The incidence of perioperative complications after coronary artery surgery was investigated by a retrospective study of all 502 patients undergoing coronary artery bypass graft (CABG) surgery in our Department between January 1st and December 31st of last year (1990). Furthermore, the influence of obesity on the early results of surgery was assessed and the effect of preoperative weight reduction on perioperative complication rates examined. Obese patients had a greater incidence of left-stem coronary artery stenosis (p less than 0.001), hyperlipidaemia (p less than 0.05), hypertension (p less than 0.05), diabetes mellitus (p less than 0.02), and were in general younger at the time of operation (57.9 +/- 8.4 vs. 60.8 +/- 8.5 years). There were no differences in the surgery performed and in operative mortality, but there were some in perioperative morbidity. Obese patients had higher rates of infection (p less than 0.02), sternal dehiscence (p less than 0.02), arrhythmias (p less than 0.02) and myocardial infarction (p less than 0.02). No significant differences were identified in obese patients with or without preoperative weight reduction, although there was a trend of better postoperative recovery and results in patients having undergone preoperative weight reduction. Analysis of our results demonstrated obesity to be an independent risk factor for perioperative complications, hospital morbidity, and length of hospitalization.

A prospective, randomized study was performed on 120 patients undergoing elective coronary bypass grafting to define the effect of the calcium channel blocker diltiazem on perioperative ischemia, arrhythmias, and myocardial function. Patients received a continuous 24-hour perioperative infusion of either diltiazem (0.1 mg/kg per hour, n = 60) or nitroglycerin (1 ltg/kg per minute, n =60). Perioperative monitoring included hemodynamic measurements, three-channel Holter monitoring, repeated assessment of 12-lead electrocardiograms, and analysis of ischemia-specific laboratory parameters (creatine kinase, creatine kinase-MB, and creatine kinase-MB-mass and troponla-T), Global and regional systolic function and diastolic compliance were assessed by means of transesophageal echocardiography. The two groups did not differ with respect to preoperative and operative data. Except for a significant reduction in perioperative heart rate, diltiazem had no influence on hemodynamic parameters. The number (17 ± 9 versus 25 ± 5, P < 0.05) and the duration (69 ± 47 versus 104 ± 87 minutes, p < 0.05) of transient ischemic events were significantly reduced as compared with the nitroglycerin group. In addition, peak values of all assessed laboratory parameters except creatine kinase were significantly lower in the diltiazem group. Patients treated with diltiazem had a lower incidence of perioperative atrial fibrillation (5 % versus 18 %, p < 0.05) and lower numbers of ventricular premature beats per hour (10± 8 versus 19 ± 22, P < 0.05) and ventricular runs per hour (5 ± 17 versus 32 ± 38, p < 0.05). Postoperatively, the percent fractional area of contraction and percent systolic wall thickening of the anterior wall were significantly improved in the diltiazem group but not in the nitroglycerin group. In addition, the postoperative diastolic flow/velocity ratio was significantly lower in the nitroglycerin group than in the diltiazem group (0.949 ± 0.391 versus 1.331 ± 0.475, P < 0.001). It is concluded that perioperative infusion of the calcium antagonist diltiazem has no adverse effect on perioperative hemodynamics and systolic myocardial function and provides potent antiischemic and antiarrhythmic protection in patients undergoing coronary bypass grafting.

No abstract

In 91 patients undergoing elective coronary bypass grafting, the anti-ischemic and anti-arrhythmic efficacy of a 24-hour infusion of either the calcium antagonist diltiazem (0.1 mg/kg per h, n = 44) or nitroglycerin (1 micrograms/kg per min, n = 47) were compared. Myocardial ischemia was diagnosed by Holter monitoring and the repeated assessment of 12-lead ECG and serum enzyme levels and defined as a transient ischemic event, transient coronary spasm or myocardial infarction. The two groups did not differ with respect to preoperative and operative data. Postoperatively, the average heart rate and pulse pressure rate were significantly lower in the diltiazem group. The incidence of postoperative atrial fibrillation (4.5 vs 19.1%, P < 0.01), transient coronary spasm (2.3 vs 11.4%, P < 0.05) and myocardial infarction (4.5 vs 8.5%, not significant) and the frequency of ventricular premature couplets/h (12.1 +/- 4.5 vs 18.1 +/- 5.1, P < 0.05) and ventricular runs/h (2.5 +/- 0.8 vs 6.5 +/- 2.8, P < 0.05) were lower in the diltiazem as compared to the nitroglycerin group. In addition, diltiazem-treated patients had significantly lower postoperative peak values of creatine kinase-MB (19.3 +/- 11.6 vs 29.3 +/- 20.6, P < 0.05). In conclusion, perioperative infusion of diltiazem is effective in reducing the incidence and extent of arrhythmias and myocardial ischemia in patients undergoing elective coronary bypass grafting as compared to patients receiving nitroglycerin.

A prospective, randomized study was performed with 66 patients undergoing elective coronary bypass surgery involving internal mammary artery (IMA) grafts to the left anterior descending artery (LAD). Patients received a continuous peri-operative infusion of either diltiazem (0.1 mg.kg-1 h-1, n = 32) or nitroglycerin (1 microgram.kg-1 min-1, n = 34) for 24 h. The aim of this study was to define the effect of the calcium channel blocker diltiazem on peri-operative ischaemia, arrhythmias and myocardial function in patients receiving arterial bypass grafts by preventing transient vasospasm. The study patients did not differ with respect to pre-operative, operative and haemodynamic data. Patients treated with diltiazem had lower numbers of ventricular premature beats/hour (8.1 +/- 7.8 vs 20.5 +/- 11.2; P < 0.05). The anti-ischaemic efficacy of peri-operative diltiazem in patients receiving IMA grafts significantly reduced the incidence and duration of transient ischaemic events (0 vs 5). Additionally, patients receiving IMA grafts and diltiazem showed significantly lower peak levels of ischaemia-sensitive laboratory parameters, as compared to IMA graft patients receiving only nitroglycerin: CK-MB: 17.3 +/- 7.7 vs 23.5 +/- 11.0, (P < 0.05); MB-M: 29.4 +/- 14.7 vs 43.1 +/- 27.4, (P < 0.05); troponin-T: 0.88 +/- 0.6 vs 1.41 +/- 0.9, (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)