Sublingual administration of captopril in patients with acute myocardial ischemia

To investigate the anti-ischemic capability of the angiotensin-converting enzyme inhibitor captopril, 10 patients with acute myocardial ischemia (angina pectoris less than 1 h, ST-segment depression greater than or equal to 0.1 mV, no rise in creatine phosphokinase) received 25 mg captopril sublingually after being treated with an intravenous infusion of nitroglycerin (3 mg/h) and heparin (1200 IU/h) for 1 hour. A control group of 10 patients received placebo instead of captopril. Results showed a decrease of the initial ST-segment depression from 0.25 +/- 0.04 to 0.2 +/- 0.03 mV (p less than 0.01) with nitroglycerin for the captopril group and from 0.26 +/- 0.05 to 0.21 +/- 0.05 mV (p less than 0.01) for the control group. An additional decrease to 0.13 +/- 0.03 mV (p less than 0.001) was measured after sublingual captopril, while no significant change was found in the placebo group (0.19 +/- 0.04 mV). In both groups, 3 patients had no incidents of angina after 1-h nitroglycerin infusion. An additional 6 patients resolved their complaints after captopril administration in contrast to only 1 after placebo. Two patients in the placebo group required increased doses of nitroglycerin because of impairment of anginal complaints. Hemodynamic measurements documented a significant drop of pulmonary vascular resistance after a 1-h infusion of nitroglycerin (-12.9% and -13.1%, respectively, p less than 0.05), while all other parameters remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)