Influence of prerandomization (baseline) variables on mortality and on the reduction of mortality by enalapril. Veterans Affairs Cooperative Study on Vasodilator Therapy of Heart Failure (V-HeFT II). V-HeFT VA Cooperative Studies Group.

BACKGROUND

The effects of hydralazine plus isosorbide dinitrate were compared with those of enalapril in 804 men receiving digoxin and diuretic therapy for chronic congestive heart failure (CHF) in the Department of Veterans Affairs Cooperative Vasodilator-Heart Failure Trial (V-HeFT II).

METHODS AND RESULTS

Patients were randomly assigned to receive 20 mg of enalapril or 300 mg of hydralazine plus 160 mg of isosorbide dinitrate daily. At 2 years, treatment with enalapril resulted in a significant (28%) reduction in mortality relative to the active control treatment. Baseline variables were examined to determine their impact on risk of mortality and on relative response to treatment. Mortality rates were significantly higher in patients with severe ventricular arrhythmias; in patients with low baseline ejection fractions, low peak oxygen consumption, and low systolic blood pressures; in patients with high cardiothoracic ratios, high scores indicating greater impairment on a quality-of-life questionnaire, and high plasma norepinephrine or renin levels; and in patients in New York Heart Association (NYHA) classes III and IV. Coronary artery disease, duration of CHF, and patient age were not predictive of mortality. Enalapril reduced mortality significantly compared with hydralazine/isosorbide dinitrate in patient subgroups with high plasma renin or norepinephrine levels and in patients with low cardiothoracic ratios. Furthermore, enalapril conferred significantly greater protection from mortality than hydralazine/isosorbide dinitrate in patients in NYHA classes I and II and in patients without arrhythmias or with < or = 10 premature ventricular contractions per hour.

CONCLUSIONS

Of the prerandomization characteristics that were predictive of mortality in patients with CHF, only neurohormone measurements, cardiothoracic ratios, arrhythmia severity, and NYHA class identified subgroups of patients who benefited most from treatment with enalapril; a treatment interaction across strata was detected only for plasma norepinephrine and NYHA class. In no patient subgroup was the mortality with enalapril treatment significantly higher than the mortality with hydralazine/isosorbide dinitrate treatment.