Aim: In non-ST elevation acute coronary syndromes (NSTEACS), early invasive management improves survival. However, since treatment strategies are urgent, not emergent, decisions to postpone invasive management due to weekend admission could affect outcome.
Methods: Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), a population-based registry capturing all cardiac admissions in southern Alberta, we compared time to cardiac catheterization, modality of revascularization, and crude and risk-adjusted mortality for NSTEACS patients presenting on weekends vs. weekdays. From 1 April 2005 to 31 October 2010, 11,981 patients were admitted to care facilities in southern Alberta (32.1% on weekends and 67.9% on weekdays).
Results: Baseline characteristics were similar. Mean time to cardiac catheterization was 67.2 h in the weekend group, compared to 62.4 h in the weekday group (p=0.03), with 34.7% of weekend and 45.1% of weekday patients receiving catheterization within 24 h of admission (p<0.0001), and 49.1 and 59.9%, respectively, within 48 h (p=0.002). Mortality at 30 days was 2.2% in the weekend group compared to 2.0% in the weekday group (p=0.58). The crude hazard ratio (HR) for 30-day mortality in the weekend group was 1.08 (95% CI 0.83-1.40). After adjusting for baseline risk factors, the HR for mortality remained non-significant (HR 1.06, 95% CI 0.82-1.38). Mortality at 1 year was also similar.
Conclusions: In a large unselected population of NSTEACS patients, weekend admission was associated with modest delays (4.8 h) in time to catheterization, but not with increased 30-day or 1-year mortality.
Keywords: Catheterization; mortality; myocardial infarction; regional variation; registry.