Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry

Objectives: The aim of this study was to compare angiographic and optical coherence tomography findings following subintimal as opposed to intraplaque recanalization of chronic total occlusions (CTOs).

Background: There is ongoing controversy regarding outcomes of intraplaque versus subintimal CTO recanalization.

Methods: Consecutive patients undergoing angiography and intravascular optical coherence tomography following CTO recanalization were included in the ISAR-OCT-CTO (Intracoronary Stenting and Angiographic Results - Optical Coherence Tomography for Chronic Total Occlusions) registry. The study endpoints were percent diameter stenosis and late lumen loss as well as rate of uncovered and malapposed struts. Independent correlates of uncovered and malapposed struts were assessed by multivariate analysis.

Results: The study included 75 patients. Intraplaque and dissection and re-entry techniques (DART) were used in 46 and 29 patients, respectively. There were no differences in terms of in-segment percent diameter stenosis (median 36.9 [interquartile range (IQR): 26.4 to 43.1] vs. 31.2 [IQR: 23.2 to 49.5]; p = 0.656), in-stent late lumen loss (0.215 mm [IQR: 0.063 to 0.495 mm] vs. 0.230 mm [IQR: 0.060 to 0.645 mm]; p = 0.837), or in-segment late lumen loss (0.030 mm [IQR: -0.278 to 0.510 mm] vs. 0.130 mm [IQR: -0.120 to 0.500 mm]; p = 0.395) at follow-up between the 2 techniques. Optical coherence tomography analysis showed comparable strut coverage (79.9% vs. 71.3%; p = 0.255) but significantly higher strut malapposition (6.6% vs. 13.6%; p < 0.001) following DART. Use of DART independently correlated with presence of strut malapposition (odds ratio: 3.41; 95% confidence interval: 1.24 to 9.36; p = 0.017) but not of strut coverage (odds ratio: 0.65; 95% confidence interval: 0.28 to 1.49; p = 0.314).

Conclusions: Intraplaque and subintimal recanalization techniques are associated with comparable mid-term angiographic results. Although the rate of uncovered struts is high following CTO recanalization, the recanalization technique does not independently correlate with presence of uncovered struts. There is a high rate of strut malapposition following CTO recanalization, particularly if achieved by means of DART.