Mechanisms for improved survival in heart failure

The two major causes of death in congestive heart failure (CHF) are progressive heart failure (approximately 60% of cases) and sudden death (30%). Sudden death in CHF is caused primarily by malignant ventricular arrhythmias. The underlying mechanism has yet to be established, but myocardial metabolic factors are probably involved. Although there is a clear association between complex ventricular arrhythmias and left ventricular function, it has not been shown convincingly that antiarrhythmic agents can reduce sudden death in CHF. Progressive deterioration of myocardial function is associated with altered myocardial energy production. Notably, the physiological effects of neuroendocrine activation in chronic CHF may be deleterious to myocardial function. The CONSENSUS study was carried out to evaluate the association between neuroendocrine activation and deterioration of myocardial function using ACE inhibitors. A marked reduction in mortality rate occurred in the enalapril-treated group, where the one-year mortality was reduced by 31%. The reduction in mortality was solely among patients with progressive CHF (a reduction of 50%); there was no difference in the incidence of sudden death. Analysis of blood samples drawn at baseline in the placebo group showed a significant positive correlation between mortality and plasma angiotensin II (P less than 0.05), aldosterone (P = 0.003), noradrenaline (P less than 0.001), adrenal levels (P less than 0.001), and atrial natriuretic peptide (P = 0.003). This was not observed in enalapril-treated patients. The significant reduction in mortality in the enalapril group was found consistently among patients with baseline hormone levels above the median value. In CHF, the underlying disease may induce serious arrhythmias and/or progressive failure.(ABSTRACT TRUNCATED AT 250 WORDS)