Development of Scoring System for Predicting Procedural Success of Cto Pci and Choosing Recanalization Strategy

The goal of this study is to develop score, which cannot only predict technical success of CTO PCI, but also can helps us make a choice of recanalization strategy.

A total of 464 CTO patients who underwent 477 PCI from 2014 to 2016 in Meshalkin National Medical Research Center were included in this study.

Procedural success was 76.7%. Five predictors of procedural success were included into the final multivariable model.: bending (1 point), calcification (1 point), ambiguous stump (1 point), “donor” artery disease (1 point), non-RCA CTO (0.5 points). Based on these predictors, 4 categories of CTO complexity were highlighted: 0-1 points (easy), 1-2 points (intermediate), 2-3 points (difficult), >3 points (very difficult). The score demonstrated a good discriminatory ability (AUC 0.709). The J-CTO score demonstrated inferior performance as compared to the new score: AUC 0.703, sensitivity 64%, specificity 65%. The choice of the threshold for choosing retrograde approach as initial strategy was based on the distribution of the complexity score points. Based on the corresponding normal distribution curves, it was suggested that retrograde approach may have an advantage in patients with a >3 points according to the novel score, which corresponds to the "very difficult" class of complexity. These data are supported by a higher percentage of successful recanalization using retrograde access in such patients (73% versus 35% using antegrade strategy).

The novel score can be used in clinical practice for predicting the success of CTO PCI and determining initial crossing strategy.