Background: A consensus definition for periprocedural myocardial infarction (MI) in coronary stent trials has not been established. Differences between a historic definition, based on modified World Health Organization (WHO) criteria, and a proposed universal definition have not been compared in a prospective clinical trial.
Methods and results: We randomly assigned 3687 patients with stable coronary artery disease to undergo stenting with either everolimus-eluting stents (2458 patients) or paclitaxel-eluting stents (1229 patients). Serial creatine kinase (CK) and CKMB or troponin measurements were obtained before and after stenting. MI was classified by protocol according to the WHO definition (total CK >2× normal with elevated CKMB) and post hoc according to the Universal/Academic Research Consortium (ARC) definition (CKMB or troponin >3× normal). Protocol MI was determined in 58 (1.6%) and universal/ARC MI in 287 (7.8%) patients within 48 hours post index procedure. There were substantial differences in frequency of universal/ARC MI if only CKMB (5.4%) or troponin (18.7%) data were included for evaluation. Total stent length was a strong predictor of both protocol and universal/ARC MI. Mortality at 2 years was low (2.3%) and was not different for either MI definition. The mortality rates did not increase with elevations of CKMB or troponin to >10× normal.
Conclusions: There was a marked difference in periprocedural MI rates according to protocol or universal/ARC MI definitions. No association was present between periprocedural MI and mortality up to 2 years by either definition.
Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00307047.