Incidence, predicting factors, and clinical outcomes of periprocedural myocardial infarction after percutaneous coronary intervention for chronic total occlusion in the era of new-generation drug-eluting stents

Objective: This study aimed to examine predictors and clinical outcomes of periprocedural myocardial infarction (PMI) after chronic total occlusion (CTO) intervention. Background: There are limited data on the clinical implications of PMI after CTO intervention in the new-generation drug-eluting stent (DES) era. Methods: We enrolled 337 patients who underwent CTO intervention and met the study criteria. We evaluated the incidence and predictors of PMI, defined as an increase in creatine kinase-MB ≥3× the upper limit of normal (ULN) after intervention and compared the occurrence rates of major adverse cardiac and cerebrovascular events (MACCE, defined as the composite of cardiac death, myocardial infarction, stent thrombosis, target-vessel revascularization, or cerebrovascular accidents) between the PMI and non-PMI groups. Results: PMI occurred in 23 (6.8%) patients after CTO intervention. Significant independent predictors were previous bypass surgery [odds ratio (OR) = 5.52, 95% confidence interval (CI) = 1.17–25.92; P = 0.03], Japan-CTO score ≥3 (OR = 7.06, 95%CI = 2.57–19.39; P < 0.001), side branch occlusion (OR = 4.21, 95%CI = 1.13–15.66; P = 0.03), and longer procedure time (OR = 4.18, 95%CI = 1.35–12.99; P = 0.01). During a median follow-up of 29.6 months, the PMI group had a significantly higher MACCE rate than the non-PMI group (23.7 vs. 5.6%, P = 0.008 by log-rank test). PMI was an independent predictor of MACCE (HR = 4.26, 95%CI = 1.35–13.43; P = 0.01). The MACCE rate gradually increased in a CK-MB-dependent fashion and was highest in patients with ≥10× ULN (P = 0.005). Conclusion: Previous bypass surgery, high Japan-CTO score, side branch occlusion, and longer procedure time were strongly related to PMI occurrence after CTO intervention. PMI was significantly associated with worse clinical outcomes in the new-generation DES era.