Background: In patients recovering from an ST-segment elevation myocardial infarction (STEMI), it is not clear whether the negative impact of stent thrombosis (ST) is different from a non-stent-related recurrent myocardial infarction (NSRMI). This study sought to assess the long-term incidence and prognostic impact of recurrent myocardial infarction (MI) after percutaneous coronary intervention (PCI) for STEMI by comparing outcomes of ST versus NSRMI.
Patients and methods: From 2001 to 2007, 1025 patients undergoing PCI for STEMI were prospectively followed up. Patients with ST, with NSRMI, and those free from recurrent MI were compared regarding mortality and major adverse cardiac and cerebrovascular events (MACCE).
Results: Recurrent MI decreased from 37 events per 1000 person/months in the first month to 3.3 events per 1000 person/months after the first year. The cumulative 5‑year incidence of ST and NSRMI was 5.27 % and 13.2 %, respectively. MACCE at 60 months after recurrence were not significantly different for patients with reinfarction but were significantly higher than for patients free from any recurrent MI (both log-rank p < 0.001). However, the cumulative all-cause death rate did not differ between the three groups (27.8 vs. 26.7 vs. 23.0 %). Compared with ST occurring in the first 30 days after PCI for STEMI, early NSRMI was associated with a significantly reduced risk for all-cause death (HR, 0.21; 95 % CI, 0.33-3.30) but this association did not persist for recurrent MIs occurring in the late (HR, 1.05; 95 % CI, 0.33-3.30) or very late follow-up periods.
Conclusion: Although ST was associated with a significant increase in adverse events in the early recovery period, in the long term, MACCE and all-cause mortality rates were comparable to those for NSRMI.
Keywords: Myocardial infarction; Primary percutaneous coronary intervention; ST-segment elevation; Stent thrombosis.