Association Between Adoption of Evidence-Based Treatment and Survival for Patients With ST-Elevation Myocardial Infarction

Study Questions:

What is the relation between the adoption of new evidence-based and guideline-recommended treatments and the related chances of short- and long-term survival in consecutive patients with ST-elevation myocardial infarction (STEMI)?


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. The main outcome measure was the estimated and crude proportions of patients treated with different medications and invasive procedures and mortality over time.


Of evidence-based treatments, reperfusion increased from 66% (95%, confidence interval [CI], 52%-79%) to 79% (95% CI, 69%-89%; p < 0.001), primary percutaneous coronary intervention from 12% (95% CI, 11%-14%) to 61% (95% CI, 45%-77%; p < 0.001), and revascularization from 10% (96% CI, 6%-14%) to 84% (95% CI, 73%-95%; p < 0.001). The use of aspirin, clopidogrel, beta-blockers, statins, and angiotensin-converting enzyme (ACE) inhibitors all increased: clopidogrel from 0% to 82% (95% CI, 69%-95%; p < 0.001), statins from 23% (95% CI, 12%-33%) to 83% (95% CI, 75%-91%; p < 0.001), and ACE inhibitors or angiotensin II receptor blockers from 39% (95% CI, 26%-52%) to 69% (95% CI, 58%-70%; p < 0.001). 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 < 0.001); from 15.0% (95% CI, 6.2%-23.7%) to 8.6% (95% CI, 2.7%-14.5%; p < 0.001); and from 21.0% (95% CI, 11.0%-30.9%) to 13.3% (95% CI, 6.0%-20.4%; p < 0.001), 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.


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


This study reports that in a nationwide cohort of patients with STEMI, the adoption of evidence-based and guideline-recommended treatments was gradual, and this increase in adherence to treatment guidelines was associated with a gradual lowering of both short- and long-term mortality. Identification of undue variations in the processes of care and highlighting areas of need for quality improvement programs are important tasks for the quality registries in health care. As physicians taking care of STEMI patients, we must partner with nurses, hospitals, practice managers, insurers, national health care organizations, and information technology to successfully implement evidence-based therapies quickly, safely, and effectively to serve the best interests of our patients.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Interventions and ACS

Keywords: Outcome Assessment (Health Care), Registries, Myocardial Infarction, Acute Coronary Syndrome, Follow-Up Studies, Sweden, Survival Analysis, Percutaneous Coronary Intervention

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