Background: Transfer delays for primary percutaneous coronary intervention may increase mortality in patients with ST-segment-elevation myocardial infarction. We examined the association between door 1-to-door 2 (D1D2) time, a measure capturing the entire transfer process, and outcomes in patients undergoing interhospital transfer for primary percutaneous coronary intervention.
Methods and results: We evaluated the relationship between D1D2 time and the 90-day incidence of death, shock, and heart failure in the subset of 2075 (36.1%) of 5745 patients who underwent interhospital transfer for primary percutaneous coronary intervention in the Assessment of Pexelizumab in Acute Myocardial Infarction trial. There was no significant difference in the 90-day incidence of death, shock, and heart failure between the transferred and the nontransferred groups (10.3% versus 10.2%; P = 0.89). The median difference in symptom-to-balloon time between the 2 groups was 45 minutes (229 versus 184; P<0.001). The primary outcome per 30-minute delay was higher for patients with a D1D2 time ≤150 minutes (hazard ratio, 1.19: 95% confidence interval, 1.06 to 1.33; P = 0.004) but not for D1D2 times >150 minutes (hazard ratio, 0.99: 95% confidence interval, 0.96 to 1.02; P = 0.496). The association between longer D1D2 time and worsening outcome was no longer statistically significant after multivariable adjustment.
Conclusions: Longer transfer times were associated with higher rate of death, shock, and heart failure among patients undergoing interhospital transfer from primary percutaneous coronary intervention, although this difference did not persist after adjusting for baseline characteristics.
Trial registration: ClinicalTrials.gov NCT00091637.