Incidence, Predictors, and Implications of Reinfarction After Primary Percutaneous Coronary Intervention in ST-Segment–Elevation Myocardial Infarction

BACKGROUND: Reinfarction after primary percutaneous coronary intervention in patients with ST-segment-elevation myocardial infarction has negative consequences. Little is known about reinfarction after drug-eluting stents and bivalirudin anticoagulation. We, therefore, sought to determine the incidence, predictors, and implications of reinfarction after primary percutaneous coronary intervention in the contemporary era. METHODS AND RESULTS: Outcomes were assessed in 3202 patients undergoing stent implantation for ST-segment-elevation myocardial infarction in the Harmonizing Outcomes with RevascularIZatiON and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial. Independent predictors of reinfarction and mortality were identified by Cox proportional hazards modeling. The cumulative incidence of reinfarction was 1.8% at 30 days, 4.0% at 1 year, and 6.9% at 3 years. Definite stent thrombosis was responsible for 76.3% of reinfarctions occurring within 30 days and 52.0% of all reinfarctions within 3 years. Independent predictors of reinfarction were current smoking, Killip class ≥2, baseline thrombocytosis, multivessel disease, symptom onset-to-balloon time, and total stent length. Randomization to bivalirudin versus heparin plus a glycoprotein IIb/IIIa inhibitor and use of drug-eluting versus bare metal stents were not significant predictors of reinfarction. Reinfarction was a powerful independent predictor of subsequent cardiac mortality (hazard ratio 95% confidence interval=7.65 4.47-13.09; P<0.0001) and all-cause mortality (hazard ratio 95% confidence interval=2.88 1.74-4.78; P<0.0001). CONCLUSIONS: Despite advances in pharmacotherapy and stents, reinfarction after primary percutaneous coronary intervention is not infrequent, in the contemporary era is most often attributable to stent thrombosis, and is strongly associated with subsequent cardiac and all-cause mortality. Further enhancements in drugs and devices to prevent reinfarction are needed to improve outcomes in high-risk patients with ST-segment-elevation myocardial infarction. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.