OPCAB surgery: a critical review of two different categories of pre-operative ejection fraction

Objective: Literature review found little information on off-pump coronary artery bypass (OPCAB) procedure in patients with poor left ventricular function and there was no information comparing the low EF and normal EF patients undergoing OPCAB procedure. Methods: Between 1/1/1998 and 6/30/1999, 387patients had surgery performed utilizing the off-pump technique and 45 of these patients had pre-operative left ventricular function of equal to or less than 30% (LVEF ≦30). The two groups (LVEF ≦30 and LVEF≫30) were compared using univariate analysis. Patients in LVEF ≦30 were older and more female gender. LVEF≪30 had more NYHA class IV patients (64 vs. 50%) and more symptoms related to depressed left ventricular function. The mean pre-operative left ventricular function was 25% in LVEF ≦30 and 56% in LVEF≫30. Pre-operative predicted risk was 6.4±5.5% in LVEF ≦30 and 2.7±4.5% in LVEF≫30 (P≪0.001). Most (≫95%) of the patients in both groups were elective status, and LVEF ≦30 patients had increased incidence of redo (11 vs. 6%, P=0.2). In LVEF≫30, 84% of the patients had stable angina while only 69% in LVEF ≦30 (P=0.009). Results: Intra-operatively no significant differences were measured in number of grafts per patient (2.7 vs. 2.8), amount of blood loss, peak CK-MB, skin-to-skin time, or OR time. Patients with LVEF ≦30 have more frequent utilization IABP during pre, intra and post-operative period. The statistical analysis yields no significance in post-operative major neurological deficit between these two groups; and are comparative to the nationally reported incidence of neurological deficit for on-pump patients. The operative mortality in the low EF group was 4.4 and 1.8% in LVEF≫30 group (P=0.23). Conclusions: Given the clinical presentation of the low EF group, higher prediction risk, longer pre-operative stay, and length of ventilation (24 vs. 8 h P=0.12) a longer surgery to discharge stay (8 vs. 6 days, P=0.02) is anticipated. Short-term clinical outcomes for both groups of OPCAB patients encouraged us to continue to offer this approach to this broad base of patient population.