Prognosis and treatment in patients admitted with acute myocardial infarction on weekends and weekdays from 1997 to 2009

Background

Less invasive treatment and poorer outcomes have been shown among patients admitted with acute myocardial infarction (AMI) on weekends compared to weekdays.

Objectives

To investigate the ‘weekend-effect’ on mortality in patients with AMI.

Methods

Using nationwide registers we identified 92,164 patients aged 30–90 years who were admitted to a Danish hospital with a first AMI from 1997 to 2009. Patients were stratified according to weekday- or weekend admissions and four time-periods to investigate for temporal changes. All-cause mortality at 2, 7, 30, and 365 days was investigated using proportional hazards Cox regression.

Results

Mortality rates were higher on weekends within seven days of admission in 1997–99 (absolute difference ranging from 0.8 to 1.1%). Weekend–weekday hazard-ratios were 1.13 (1.03–1.23) at day 2 and 1.10 (1.01–1.18) at day 7. There were no significant differences in 2000–09 and estimates suggested an attenuation of the initial ‘weekend-effect’.Overall, the use of coronary angiography (34.9% vs. 72.3%) and percutaneous coronary intervention (6.6% vs. 51.0%) within 30 days increased, as did the use of statins (49.9% vs. 80.1%.) and clopidogrel (26.7% vs. 72.7%). The cumulative mortality decreased during the study period from 5.4% to 2.5% at day of admission, from 19.5% to 11.0% at day 30 and from 28.0% to 19.0% at day 365 (all tests for trend p < 0.0001).

Conclusions

No persistent ‘weekend-effect’ on mortality was present in patients with AMI in 1997–2009. Overall, mortality rates have decreased concomitantly with an increased use of current guideline-recommended invasive and medical therapy.