Scoring System for Identification of ``Survival Advantage'' after Successful Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

Background: Percutaneous coronary intervention (PCI) is widely used in patients with chronic total occlusion (CTO), but its benefit in improving long-term outcomes is controversial. We aimed to develop a prediction score for grading ``survival advantage'' conferred by successful results of CTO-PCI and a scoring system for prediction of the influence of CTO-PCI results on major adverse cardiac and cerebrovascular events (MACCEs). Methods: Follow-up data of 2625 patients who underwent CTO-PCI at 65 Japanese centers were analyzed. An integer scoring system was developed by including statistical effect modifiers on the association between successful CTO-PCI and one-year mortality. Results: Follow-up at 12 months was completed in 2034 patients. During follow-up, 76 deaths (3.7%) occurred. Patients with successful CTO-PCI had a better one-year survival than patients with failed CTO-PCI (log rank P = 0.016). Effect modifiers for the association between successful procedure and one-year mortality included diabetes (P interaction = 0.043), multivessel disease (P interaction = 0.175), Canadian Cardiovascular Society class >= 2 (P interaction = 0.088), and prior myocardial infarction (MI) (P interaction = 0.117). Each component was assigned a single point and summed to develop the scoring system. The patients were then categorized to specify the prediction of survival advantage by successful PCI: <= 2 (normal) and >= 3 (distinct). The differences in one-year mortality between patients with successful and failed treatment were 0.7% and 11.3% for normal and distinct score categories, respectively. In the scoring system for MACCE, score components were prior MI (P interaction = 0.19), left anterior descending artery (LAD)-CTO (P interaction = 0.079), and reattempt of CTO-PCI (P interaction = 0.18). The differences in one-year MACCEs between successful and failed patients for each score category (0, 1, and >= 2) were 1.7%, 7.5%, and 15.1%, respectively. Conclusions: The novel scoring system assessing the advantage of successful PCI can be easily applied in patients with CTO. It is a valid instrument for clinical decision-making while assessing the survival advantage of CTO-PCI and the influence of procedural results on MACCEs.