Does Chronic Obstructive Pulmonary Disease Impact Outcome after Coronary Artery Bypass Grafting? A Population-Based Retrospective Study in Germany

Background: The interaction between chronic obstructive pulmonary disease (COPD) and coronary artery bypass grafting (CABG) is discussed controversial. Methods: In this population-based retrospective analysis including non-emergency CABG in Germany between 2015 and 2021, the aim was to compare in-hospital mortality, hospital length of stay (HLOS), and perioperative ventilation time (VT) in patients affected by COPD and not affected by COPD. In addition, we compared outcomes after off-pump coronary artery bypass (OPCAB) and on-pump coronary artery bypass (ONCAB) surgery and outcomes after CABG with a minimally invasive technique with and without cardiopulmonary bypass (CPB) in COPD patients. Results: Of the 274,792 analyzed cases undergoing non-emergency CABG, 7.7% suffered from COPD. COPD patients showed a higher in-hospital mortality (6.0% vs. 4.2%; p < 0.001), a longer HLOS (13 days (10-19) vs. 12 days (9-16); p < 0.001), and a longer VT (33 h (11-124) vs. 28 h (9-94); p < 0.001). In subgroup analyses, COPD patients undergoing OPCAB surgery showed a lower in-hospital mortality (3.5% vs. 6.4%; p < 0.001), a shorter HLOS (12 days (9-16) vs. 13 days (10-19); p < 0.001) and a shorter VT (20 h (10-69) vs. 36 h (11-135); p < 0.001) compared to ONCAB surgery. Regression analyses confirmed that using cardiopulmonary bypass in COPD patients is associated with a higher risk of in-hospital mortality (OR, 1.86; 95% CI: 1.51-2.29, p < 0.001), a longer HLOS (1.44 days; 95% CI: 0.91-1.97, p < 0.001), and a longer VT (33.67 h; 95% CI: 18.67-48.66, p < 0.001). In further subgroup analyses, COPD patients undergoing CABG with a minimally invasive technique without CPB showed a lower in-hospital mortality (3.5% vs. 16.5%; p < 0.001) and a shorter VT (20 h (10-69) vs. 65 h (29-210); p < 0.001) compared to CABG with a minimally invasive technique and CPB. Regression analyses confirmed that using CPB in COPD patients undergoing CABG with a minimally invasive technique is associated with a higher risk of in-hospital mortality (OR, 4.80; 95% CI: 2.42-9.51, p < 0.001). Conclusions: COPD negatively impacts outcomes after non-emergency CABG. According to our results, OPCAB surgery and CABG with a minimally invasive technique without CPB seem to be beneficial for COPD patients. Further studies should be performed to confirm this.