Noncardioplegic myocardial protection in high-risk coronary artery bypass grafting

Introduction

This study was undertaken to determine whether intermittent aortic cross-clamping in the fibrillating heart can be used successfully in high-risk coronary artery bypass grafting.

Method

From 1 January 1988 to 30 April 2000, 25,887 patients underwent isolated coronary bypass grafting for coronary artery disease at our institution. In all cases, myocardial protection consisted of intermittent aortic cross-clamping in the fibrillating heart under mild hypothermia. A total of 908 patients (797 male [88%]; mean age 60.1 ± 9.5 years, range 29-78 years) were suffering from ischaemic cardiomyopathy defined as global (left ventricular ejection fraction <30%) and regional wall motion abnormalties. The pre-, peri- and postoperative data for this subgroup were entered prospectively into a database.

Results

Mean aortic cross-clamp time was 25.01 ± 8.2 min (range 0-46 min), mean perfusion time was 60.8 ± 26.3 min (range 19-336 min), and the number of bypass grafts per patient was 3.11 ± 0.927. Weaning from extracorporeal circulation was possible without catecholamines in 348 patients (38%); 560 (62%) received dopamine intravenously. Intra-aortic balloon counterpulsation was used in 85 patients (9%) and assist devices were used in nine patients. Twenty-eight patients (3.1%) suffered from perioperative myocardial infarction, 96 patients developed ventricular arrhythmia and 191 atrial fibrillation. Ventilatory support for longer than 24 h was required by 118 patients. Eighteen patients (2.0%) died within 30 days of the operation.

Conclusion

Intermittent aortic cross-clamping in the fibrillating heart can be used safely for myocardial protection in all patients undergoing surgical revascularization. The results even in this high-risk group of patients compare favourably with all published series utilizing other forms of myocardial protection. Furthermore, this method is easy to use and cost neutral.