Prognostic implications of unrecognized myocardial infarction before elective percutaneous coronary intervention

Unrecognized myocardial infarction (UMI) is associated with adverse outcomes. This prospective, single-center study elucidated the prevalence and prognostic significance of UMI before elective percutaneous coronary intervention (PCI) using delayed-enhancement cardiac magnetic resonance (DE-CMR). We enrolled 236 patients with stable coronary artery disease who underwent DE-CMR before elective PCI. The prevalence of UMI and the association of clinical and CMR-derived variables with major adverse cardiac events (MACE), defined as cardiovascular death, nonfatal MI, hospitalization for congestive heart failure, and unplanned late revascularization, were assessed. Final analysis revealed that 63/213 (29.6%) patients had UMI. Target territory UMI was observed in 38 patients (17.8% of the total cohort, 60.3% of patients with UMI). UMI was significantly associated with sex, diabetes mellitus, left ventricular ejection fraction, SYNTAX score, and fractional flow reserve in the target vessels. During follow-up (median, 23 months), MACE occurred in 17 (27.0%) patients with UMI and 17 (11.3%) without UMI (P = 0.001). Multivariable modeling revealed that UMI (hazard ratio: 2.18, 95%CI, 1.10-4.33, P = 0.001) was an independent predictor of MACE. Kaplan-Meier analysis indicated that the presence of UMI was significantly associated with a higher incidence of MACE. UMI was independently associated with a greater risk of MACE after successful PCI.