Clinical outcomes of early repatriation for patients with ST-segment elevation myocardial infarction: a propensity-matched analysis

Background — Given limitations on hospital resources, patients with STEMI who undergo successful primary PCI are often repatriated to non-PCI centers. However, the safety of this practice is not clear. The study objective was to evaluate the safety of early repatriation of ST elevation myocardial infarction (STEMI) patients post primary percutaneous coronary intervention (PCI) to a non-PCI center, compared to ongoing treatment at the PCI center.

Methods — Consecutive STEMI patients, who received primary PCI at one of four PCI hospitals in Toronto, Canada between 2010 and 2012 were identified. Patients with shock or who died within 24 hours of presentation were excluded. Outcomes of interest were all-cause mortality and readmission for recurrent myocardial infarction (MI) at 1 year. In order to account for confounding due to the observational nature of our data, propensity score matched pairs of patients who were repatriated versus non-repatriated were identified.

Results — Using the propensity score, 430 well-matched pairs were identified, representing our cohort. There was no significant difference between repatriated and non-repatriated groups in 1-year mortality (repatriated: 6.7%, non-repatriated: 5.6%, Hazard ratio (HR) 1.18, 95% confidence interval (CI) 0.69-2.03, p= 0.545). The 1-year readmission rates for MI were significantly greater for the repatriated group compared to the non-repatriated group (repatriated: 12.1%, non-repatriated: 5.8%, HR 2.09, 95% CI 1.30-3.36, p= 0.002).

Conclusions — A strategy of early repatriation of STEMI patients was associated with a higher rate of readmission for MI. The study raises questions regarding the safety of an early repatriation strategy that merit further research.