Conditions: Congestive Heart Failure
Keywords: heart failure diastolic dysfunction systolic dysfunction preclinical natriuretic peptide B-type natriuretic peptide cyclic guanosine monophosphate
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 58
Healthy volunteers: yes

Brief summary:
In congestive heart failure, cardiac output is low, blood pressure is high, and the body becomes congested with fluid. In normal people, when there is high blood pressure, the heart muscle cells secrete a hormone that excretes sodium and water in the urine, reducing blood pressure. The action of this hormone is called the natriuretic response. The purpose of this study is to determine if nesiritide can improve an impaired natriuretic response in subjects with asymptomatic systolic heart failure or asymptomatic diastolic heart failure.

Detailed description:
The American Heart Association and the American College of Cardiology define stage B heart failure (HF) as asymptomatic subjects with abnormal heart structure/function. With the advancement of cardiac imaging and biomarkers, abnormal heart structure and function can be detected before the development of symptoms. Stage B HF can represent either diastolic or systolic dysfunction and both are at increased risk of adverse cardiac events and development of symptomatic HF.

The broad objective of this study is to define the integrated cardiorenal response to acute volume expansion (VE) in humans with presystolic dysfunction (PSD), prediastolic dysfunction (PDD), and normal cardiac function. We hypothesized that there is an impaired cardiorenal endocrine response to acute VE in PSD and PDD which is characterized by the lack of appropriate activation of urinary cGMP and urinary sodium excretion. Further, we hypothesized that PSD, PDD, and normal control subjects would respond similarly to exogenous administration B-type natriuretic peptide (BNP).

The natriuretic peptides (NPs) are a family of structurally similar but genetically distinct peptides with vasodilating, natriuretic, renin inhibiting, and lusitropic properties. Acute peptide therapy with brain natriuretic peptide (BNP) infusion has recently been approved by the FDA as a therapeutic strategy for the treatment of acute human decompensated congestive HF. We will determine the effects of acute subcutaneous BNP or placebo administration on the integrated cardiorenal and humoral response to acute sodium load (sodium chloride 0.9% 0.25 ml/kg/min for 1 hour) in three groups of subjects: Group 1 normal controls, Group 2 with PSD, and Group 3 with PDD. Doppler echocardiography and tonometry will be used to measure cardiac and vascular function before and during the sodium load. Renal function studies will assess sodium excretion, renal plasma flow, and glomerular filtration rate at baseline, during, and after the sodium load. Blood will be drawn for humoral analysis including catecholamines, renin, aldosterone, angiotensin II, atrial natriuretic peptide (ANP), BNP, and cyclic guanosine monophosphate (cGMP) at baseline, during, and after the sodium load.

Arms:
arm 1: In the first intervention period the subjects received subcutaneous placebo given in the abdomen. After a lead in period of 15 minutes, the acute saline load was administered. There was a 2 week washout period. In the second intervention period, the subjects received subcutaneous nesiritide given in the abdomen. After a lead in period of 15 minutes, the acute saline load was administered. arm 2: In the first intervention period the subjects received subcutaneous nesiritide given in the abdomen. After a lead in period of 15 minutes, the acute saline load was administered. There was a 2 week washout period. In the second intervention period, the subjects received subcutaneous placebo given in the abdomen. After a lead in period of 15 minutes, the acute saline load was administered.

Interventions: intervention 1: Nesiritide intervention 2: Placebo intervention 3: Saline
Intervention descriptions: intervention 1: The first 10 subjects in each group will receive a dose of 5 ug/kg and the next ten subjects will receive 10 ug/kg. intervention 2: The pharmacy created a placebo subcutaneous injection volume to match the volume of the nesiritide dose. intervention 3: Normal saline 0.9% 0.25 ml/kg/min for 60 minutes

Protocol document: