Predictors of restenosis following contemporary subintimal tracking and reentry technique: The importance of final TIMI flow grade

Objectives To identify predictors of restenosis after recanalization of chronic total occlusions (CTOs) with the Subintimal Tracking And Reentry (STAR) technique. Background STAR is associated with high rates of restenosis but the associated factors are not clear. Understanding the underlying mechanisms may be important to improve STAR outcomes and possibly other contemporary CTO recanalization techniques utilizing extensive subintimal dissection and stenting. Methods We retrospectively analyzed 211 lesions that underwent a STAR procedure (between 2002 and 2013) with a final Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3. One-hundred and nineteen lesions that received drug eluting stents (DES) and underwent follow-up angiography were included in the final analysis. Results Of the 119 lesions treated with DES following STAR, 75 restenoses were observed (63.0%). Utilizing multivariate analysis, TIMI flow grade in the recanalized artery following stent implantation at the end of the index procedure was the only independent predictor of restenosis. Conclusions Following recanalization of a CTO with STAR, final TIMI flow predicted future restenosis or reocclusion. As a bailout technique, STAR resulted in a high acute success rate with good safety and acceptable long-term results. When poor flow is observed following recanalization, and prior to stent implantation, a two-step strategy whereby a second procedure is performed at an interval to maximize coronary flow at the end of the procedure may be considered with the goal to reduce the risk of future restenosis or total vessel occlusion following STAR.