New guidelines for treating heart attacks

Jul 8 2004

If your chest pain worsens and lasts more than five minutes, especially if you’re short of breath, feel weak, nauseated or lightheaded, call 9-1-1—you could be having a heart attack.

That’s one of several recommendations of the new American College of Cardiology/American Heart Association Guidelines for treating heart attacks.

The new guidelines detail the best way for physicians to manage patients with ST elevation myocardial infarction (STEMI), a severe heart attack in which an artery is completely blocked. They are published today at www.americanheart.org and www.acc.org. They will appear in the June 15 rapid access issue of Circulation: Journal of the American Heart Association, and the July 21 issue of the Journal of the American College of Cardiology.

Each year an estimated 500,000 Americans have a STEMI. Treating this type of heart attack requires fast action because if blood flow is not restored to the heart within 20 minutes permanent damage will occur, said Elliott M. Antman, M.D., professor of medicine at Harvard Medical School and director of the Samuel A. Levine Cardiac Unit at Brigham and Women’s Hospital in Boston. While some heart muscle can be saved if patients are treated later, more of it is lost with every minute treatment is delayed.

Speedy treatment not only means the difference between life and death, but also between disability and a return to an active lifestyle after a heart attack.

“The message that we are trying to get across to patients is this: They need to enter the medical system much more rapidly than they are currently,” said Antman, who chaired the writing committee and the ACC/AHA task force that drafted the new practice guidelines.

Many patients say they delay seeking treatment because “they’re embarrassed; they worry that they are crying wolf” because the symptoms may be caused by indigestion or other non-heart attack conditions.

“It is not unusual for patients to wait two hours or longer before seeking treatment when they should get help as quickly as possible to minimize damage to their hearts,” he said. “Women in particular delay longer because many still adhere to a message of the past identifying men as those primarily at risk for heart attacks.”

Other heart attack symptoms include chest discomfort with or without radiation to the arms, back, neck, jaw or stomach, and excessive sweating. The new guidelines also help make it easier to determine treatment.

Antman said earlier guidelines weren’t always helpful to physicians who needed to make fast decisions about treatment. The new guidelines have been organized so that all medical personnel—emergency medical technicians who are first on the scene, emergency department staff, and the cardiologists treating the patients—can quickly identify the most appropriate treatments.

For example, one of the most crucial decisions when treating heart attack patients is whether to open the blocked artery with a clot-busting drug or by using tiny flexible tubes called stents that prop open blocked arteries. The new guidelines distill this decision to four issues:

• How much time has passed since the onset of symptoms?
• How great is the risk of dying?
• How great is the risk of bleeding in the brain if clot-busting drugs are used?
• Realistically, how much time will it take to get the patient into a cardiac catheterization lab for stenting?
• The guidelines also include clear instructions about medical treatments after heart attack. For example, the guidelines recommend that patients should take aspirin daily and receive beta-blockers (to reduce the risk of irregular heart rhythm) after heart attack.

“We also strongly endorse the use of angiotensin-converting enzyme (ACE) inhibitors for all patients to improve heart function,” Antman said. “For those patients who cannot tolerate an ACE inhibitor, we suggest an angiotensin receptor blocker (ARB).”

The new guidelines also recommend that heart attack patients with levels of “bad” low-density lipoprotein cholesterol (LDL) of 100 milligrams per deciliter (mg/dL) or higher receive cholesterol-lowering statin drugs upon hospital discharge. The goals should be to reduce LDL to “substantially less” than 100 mg/dL.

“This is more aggressive than the original ATP III goal recommended by the National Cholesterol Education Panel,” said Sidney C. Smith Jr., M.D., co-chair of the joint task force and past-president of the American Heart Association. “Based on the results of large clinical trials of statin drugs, we’re finding that the lower the LDL, the better. This change in practice could significantly improve outcomes for patients recovering from heart attack.”

Writing committee members also include Daniel T. Anbe, M.D.; Paul Wayne Armstrong, M.D.; Eric R. Bates, M.D.; Lee A. Green, M.D., M.P.H.; Mary Hand, M.S.P.H., R.N.; Judith S. Hochman, M.D.; Harlan M. Krumholz, M.D.; Frederick G. Kushner, M.D.; Gervasio A. Lamas, M.D.; Charles J. Mullany, M.B., M.S.; Joseph P. Ornato, M.D.; David L. Pearle, M.D.; and Michael A. Sloan, M.D.

The American College of Cardiology, a 30,000-member nonprofit professional medical society and teaching institution, is dedicated to fostering optimal cardiovascular care and disease prevention through professional education, promotion of research, leadership in the development of standards and guidelines, and the formulation of health care policy.