Coronary ARteriogenesis With Combined Heparin and EXercise Therapy in Chronic Refractory Angina
Phase: NA
Conditions: Refractory Angina, Chronic Stable Angina
Sponsor: Clinical Centre of Serbia

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Coronary ARteriogenesis with combined Heparin and 
EXercise therapy in chronic refractory Angina (CARHEXA): 
A phase 3 double-blind, placebo-controlled, parallel group 
study  
  
 
 
 
 
 
 
 
 
 
 
December 25, 2012 

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ABSTRACT 
Background: Although experimental studies on the stimulation of coronary arteriogenesis have 
been promising, not a single drug has been proved to be applicable in clinical practice, either due to 
lack of efficacy or because of undesired side effects. Encouraging results have been obtained with 
combination of heparin (H)) coupled with a stress inducing ischemia and augmenting shear stress, 
such as exercise.  
Aim: to establish the coronary arteriogenetic efficacy of H combined with exercise in patients with 
intractable coronary artery disease. 
Methods: We will recruit 60 "no-option" patients with chronic stable angina refractory to optimal 
medical management, and not suitable for percutaneous and/or surgical revascularization therapy. 
As further inclusion criteria eligible patients are able to exercise (and enter a cardiac rehabilitation 
program). In a prospective, randomized, double-blind study design these "no-option" patients will 
be allocated (30 for each of the 2 groups) to one of 2 treatment groups: 1) standard physical 
rehabilitation (i.v. placebo 10 min prior to each of 2 exercise session per day for 5 days a week for 2 
weeks); 2) drug-primed  physical rehabilitation (same modality as 1, but with H, 100 UI/Kg up to a 
maximum of 5.000 IU iv, 10 min prior to the exercise).  All patients will undergo exercise stress 
echo (with wall motion score index, coronary flow reserve on left anterior descending and global 
longitudinal strain evaluation) and cardiac CT (with coronary collateral assessment) both before and 
after the therapy cycle.  
Endpoints. Clinical and imaging (by blinded observers) assessment will be performed before and 
after treatment. Primary clinical endpoint is Canadian Cardiovascular Society (CCS) angina 
severity, ranging from class 1 (mild) to 4 (severe). Secondary stress imaging functional endpoint 
is peak Wall Motion Score Index (WMSI) at stress echo (ancillary endpoints: global longitudianl 
strain and coronary flow reserve).  Tertiary imaging endpoint is Coronary Collateral Circulation 
Score at cardiac CT. 
 
 
 

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Epidemiological and clinical background 
The optimal treatment of coronary artery disease (CAD) involves reducing the ischemic burden, 
lowering the risk of future adverse cardiac events, and relieving symptoms of angina pectoris. 
Medical and mechanical therapies have played a major role in reducing the morbidity and mortality 
associated with ischemic heart disease. Despite the success of these conventional therapies, there 
are patients with coronary artery disease (CAD) who continue to experience angina despite 
maximal medical and revascularization therapy. Therapeutic angiogenesis represents a novel 
treatment option for these “no-option” patients with refractory ischemic coronary disease. A 
growing body of evidence has revealed the potential of therapeutic angiogenesis with gene, protein, 
or cell-based therapies. The goal of therapeutic angiogenesis is to induce the formation of new 
vessels that can enhance blood flow to areas that no longer have adequate blood supply. Although 
cardiovascular mortality attributable to ischemic heart disease has recently declined, it is still the 
leading cause of death in the Western countries. The associated morbidity and mortality of ischemic 
heart disease produces a considerable burden on the healthcare system. The number of patients with 
chronic stable angina has been estimated to be 16,500,000 (Gibbons et al, 2003). Given the ongoing 
obesity epidemic, increased incidence of diabetes mellitus, and an aging population, this impressive 
number will likely continue to grow. With a better understanding of the patho-physiology of 
ischemic heart disease over the last several decades, there have been tremendous advances in the 
treatment of CAD. Novel pharmacological agents, improved revascularization techniques, and 
better risk assessment tools have enabled healthcare practitioners to manage patients with ischemic 
heart disease more efficiently. Despite these advances, there is a growing population of patients 
who continue to be disabled by chronic angina. Healthcare providers have numerous treatment 
options to provide angina relief for these patients. Current guidelines for chronic stable angina 
recommend quitting smoking, blood pressure control, intensive lipid-lowering therapy, adequate 
physical activity, achievement of ideal body weight, and diabetes control. Medications routinely 
prescribed include anti-platelet therapy, statins, angiotensin-converting enzyme (ACE) inhibitors, 
beta-blockers, calcium channel blockers, nitrates and more recently ranolazine. Revascularization 
either with percutaneous coronary intervention or surgical bypass is part of the management of 
chronic CAD as well. When standard treatment measures are inadequate to control angina, novel 
approaches are needed. The European Society of Cardiology has defined refractory angina as a 
“chronic condition (>3 months) characterized by the presence of angina caused by coronary 
insufficiency in the presence of CAD which cannot be controlled by a combination of medical 

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therapy, angioplasty, and coronary bypass surgery” (Mannheimer C et al, 2002). Although the 
epidemiology of refractory angina is unclear and descriptive epidemiological studies are urgently 
needed, recent data indicate that the number of patients with refractory angina not amenable to 
revascularization on optimal medical therapy (“no-option” patients) is at least 150,000 per year in 
the US alone (Williams B et al. 2010).   
The clinically elusive goal of therapeutic coronary arteriogenesis 
Patients with severe CAD commonly develop collateral flow to ischemic myocardial territories that 
ameliorate or in some cases, eliminate myocardial ischemia. However, there are many patients in 
whom this patho-physiological angiogenic response is inadequate to control angina symptoms.  
After birth, new blood vessel formation proceeds via angiogenesis or arteriogenesis. Angiogenesis 
(capillary sprouting) results in higher capillary density. Arteriogenesis (rapid production of 
collateral arterioles) is potentially able to significantly alter the outcome of coronary and peripheral 
artery disease. The processes share some growth factors but differ in many respects. Arteriogenesis 
is by far the most efficient adaptive mechanism for the survival of the internal organs such as heart 
because of its ability to conduct, after adaptive growth, relatively large blood volumes per unit of 
time. An increase in the number of capillaries, the results of stimulated angiogenesis, is unable to do 
this (Buschmann I and Schaper W, 1999).  
The goal of therapeutic angiogenesis is to enhance the formation of new vessels that can provide 
arterial blood flow to myocardial regions with inadequate blood supply. Therapeutic angiogenesis 
can be accomplished using three approaches: gene therapy delivered locally (FGF and VEGF); 
cytokines stimulating angiogenesis (MP1, PIGF, etc); hematopoietic/angiogenic stem cells. 
Although experimental studies on the stimulation of arteriogenesis has been promising, not a single 
drug have been proved to be applicable in clinical practice, either due to lack of efficacy or because 
of undesired side effects (Schirmer et al 2009). 
Pharmacologic approaches to enhance coronary arteriogenesis. 
 Our approach is based on the combination of pharmacological stimuli (with heparin) on top of a 2-
week cycle of physical rehabilitation (in patients capable to exercise). The rationale for this 
chemical-physical cocktail stems from the fact that increase in shear stress (achieved with exercise),  
or heparin – when used alone - have no significant  coronary arteriogenetic effect, which is 
consistently present, and clinically significant, when the two stimuli are coupled   (Fujita M et al. 
1988). The basic principle of heparin treatment is potentiation of angiogenic growth factors, which 

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are overexpressed by increased shear stress at the site of pre-existing collateral vessels as a result of 
exercise or pacing. Although the precise mechanisms by which heparin potentiates arteriogenesis 
remain to be completely elucidated, heparin administration combined with exercise (Tateno S et al 
2001) has great potential in treating patients with effort angina who are not indicated for 
conventional reperfusion therapy.  
Study hypothesis 
In the large and expanding population of "no-option" patients with refractory angina, a clinically 
significant coronary arteriogenetic effect can be obtained through a combination of pharmacological 
(heparin) and physical (rehabilitation exercise program) stimuli, when used in combination.     
Overall study design  
We will recruit 60 patients with chronic stable angina refractory to medical management, and not 
suitable for percutaneous and/or surgical revascularization therapy. As additional criterion for 
treatment eligibility, patients will have exercise capacity allowing to enter a rehabilitation program.  
In a prospective, randomized, open-label study design these "no-option" patients will be allocated 
(30 for each group) to 2 treatments:    1) standard physical rehabilitation (2 exercise session per day 
for 5 days a week for 2 weeks); 2) drug-primed physical rehabilitation (same modality as 1, but with 
H, 100 UI/Kg up to a maximum of 5.000 IU iv, 10 min prior to the exercise).  All patients will 
undergo exercise stress echo (with wall motion score index, coronary flow reserve on left anterior 
descending and global longitudinal strain evaluation) and cardiac CT (with coronary collateral 
assessment) both before and after then therapy cycle.  
Inclusion criteria: patients with documented coronary artery disease not amenable of further 
treatment and belonging to the “no-option” category (see above definition), with symptoms 
consistent with angina pectoris.  
Exclusion criteria: patients with unstable angina, recent acute myocardial infarction, uncontrolled 
hypertension, haemodynamically significant valvular heart disease, bronchial asthma and 
neurologic and/or orthopedic illnesses that limit exercise capacity will be excluded. Patients 
receiving vitamin K antagonist will be excluded. Patients should not be actively involved in 
programmes of cardiac rehabilitation or exercise training.    
All medications will remain unaltered during the study 

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Clinical and imaging (by blinded observers) assessment will be performed before and after 
treatment. Primary clinical endpoint is Canadian Cardiovascular Society (CCS) angina severity, 
ranging from class 1 (mild) to 4 (severe). Secondary stress imaging functional endpoint is peak 
Wall Motion Score Index (WMSI) at stress echo (ancillary endpoints: global longitudianl strain and 
coronary flow reserve). Tertiary imaging endpoint is Coronary Collateral Circulation Score  at 
cardiac CT. 
Detailed Work Plan 
The overall architecture of the project is structured into work-packages (WP) that will be run by 
separate teams, in parallel with each other:  
WP0- Study design and statistical plan    
WP1- Patient recruitment and treatment  
WP2-Assessment of treatment effect on inducible ischemia by stress echo 
WP3- Assessment of Coronary Collateral Circulation by MDCT  
  
WP0- Study design and Statistical plan  
Sample size calculation. The study is sized to detect with 80% power a clinically significant 
difference in the chosen endpoints with alpha=0.05.  For primary endpoint, a Canadian Class 
Angina = 2.5, with 0.5 standard deviation, and with an expected, clinically significant improvement 
of 0.5 will lead to a sample size of 16 patients per arm (94 % power with 25 patients per arm). For 
secondary endpoint, a peak WMSI = 1.4, with 0.25 standard deviation, and with an expected, 
clinically significant improvement of 0.2 will lead to a sample size of 25 patients per arm.  Overall a 
drop-out rate of 20 % is expected, and therefore 60 patients will be initially considered and 50 are 
expected to complete the trial (25 for each arm)   
Statistical plan: All continuous data will be given as mean+ SD. Baseline characteristics between 
the groups will be analyzed by Student t test for continuous data and chi-square/Fisher exact test for 
categorical data. Outcomes at follow-up examinations will be analyzed with chi-square test (for 
angina class) and paired Student t test (for approximately normally distributed data such as Wall 
Motion score index). Differences are considered statistically significant at a 2-sided P value of 

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<0.05. Electronic Case Report form preparation, ad interim and final data analysis will be 
performed by the Biometry Unit of the Institute of Clinical Physiology.   
Core lab reading: All imaging data will be read by a single reader blinded to patient identity and 
study conditions. 
Expected results: The group treated with active drug therapy will show a significant improvement 
of clinical, functional and perfusion indices when compared to standard rehabilitation therapy   
WP1- Patient recruitment and treatment  
CARHEXA is a prospective, randomized, single-center study: clinical enrollment and data 
collection will be done by Belgrade Unit. The Belgrade center has a recent tradition of clinical and 
scientific excellence in the field of diagnosis and treatment of coronary artery disease and has the 
facilities required to complete the study.   
Ethical Committee submission will be presented at local authority by the Belgrade Unit, also 
responsible of clinical enrollment and data collection. We will recruit 60 patients with chronic 
stable angina refractory to medical management and not suitable for percutaneous and/or surgical 
revascularization therapy (see the above definition of “no-option” patients). In a prospective, 
randomized, open-label study design these "no-option" patients will be allocated (30 for each of the 
2 groups) to one of 2 treatment groups: 1) standard physical rehabilitation (2 exercise session per 
day for 5 days a week for 2 weeks) with placebo (iv saline 10 min prior to exercise) ; 2) drug-
primed  physical rehabilitation (same modality as 1, but with H, 100 UI/Kg up to a maximum of 
5.000 IU iv, 10 min prior to the exercise).     
The Canadian Cardiovascular Society (CCS) classification of angina severity, ranging from class 1 
(mild) to class 4 (severe), is used routinely in patients with coronary artery disease and is a 
recognized marker for disease progression. 
The SAQ is a 19- item questionnaire that measures 5 clinically important dimensions of health in 
patients with CAD: angina frequency, angina stability, physical limitations, treatment satisfaction, 
and disease perception/QOL. Each domain has a score ranging from 0 to 100, with higher scores 
indicating less disease burden. The quality of life assessed with SAQ has been shown to correlate 
with long-term survival and hospitalization for acute coronary syndrome among patients with 
chronic CAD (Spertus JA et al, Circulation 2002). 

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Intravenous injections will be given by a study nurse not involved in the process of data acquisition 
and analysis.   
WP2: Assessment of treatment effect on inducible ischemia by Stress Echo   
Background: Stress echocardiography is an established technique for the diagnostic and prognostic 
evaluation of coronary artery disease. Wall motion score index assesses in a semi-quantitative  way  
the extent of inducible ischemia, which is  related to the anatomic and prognostic severity of 
underlying coronary artery disease. Noninvasive external pacing has the same accuracy as other 
physical and pharmacological stressors, and can be the first-choice option in patients with 
permanent pacemaker   (Sicari et al. 2009). 
Methods: All patients will undergo a resting echo and a stress echo, with either heparinized 
exercise (Group 1) or exercise (Group 2), according to standard clinical protocol   (Sicari R   et al, 
Eur Heart J 2009). Resting echo will assess all left ventricular function and remodeling indices, as 
previously described (Bolognese L et al, Circulation 2004). No change in underlying optimal 
conventional medical therapy will be done, except for clinically driven reasons, during the study 
period. Wall Motion Score Index (each segment from 1=normal to 4=dyskinetic in a 17 segment 
model of left ventricle) will be calculated at baseline and peak stress following the standard 
protocols of European Association of Echocardiography. In all patients a quantitative assessment of 
longitudinal strain by 2D speckle tracking will be performed.  
WP3: Assessment of Coronary Collateral Circulation by MDCT 
Cardiac CT will be performed to assess coronary collateral circulation in all patients before and 
after 2-week exercise. A collateral circulation will be graded by coronary CT angiography score 
where 0-2 means poorly developed collaterals and score 3 will be considered as well developed 
collaterals (0 = absence of distal filling; 1 = partial distal filling, with a length less than one-third of 
the segment; 2 = partial distal filling, with a length between one-third and two-thirds of the 
segment; 3 = complete or partial distal filling, with a length longer than two-thirds of the segment). 
CT angiography scores correspond fully to Rentrop classificatio. Also we will look for change in 
growth of baseline bridging collaterals at 2 weeks (0 = not present, 1 =  present). 
 
 

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