Rhode Island Diastolic Dysfunction - Heart Failure

Not Applicable

Completed

Conditions: Heart Failure
Cardiovascular Disease

Interventions: Drug: Kuvan

Registration Number: NCT02353312

Lead Sponsor: Providence VA Medical Center

Brief Summary: To study the hypothesis that treating patients with underlying diastolic dysfunction with oral Kuvan® (BH4, also known as tetrahydrobiopterin) in addition to current best practices will improve metabolic and echocardiographic diastolic function parameters.

Detailed Description: Congestive heart failure carries a significant epidemiologic and economic burden in today's healthcare system and is associated with increased morbidity and mortality in those affected.

There are approximately 5 million people in the United States with heart failure, and of those, nearly half have heart failure with preserved ejection fraction (HFpEF). HFpEF, also referred to as diastolic heart failure, is a clinical syndrome characterized by prolonged relaxation of the myocardium resulting in symptoms including dyspnea, edema, fatigue, and decreased exercise tolerance, which are clinically indistinguishable from the presentation of heart failure with reduced ejection fraction (HFrEF). The underlying mechanisms in diastolic dysfunction are not clearly elucidated, making targeted therapy a challenge. There are currently no FDA approved treatments for this syndrome, and multiple clinical trials have demonstrated that standard treatments for systolic heart failure are ineffective in treating diastolic dysfunction. One of the proposed underlying mechanisms of diastolic dysfunction is via the reduction of nitric oxide (NO), an endothelium-derived vasodilator that regulates blood pressure and regional blood flow. In 2010, Silberman et al. examined the effect of cardiac oxidation on nitric oxide and found that depletion of tetrahydrobiopterin (BH4), an essential cofactor in the production of nitric oxide, causes uncoupling of nitric oxide synthase, impaired relaxation of cardiac myocytes, and leads to subsequent diastolic dysfunction. The authors further went on to demonstrate that treatment with BH4 can improve diastolic dysfunction in a hypertensive mouse model as well as in isolated cardiac myocytes and may play a role in the treatment of HFpEF.

To the investigators' knowledge, the role of BH4 in treating diastolic dysfunction in human subjects has not been studied.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 28

Inclusion Criteria

Male and female U.S. Veteran patients over the age of eighteen, with echocardiographic findings of >= Grade 2 diastolic dysfunction [as per American Society of Echocardiography guidelines] and
Diagnosis of hypertension, diabetes, or heart failure in medical records.
Eligible subjects must be ambulatory (not dependent on any ambulatory assist devices including cane or walker).

Exclusion Criteria

Any history of documented ejection fraction <50%
Significant COPD (defined as oxygen-dependent COPD)
Acute coronary syndrome within the past three months defined by EKG changes and biomarkers of myocardial necrosis (ie. elevated troponin) in the setting of chest pain or an anginal equivalent)
Presence of hypertrophic cardiomyopathy
Presence of infiltrative/restrictive cardiomyopathy
Echocardiographic evidence of moderate or severe aortic or mitral valve stenosis or regurgitation
Previously diagnosed phenylketonuria
End stage renal disease requiring hemodialysis
Pre-existing seizure disorder
Terminal illness (not including heart failure) with expected survival of one year or less
Females who are pregnant or breastfeeding. All females of child bearing age will undergo pregnancy testing prior to randomization.
Recent hospitalization within three months.
Previous Bioprosthetic and/or mechanical aortic or mitral valves

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Initial Intervention Arm	Kuvan	Kuvan® supplementation in addition to standard care for heart failure for three months. At the end of three months, stop Kuvan®, patients will only receive Standard care for heart failure for another 3 months
Delayed Intervention Arm	Kuvan	Standard care for heart failure for three months. At the end of three months, Starting Kuvan® supplementation in addition to Standard care for heart failure for another 3 months

Primary Outcome Measures

Name	Time	Method
Change From Baseline in Oxygen Consumption During Maximal Bike Exercise	Baseline (period 0), 3 mos (period 1), 6 mos (period 2)	The change from baseline in oxygen consumption during maximal bike exercise. This was measured using cardiopulmonary exercise tress test (CPET), recorded in milliliters per kilogram per minute (mL/kg/min). Higher oxygen consumption scores indicate better aerobic capacity and cardiovascular function. An increase in oxygen consumption from baseline to post-intervention signifies an improvement in these areas. Conversely, a decrease would indicate a decline in aerobic capacity and cardiovascular health.

Secondary Outcome Measures