Acute and long-term effects of captopril on exercise cardiac performance and exercise capacity in congestive heart failure.

Although in many studies patients in heart failure treated with captopril have shown acute haemodynamic improvement at rest, little information is available about the haemodynamic response to captopril during exercise or about its effect on exercise tolerance. Haemodynamic measurements were taken at rest and during upright bicycle exercise before and during the first two days of captopril treatment in 15 patients with stable congestive heart failure. At rest, the heart rate and mean arterial pressure both declined (84 ± 11 to 78 ± 7 beats/min ( < 0.25) and 85 ± 9 to 64 ± 8 torr ( < 0.001), the left ventricular filling pressure dropped dramatically (26 ± 9 to 15 ± 7 torr ( < 0.001) while cardiac and stroke indices rose (2.0 ± 0.5 to 2.5 ± 0.61/min/m ( < 0.001) and 25 ± 8 to 33 ± 7 ml/min ( < 0.001). Similar directional changes occurred during exercise, with heart rate, mean arterial pressure, and left ventricular filling pressure at maximum exercise all falling (123 ± 15 to 115 ± 16 beats/min ( < 0.01); 93 ± 17 to 86 ± 14 torr ( < 0.05); and 35 ± 10 to 30 ± 11 torr ( < 0.001) respectively). Maximum cardiac index rose slightly, from 3.6 ± 0.7 to 3.9 ± 0.6 l/min/m, acutely, but the change was not significant. Six patients studied taking captopril long term underwent elective recatheterisation after 3 months. In these, either the beneficial haemodynamic changes seen with short-term treatment persisted or further improvement was noted, both at rest and during exercise. Most impressively, maximum exercise index rose from 3.6 ± 0.7 to 4.6 ± 1.01/min/m ( < 0.05) and this was associated with an increase in exercise duration (8.0 ± 2.2 to 11.5 ± 1.4 minutes ( < 0.05), exercise work load (332 ± 32 to 468 ± 52 kilopond-metres min, ( < 0.05) and maximum oxygen consumption (11.8 ± 2.6 to 15.6 ± 2.7 ml/min/kg, ( < 0.05). These findings indicate that captopril is beneficial during activity as well as at rest and that chronic treatment increases exercise capacity.