Is off-pump superior to conventional coronary artery bypass grafting in diabetic patients with multivessel disease?

Abstract

Objective: Diabetic patients often present with diffuse coronary disease than nondiabetic patients posing a greater surgical challenge during off-pump revascularization. In this study, the safety, feasibility, and completeness of revascularization for this subset of patients was assessed.

Methods: From 2002 to 2008, 1015 diabetic patients underwent myocardial revascularization. Patients received either off-pump coronary artery bypass (OPCAB; n = 540; 53%) or coronary artery bypass grafting (CABG; n = 475; 47%). Data collection was performed prospectively and data analysis was done by propensity-score (PS)-adjusted regression analysis. Primary endpoints were mortality, major adverse cardiac and cerebrovascular events (MACCEs), and a composite endpoint including major noncardiac adverse events (MNCAEs) such as respiratory failure, renal failure, and rethoracotomy for bleeding was applied. An index of complete revascularization (ICOR) was defined to assess complete revascularization by dividing the total number of distal anastomoses by the number of diseased vessels. Complete revascularization was assumed when ICOR was >1.

Results: OPCAB patients had a significantly lower mortality-rate (1.1% vs 3.8%; propensity-adjusted odds ratio (PAOR) = 0.11; p = 0.018) and displayed less frequent MACCE (8.3% vs 17.9%; PAOR = 0.66; p = 0.07) including myocardial infarction (1.3% vs 3.2%; PAOR = 0.33; p = 0.06) and stroke (0.7% vs 2.3%; PAOR = 0.28; p = 0.13). Similarly, a significantly lower occurrence of the noncardiac composite endpoint (MNCAE) (PAOR = 0.46; confidence interval (CI) 95% 0.35-0.91; p < 0.001) was detected. In particular, lesser respiratory failure (0.9% vs 4.3%; PAOR = 0.24; p = 0.63) and pleural effusions (3.3% vs 7.5%; PAOR = 0.45; p = 0.04) occurred, so that fast extubation (≤ 12 h postoperative) was more frequently possible (58.3% vs 34.2%; PAOR = 1.64; p = 0.007). The number of arterial grafts was significantly higher among OPCAB patients (1.54 ± 0.89 vs 1.33 ± 0.81; p = 0.006) due to a more frequent use of the right-internal mammary artery (35.6% vs 22.9%; p < 0.001). ICOR was significantly higher among CABG patients (1.24 ± 0.34 vs 1.30 ± 0.28; p = 0.001). However, for similar proportions in both groups, an ICOR > 1 was achieved clearly indicating complete revascularization (94.3% vs 93.7%; p = 0.24).

Conclusions: OPCAB offers a lower mortality and superior postoperative outcomes in diabetic patients with multivessel disease. Arterial grafts are used more frequently that may contribute to better long-term outcomes and the OPCAB approach does not come at the cost of less complete revascularization.