Development of a Novel Score to Predict Urgent Mechanical Circulatory Support in Chronic Total Occlusion Percutaneous Coronary Intervention

ABSTRACT Background Estimating the likelihood of urgent mechanical circulatory support (MCS) can facilitate procedural planning and clinical decision making in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Methods We analyzed 2,784 CTO PCIs performed between 2012 and 2021 at 12 centers. The variable importance was estimated by a bootstrap applying a random forest algorithm to a propensity-matched sample (a ratio of 1:5 matching cases with controls on center). The identified variables were used to predict the risk of urgent MCS. The performance of the risk model was assessed in-sample as well as on 2411 out-of-sample procedures who did not require urgent MCS. Results Urgent MCS was used in 62 (2.2%) of cases. Patients who required urgent MCS were older (70 [63, 77] vs. 66 [58, 73] years, p=0.003) compared with those who did not require urgent MCS. Technical (68% vs. 87%, p<0.001) and procedural successes (40% vs. 85%, p<0.001) were lower in the urgent MCS group compared with no urgent MCS cases. The risk model for urgent MCS use included retrograde crossing strategy, left ventricular ejection fraction, and lesion length. The resulting model demonstrated good calibration and discriminatory capacity with AUC (95%CI) of 0.79 (0.73, 0.86) and specificity and sensitivity of 86% and 52%, respectively. On the out-of-sample set, the specificity of the model was 87%. Conclusion The PROGRESS CTO MCS score can help estimate the risk of urgent MCS use during CTO PCI. What Is Known? Estimating the likelihood of urgent mechanical circulatory support (MCS) can facilitate procedural planning and clinical decision making in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). What the Study Adds? We developed a risk model for urgent MCS use during CTO PCI using retrograde crossing strategy, left ventricular ejection fraction, and lesion length. Use of the PROGRESS CTO urgent MCS score may facilitate patient selection for prophylactic hemodynamic support optimizing the risk benefit ratio of the procedure.