Impact of Multi-Arterial Revascularization on Long-Term Major Adverse Cardiovascular Events after Coronary Bypass in 23,798 Patients

BACKGROUND This study evaluated the association between multiarterial versus single arterial bypass grafting (SAG) and all-cause mortality and major adverse cardiocerebrovascular events (MACCE), overall and across different patient subgroups from a Middle-Eastern nation. METHODS This single-center retrospective cohort study included 23798 patients. MAG and SAG groups were balanced using inverse probability weighting (IPW). Associations between MAG and outcomes were assessed using Cox regression. A series of covariate-adjusted Cox models were conducted to evaluate the effect of MAG on outcomes at different levels of independent variables, including age, sex, and cardiovascular risk factors. RESULTS In the study population (73.9% male, 65.11±9.94 years), 986 patients (4.1%) underwent MAG. Compared to the SAG group, MAG had lower crude mortality (14.1% vs. 21.6%) and MACCE (28.8% vs. 34.7%) rates during follow-up (9.23 [9.13-9.33] years). Although MAG was significantly associated with reduced risk of study outcomes at the univariate level, these associations disappeared after matching (all-cause mortality: IPW-Hazard ratio: 0.90 [95% confidence interval[CI]:0.67-1.22]; MACCE: IPW-Hazard ratio: 0.94 [95%CI:0.76-1.15]). However, covariate-adjusted models indicated that MAG was associated with a significantly reduced risk of adverse events, particularly MACCE, in men, younger patients, and those without risk factors. CONCLUSIONS MAG was not associated with improved post-surgery outcomes among the total CABG population. Our findings, however, should be interpreted in the context of a relatively low total institutional MAG burden. Choosing a second arterial conduit over saphenous vein grafts in specific patient subgroups might be reasonable. This hypothesis-generating finding should be investigated in future clinical trials in these patients.