Differential Rates and Clinical Significance of Periprocedural Myocardial Infarction After Stenting or Bypass Surgery for Multivessel Coronary Disease According to Various Definitions

OBJECTIVES This study sought to estimate the differential incidence and prognostic significance of periprocedural myocardial infarction (MI) according to various definitions. BACKGROUND In trials comparing percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), the primary composite endpoint is very sensitive to the definition of MI. Especially, the definition of periprocedural MI has considerably varied, and uniform criteria are still unsettled. METHODS We evaluated 7,697 patients with multivessel disease who received PCI (n = 4,514) or underwent CABG (n = 3,183) between 2003 and 2013, and for whom serial measurement of creatine kinase-MB was available. According to various MI definitions (second and third universal definitions and the Society for Cardiovascular Angiography and Interventions definition), we assessed the prevalence and prognostic significance of periprocedural MI after both PCI and CABG. Patients were followed for major cardiovascular events (death from cardiovascular causes and spontaneous MI) and death for a median of 4.7 years. RESULTS According to various definitions of MI, there was a substantial difference in the rates of periprocedural MI after PCI and CABG (18.7% vs. 2.9% by second universal; 3.2% vs. 1.9% by third universal; and 5.5% vs. 18.3% by Society for Cardiovascular Angiography and Interventions definition). The presence of periprocedural MI was associated with increased risks of major cardiovascular events after both PCI and CABG regardless of MI definition. The risk-adjusted 5-year rates of future major cardiovascular events after occurrence of periprocedural MI were similar after PCI and CABG in second and third universal definition. However, using Society for Cardiovascular Angiography and Interventions definition, the rates of major cardiovascular events were significantly higher after PCI than after CABG (24.3% vs. 20.4%; hazard ratio: 1.61; 95% confidence interval: 1.07 to 2.41; p = 0.02). CONCLUSIONS There were substantial differences in incidence and clinical relevance of periprocedural MI according to various contemporary, widely used definitions of MI. (C) 2017 by the American College of Cardiology Foundation.