Antiischemic effects of nicardipine and nitroglycerin after coronary artery bypass grafting

Background. We assessed the efficacy of a continuous infusion of nicardipine and nitroglycerin in reducing the incidence and severity of perioperative myocardial ischemia during elective coronary artery bypass grafting procedures in a prospective, randomized, controlled study. Methods. Patients received either nicardipine infusion (0.7 to 1.4 mu g.kg (-1).min(-1); n = 30) or nitroglycerin (0.5 to 1 mu g.kg.(-l).min(-1); n = 30) or neither medication (n = 17) after aortic occlusion clamp release and for 24 hours postoperatively. Myocardial ischemic episodes (MIE) were considered to have occurred with ST-segment depressions: or elevations of at least 1 mm and at least 2 mm (for both depressions or elevations), each at J + 60 ms and lasting at least 1 minute, using a two-channel Holter monitor. Results. Only nicardipine significantly decreased the duration (p = 0.02) of the l-mm or greater minutes per hour (3.2 + 1.2 minutes per hour) and eliminated the number (p = 0.02) of the 2-mm or greater minutes per hour (zero minutes per hour) when compared with control patients (17.2 +/-: 5.6 minutes per hour and 0.17 minutes per hour, respectively) during the intraoperative postbypass period. Conclusions. Our results suggest that nicardipine lessened the severity of myocardial ischemia shortly after coronary revascularization and could be considered as an alternative to standard antiischemic therapy. (C) 1999 by The Society of Thoracic Surgeons.