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Physiological Effects of Grape Seed Extract in Diastolic Heart Failure

Phase 1
Completed
Conditions
Diastolic Heart Failure
Oxidative Stress
Heart Failure With Preserved Ejection Fraction
Hypertension
Hypertensive Heart Disease
Interventions
Drug: grape seed extract (MegaNatural BP, Polyphenolics, Inc.)
Registration Number
NCT01185067
Lead Sponsor
University of Michigan
Brief Summary

Diastolic heart failure (also known as "heart failure with normal ejection fraction" or "heart failure with preserved ejection fraction") occurs even though the heart muscle's pumping function is normal. In many cases diastolic heart failure is related to stiffening of the heart and blood vessels in people who have high blood pressure. Current guidelines suggest that patients should limit the salt content of their diet, as too much salty food can cause fluid retention and other problems in diastolic heart failure. Studies in animals with diastolic heart failure suggest that antioxidant chemicals found in grapes can block some of the harmful effects of salty diets. Because it is often difficult for patients with diastolic heart failure to maintain a low salt diet, the investigators are researching the effects of the antioxidant properties of grape seed extract, a natural supplement made from grape seeds. The investigators hypothesize that supplementing the diet with grape seed extract (GSE) can decrease the levels of harmful chemicals and improve heart and blood vessel function in patients with diastolic heart failure and a history of high blood pressure.

The University of Michigan research group plans to enroll 25 patients with a history of high blood pressure and diastolic heart failure in a research study. The study will assess the effects of GSE on hormones and other chemicals that can cause heart and blood vessel damage. The investigators will also study the effects of GSE on the ability of the blood vessels and heart muscles to relax at the proper time and speed. Finally, the investigators will observe how GSE affects participants' overall ability to exercise, quality of life, and blood pressure control. Study participants will be randomly assigned to take either GSE or placebo (looks like but does not contain GSE) capsules twice a day for six weeks. After a two-week break, all subjects will cross over to the opposite group of capsules for an additional six-week period. At the start of the study and at the end of each six-week time period study participants will have non-invasive heart and blood vessel testing, blood work and urine tests, and blood pressure monitoring.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
15
Inclusion Criteria

Inclusion:

  • Signs and symptoms of heart failure
  • Left ventricular ejection fraction ≥ 50% (contrast ventriculography, echocardiography, nuclear scintigraphy, MRI or CT imaging)
  • Diastolic dysfunction on previous echocardiogram/catheterization, or indeterminate diastolic function with supporting evidence of heart failure (HF) (as per European Society of Cardiology guidelines)
  • History of systemic hypertension
  • Age ≥ 50 years
  • Willing to adhere to prescribed course of supplementation
  • Informed consent
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Exclusion Criteria
  • Daily intake of antioxidant supplements or vitamins beyond that provided in a standard daily multivitamin (e.g. high-dose vitamin E or vitamin C)
  • NYHA Class IV heart failure symptoms (except during previous hospitalization)
  • Hospitalization for decompensated heart failure within past one month
  • Severely uncontrolled hypertension (SBP ≥ 180 and.or DBP ≥ 100 at rest, on current antihypertensive regimen
  • Uncontrolled diabetes mellitus (hemoglobin A1C > 9%)
  • Severe renal (estimated GFR < 30 ml/min) or hepatic disease/failure
  • Severe anemia (Hgb < 9)
  • Primary exercise limitation due to severe pulmonary disease
  • Unacceptably poor echocardiographic images for analysis
  • Worse than moderate mitral or aortic stenosis or insufficiency.
  • Non-hypertensive cause of HFpEF (e.g. valvular disease, congenital heart disease, amyloidosis, sarcoidosis, constrictive pericardial syndromes)
  • Myocardial infarction or unstable angina, including new or worsening anginal syndrome, within the past three months
  • Uncontrolled arrhythmia (including non rate-controlled atrial fibrillation)
  • Terminal illness expected to result in death within six months or active solid-organ cancer
  • Psychiatric disorder (or dementia) with potential to compromise adherence
  • Changes in medical regimen for heart disease or hypertension within past 1 month (except diuretic dose adjustment)
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Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
maltodextrin capsulegrape seed extract (MegaNatural BP, Polyphenolics, Inc.)Maltodextrin capsules (matched for appearance and taste to grape seed extract capsules) twice daily for six weeks
grape seed extract capsulegrape seed extract (MegaNatural BP, Polyphenolics, Inc.)Grape seed extract (MegaNatural BP, Polyphenolics, Inc.) 300 milligram capsules twice daily for six weeks
Primary Outcome Measures
NameTimeMethod
Brachial artery flow-mediated dilation (FMD)Post-six weeks of investigational drug and placebo intervention

Ultrasound measure of conduit artery endothelial function

Secondary Outcome Measures
NameTimeMethod
EndoPAT arterial endothelial functionPost-six weeks of investigational drug and placebo intervention

Plethysmographic measure of resistance arterial endothelial function

Resting and post-exercise ventricular systolic and diastolic functionPost-six weeks of investigational drug and placebo intervention

Standard and novel echocardiographic measures including strain/strain rate

Maximal exercise capacity and oxygen consumptionPost-six weeks of investigational drug and placebo intervention
24-hour blood pressurePost-six weeks of investigational drug and placebo intervention

Mean and diurnal variation

Carotid-femoral pulse wave velocityPost-six weeks of investigational drug and placebo intervention
Urinary 8-isoprostanesPost-six weeks of investigational drug and placebo intervention

Measure of oxidative stress

Heart failure related quality of lifePost-six weeks of investigational drug and placebo intervention

Minnesota Living With Heart Failure Questionnaire

Trial Locations

Locations (1)

University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

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