Effects of nicardipine and nitroglycerin on perioperative myocardial ischemia in patients undergoing coronary artery bypass surgery.

Perioperative myocardial ischemic episodes are predictive of adverse cardiac outcomes after coronary artery bypass surgery. We compared the efficacy of continuous infusions of nicardipine (group NIC) and nitroglycerin (group NTG) in reducing the frequency and severity of myocardial ischemic episodes. Patients received either a nicardipine infusion, 0.7 to 1.4 microg/kg/min (n = 30), nitroglycerin infusion, 0.5 to 1 microg/kg/min (n = 30), or neither medication (group C; n = 17) after aortic occlusion clamp release and for 24 hours postoperatively. Myocardial ischemic episodes were considered as ST segment depressions or elevations of 1 mm or greater from baseline, each at J + 60 milliseconds and lasting 1 minute or greater, using a two-channel Holter monitor. Only nicardipine significantly decreased the duration (3.2 +/- 1.2 min/h) and the area under the ST time curve (AUC; 5.7 +/- 15.7 AUC/h) of 1-mm or greater myocardial ischemic episodes compared with group C (17.2 +/- 5.6 min/h and 30.1 +/- 49 AUC/h, respectively) during the intraoperative postbypass period. A trend toward lower frequency, duration, and area under the ST time curve of myocardial ischemic episodes was observed in group NIC compared with group NTG. Cardiac indices and mixed venous oxygen saturations were significantly greater, whereas systemic pressures were less in group NIC compared with group NTG for the same period. These results suggest that nicardipine, but not nitroglycerin, decreased the duration and area under the ST time curve of myocardial ischemic episodes shortly after coronary revascularization. Larger studies are required to verify the efficacy of nicardipine in reducing the severity of myocardial ischemia during cardiac surgery.

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 microg x kg(-1) x min(-1); n = 30) or nitroglycerin (0.5 to 1 microg x kg(-1) x 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 1-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.