January 7, 2020
Infrapop‐CTO Score Developed to Predict Success of Anterograde Crossing in CLI Patients
January 7, 2020—The development and validation of the Infrapop‐CTO Score, a predictive score for anterograde crossing of infrapopliteal chronic total occlusions (CTOs), were described in an article published by Damianos G. Kokkinidis, MD, et al in Catheterization & Cardiovascular Interventions.
According to the investigators, patients with critical limb ischemia (CLI) often have infrapopliteal CTOs and although revascularization is indicated to prevent major amputation, anterograde crossing of these lesions can be challenging with high failure rates. Therefore, they sought to develop and validate a scoring system that can adequately predict successful anterograde crossing of infrapopliteal CTOs.
The Infrapop‐CTO score, which can stratify the procedural complexity of infrapopliteal CTOs based on the likelihood of successful anterograde crossing, may help to direct optimal approaches toward infrapopliteal revascularization of patients with CLI, concluded the investigators in Catheterization & Cardiovascular Interventions.
As summarized by the investigators, the analysis included a total of 213 infrapopliteal CTOs. Of these, 147 were successfully crossed with the anterograde approach versus 66 in which anterograde crossing failed.
The investigators used backward stepwise selection (P for retention < .05) was used to create a multivariable logistic regression model for the prediction of successful anterograde crossing using variables that were found to have a P < .1 in univariate analysis. The model was internally validated with bootstrapping and demonstrated excellent discriminatory ability (C‐statistic, 0.78; Hosmer‐Lemeshow P = .61).
They created a point score based on the beta‐coefficient of the model variables, with one point assigned for the presence of a noncentral (blunt) stump, one point for severe calcification at the entry site, and two points each for nonrestenotic lesions or lesion length > 200 mm.
The score was shown to have an excellent discriminatory ability for successful crossing, with low scores (0–2) associated with low failure rates (10%) and high scores associated with high failure rates (79%), reported the investigators in Catheterization & Cardiovascular Interventions.