Prehospital Transfer Pathway and Mortality in Patients Undergoing Primary Percutaneous Coronary Intervention

Background: It is recommended that not only door-to-balloon time but also prehospital delay for primary percutaneous coronary intervention (PCI) should be improved. We investigated the effect of prehospital transfer pathway on onset-to-balloon time and prognosis in patients with ST-segment elevation myocardial infarction (STEMI) in Japan. Methods and Results: We analyzed data from 540 consecutive patients with primary PCI for STEMI. Patient clinical data and mortality were compared between patients who visited the family physician or non-PCI-capable hospitals and were then transferred to PCI-capable centers (indirect transfer patients), and those who directly visited PCI-capable centers (direct transfer patients). Onset-to-balloon time was longer in indirect transfer patients than in direct transfer patients (mean, 270 min; range, 180-480 min vs. 180 min, 120-240 min; P< 0.001). In addition, patient prognosis was evaluated on Cox proportional regression analysis. Cardiac death and all-cause death were significantly higher in indirect transfer patients (odds ratios [OR], 2.17; 95% confidence intervals [95% CI]: 1.17-4.01, P= 0.01; OR, 1.71; 95% CI: 1.09-2.68, P= 0.02). These results were confirmed using propensity score matching for adjusted analyses. Conclusions: Patients with indirect transfer to regional emergency departments of PCI centers had longer onset-to-balloon time and worse prognosis than those with direct transfer.