Physiological Effects of Grape Seed Extract in Diastolic Heart Failure
Status:
Completed
Trial end date:
2014-02-24
Target enrollment:
Participant gender:
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.