Effect of vasodilator therapy on mortality in chronic congestive heart failure

The reduction of mortality in patients with chronic congestive heart failure treated with the vasodilator regimen hydralazine and isosorbide dinitrate compared to those treated with placebo or prazosin in the Veterans Administration Cooperative Study (V-HeFT) was examined in order to explore the possible mechanism of the favourable effect. Similar efficacy in coronary and non-coronary disease patients tends to discount a prominent effect on myocardial perfusion. The most likely explanation for the prolonged survival on the effective vasodilator regimen is that these drugs tend to increase left ventricular ejection fraction, probably by a sustained effect on preload and impedance.