Relationship Between the Completeness of Revascularization and Myocardial Injury in Patients Treated With Percutaneous Coronary Intervention

Abstract

Background: Clinical outcomes of patients suffering periprocedural myocardial injury and undergoing incomplete revascularization (IR) following percutaneous coronary intervention (PCI) has never been investigated.

Objective: To investigate the relationship between different thresholds of post-PCI cardiac troponin (cTn) elevation and revascularization completeness in determining long-term clinical outcomes.

Methods: Patients were stratified in tertiles according to preprocedural SYNTAX score (SS) (low: 0-6; medium: >6-11; high: >11) and residual SS (low: 0-4; medium: >4-8; high: >8). IR was defined by a rSS value >4. Three thresholds of myocardial injury were pre-specified: 5×, 35× and 70× 99th percentile upper reference limit (URL) increase of baseline cTn. Primary outcome was a composite of major adverse cardiac events (MACE) at two years of follow-up.

Results: 1061 patients undergoing PCI for stable coronary artery disease were enrolled. IR occurred in 249 (23.4 %) and major myocardial injury in 540 (50.9 %). Patients belonging to the highest tertile of SS showed an increased risk of experiencing IR and periprocedural myocardial injury. Two-year follow-up was available in 869. At multi-variate Cox's regression analysis, patients undergoing IR + cTn > 35 × URL and IR + cTn > 70 × URL showed an increased risk of MACE [HR 2.30 (1.19-4.41) and HR 3.20 (1.38-7.41); respectively].

Conclusions: Periprocedural myocardial injury is critically associated with MACE at two-year follow-up in patient treated with PCI who achieve IR. Despite conflicting evidence exists regarding the influence of periprocedural myocardial injury on clinical outcomes, patients undergoing IR seem to represent a high-risk subgroup.

Keywords: Coronary artery disease; Myocardial injury; Percutaneous coronary intervention.