Treatment for Heart Attacks Can Vary By Geographic Location

Researchers find beneficial treatments are underused

CHICAGO -- Researchers find noticeable geographic variations in the seven therapies used as a measure of quality treatment after a heart attack. As a result, key treatments are being underused, notes an article in the February 17 issue of The Journal of the American Medical Association (JAMA).

Gerald T. O'Connor, Ph.D., D.Sc., of Dartmouth Medical School in Hanover, N.H., and colleagues studied the geographic differences of seven therapies identified by the Cooperative Cardiovascular Project (CCP), as indicators of the quality of treatment received after an acute myocardial infarction (AMI), or heart attack. The researchers studied a national sample of 186,800 Medicare beneficiaries hospitalized with AMI.

"Substantial geographic variation exists in the treatment of patients with acute myocardial infarction, and these gaps between knowledge and practice have important consequences," according to the authors. "Therapies with proven benefit for AMI are underused despite strong evidence that their use will result in better patient outcomes."

Approximately 1.5 million people in the United States experience AMI each year, and approximately one-third of these patients die in the acute phase of the AMI. The annual costs associated with acute myocardial infarction exceeds $60 billion.

The researchers found that aspirin was used frequently both during hospitalization (86 percent) and at discharge (78 percent) for ideal patients. Most patients (82 percent) with impaired left ventricular function had calcium channel blocking agents withheld at hospital discharge. Two-thirds of eligible patients (67 percent) received reperfusion (opening of arterial blockage) using either thrombolytics (treatment used to break up a clot blocking an artery) or coronary angioplasty during first 12 hours of hospitalization. Less than two-thirds of patients who were considered eligible (60 percent) were prescribed ACE inhibitors at hospital discharge. Only half (50 percent) of eligible patients were prescribed beta-blocking agents at hospital discharge. Less than half (42 percent) of patients who are current cigarette smokers received smoking cessation advice.

Other findings include:

• Most of the lower rates of prescribing aspirin during hospitalization were in the South Central and Southeast regions
• Rates of use for aspirin prescribed at hospital discharge were highest in the Northeast, North Central and Mountain regions
• There was no clear geographic pattern for withholding calcium channel blocking agents from patients with impaired left ventricular function
• Lowest rates of use for reperfusion using either thrombolytics or coronary angioplasty during first 12 hours of hospitalization were in the South Central and mid-Atlantic states
• Rates were somewhat higher in the North Central region, but there was no clear geographic pattern for ACE inhibitor use at hospital discharge
• Rates of use for beta-blocking agents prescribed at hospital discharge were highest in the Northeast and North Central regions; lowest in South Central and Southeast regions
• Rates were highest in Alaska and the mountain states and lowest in the South Central and Southeast regions for smoking cessation advice given to current cigarette smokers

The CCP was the first national project of the Health Care Financing Administration's quality improvement project for Medicare beneficiaries. CCP began with the establishment of a joint Health Care Financing Administration and American Medical Association Steering Committee for the CCP. The practices that will increase and improve positive patient outcomes and reduce the use of possibly harmful therapies after an acute myocardial infarction were based on treatment guidelines published by the American College of Cardiology, the American Heart Association and expert consensus using an intensive review process.

The authors speculate that the reasons these therapies are not more widely used is that physicians may not be aware of the guidelines, may disagree with the recommendations or that they may perceive the guidelines as taking away their professional freedom in the decision-making process. The authors also note that changes in behavior tend to lag behind the knowledge of new treatment guidelines.

"Acute myocardial infarction is a common and serious condition, and the evidence from clinical trials strongly suggests that adherence to these established guidelines will result in better patient outcomes," the authors write. "It is undoubtedly true that some acute myocardial infarction patients experience unnecessary morbidity or mortality because they receive substandard medical care. This study finds that there is currently unrealized potential for more effective care of patients with acute myocardial infarction."(JAMA. 1999;281:627-633)

To contact Gerald T. O'Connor, Ph.D., D.Sc., call Hali Wickner at 603/650-1520. For more information, contact the AMA's Brian Pace at 312/464-4311. E-mail: Brian_Pace@ama-assn.org

Editor's Note: All support for this study was provided by the Health Care Financing Administration, Baltimore.

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