Periprocedural Myocardial Injury and Long-Term Clinical Outcome in Patients Undergoing Percutaneous Coronary Interventions of Coronary Chronic Total Occlusion.

Background: Periprocedural myocardial injury (PMI) after percutaneous coronary intervention (PCI) might occur more frequently during challenging procedures such as PCI of chronic coronary total occlusion (CTO). The prognostic implication of PMI in CTO-PCI remains unclear.

Methods: From January 2006 to September 2012, a total of 715 consecutive patients undergoing CTO-PCI were screened at three centers. Only patients with available pre-PCI and post-PCI troponin (cTn) were included (n = 442). PMI was defined as an elevation of cTn >5x the upper reference limit (URL), or a rise of cTn >20% if baseline values were elevated.

Results: Patients were grouped into: (1) successful CTO-PCI and no-PMI (Group A; n = 195); (2) successful CTO-PCI with PMI (Group B; n = 133); failed CTO-PCI (Group C; n = 114). Occurrence of major adverse cardiovascular event (MACE) was assessed in 431 patients (97%), at a median follow-up of 25 months, and were significantly lower in patients successfully treated without PMI occurrence, while increased in cases of PMI or failed CTO-PCI (Group A, 9%; Group B, 15%; Group C, 28%; hazard ratio, 1.57 (95% confidence interval, 1.12-2.18); P<.01). At Kaplan-Meier analysis, MACE-free survival was significantly higher in Group A (log-rank, 21.46; P<.001).

Conclusion: Successful CTO revascularization is still associated with a better long-term clinical outcome vs patients in whom it failed, regardless of the occurrence of PMI.