Periprocedural myocardial infarction is associated with increased mortality in patients with coronary artery bifurcation lesions after implantation of a drug‐eluting stent

OBJECTIVES: The present study aimed to investigate the association between periprocedural myocardial infarction (PMI), defined by creatine kinase (CK)-MB or troponin I (TNI) level elevations >5 times the 99 th percentile of the upper reference limit (URL) within 48 hr after implantation of a drug-eluting stent (DES), and one-year mortality in patients with coronary bifurcation. BACKGROUND: PMI is reported to be associated with increased one-year mortality after DES implantation. However, the prevalence and association of PMI with mortality after stenting bifurcation lesions remains unclear. METHODS: We prospectively followed 1,971 patients with true coronary bifurcations who underwent DES implantation as part of the multicenter DEFINITION study. These patients were grouped into categories based on PMI outcome: Non-PMI, CKMB-PMI, TNI-PMI, and CKMB/TNI-PMI. The primary endpoint was the rate of all-cause mortality at one year. RESULTS: PMI occurred in 11.4% of patients by CKMB criteria and 41.3% of patients by TNI criteria. At one-year follow-up, the mortality rate was 2.3% in the entire patient population. However, mortality was significantly higher in the CKMB-PMI (6.4%) and CKMB/TNI-PMI (6.1%) groups compared to the Non-PMI (1.7%) and TNI-PMI (2.1%) groups (all P < 0.05). A 10-fold increase in TNI levels resulted in similar PMI rate (5.2%) and mortality risk (adjusted HR 2.7, 95% CI 3.0-5.2) as a fivefold increase in CKMB levels. CONCLUSIONS: PMI, as defined by CKMB elevations following coronary bifurcation lesion stenting, was associated with increased one-year mortality. Additionally, to attain an equal frequency of PMI, the elevation in TNI levels needed to be twice as high as the elevation in CKMB levels.