Introduction Clinical guidelines recommend treatment with evidence-based (EB) drug therapy (antiplatelets, β-blockers, agents acting on the renin-angiotensin system, statins) for patients with acute myocardial infarction (AMI). Results on long term outcomes from observational population studies are scarce.

Objectives Analysing the association between EB drug therapy and 2 years mortality in AMI patients.

Methods Twothousand-twohundred-and-four AMI patients, discharged in 2006 and resident in Rome were selected from the Hospital Information System, excluding deaths during the first month after discharge. Exposure information was collected from the drug claims data considering EB drug prescriptions at discharge and during the first month; exposure was defined as at least one prescription, comparing different composite treatments (1, 2, 3 or 4 EB drug groups). The association between exposure to EB drug therapy and all-cause mortality during a 24 months follow-up was analysed through logistic regression, adjusting for gender, age and co-morbidities.

Results Most patients were treated with EB drug combinations (0: 9.5%, 1: 4.6%, 2: 14.7%, 3: 30.1%, 4: 41.1%); 7.4% of the patients died during follow-up. Mortality risk decreased with increasing number of prescribed EB drugs; combinations of 3 or 4 EB drugs were associated with a significant protective effect vs no EB drugs (4 vs 0 EB drugs: OR_adj=0.46; 95% CI 0.27 to 0.78; 3 vs 0 EB drugs: OR_adj=0.50; 95% CI 0.29 to 0.86; 2 vs 0 EB drugs: OR_adj=0.69; 95% CI 0.39 to 1.23; 1 vs 0 EB drugs: OR_adj=0.49; 95% CI 0.21 to 1.13).

Conclusions In Rome, most patients are treated with EB drugs after AMI; first-month poly-drug therapy is associated with reduction in 2 years mortality.