the Mayo Clinic from the Heart Failure Clinic, Community Internal Medicine, 
General Internal Medicine, and past participants of Dr. Chen’s studies. In addition, we also now have in place a 
new web-based patient identification system developed at Mayo by the Cardiovascular Research Program. 
Upon identification of a subject, the study will be explained in detail by the investigators or study co-ordinator, 
the consent form reviewed, questions answered, and the consent form signed.   
 
Potential benefits of the proposed research to the subjects and others 
Subjects participating in specific aims 2 may potentially benefit from this study, with improved ventricular, renal 
and humoral function.  More importantly, these studies will provide us new insights into the human cardiorenal 
syndrome that may allow us to develop new therapeutic strategies, which may benefit others with the same 
problem.   
 
Importance of knowledge to be gained 
This research will provide us new insights into the human cardiorenal syndrome that may allow us to develop 
new therapeutic strategies, which may benefit others with the same problem. 
 
Data and safety monitoring plan 
 
All clinical trial protocols carried out in the Mayo Clinic will have a Data Safety and Monitoring Plan 
incorporated into the protocol which will have to be reviewed and approved by Mayo Institutional Review Board 
(IRB).  Our plan includes the formation of an internal safety monitoring committee consisting of 2 cardiologists: 
Dr 
 and Dr 
, and one nephrologist, Dr. 
.  All adverse and serious 
adverse events occurring between consent and final study visit will be reported to the safety monitoring 
committee, NIH and our IRB.  Furthermore, the safety monitoring committee will review adverse events after 
10 and 30 subjects have completed the protocol. The recommendations of the safety committee after each 
review will be submitted to the IRB. All serious adverse events will be reported as described below. 
 
 
 A plan for reporting Serious Adverse Events (SAE) to the IRB  
 
A Serious Adverse Event is defined as an event with any of the following outcomes: 
• 
Death  
• 
Life-threatening adverse drug or device experience  
• 
Inpatient hospitalization or prolongation of existing hospitalization  
• 
Persistent or significant disability/incapacity  
Unanticipated Problem Involving Risk to Subjects or Others (UPIRTSO):  
 
Mayo Clinic's IRB and OHRP defines unanticipated problem/event involving risk to subjects or 
others (UPIRTSO) as any problem or event that was 1) serious; 2) unanticipated; AND 3) at least 
possibly related to the research procedures. 

 
13 
Serious: Serious problems/events can be well defined and include death; life threatening adverse 
experience; hospitalization: inpatient, new, or prolonged; disability/incapacity: persistent or significant; 
birth defect/anomaly; and/or per protocol OR may be problems/events that in the opinion of the local 
Investigator may have adversely affected the rights, safety, or welfare of the subjects or others, or 
substantially compromised the research data. 
Unanticipated: (unexpected) problems/events are those that are not already described as potential 
risks in the consent form, not listed in the Investigator's Brochure, or not part of an underlying 
disease. A problem/event is "unanticipated" when it was unforeseeable at the time of its occurrence. 
A problem/event is "unanticipated" when it occurs at an increased frequency or at an increased 
severity than expected. 
Related: A problem/event is "related" if it is possibly, probably or definitely related to the research 
study 
 
Mayo IRB 
 
Regardless of causality, the investigator will report SAE to DSMB within 72 hours of knowledge 
of the event to determine the relationship between the event and the study intervention. If the event 
was definitely related, probably related or possibly related to the study intervention, the PI will submit 
the UPIRTSO form to Mayo IRB within 72 hours, and include any relevant documents such as 
medical record notations or reports with the name and medical record number of the individual 
removed. Assess whether protocol modifications are required as a result of the UPIRTSO. The 
Investigator must provide an explanation on the UPIRTSO form explaining what corrective actions 
have already been taken.  
 
The following section is the Mayo IRB’s policy for handing a UPIRTSO report: 
  
  
 
 
 
  
 
 
 
 
  
 
 
 
  
 
 
  
 
  
 
  

 
14 
• 
  
 
  
 
  
 
  
 
  
 
  
 
 
  
  
  
 
  
 
 
  
 
  
 
 
  
 
 
  
 
  
 
 
  
  
  
 
  
 
  
 
  

 
15 
  
 
  
 
  
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
 
 
 
  
 
 
 
 
 
3. The names and contact information for study personnel to be contacted in the event of questions 
regarding adverse events and serious adverse events among study participants.   
  
Subjects can call Dr. Horng Chen, telephone 
, at any time about any question on the studies 
including adverse events and serious adverse events. 
 
 
 
 
 
 
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