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The following is a summary of “Chronic Total Occlusions and Coronary Artery Bypass Grafting Outcomes,” published in the August 2024 issue of Surgery by Gikandi et al.

This study aimed to explore the impact of chronic total occlusions (CTO) and their grafting on outcomes in patients undergoing coronary artery bypass grafting (CABG). Chronic total occlusions, defined as 100% occluded coronary lesions persisting for three months or longer, present a unique challenge in surgical revascularization, with implications for patient outcomes.

In this post hoc analysis of the REGROUP trial, which randomized veterans undergoing isolated on-pump CABG to either endoscopic or open vein harvest between 2014 and 2017, patients were stratified based on the presence of at least one CTO and whether all identified CTO vessels were successfully bypassed. The primary outcomes assessed were rates of major adverse cardiac events (MACE), focusing on the potential survival benefits associated with complete CTO grafting.

Among the 1,149 patients included in the analysis, 453 (39.4%) had at least one CTO. Over a median follow-up period of 4.7 years (interquartile range 3.84-5.45), the overall MACE rates were similar between patients with CTO (23.4%) and those without (22.2%), with an adjusted hazard ratio (AHR) of 0.92 (95% CI 0.70-1.20), indicating no significant difference in outcomes based on CTO presence alone. Similarly, when comparing patients with complete CTO grafting to those with incomplete grafting, MACE rates were 23.1% vs. 25.0%, respectively (AHR 0.95, 95% CI 0.57-1.57), suggesting that complete CTO grafting did not result in a statistically significant reduction in adverse events.

However, a noteworthy finding emerged in a subgroup of patients with right coronary artery (RCA) dominance who underwent left anterior descending artery (LAD) grafting. In these patients, bypassing a CTO in the dominant RCA was associated with significantly lower all-cause mortality, with an adjusted hazard ratio of 0.38 (95% CI 0.17-0.83), suggesting a potential survival benefit in this population.

In conclusion, this subanalysis of the REGROUP trial indicates that the presence of CTO or complete grafting of CTO vessels does not significantly alter the overall rates of MACE in patients undergoing CABG. However, the potential survival advantage observed in patients with RCA dominance and LAD grafting who received complete RCA CTO grafting warrants further investigation to understand the clinical implications better and to guide surgical decision-making in this complex patient subset.

Source: sciencedirect.com/science/article/abs/pii/S0022522324007001