Chronic total occlusions and coronary artery bypass grafting outcomes

To investigate the association between the presence and grafting of chronic total occlusions (CTOs) and coronary artery bypass grafting (CABG) outcomes.

This was a post hoc analysis of the Randomized Endograft vs Open Prospective (REGROUP) trial, which randomized veterans undergoing isolated on-pump CABG to endoscopic versus open vein harvest (2014-2017). Patients were stratified on the basis of the presence of at least 1 CTO vessel (a 100% occluded coronary lesion for greater than or equal to 3 months) and according to whether all CTO vessels were bypassed. Rates of major cardiac adverse events (MACE) were compared.

At least 1 CTO was present in 453 of 1149 patients (39.4%). Over a median follow-up of 4.7 years (interquartile range, 3.84-5.45), MACE rates were 23.4% versus 22.2% for the CTO versus no CTO group, respectively (adjusted hazard ratio [aHR], 0.92; 95% confidence interval [CI], 0.70-1.20). MACE rates for patients with complete CTO grafting versus not were 23.1% versus 25.0%, respectively (aHR, 0.95; 95% CI, 0.57-1.57). In patients with right coronary dominance undergoing left anterior descending artery grafting, bypassing a right coronary artery CTO was associated with significantly lower rates of all-cause mortality (aHR, 0.38; 95% CI, 0.17-0.83).

In this REGROUP trial subanalysis, neither CTO presence or complete grafting of CTO vessels was associated with significantly different rates of MACE. However, the finding of possible survival benefit among a subgroup of patients undergoing grafting of a dominant RCA CTO vessel alongside left anterior descending artery grafting warrants additional study.