Treatment and outcomes of patients with evolving myocardial infarction: experiences from the SYNERGY trial

Abstract

Aims: Patients with myocardial infarction (MI) presenting immediately after symptom onset may be treated less aggressively due to their non-elevated troponin status. We compared the initial treatment and clinical outcomes of patients presenting with evolving MI (EMI) with those presenting with MI.

Methods and results: This study analysed data from the Superior Yield of the New strategy of Enoxaparin, Revascularisation, and Glycoprotein IIb/IIIa inhibitors (SYNERGY) trial, which enrolled patients meeting at least two of the following: age >or= 60 years, elevated cardiac biomarkers, or ST-segment changes. Patients were stratified by troponin results obtained within 12 h of presentation: EMI [initial troponin (-), second troponin (+)], MI [initial troponin (+)], and no MI at enrolment [first and second troponin (-)]. Comparisons were made using Wilcoxon rank-sum and chi(2) tests. Of the 8,309 patients with complete data, 5,503 (66%) had MI, 1,686 (20%) had EMI, and 1,120 (13%) had no MI. Treatment patterns prior to enrolment were similar among EMI and MI patients [aspirin (88 vs. 86%), beta-blockers (62 vs. 61%), heparin (83 vs. 81%), and glycoprotein IIb/IIIa inhibitors (23 vs. 24%)]. Similar rates of percutaneous coronary intervention (48 vs. 50%) and coronary artery bypass grafting (21 vs. 22%) were seen after enrolment. Patients presenting with MI had a higher rate of death or recurrent MI compared with patients with EMI [16 vs. 13%, adjusted OR 1.22 (95% CI 1.04, 1.44)].

Conclusion: Initial treatment patterns were similar among patients with EMI and MI in the SYNERGY trial. Patients with EMI had lower rates of death or re-infarction at 30 days compared with patients presenting with positive troponin results.