New guidelines for cardiac testing and treatments

People with heart disease should take special precautions before undergoing any kind of surgery, even noncardiac surgery, to reduce their risk of a cardiac event, according to new joint guidelines from the American College of Cardiology and the American Heart Association.

The American College of Cardiology/American Heart Association 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery will be published online ahead of print on September 27 in the October 23, 2007, issues of Circulation: Journal of the American Heart Association and the Journal of the American College of Cardiology.

The guidelines – an update of those published in 2002 – provide a framework for considering a person's risk of a cardiac event in the “perioperative” (during or immediately after) period of noncardiac surgery.

According to the recommendations, patients should not stop taking cholesterol-lowering drugs before surgery. In addition, the guidelines say that many people with heart disease can safely undergo noncardiac surgery without first “fixing” their heart disease with an artery-opening procedure or coronary bypass grafting. The guidelines also address how best to treat those people who need a heart procedure before noncardiac surgery, have coronary stents or require anti-clotting medication.

“In the past we had to go on indefinite evidence, but now there are a number of studies published to help us direct best practices,” said Lee A. Fleisher, M.D., chair of the guideline writing committee. “Statin use wasn't even addressed in the previous guidelines. New trials have shown us that patients should continue taking them.”

In the case of non-emergency or elective procedures, the guidelines say that intervention (such as bypass surgery or angioplasty) is rarely necessary to lower the risk of surgery unless a patient would need the intervention anyway. If the noncardiac surgery is an emergency, heart testing should be forgone and a patient should go straight to an operating room.

The guidelines recommend that patients undergo evaluation and treatment before noncardiac surgery only for “active” cardiac conditions such as unstable coronary syndromes (severe angina), decompensated heart failure, significant heart rhythm disturbances (arrhythmias) or severe heart valve disease.

“Previously, to have someone ready for surgery, many people needed diagnostic tests to look at the extent of heart disease,” said Fleisher, chair of the Department of Anesthesiology and Critical Care at the Hospital of the University of Pennsylvania. “We would do a lot of screening, and we might fix their heart disease to get them ready for the noncardiac surgery. We know now that surgical outcomes are the same in many people whether or not we fix the heart disease first.”

The difference in whether heart procedures reduce the risk of surgery is whether a person's heart disease is either severe or symptomatic – both of which would require treatment regardless of the impending surgery. “Several trials now show that in people without symptomatic heart disease, fixing the heart first doesn't make much of a difference in how well they do in surgery,” Fleisher said.

Thus, the surgical setting shouldn't be the only catalyst for a heart procedure. Fleisher said angioplasty with stenting might even increase the risk of perioperative heart problems. The risk of heart attack increases in the four to six weeks immediately after receiving a stent, so patients are prescribed anti-clotting medication during this period. This risk, and the duration of anti-clotting therapy, is up to one year for patients who received a coated or drug-eluting stent.

Due to the risks of excessive bleeding common to any surgery, patients were previously advised to stop taking their anti-clotting drugs prior to surgery. “We now know that the antiplatelet medication is very important after stent placement, and we advocate stopping it for as little time as possible,” Fleisher said.

For patients who need non-urgent or elective noncardiac surgery, and who need to undergo an artery-opening procedure beforehand, the guidelines recommend angioplasty using a bare metal stent followed by four to six weeks of anti-clotting therapy.

For patients who already have a drug-eluting coronary stent and need to undergo urgent noncardiac surgery that requires stopping the prescription anti-clotting drug, the guidelines recommend continuing aspirin therapy if possible, and restarting the prescription medicine as soon as possible.

The guidelines recommend coronary artery bypass grafting or angioplasty before a noncardiac surgery for patients with severe or symptomatic heart disease, such as having two or more blood vessels blocked, unstable angina or heart attack symptoms.

“In general,” according to the guidelines, “indications for further cardiac testing and treatments are the same as in the non-operative setting, but their timing is dependent on several factors.” These factors include the urgency of noncardiac surgery, the patient's specific risk factors and the type of surgery (whether it's a lower-risk or higher-risk procedure). Preoperative testing should be limited to those circumstances in which test results will affect a patient's treatment.