Comparative Evaluation of Off-Pump versus On-Pump Coronary Artery Bypass Grafting on Early Postoperative Inflammatory Markers and 30Day Mortality: A Prospective Cohort Study

Background: Coronary artery bypass grafting (CABG) remains the cornerstone revascularization strategy for multivessel coronary artery disease. Cardiopulmonary bypass (CPB) utilized during on-pump CABG (ONCAB) is known to provoke a systemic inflammatory response that may adversely influence postoperative outcomes. Off-pump CABG (OPCAB) avoids CPB, theoretically mitigating this inflammatory cascade, yet the comparative clinical significance of attenuated inflammation on hard clinical endpoints remains contested. Methods: A prospective cohort study was conducted at cardiac surgery center. A total of 342 consecutive patients undergoing isolated primary CABG were enrolled: 168 in the OPCAB group and 174 in the ONCAB group. Inflammatory markers were measured preoperatively and at 6, 24, and 72 hours postoperatively. Primary outcomes included peak postoperative inflammatory marker concentrations and 30-day mortality. Results: Peak CRP levels were significantly lower in the OPCAB group (98.4 ± 32.7 vs. 142.6 ± 41.3 mg/L; p < 0.001). Similarly, peak IL-6 (186.3 ± 72.4 vs. 298.7 ± 94.8 pg/mL; p < 0.001) and peak PCT (1.24 ± 0.68 vs. 3.87 ± 1.92 ng/mL; p < 0.001) were significantly attenuated in OPCAB patients. Thirty-day mortality was 1.8% in the OPCAB group versus 4.0% in the ONCAB group (p = 0.219). After multivariable adjustment, elevated peak IL-6 concentration was independently associated with 30-day mortality (adjusted OR = 1.008; 95% CI: 1.003–1.014; p = 0.002). Conclusion: OPCAB significantly attenuates the early postoperative systemic inflammatory response compared to ONCAB. While a trend toward reduced 30-day mortality was observed with OPCAB, this difference did not achieve statistical significance. Elevated IL-6 independently predicted early mortality, suggesting that inflammation modulation may represent a mechanistic pathway through which surgical technique influences clinical outcomes.