Association of daytime vs. non-daytime presentation with reperfusion times and clinical outcomes among STEMI patients complicated by cardiogenic shock

Abstract Background Patients with ST-elevation myocardial infarction complicated by cardiogenic shock (STEMI-CS) experience delays in reperfusion and worse outcomes compared to STEMI alone. Non-daytime presentation among STEMI-CS patients has the potential to adversely impact time to revascularization and subsequent clinical outcomes. However, this has not been well-described in contemporary STEMI systems. Purpose The primary objective of this study was to investigate the association between time of presentation and both reperfusion times and in-hospital outcomes among STEMI-CS patients. Methods We performed a retrospective analysis of patients presenting with STEMI-CS from the prospectively collected Vancouver Coastal Health Authority STEMI registry (January 2010 to June 2024). Time of presentation was defined as time of first medical contact (FMC) and was categorized as "daytime" (8AM to 4:59 PM), "evening" (5PM to 11:59PM) or "night" (12AM to 7:59 AM). The primary outcome was in-hospital mortality. The secondary outcome was in-hospital major adverse cardiovascular event, defined as a composite of the first occurrence of mortality, cardiac arrest, heart failure, intracerebral hemorrhage, cerebrovascular accident, or reinfarction. Results Among 4012 STEMI patients who underwent percutaneous coronary intervention, 337 presented with CS (8.4%): 87 (25.8%) presented in the evening and 84 (24.9%) presented at night. There were no statistically significant differences in baseline demographics between times of presentation. Symptom onset to FMC was longer in patients who presented at night compared to daytime (40.5 minutes vs 24.5 minutes, p = 0.001). Among patients who presented to a PCI-capable hospital (n = 295), time from FMC to device deployment was progressively longer from daytime to evening to night (110 min vs 114 min vs 128 min, p = 0.002). The longest delay occurred with increased emergency department (ED) dwell time during evening and nighttime (45 min vs 57 min vs 61.5 min, p = 0.001). Time of day was associated with a trend towards increased in-hospital mortality (36.7% vs 41.4% vs 51.2%, p = 0.017) and major adverse cardiovascular outcomes (77.1% vs 80.5% vs 85.2%, p = 0.08). Conclusion Nearly 1 in 2 STEMI-CS patients present during non-daytime hours, which was associated with significantly delayed reperfusion times and may influence clinical outcomes. Strategies to address system factors associated with non-daytime hour presentation are warranted.