Effect of treatment delay on outcomes in patients with acute myocardial infarction transferred from community hospitals for primary percutaneous coronary intervention

Outcomes were evaluated in 1,841 consecutive patients with acute myocardial infarction treated with primary percutaneous coronary intervention from 1984 to 2000 comparing patients transferred from community hospitals (n = 680) with patients presenting locally (n = 1,161). Baseline variables were similar except transferred patients had fewer prior infarctions (13% vs 21%, p <0.001) and underwent less prior bypass surgery (2.8% vs 6.0%, p = 0.002). Median times from symptom onset to emergency department arrival were similar, but door-to-balloon times and reperfusion times were approximately 1 hour longer in transferred patients (2.8 vs 1.9 hours [p <0.001] and 4.5 vs 3.5 hours [p <0.001], respectively). Despite longer treatment times, there were no significant differences between transferred and nontransferred patients in 30-day mortality (7.6% vs 8.1%, p = 0.73), reinfarction, urgent target vessel revascularization, stroke, and late mortality. After adjusting for differences in baseline variables, mortality remained similar between transferred and nontransferred patients (odds ratio 0.90, 95% confidence interval 0.59 to 1.36). Peak cardiac enzyme values were higher in transferred patients, but there were no differences in 6-month ejection fractions between groups. In conclusion, patients transferred from community hospitals for primary percutaneous coronary intervention have almost 1-hour additional treatment delay, but this does not appear to have a major adverse effect on clinical outcomes. These data should encourage further randomized trials to evaluate the role of transfer for mechanical reperfusion in patients presenting to community hospitals with acute myocardial infarction.