Predictors of total mortality and sudden death in mild to moderate heart failure

Abstract

The relation between baseline clinical variables and subsequent mortality was examined in 295 patients with mild to moderate heart failure who participated in a multicenter trial comparing the effect on treadmill exercise tolerance of captopril, digoxin and placebo given in addition to a diuretic drug. At baseline study, all patients had a left ventricular ejection fraction ≤40%; 81% were in New York Heart Association functional class II. The etiology of heart failure was ischemic in 62% and nonischemic in 38%.During an average follow-up period of 16 months, 47 patients (16%) died and 24 deaths were classified as sudden. By univariate analysis, left ventricular ejection fraction, ventricular premature beat frequency, couplet frequency, ventricular tachycardia frequency, functional class, treadmill exercise time and nonischemic heart disease were statistically associated with mortality. With multiple logistic regression analysis, left ventricular ejection fraction was identified as the variable most closely associated with total mortality (p = 0.006). Twenty-seven percent of patients with an ejection fraction ≥20% died compared with 7% with an ejection fraction ≥30%. Ventricular tachycardia frequency on Holter monitoring was independently associated with both total mortality (p = 0.008) and sudden death (p = 0.003). Patients with a ventricular tachycardia frequency of >0.088 events/h had a mortality rate of 34% compared with 12% in those without ventricular tachycardia.In the multivariate model, functional class (p = 0.02) and etiology of nonischemic heart disease (p = 0.04) remained as independent predictors of mortality, whereas treadmill exercise duration did not. The mortality rate was 23% in patients with nonischemic heart disease; it was 12% in patients with congestive heart failure on the basis of coronary artery disease. These data allow the identification of high risk patients and subgroups, and should prove useful in designing future trials examining mortality in heart failure.