16-year follow-up of the Danish Acute Myocardial Infarction 2 (DANAMI-2) trial: primary percutaneous coronary intervention vs. fibrinolysis in ST-segment elevation myocardial infarction

Aims: The DANish Acute Myocardial Infarction 2 (DANAMI-2) trial found that interhospital transport to primary percutaneous coronary intervention (pPCI) was superior to fibrinolysis at the local hospital in patients with ST-segment elevation myocardial infarction (STEMI) at 30 days. The present study investigates the 16-year cardiovascular outcomes.

Methods and results: We randomized 1572 STEMI patients to pPCI or fibrinolysis at 24 referral hospitals and 5 invasive centres in Denmark. Patients randomized to pPCI at referral hospitals were immediately transported to the nearest invasive centre. The main endpoint of the current study was a composite of death or rehospitalization for myocardial infarction (MI). Outcome information beyond 3 years was obtained through Danish health registries. After 16 years, pPCI-treated patients had a sustained lower rate of composite endpoint compared to patients treated with fibrinolysis in the overall cohort [58.7% vs. 62.3%; hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.76-0.98], and among patients transported for pPCI (58.7% vs. 64.1%; HR 0.82, 95% CI 0.71-0.96). No difference in all-cause mortality was found, but cardiac mortality was reduced by an absolute of 4.4% in favour of pPCI (18.3% vs. 22.7%; HR 0.78, 95% CI 0.63-0.98). pPCI postponed a main event with 12.3 months in average compared to fibrinolysis (95% CI 5.0-19.5).

Conclusion: The benefit of pPCI over fibrinolysis was maintained at 16-year follow-up. pPCI reduced the composite endpoint of death or rehospitalization for MI, reduced cardiac mortality, and delayed average time to a main event by approximately 1 year.