Clinical and haemodynamic responses to captopril and hydralazine in chronic congestive heart failure: the importance of preload reduction

Which vasodilator drug in patients with chronic heart failure? A randomised comparison of captopril and hydralazine

1. Fifty patients with symptoms due to chronic heart failure despite diuretic therapy were randomised to receive additional treatment with either hydralazine or captopril. The dose was titrated; 24 received hydralazine and 26 captopril up to a maximum daily dosage of 225 mg and 75 mg respectively. Forty-three patients had coronary heart disease and seven dilated cardiomyopathy. 2. Dyspnoea and tiredness were assessed using a visual analogue scale (0-100) before and during 12 weeks' treatment. Captopril produced a significantly greater reduction in breathlessness (F = 31.6, P less than 0.001) and tiredness (F = 65.8, P less than 0.001) compared with hydralazine. 3. There was an increase in treadmill exercise time during treatment with both hydralazine (from 5.5 (3.47-7.53) min to 6.9 (4.87-8.93) min), and captopril (from 5.0 (3.05-6.95) min to 7.8 (5.85-9.75) min), but the degree of improvement was significantly greater in the patients treated with captopril (F = 7.4, P less than 0.001). 4. There was no significant change in right ventricular ejection fraction (from 27.9 (19.3-36.5)% to 28.7 (20.1-37.3)%) or left ventricular ejection fraction (from 22.2 (14.2-30.2)% to 23.9 (15.9-31.9)%) during treatment with hydralazine. However, both right and left ventricular ejection fraction increased significantly during treatment with captopril (from 27.1 (18.9-35.3)% to 32.0 (23.8-40.2)%, P less than 0.05; and from 25.0 (17.2-32.8)% to 29.6 (21.8-37.4)%, P less than 0.05 respectively). 5. These results suggest that in patients with symptoms due to chronic heart failure despite diuretic therapy, treatment with captopril produces a greater symptomatic and haemodynamic improvement than treatment with hydralazine.