Periprocedural myocardial infarction (PMI) is myocardial injury that occurs during revascularization procedures, such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). What remains unclear is the prognostic implications of periprocedural myocardial infarction and the extent of myonecrosis that is prognostically significant.
In the EXCEL (Evaluation of XIENCE vs Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, researchers assessed the following: the association between PMI and 3-year prognosis, the effect of treatment modality (PCI vs CABG) on PMI prognosis after LM revascularization and the relationship between different creatine kinase (CK)-MB biomarker thresholds and mortality.
In a sub-study of the EXCEL trial, a total of 1858 patients with left main coronary artery disease and low or intermediate SYNTAX scores were randomized and underwent either PCI with fluoropolymer-based cobalt-chromium everolimus-eluting stents (n=935 patients) or CABG (n=923 patients). The primary endpoint was the rate of death from any cause, stroke or myocardial infarction at 3 years, analyzed by intention-to-treat.
Periprocedural myocardial infarction occurred more often in the CABG (n=56) group than patients undergoing PCI (n=34) [odds ratio: 0.61, 95% CI 0.40 to 0.93; P=0.02]. In addition, periprocedural myocardial infarction was associated with increased risk of cardiovascular death (adjusted hazard ratio (HR): 2.63, 95% CI 1.19 to 5.81; P=0.02) and all-cause death at 3-years (adjusted HR: 2.28, 95% CI 1.22 to 4.29, P=0.01) following either CABG or PCI. Only extensive myonecrosis (CK-MB ≥10x upper reference limit) was prognostically important, associated with increased 3-year all-cause and cardiac death.
This study underlines the importance of routine cardiac biomarker assessment after both PCI and CABG and supports the argument that large periprocedural myocardial infarction negatively affects long term prognosis. Investigators of the EXCEL trial recently presented results at 5 years at TCT 2019.
Author: Catherine Sobara
Original Article: European Heart Journal (2019) 0, 1–12 . doi:10.1093/eurheartj/ehz113