New ST-elevation Myocardial Infarction Guidelines Emphasize Speed and Aggressive Treatment and Lower Low-density Lipoprotein Cholesterol Levels

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Citation
US Cardiology 2004;2004:1(1):17-20

In July 2004, the American College of Cardiology (ACC) and the American Heart Association (AHA) Joint Task Force on Practice Guidelines released new practice guidelines for ST-elevation myocardial infarction (STEMI), which emphasize the need for speed when chest pain or other symptoms of a heart attack strike. Speedy treatment not only means the difference between life and death but also between disability and a return to an active lifestyle. Treating STEMI requires fast action because, if blood flow is not restored to the heart within 20 minutes, serious damage or death occurs.

The guidelines are organized to make it easier for physicians and other medical personnel to quickly identify the information they need to provide the best treatment. The content outline follows the chronological flow of a patientÔÇÖs interface with physicians and other healthcare workers, providing clear treatment instructions for acute STEMI stages, possible percutaneous coronary intervention (PCI) or more, and hospitalization if necessary. In addition, specific guidelines about medical treatments pre- and post-STEMI, and aggressive recommendations for secondary treatment and long-term management are provided. Of particular note are the recommendations regarding more aggressive cholesterol-lowering therapy recommendations that are reinforced by the recently released update of the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) guidelines.

The ACC and AHA have jointly engaged in the production of practice guidelines in the area of cardiovascular disease since 1980. This effort is directed by the ACC/AHA Task Force on Practice Guidelines, whose charge is to develop and revise practice guidelines for important cardiovascular diseases and procedures.

The first practice guideline, written in 1990 under the auspices of the ACC/AHA Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures, was Guidelines for the Early Management of Patients with Acute Myocardial Infarction. Over the years, as information grew, the purpose and text of the guidelines evolved. After 1990, the next effort came from the ACC/AHA Task Force on Practice Guidelines, which began work in 1994 and produced ACC/AHA Guidelines for the Management of Patients with Acute Myocardial Infarction, using the term 'acute coronary syndromeÔÇÖ to reflect the emerging overarching concept that disruption of a vulnerable or high-risk plaque causes an episode of ischemic discomfort. Emphasis was placed on the 12-lead electrocardiogram (ECG) that was used to categorize patients into two broad cohorts - those presenting with ST-elevation and those presenting without ST-elevation (ultimately diagnosed as unstable angina or non-Q-wave MI depending on whether a biomarker of necrosis was detected in the patientÔÇÖs blood).

The ACC/AHA Guidelines for the Management of Patients with UA/STEMI were published in 2000 and updated electronically in 2002. Although considerable improvement has occurred in the process of care for patients with STEMI, the ACC and AHA realize that room for improvement always exists.These newest guidelines focus on the numerous advances in the diagnosis and management of patients with STEMI since 1999. The guidelines are divided into the following sections:

  • pathology;
  • management prior to STEMI;
  • onset of STEMI;
  • initial recognition and management in the emergency department;
  • hospital management; and
  • long-term management.

The detailed discussion of types of examinations, treatments, drugs, and other procedures are then placed in the context of the stage of the patient interaction. All sections contain in-depth discussions of the various evaluations, exams, and treatments according to the patientÔÇÖs status. The section that deals with management prior to a STEMI incident emphasizes the importance of patient education to prevent STEMI and, if symptoms occur, to act quickly. For that reason, the guidelines emphasize educating patients to take action and enter the medical system much more rapidly than at present. Too many patients delay seeking treatment for fear of being embarrassed because symptoms may be indigestion or something similar. Women in particular delay longer than they should because they still consider men to be the ones vulnerable to heart attacks. Section six, which addresses the initial recognition and management of STEMI in the emergency department, contains the centerpiece of the guidelines - selection of the reperfusion therapy. The new guidelines assist physicians in making the decision by providing questions for them to ask.

The next logical step in the guidelines is medical treatment for a hospitalized patient. Section seven includes the general measures taken along with discussion of risk stratification, medication assessments, coronary artery bypass graft surgery decisions, and convalescence, discharge, and post-MI care.

Secondary Prevention and National Cholesterol Education Program Guidelines

In discussing secondary prevention, the task force provides forceful guidelines that go beyond recommending that patients take aspirin daily and receive beta-blockers to reduce the risk of irregular heart rhythm. Use of angiotensin converting enzyme (ACE) inhibitors is strongly endorsed, and for patients who cannot tolerate ACE inhibitors, angiotensin receptor blockers (ARB) are suggested. It is also suggested that physicians be more aggressive with their patients regarding weight management, smoking cessation, and diabetes management, among other factors.

One set of recommendations calls for a more aggressive approach to controlling low-density lipoprotein cholesterol levels (LDL) through a shift to much lower acceptable LDL levels. Interestingly, the NCEP Adult Treatment Panel III released updated guidelines on the 13 July 2004 that coincide with the task forceÔÇÖs recommendations.

According to the NCEP updated guidelines, which were endorsed by the National Heart, Lung, and Blood Institute (NHLBI), the American College of Cardiology Foundation (ACCF), and the AHA, the five clinical trials of statin therapy conducted since their initial report in 2001 confirm the importance of targeting LDL in cholesterol-lowering therapy, establish the effectiveness of using statins, and set new goals for lowering LDL cholesterol.

For high- and very high-risk patients, NCEP reportÔÇÖs recommendations are that the overall goal remains an LDL level of less than 100mg/dL, but for people at very high risk, a group that is considered a 'sub-setÔÇÖ of the high-risk category, the update offers a new therapeutic option of treating under 70mg/dL. For the very high-risk patients, whose LDL levels are already below 100mg/dL, there is also an option to use drug therapy to reach less than 70mg/dL. For high-risk patients overall, the update lowers the threshold for drug therapy to an LDL of 100mg/dL or higher and recommends drug therapy for those high-risk patients whose LDL is 100-129mg/dL.

In Conclusion

It is important that the medical professions play a significant role in critically evaluating the use of diagnostic procedures and therapies in the management or prevention of disease. Rigorous and expert analysis of available data documenting relative benefits and risks of procedures and therapies can produce helpful guidelines that improve the effectiveness of care, optimize patient outcomes, and generally have a favorable impact on the overall cost of care by focusing resources on the most effective strategies.

Practice guidelines are intended to assist practitioners in clinical decision-making. However, the ultimate judgment regarding care of a particular patient must be made by the clinician and patient in light of all of the circumstances presented by that patient.

On occasion, an updating of guidelines may result in important new developments and recommendations in the area of cardiovascular disease and care. The information and recommendations in both the ACC/AHA Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction and the NCEP ATD III Update should perhaps be considered in this context. Ôûá

When citing this document, the ACCF and the AHA would appreciate the following citation format: Antman EA, Anbe DT, Armstrong PW, Bates ER, Green LA, Hand M, Hochman JS, Krumholz HM, Kushner FG, Lamas GA, Mullany CJ, Ornato JP, Pearle DL, Sloan MA, Smith SC. ACC/AHA guidelines for the management of patients with st-elevation myocardial infarction: executive summary: a report of the ACC/AHA Task Force on Practice Guidelines (Committee to revise the 1999 guidelines on the management of patients with acute myocardial infarction). The document and full text guidelines are available in the 3 August rapid access issue of Circulation: Journal of the American Heart Association, and the 4 August issue of the Journal of the American College of Cardiology.The document and the full-text guideline are available on the websites of the American College of Cardiology (www.acc.org) and the American Heart Association (www.americanheart.org).

Writing committee members include: Daniel T Anbe, MD; Paul Wayne Armstrong, MD; Eric R Bates, MD; Lee A Green, MD, MPH; Mary Hand, MSPH, RN; Judith S Hochman, MD; Harlan M Krumholz, MD; Frederick G Kushner, MD; Gervasio A Lamas, MD; Charles J Mullany, MB, MS; Joseph P Ornato, MD; David L Pearle, MD; and Michael A Sloan, MD.
 

References
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