Underutilization of ACE Inhibitors in Heart Failure

New England Journal of Medicine, 327(10), 685-691

Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces mortality among survivors of acute myocardial infarction, but whether to use ACE inhibitors in all patients or only in selected patients is uncertain. We screened 6676 consecutive patients with 7001 myocardial infarctions confirmed by enzyme studies. A total of 2606 patients had echocardiographic evidence of left ventricular systolic dysfunction (ejection fraction, < or = 35 percent). On days 3 to 7 after infarction, 1749 patients were randomly assigned to receive oral trandolapril (876 patients) or placebo (873 patients). The duration of follow-up was 24 to 50 months. During the study period, 304 patients (34.7 percent) in the trandolapril group died, as compared with 369 (42.3 percent) in the placebo group (P = 0.001). The relative risk of death in the trandolapril group, as compared with the placebo group, was 0.78 (95 percent confidence interval, 0.67 to 0.91). Trandolapril also reduced the risk of death from cardiovascular causes (relative risk, 0.75; 95 percent confidence interval, 0.63 to 0.89; P = 0.001) and sudden death (relative risk, 0.76; 95 percent confidence interval, 0.59 to 0.98; P = 0.03). Progression to severe heart failure was less frequent in the trandolapril group (relative risk, 0.71; 95 percent confidence interval, 0.56 to 0.89; P = 0.003). In contrast, the risk of recurrent myocardial infarction (fatal or nonfatal) was not significantly reduced (relative risk, 0.86; 95 percent confidence interval, 0.66 to 1.13; P = 0.29). Long-term treatment with trandolapril in patients with reduced left ventricular function soon after myocardial infarction significantly reduced the risk of overall mortality, mortality from cardiovascular causes, sudden death, and the development of severe heart failure. That mortality was reduced in a randomized study enrolling 25 percent of consecutive patients screened should encourage the selective use of ACE inhibition after myocardial infarction.

To define better the efficacy of vasodilator therapy in the treatment of chronic congestive heart failure, we compared the effects of hydralazine and isosorbide dinitrate with those of enalapril in 804 men receiving digoxin and diuretic therapy for heart failure. The patients were randomly assigned in a double-blind manner to receive 20 mg of enalapril daily or 300 mg of hydralazine plus 160 mg of isosorbide dinitrate daily. The latter regimen was identical to that used with a similar patient population in the effective-treatment arm of our previous Vasodilator-Heart Failure Trial. Mortality after two years was significantly lower in the enalapril arm (18 percent) than in the hydralazine-isosorbide dinitrate arm (25 percent) (P = 0.016; reduction in mortality, 28.0 percent), and overall mortality tended to be lower (P = 0.08). The lower mortality in the enalapril arm was attributable to a reduction in the incidence of sudden death, and this beneficial effect was more prominent in patients with less severe symptoms (New York Heart Association class I or II). In contrast, body oxygen consumption at peak exercise was increased only by hydralazine-isosorbide dinitrate treatment (P less than 0.05), and left ventricular ejection fraction, which increased with both regimens during the 2 years after randomization, increased more (P less than 0.05) during the first 13 weeks in the hydralazine-isosorbide dinitrate group. The similar two-year mortality in the hydralazine-isosorbide dinitrate arms in our previous Vasodilator-Heart Failure Trial (26 percent) and in the present trial (25 percent), as compared with that in the placebo arm in the previous trial, (34 percent) and the further survival benefit with enalapril in the present trial (18 percent) strengthen the conclusion that vasodilator therapy should be included in the standard treatment for heart failure. The different effects of the two regimens (enalapril and hydralazine-isosorbide dinitrate) on mortality and physiologic end points suggest that the profile of effects might be enhanced if the regimens were used in combination.