Comparison of long-term outcomes between off-pump and on-pump coronary artery bypass grafting using Japanese nationwide cardiovascular surgery database

Objectives: In Japan, off-pump coronary artery bypass (OPCAB) is more common than on-pump coronary artery bypass. Superior early results of OPCAB have been reported; however, long-term results were still unclear. Purpose of this study is to evaluate the clinical outcomes of OPCAB in Japan using Japan Adult Cardiovascular Surgery Database. Methods: Between 2008 and 2010, 23,633 patients who underwent isolated coronary artery bypass were reported in database. We selected the cases from the hospital with mean annual coronary surgery volume of more than 50. Among the total of 7724 cases at 41 institutions, 2150 (31.2%) on-pump coronary artery bypass (ONCAB) and 5574 (68.8%) OPCAB cases were included. Propensity score (PS) matching was performed using PS developed from patient characteristics and preoperative factors resulting in 2007 cases matched pairs. Long-term follow-up data on patients’ mortality and stroke were collected. Results: In-hospital mortality was significantly lower in OPCAB (ONCAB 1.1%, OPCAB 0.4% p = 0.01). Stroke was low in OPCAB group (ONCAB 1.7%, OPCAB 0.8%, p = 0.01). There was no statistically significant difference between OPCAB and ONCAB regarding 7-year overall survival (86.1% vs 88.1% respectively), composite outcomes (72.0% vs 73.9% respectively), or cardiac deaths (97.3% vs 97.1% respectively). Subgroup analysis (more than 75 years old) showed a worse trend in OPCAB group. Only in OPCAB group, incomplete revascularization significantly influenced 7-year survival. Conclusions: OPCAB is associated with early prognostic benefits; however, it might be less favorable outcomes in the long term when patients are older or with incomplete revascularization.