Increase in Evidence-Based Treatments Followed by Decreased Risk of Death in Heart Attack Patients

In an analysis of data from a coronary care registry in Sweden, between 1996-2007 there was an increase in the prevalence of use of evidence-based invasive procedures and pharmacological therapies for treatment of a certain type of heart attack, and a decrease in the rate of death at 30 days and one year after a heart attack for these patients, according to a study in the April 27 issue of JAMA.

Although recent population-based studies indicate a reduction in incidence, ST-elevation myocardial infarction (STEMI; a certain pattern on an electrocardiogram following a heart attack) is still a major health issue worldwide. Over the last 15 years a series of large-scale prospective randomized trials have documented the efficacy and safety of several new treatments available for patients with heart attack. "Over the years, several generations of international and national guidelines have been presented to support the implementation of these evidence-based treatments in clinical practice," the authors write. "However, only limited information is available on the speed of implementation of these new treatment strategies and its association with long-term survival in real-life health care."

Tomas Jernberg, M.D., Ph.D., of Karolinska University Hospital, Stockholm, Sweden, and colleagues conducted a study to examine the adoption of new treatments for STEMI and short- and long-term survival.

The study included data from the Register of Information and Knowledge about Swedish Heart Intensive Care Admission, which records baseline characteristics, treatments, and outcome of patients with acute coronary syndrome admitted to almost all hospitals in Sweden. This study included 61,238 patients with a first-time diagnosis of STEMI between 1996 and 2007. The authors examined the proportions of patients treated with different medications and invasive procedures and the mortality rate over this time period.

The researchers found that of evidence-based in-hospital treatments known to influence outcomes, use of reperfusion treatment (i.e., thrombolysis or primary percutaneous coronary intervention [PCI; procedures such as balloon angioplasty or stent placement used to open narrowed coronary arteries]) showed an increase from 66 percent to 79 percent, primary PCI from 12 percent to 61 percent, any revascularization (i.e., PCI or bypass surgery) within 14 days from 10 percent to 84 percent and average use of glycoprotein Ilb/lIIa inhibitors from 0 percent to 55 percent. However, large variations existed between hospitals regarding speed of implementation of new treatments.

The estimated use of aspirin, clopidogrel, beta-blockers, statins, and ACE inhibitors or angiotensin receptor blockers (ARBs) all continuously increased over the study period, clopidogrel from 0 percent to 82 percent, statins from 23 percent to 83 percent, and ACE inhibitor or ARB from 39 percent to 69 percent. There was also variation between hospitals in the implementation of these medications.