On-Pump/Beating-Heart Myocardial Protection for Isolated or Combined Coronary Artery Bypass Grafting in Patients with Severe Left Ventricle Dysfunction: Assessment of Myocardial Function and Clinical Outcome

Abstract

Myocardial protection in coronary artery bypass grafting (CABG) with severe left ventricular (LV) dysfunction is still a surgical dilemma. Preoperative myocardial infarction (MI) and postoperative low output syndrome are serious complications in cases of inadequate protection of the heart, which has limited myocardial reserve. The aim of this study was to evaluate myocardial function and clinical outcome after on-pump/beating-heart CABG in patients with severe LV dysfunction. Between March 2001 and March 2004, clinical, operative, and postoperative data were prospectively collected from patients with LV ejection fraction (EF) < 30% who underwent on-pump/beating-heart CABG and associated procedures. There were 46 patients and the mean patient age was 58.38 +/- 9.23. The mean EF was 25.6 +/- 2.8%. Operating time was 275 +/- 63 minutes. The frequency of distal anastomosis was 3.06 +/- 1.04. Twenty-four patients required aneurysmectomy in addition to CABG, and 2 of the 24 required mitral repairs. Inotropic support was required in 14 patients (30%) and 5 of them (10.9%) also required IABP. The LV EF improved significantly after the operation when compared to preoperative measurements (25.6 +/- 2.8 versus 33.64 +/- 4.69, P < .05). Hospital mortality rate was 4.3% (2 of the 46 patients). No mortality was observed at a mean followup of 16 months after discharge from the hospital. On-pump/beating-heart CABG technique is effective in protecting myocardial functions in patients with severe LV dysfunction. The main advantage of the on-pump/beating-heart technique is the ability it provides one to perform complete revascularization, and intracavitary procedures with low morbidity and mortality even in impaired LV function.