Effect of day- and night-time admissions on long-term clinical outcomes of patients with acute myocardial infarction treated with percutaneous coronary intervention.

Introduction: It has been suggested that the time of admission during the day and night may influence the clinical outcomes of patients with acute myocardial infarction (AMI) treated with percutaneous coronary intervention (PCI).

Objectives: The aim of this study was to assess the impact of day- and night‑time admissions on the clinical outcomes of patients with AMI undergoing PCI.

Patients And Methods: This retrospective cohort study was based on the data on PCIs performed in Poland from January 2014 to December 2017, prospectively collected in the National Registry of Invasive Cardiology Procedures (ORPKI). Day hours were defined as the time interval between 7:00 am and 10:59 pm. The study endpoints included the all‑cause in‑hospital mortality rate and major adverse cardiovascular and cerebrovascular events (MACCEs) at 30‑day,12‑month, and 36‑month follow‑up.

Results: A total of 2919 patients were included in the study (2462 [84.3%] treated during the day hours). ST‑segment elevation myocardial infarction (1993 [68.3%]) was the main indication for PCI. We demonstrated that the 30‑day mortality rate was significantly higher in patients treated during the night hours than during the day hours (P = 0.01). Night hours were also among the independent predictors of increased 30‑day mortality (hazard ratio, 1.54; 95% CI, 1.11-2.16; P = 0.01). No significant differences were observed in in‑hospital, 12‑month, and 36‑month mortality rates between patients treated during the night and day hours. There were no significant differences in the MACCE rates at the follow‑up timepoints.

Conclusions: Primary PCI for AMI is associated with increased 30‑day mortality among patients treated during the night hours compared with those managed during the day hours.