Association Between Adoption of Evidence-based Treatment and Survival for Patients with ST-elevation Myocardial Infarction

Context: Only limited information is available on the speed of implementation of new evidence-based and guideline-recommended treatments and its association with survival in real life health care of patients with ST-elevation myocardial infarction (STEMI).

Objective: To describe the adoption of new treatments and the related chances of short- and long-term survival in consecutive patients with STEMI in a single country over a 12-year period.

Design, Setting, And Participants: The Register of Information and Knowledge about Swedish Heart Intensive Care Admission (RIKS-HIA) records baseline characteristics, treatments, and outcome of consecutive patients with acute coronary syndrome admitted to almost all hospitals in Sweden. This study includes 61,238 patients with a first-time diagnosis of STEMI between 1996 and 2007.

Main Outcome Measures: Estimated and crude proportions of patients treated with different medications and invasive procedures and mortality over time.

Results: Of evidence-based treatments, reperfusion increased from 66% (95%, confidence interval [CI], 52%-79%) to 79% (95% CI, 69%-89%; P < .001), primary percutaneous coronary intervention from 12% (95% CI, 11%-14%) to 61% (95% CI, 45%-77%; P < .001), and revascularization from 10% (96% CI, 6%-14%) to 84% (95% CI, 73%-95%; P < .001). The use of aspirin, clopidogrel, β-blockers, statins, and angiotensin-converting enzyme (ACE) inhibitors all increased: clopidogrel from 0% to 82% (95% CI, 69%-95%; P < .001), statins from 23% (95% CI, 12%-33%) to 83% (95% CI, 75%-91%; P < .001), and ACE inhibitor or angiotensin II receptor blockers from 39% (95% CI, 26%-52%) to 69% (95% CI, 58%-70%; P < .001). The estimated in-hospital, 30-day and 1-year mortality decreased from 12.5% (95% CI, 4.3%-20.6%) to 7.2% (95% CI, 1.7%-12.6%; P < .001); from 15.0% (95% CI, 6.2%-23.7%) to 8.6% (95% CI, 2.7%-14.5%; P < .001); and from 21.0% (95% CI, 11.0%-30.9%) to 13.3% (95% CI, 6.0%-20.4%; P < .001), respectively. After adjustment, there was still a consistent trend with lower standardized mortality over the years. The 12-year survival analyses showed that the decrease of mortality was sustained over time.

Conclusion: In a Swedish registry of patients with STEMI, between 1996 and 2007, there was an increase in the prevalence of evidence-based treatments. During this same time, there was a decrease in 30-day and 1-year mortality that was sustained during long-term follow-up.