Clinical Implications of Periprocedural Myocardial Injury in Patients Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion: Role of Antegrade and Retrograde Crossing Techniques.

Aims: Periprocedural myocardial injury (PMI) is frequently observed after percutaneous coronary interventions (PCI) for chronic total occlusion (CTO). We aimed to investigate the prognostic impact of PMI with the antegrade as compared to the retrograde crossing technique. Methods and results: A total of 1,909 patients undergoing CTO PCI were stratified according to the presence/ absence of PMI (elevation of cardiac troponin T [cTnT] > 5x99th percentile of normal), and divided according to tertiles of the difference between peak and baseline cTnT Within 24 hours (Delta cTnT). The primary endpoint was all-cause mortality at a median follow-up of 3.1 (interquartile range 3.0-4.4) years. PMI occurred in 19.4% and 25.4% after antegrade (n=1,447) and retrograde (n=462) procedures (p< 0.001). PMI was significantly associated with mortality after antegrade (adjusted HR 1.39, 95% CI: 1.02-1.88, p=0.04), but not retrograde CTO PCI (adjusted HR 0.93, 95% CI: 0.53-1.63, p=0.80, p(int) = 0.02). With tertiles of Delta cTnT (Y1: 11.0%, T2: 18.6%, T3: 21.6%, log-rank p< 0.001). Conclusions: Periprocedural myocardial injury was significantly associated with all-cause mortality following antegrade, but not retrograde CTO PCI. Hence, the higher risk of PMI following retrograde procedures did not translate into worse survival.