The treatment of heart failure. A methodological review of the literature.

In this article literature concerning the major drugs used in the treatment of heart failure is reviewed. Because of major discrepancies in results from short term and uncontrolled studies versus long term randomised control trials, only the latter group of studies are addressed in detail. Of 3 randomised control trials of digoxin, 1 has been positive, and 2 negative. Digoxin is probably of benefit to a minority of heart failure patients. Four randomised control trials of oral nitrates have shown a reduction in left ventricular filling pressure, and trends favouring active treatment for the indices of exercise capacity and functional status. Of 2 randomised control trials of hydralazine one is totally negative, the other difficult to interpret because of major loss of patients to followup. Of 5 trials of quinazolone derivatives (prazosin and trimazosin), 2 have been positive, 2 showed non-statistically significant trends favouring active treatment, and 1 was completely negative. These results are consistent with a modest benefit of prazosin and trimazosin in some heart failure patients. Five trials of angiotensin-converting enzyme inhibitors (captopril and enalapril) have shown dramatic and consistent benefit in exercise capacity and functional status. These results support a clinical policy of initial treatment with diuretics and addition of either captopril or enalapril for patients who remain symptomatic on optimal diuretic therapy. A trial of digoxin is warranted in patients whose functional capacity remains reduced on this regimen.