Targeting Central Pulsatile Hemodynamics in Chronic Kidney Disease

Study Overview
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Brief Summary
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Heart failure (HF) is an epidemic and is a major burden on the US healthcare system. The most common cardiovascular endpoint is HF. Thus, novel interventions to prevent HF in chronic kidney disease (CKD) are highly desirable. This study will assess: the variability in the response to isosorbide mononitrate (ISMN) therapy; the degree of change in central hemodynamics and cardiac endpoints through analysis of changes in left ventricle (LV) mass, diffuse myocardial fibrosis, and myocardial systolic and diastolic function.

Detailed Description
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This is a open label, parallel arm, randomized study of ISMN with or without vitamin C to improve exercise capacity and LV remodeling in CKD. Twenty subjects with CKD will be enrolled in this study and three different daily doses of sustained release isosorbide mononitrate (SR-ISMN) will be administered over time accompanied by a random administration of vitamin C in half of the subjects (500 mg three times daily). Before administration of SR-ISMN, baseline assessments will be performed. These include arterial tonometry, Doppler echocardiography, reflection magnitude measurements, a bicycle exercise test, activity monitoring, cardiac MRI, 24-hour blood pressure monitoring, and blood drawing. After these assessments, a dose of 30 mg of SR-ISMN will be administered daily (either with or without vitamin C) for the first week, 60 mg SR-ISMN for the second week, and 120 mg for the third week. After each week, blood pressure and central hemodynamics will be assessed. The third week visit also includes the bicycle exercise study and initiating the long term dose (60 or 120 mg) of SR-ISMN. In the long-term phase, blood pressure and hemodynamics are assessed at 12-weeks post initiation of the study medication(s). After 24 weeks we will perform the final assessment, which includes the same tests performed during the baseline assessment. Enrollment will take place at the Hospital of the University of Pennsylvania and the Penn Presbyterian Medical Center.

Official Title
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Targeting Central Pulsatile Hemodynamics in Chronic Kidney Disease

Conditions
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Renal Insufficiency, Chronic

Intervention / Treatment
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* Drug: ISMN
* Dietary Supplement: Vitamin C


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic kidney disease stage 3 Elevated left ventricular mass index or LV posterior wall thickness >1.4 cm documented in a clinically indicated echocardiographic or MRI examination within the previous 24 months or electrocardiographic LV hypertrophy Stable medical therapy as defined by no addition, removal or change in dosage >100% of Angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers, beta-blockers, or calcium channel blockers for > 30 days Current therapy with an ACE inhibitor, hydralazine or a statin, all of which have been shown to reduce nitrate tolerance Exclusion Criteria: A clinically- indicated stress test demonstrating significant myocardial ischemia within 1 year of enrollment, not followed by coronary revascularization Rhythm other than sinus (i.e., atrial fibrillation) Non-cardiac condition limiting life expectancy to <1 year Current or anticipated future need for long acting organic nitrate therapy Severe aortic or mitral valve disease Hypertrophic cardiomyopathy Known infiltrative or inflammatory myocardial disease (amyloid, sarcoid) Pericardial disease Primary pulmonary arteriopathy History of myocardial infarction, unstable angina, percutaneous transluminal coronary angiography (PTCA) or coronary artery bypass grafting (CABG) within 60 days, or requirement for either PTCA or CABG at the time of consent Resting heart rate (HR) >100 bpm A reduced LV ejection fraction (EF<50%) Known severe liver disease (AST >3x normal, alkaline phosphatase or bilirubin >2x normal) Allergy to ISMN Current therapy with phosphodiesterase inhibitors, such as sildenafil, vardanafil or tadalafil Therapy with rosiglitazone Current pregnancy or a positive urine pregnancy test; women who become pregnant during the study will be discontinued from the trial Therapy with warfarin History of kidney stones History of glucose-6-phosphate dehydrogenase (G6PD) deficiency Systolic blood pressure <110 mmHg or diastolic blood pressure <40 mmHg; Contraindications to a cardiac MRI: (a) Central nervous system aneurysm clips; (b) Implanted neural stimulators; (c) Implanted cardiac pacemaker or defibrillator; (d) Cochlear implant; (e) Ocular foreign body (e.g. metal shavings); (f) Other implanted medical devices: (e.g. drug infusion ports); (g) Insulin pump; (h) Metal shrapnel or bullet; (i) Claustrophobia; (j) Extreme obesity rendering the patient unable to fit into narrow-bore scanners; (k) Unwillingness of the patient to undergo a cardiac MRI.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ISMN Only<br>Patients receive only ISMN | Drug: ISMN<br> <br> |
| Experimental: ISMN AND Vitamin C<br>Patients receive both ISMN and Vitamin C | Drug: ISMN<br> <br> Dietary Supplement: Vitamin C<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in LV Mass | Variability seen in change in LV mass with ISMN administration measured with steady-state free precession cardiac MRI, outcomes reflect the change, in grams | Measured at Baseline Visit and 24 Week Visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Diffuse Myocardial Fibrosis | Myocardial ECV was assessed using a modified Look-Locker inversion recovery sequence to assess T1 times before and following the IV administration of gadolinium contrast in a mid-ventricular short-axis slice. Parameters for modified Look-Locker inversion recovery were: field of view=340mm2; matrix size=144×192; slice thickness=6mm; repetition time=2.4ms; echo time=1.18ms; flip angle=30 degrees, bandwidth=1000 Hz/pixel, integrated parallel acquisition techniques=2. Myocardial T1measurements were performed before and at several time points (5, 10, 15, and 20-40 min) post-gadolinium administration. Modified Look-Locker inversion recovery was performed with a 5-3-3 schema with (2 inversions, 5 echo times after inversion 1, 3 T1 recovery heartbeats, and 3 echo times after inversion 2). All T1 measurements were used to compute lambda (the myocardium-blood partition coefficient) as the slope of the myocardial 1/T1 over the blood 1/T1 change, by linear regression. | Measured at Baseline Visit and 24 Week Visit | 
| Changes in Myocardial Systolic and Diastolic Function | Variability in changes in myocardial function with ISMN administration, assessed via systolic longitudinal strain (measured with tissue tracking MRI) with adequate data for tissue tracking. Strain is the shortening during contraction, expressed as a promotion of the end-diastolic myocardial length. Shortening is indicated by a negative value. Strain is a unit-less metric and is thus expressed in %. A change with negative sign indicates more pronounced shortening of baseline compared to 6 months; a change with positive sign indicates less pronounced shortening during contraction. | Measured at Baseline Visit and 24 visits | 
| Pulse Wave Reflection Magnitude | Measured by arterial tonometry and echocardiography. The data reflects estimated changes in each group utilizing all available measurements, collected at all timepoints (baseline visit and weeks 1, 2, 3, 12, and 24 visits). Numbers are estimated changes in each group utilizing available measurements. The change represents the absolute change in the ratio of backward to forward wave amplitudes, multiplied by 100. | Measured between Baseline Visit-Week 24 | 
| Aerobic Capacity | Variability in changes in aerobic capacity (peak oxygen consumption during maximal supine bicycle exercise test) | Change from Baseline at Week 24 reported | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Kidney Diseases, Chronic Kidney Insufficiency, Chronic Renal Diseases, Chronic Renal Insufficiency, Kidney Insufficiency, Chronic, Cardiac Failure, Congestive Heart Failure, Heart Decompensation, Heart Failure, Congestive, Myocardial Failure