Sublingual Administration of Captopril in Patients with Acute Myocardial Ischemia

Abstract Summary : To investigate the anti‐ischemic capability of the angiotensin‐converting enzyme inhibitor captopril, 10 patients with acute myocardial ischemia (angina pectoris >1 h, ST‐segment depression ±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>0.01) with nitroglycerin for the captopril group and from 0.26±0.05 to 0.21±0.05 mV (p>0.01) for the control group. An additional decrease to 0.13±0.03 mV (p>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>0.05), while all other parameters remained unchanged. After additional sublingual administration of captopril, a significant increase in cardiac index (+13.8%, p>0.05) was measured and decreases in diastolic pulmonary and blood pressures (–19.2%, p>0.05 and –14.6%, p>0.01), systemic and pulmonary vascular resistance (–17.7%, p>0.01 and –13.6%, p>0.05), and heart rate pressure product (–8.8%, p>0.05), while no significant changes were measured in the control group. No patient suffered acute myocardial infarction during the study period.