On- vs off-hours primary percutaneous coronary intervention: a single-center 5-year experience

In patients with ST-segment elevation myocardial infarction (STEMI) treatment delay significantly affects outcomes. The effect of admission time in STEMI patients is unknown when percutaneous coronary intervention (PCI) is the preferred reperfusion strategy. This study aimed to determine the association between STEMI outcomes and the timing of admission in a PCI center in south-western Europe.

This retrospective cohort study analyzed the local electronic data from 1222 consecutive STEMI patients treated with PCI. On-hours were defined as admission from Monday to Friday between 8:00 AM and 6:00 PM on non-national holidays.

A total of 439 patients (36%) were admitted on-hours and 783 patients (64%) were admitted off-hours. Baseline characteristics were well-balanced between the 2 groups, including the percentage of patients admitted in cardiogenic shock (on-hours 5% vs off-hours 4%; P = .62). The median time from first medical contact to reperfusion did not differ between the 2 groups (on-hours 120 minutes vs off-hours 123 minutes, P = .54) and no association was observed between admission time and in-hospital mortality (on-hours 5% vs off-hours 5%, P = .90) or 1-year mortality (on-hours 10% vs off-hours 10%, P = .97). Survival analysis showed no differences in on-hours PCI vs off-hours PCI (HR, 1.1; 95%CI, 0.74-1.64; P = .64).

In a contemporary emergency network, the timing of STEMI patients' admission to the PCI center was not associated with reperfusion delays or increased mortality.