Heart Attack Treatment With a Stent: Daytime Versus Night and Weekend Care
Compares outcomes of emergency stenting for ST-elevation heart attack at different times of day.
Plain-language title generated from the registry record
Registry title: On vs Off-hour PPCI in STEMI Patients
Key facts
- Where
- Asyut, EgyptSee the site
Where in Egypt
- Assiut University Heart HospitalAsyut, EgyptNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Assiut University
- Trial code
- NCT07860086
- Record updated
- 6 October 2026
- Original description
ST-elevation myocardial infarction (STEMI) remains a leading cause of morbidity and mortality globally, and timely reperfusion with primary percutaneous coronary intervention (PPCI) is the gold-standard treatment1. Current guidelines recommend a door-to-balloon (DTB) time of 90 minutes or less, as the benefits of PPCI increase in direct correlation with the brevity of reperfusion time.Read full original descriptionShow less
On- Versus Off-Hour Primary Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction Patients
ST-elevation myocardial infarction (STEMI) remains a leading cause of morbidity and mortality globally, and timely reperfusion with primary percutaneous coronary intervention (PPCI) is the gold-standard treatment1. Current guidelines recommend a door-to-balloon (DTB) time of 90 minutes or less, as the benefits of PPCI increase in direct correlation with the brevity of reperfusion time.
However, there is consistent epidemiological evidence that STEMI patients presenting during off-hours (nights, weekends, and holidays) experience delays in reperfusion and worse in-hospital outcomes compared to those presenting during regular business hours. Two competing hypotheses dominate the literature. The systems hypothesis suggests that delays in care delivery during nights and weekends-including longer catheterization laboratory activation time, reduced availability of experienced operators, and logistical constraints-are the primary drivers of worse outcomes. In support of this, some studies have found that the mortality difference between off-hours and on-hours presentations is attenuated after adjusting for DTB time (Chung et al., 2020), suggesting that system-level process measures may be actionable targets for quality improvement.
Alternatively, the intrinsic severity hypothesis suggests that nocturnal STEMI presentations represent inherently more severe infarcts-characterized by higher thrombus burden, larger myocardial infarction size, and more frequent complications such as cardiogenic shock-independent of how rapidly reperfusion is achieved. Recent studies examining circadian variation in infarct size and myocardial injury biomarkers have found evidence of larger infarcts and worse systolic function in nocturnal-onset STEMI, with long-term mortality implications.
Critically, the vast majority of evidence in this field derives from retrospective registry data, particularly from North American and Western European cohorts. Data from the Middle East and North Africa (MENA) region, where demographic and healthcare system profiles differ substantially from developed nations, are essentially absent from the literature. Furthermore, contemporary data on the prospective relationships between time-of-PPCI, operator experience, procedural quality parameters (such as myocardial blush grade and ST-segment resolution), and outcomes remain limited.
A prospective study with granular intra-procedural data collection offers the opportunity to: (1) quantify the magnitude of the off-hours effect in a Middle Eastern context; (2) decompose the DTB time into its components to identify specific system bottlenecks; (3) assess whether operator seniority and team composition confound or mediate the off-hours effect6; and (4) evaluate whether procedural quality metrics (reperfusion grade, thrombus burden, microvascular perfusion) differ between daytime and nighttime PPCI and contribute to outcome disparities independent of system factors.
Inclusion: Age ≥18 years; Acute STEMI eligible for Primary Percutaneous Coronary Intervention; Symptom onset ≤24 hours prior to hospital presentation.
Exclusion: Intra-aortic balloon pump or mechanical circulatory support initiated prior to diagnostic angiography (devices initiated post-PPCI are not exclusions); Cardiogenic shock secondary to mechanical complication (acute mitral regurgitation, ventricular septal defect, free wall rupture) rather than myocardial infarction; Expected survival <30 days from non-cardiac causes; Previous myocardial infarction with known LV dysfunction (baseline LVEF <30%); Indication for emergent coronary artery bypass grafting at presentation (e.g., left main occlusion unsuitable for PCI).