A Meta-Analysis of Early, Mid-term and Long-Term Mortality of On-Pump vs. Off-Pump in Redo Coronary Artery Bypass Surgery

We aimed to compare the early, mid-term, and long-term mortality between on-pump vs. off-pump redo coronary artery bypass grafting (CABG). We conducted a systematic search for studies comparing clinical outcomes of patients who underwent on-pump vs. off-pump redo CABG. We pooled the relevant studies quantitatively to compare the early (perioperative period, whether in hospital or within 30 days after discharge), mid-term (≥1 year and <5 years), and long-term (≥5 year) mortality of on-pump vs. off-pump redo CABG. A random-effect model was applied when there was high heterogeneity (I(2) > 50%) between studies. Otherwise, a fixed-effect model was utilized. After systematic literature searching, 22 studies incorporating 5,197 individuals (3,215 in the on-pump group and 1,982 in the off-pump group) were identified. A pooled analysis demonstrated that compared with off-pump redo CABG, on-pump redo CABG was associated with higher early mortality (OR 2.11, 95%CI: 1.54–2.89, P < 0.00001). However, no significant difference was noted in mid-term mortality (OR 1.12, 95%CI: 0.57–2.22, P = 0.74) and long-term mortality (OR 1.12, 95%CI: 0.41–3.02, P = 0.83) between the two groups. In addition, the complete revascularization rate was higher in the on-pump group than the off-pump group (OR 2.61, 95%CI: 1.22–5.60, P = 0.01). In conclusion, the off-pump technique is a safe and efficient alternative to the on-pump technique, with early survival advantage and similar long-term mortality to the on-pump technique in the setting of redo CABG, especially in high-risk patients. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021244721.