Percutaneous Coronary Revascularization for Chronic Total Occlusions: A Novel Predictive Score of Technical Failure Using Advanced Technologies

OBJECTIVES The aims of this study were to describe the 10-year experience of a single operator dedicated to chronictotal occlusion (CTO) and to establish a model for predicting technical failure.BACKGROUND During the last decade, the interest in percutaneous coronary interventions (PCIs) of chronic totalocclusions (CTOs) has increased, allowing the improvement of success rate.METHODS One thousand nineteen patients with CTO underwent 1,073 CTO procedures performed by a single CTOdedicatedoperator. The study population was subdivided into 2 groups by time period: period 1 (January 2005 to December2009, n ¼ 378) and period 2 (January 2010 to December 2014, n ¼ 641). Observations were randomly assigned to a derivationset and a validation set (in a 2:1 ratio). A prediction score was established by assigning points for each independentpredictor of technical failure in the derivation set according to the beta coefficient and summing all points accrued.RESULTS Lesions attempted in period 2 were more complex in comparison with those in period 1. Compared with period1, both technical and clinical success rates significantly improved (from 87.8% to 94.4% [p ¼ 0.001] and from 77.6% to89.9% [p < 0.001], respectively). A prediction score for technical failure including age $75 years (1 point), ostial location(1 point), and collateral filling Rentrop grade <2 (2 points) was established, stratifying procedures into 4 difficultygroups: easy (0), intermediate (1), difficult (2), and very difficult (3 or 4), with decreasing technical success rates. Inderivation and validation sets, areas under the curve were comparable (0.728 and 0.772, respectively).CONCLUSIONS With growing expertise, the success rate has increased despite increasing complexity of attemptedlesions. The established model predicted the probability of technical failure and thus might be applied to grading thedifficulty of CTO procedures. (J Am Coll Cardiol Intv 2016;-:-–-) © 2016 by the American College of CardiologyFoundation.