A Contemporary Definition of Periprocedural Myocardial Injury After Percutaneous Coronary Intervention of Chronic Total Occlusions.

Objectives: The aim of this study was to assess the prognostic impact of post-procedural troponin T increase and mortality in patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) to define the threshold at which procedure-related myocardial injury drives mortality.

Background: Coronary CTO recanalization represents the most technically challenging PCI. The complexity harbors a significant increased risk for complications with CTO PCI with compared with non-CTO PCI. However, there are evidenced biomarker cutoff levels that help identify those patients at risk for unfavorable clinical outcomes.

Methods: A total of 3,712 consecutive patients undergoing PCI for at least 1 CTO lesion were enrolled, and comprehensive troponin T measurements were performed 6, 8, and 24 h after the procedure. All-cause mortality was defined as the primary study endpoint.

Results: Using spline curve analysis, a more than 18-fold increase of troponin above the upper reference limit was significantly associated with mortality. In a Cox regression analysis, the crude hazard ratio was 2.32 (95% confidence interval: 1.83 to 2.93; p < 0.001) for a ≥18-fold increase compared with patients with post-procedural troponin increase <18-fold of the upper reference limit. Results remained virtually unchanged after bootstrap- or clinical confounder-based adjustment.

Conclusions: This large-scale outcome study demonstrates for the first time the prognostic value of post-procedural troponin T elevation after PCI in patients with CTOs. A threshold was defined for procedure-related myocardial injury in patients with CTOs to differentiate them from those without CTOs that may help guide post-procedural clinical care in this high-risk patient population.