Background: Randomized clinical trials have found that early invasive strategies reduce mortality, myocardial infarction (MI), and rehospitalization compared with a conservative invasive approach in acute coronary syndromes (ACSs), but the effectiveness of such strategies in real-world settings is unknown.

Objective: To investigate adverse cardiovascular outcomes of an early versus conservative invasive strategy in a national cohort of patients with ACSs.

Design: Retrospective cohort study.

Setting: Administrative health care data on hospitalizations, procedures, and outcomes abstracted from the Danish national registries and covering all acute invasive procedures in patients presenting with an ACS.

Patients: 19 704 propensity score-matched patients hospitalized with a first ACS between 1 January 2005 and 31 December 2011.

Measurements: Risk for cardiac death or rehospitalization for MI within 60 days of hospitalization.

Results: Compared with a conservative approach, early invasive strategies were associated with a lower risk for cardiac death (cumulative incidence, 5.9% vs. 7.6%; adjusted hazard ratio [HR], 0.75 [95% CI, 0.66 to 0.84]; P < 0.001). Similar results were found for rehospitalization for MI (cumulative incidence, 3.4% vs. 5.0%; adjusted odds ratio, 0.67 [CI, 0.58 to 0.77]; P < 0.001) and all-cause death (cumulative incidence, 7.3% vs. 10.6%; adjusted HR, 0.65 [CI, 0.59 to 0.72]; P < 0.001).

Limitation: Potential residual confounding due to lack of core clinical variables.

Conclusion: In this real-world cohort of patients with a first hospitalization for an ACS, the use of an early invasive treatment strategy was associated with a lower risk for cardiac death and rehospitalization for MI compared with a conservative invasive approach.

Primary Funding Source: Department of Cardiology, University Hospital Gentofte.