Patients who receive evidence-based treatments after a certain type of heart attack have a lower risk of death within 30 days and one year, Swedish researchers from the Karolinska University Hospital report in JAMA (Journal of the American Medical Association). STEMI (ST-elevation myocardial infarction) – a specific electrocardiogram pattern after a heart attack – continues to be a major health issue globally, despite recent population-based studies showing a reduction in rates.

The authors explain that several large-scale prospective randomized trials have examined the efficacy and safety of numerous novel heart attack treatments since 1995.

The researchers write:

“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., and team set out to determine how effective new treatments for STEMI were regarding short- and long-term survival. They gathered data from the Register of Information and Knowledge about Swedish Heart Intensive Care Admission, which includes baseline characteristics, therapies and outcomes for patients with acute coronary syndrome who were hospitalized in Sweden. It involved 61,238 individuals who were hospitalized between 1996 and 2007 with a first-time diagnosis of STEMI. The researchers were specifically looking at what medications and invasive procedures patients received and how they affected mortality rates.

They found that the following evidence-based in-hospital treatments had the following impact on outcomes:

  • Reperfusion treatment, such as thrombolysis or primary percutaneous coronary intervention (PCI) showed an increase from 66% to 79%
  • Primary PCI showed an increase from 12% to 61%
  • Revascularization with 14 days from 10% to 84%
  • Average glycoprotein Ilb/lIIa inhibitor use from 0% to 55%

Examples of PCI include balloon angioplasty or stent placement used to open narrowed coronary arteries.

The authors noted that the speed of implementation of new treatments varied enormously between hospitals.

The authors wrote:

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% to 82%, statins from 23% to 83%, and ACE inhibitor or ARB from 39% to 69%. There was also variation between hospitals in the implementation of these medications.

There was a continuous, steady decrease in in-hospital complications over a 12-year period. The percentage of patients experiencing a new myocardial infarction while in hospital dropped from 4% to 1%.

Between 1996 and 2007 the reduction in mortality 30 days and 1 year after a heart attack dropped:

  • 12% to 7.2% among those receiving aspirin, clopidogrel, beta-blockers, statins, and ACE inhibitors or angiotensin receptor blockers
  • 15% to 8.6% among those given statins
  • 21% to 13.3% among those given ACE inhibitors or ARB

The authors add that the mortality decrease was sustained over the 12-year survival analyses.

They wrote:

“The first finding of this study, in a nearly complete nationwide cohort of patients with STEMI, is that the adoption of evidence-based and guideline-recommended treatments was gradual. The initial large variation in treatments between hospitals gradually decreased with an increase in equality of care over time. The second finding is that this increase in adherence to treatment guidelines is associated with a gradual lowering of both short- and long-term mortality, which could not be explained by changes in baseline characteristics.

From 1996 to 2007, the 30-day mortality has been more than halved with an absolute reduction of almost 8 percent. The improvements in survival tended to be greater in the latter part of this 12-year period.”

In 2007, the average patient with STEMI lived 2.7 years longer than those in 1995.

Debabrata Mukherjee, M.D., of the Texas Tech University Health Sciences Center, El Paso, Texas, wrote:

“They point to an opportunity to improve the quality of care provided to patients with STEMI by decreasing the lag time for adoption of life-saving therapies and improving adherence to evidence-based care across hospitals.

The difficulty in disseminating and implementing new technology as reported in the current study is not unique to health care; the slow adoption of innovation has been documented in fields as different as agriculture, education, and communication. Successful training of clinicians in implementing new therapies requires a balance of both didactic training, defined as the methods used for information transfer such as written materials, lectures, and workshops, and competence training, defined as the process of acquiring skills necessary to administer a treatment skillfully and with fidelity.

Quality improvement exercises that promote the use of systems that embed guideline knowledge into the care process are often more successful than simple dissemination of information.”

“Association Between Adoption of Evidence-Based Treatment and Survival for Patients With ST-Elevation Myocardial Infarction”
Tomas Jernberg, MD, PhD; Per Johanson, MD, PhD; Claes Held, MD, PhD; Bodil Svennblad, MsC; Johan Lindbäck, MsC; Lars Wallentin, MD, PhD
JAMA. 2011;305(16):1677-1684. doi: 10.1001/jama.2011.522

Written by Christian Nordqvist