Mechanism of death in heart failure. The Vasodilator-Heart Failure Trials. The V-HeFT VA Cooperative Studies Group

The Vasodilator-Heart Failure Trial (V-HeFT) data base provides information on the mechanism of death of male veterans entered into two trials that evaluated the effect of vasodilator therapy on survival in heart failure.

Men aged 18-75 years with heart failure were recruited at 13 Department of Veterans Affairs Medical Centers. In V-HeFT I, 283 of 642 patients (44%) died during follow-up (average, 2.3 years), and in V-HeFT II, 285 of 804 randomized patients (35.5%) died during follow-up (average, 2.5 years). Mechanism of death was established centrally using a standardized classification. In V-HeFT I, 124 of the 283 deaths (43.8%) were sudden with no worsening of symptoms; in V-HeFT II, 104 of the 285 deaths (36.5%) were sudden. An average of 31.5% of the deaths (31.4% and 31.6%, respectively) in the two trials was due to pump failure. The proportion of sudden deaths that occurred without worsening of symptoms was similar in patients with and without ischemic heart failure. Sudden deaths tended to occur earlier and pump failure deaths later in both V-HeFT studies. There was a trend for a lower percentage of cardiac deaths from pump failure and a higher percentage from sudden death in subgroups with higher peak exercise oxygen consumption (VO2), higher ejection fraction, and lower plasma norepinephrine levels. The proportion of deaths that occurred suddenly was similar in placebo, prazosin, and hydralazine plus isosorbide dinitrate treatment groups but was significantly lower in the enalapril treatment group. In V-HeFT I, measures of cardiac function and VO2 predicted pump failure death and sudden death. In V-HeFT II, VO2 and cardiothoracic ratio were independent predictors of all-cause deaths and pump failure deaths; only ejection fraction was an independent predictor of both pump failure and sudden death.

Although mechanistically distinct terminal events can be identified in patients with heart failure and physiological measurements can provide some insight into the risk of these disparate events, sudden death and pump failure death both appear largely to be linked to the severity of cardiac dysfunction and symptoms. Strategies to identify individuals for selective preventive therapy are not yet practical.