Perioperative Myocardial Protection with Continuous Infusion of Diltiazem in Coronary Bypass Surgery

Abstract

In a randomized study 120 patients undergoing elective coronary artery bypass grafting were investigated to evaluate the perioperative antiischemic and antiarrhythmic efficacy of diltiazem. The patients received a continuous, perioperative infusion of either diltiazem 0.1 mg/kg/h, N = 60) or nitroglycerin (control group lpg/kg/min, N = 60) over a period of 24 hours. Perioperative monitoring included hemodynamic measurements and 3-channel Holter monitoring up to 24 hours postoperatively; repeated assessment of 12–lead electrocardiogram; and analysis of ischenlia-specific laboratory parameters (CK-MB and troponin-T). Myocardial function was assessed preoperatively at 1 and 4 hours after cardiopulmonary bypass by transesophageal echocardiography (TEE, short axis view, monoplane 5 MHz faced array transducer). The 2 groups did not differ with respect to preoperative and operative data. Except for a significant reduction in perioperative heart rate by an average of 9 beats/min, diltiazem had no influence on hemodynamic parameters. The antiischemic efficacy of diltiazem led to a reduction of the number (17 ± 9 vs. 25 ± 5, p < 0.05) and duration (69 ± 47 vs. 104 ± 87 min, p < 0.05) of transient ischemic events and a lower incidence of perioperative myocardial infarction (3.3 vs. 6.7%) as compared to the nitroglycerin group. Peak values of CK-MB and troponin-T were significantly lower in the diltiazem group. Patients treated with diltiazem had a lower incidence of perioperative atrial fibrillation (5 vs. 18%, p < 0.05) and lower numbers of ventricular premature beats/hour (10 ± 8 vs. 19 ± 22, p < 0.05). The postoperative increase in myocardial function was more pronounced in the diltiazem group. The perioperative infusion of diltiazem does not adversely affect perioperative hemodynamics and myocardial contractility but provides potent antiischemic and antiarrhythmic protection of patients undergoing coronary artery bypass grafting. Future investigations must focus on the role of diltiazem in the improvement of long-term prognosis after coronary bypass surgery.