Preventing Heart Attacks During Surgery: Drugs Not Foolproof

(Ivanhoe Newswire) -- The prescription of beta blockers to prevent heart attack during non-cardiac surgery does not prevent cardiac events in all cases, and can even be dangerous to some patients.

Cardiac complications around the time of non-cardiac surgery are relatively common and can be serious, prolonging hospitalizations and increasing costs. Beta blockers, designed to help protect against heart attack, routinely have been prescribed immediately preceding surgery. A new study finds, however, that while there was a reduction in perioperative myocardial infarction and primary cardiac events, the use of beta blockers also was associated with higher rates of stroke and overall mortality.

"Any surgery, particularly a high-risk procedure, is a stress on the heart, especially for those with underlying circulation problems or other cardiovascular risk factors," Kirsten E. Fleischmann, M.D., M.P.H., chair of the 2009 writing group that reviewed the latest evidence on the perioperative use of beta blockers, was quoted as saying. "In general, the higher the risk from a cardiovascular standpoint, the more likely a patient will benefit from beta blockers. However, newer data from the Perioperative Ischemic Evaluation (POISE) trial suggest that starting higher doses of beta blockers acutely on the day of surgery is associated with risk as well, so careful patient selection, dose adjustment and monitoring throughout the perioperative period is key."

The recommendation to continue beta blockers perioperatively in those patients who are already receiving them remains current. The researchers advise that beta blockers are appropriate for patients undergoing vascular surgery who are at high risk for heart attacks because of abnormal stress test results or known coronary artery disease, for high risk patients undergoing intermediate risk surgery, or for those with multiple risk factors such as diabetes, a history of heart failure or significant kidney disease.

The authors caution that when beta blockers are started in patients not yet taking them, the medication should be initiated well before the procedure and titrated up as blood pressure and heart rate allow.

"We recommend beta blockers be started well in advance of surgery and not at higher doses right off the bat," Dr. Fleischmann said. "Physicians must be vigilant in assessing patients' cardiac risk and weighing this against potential side effects of the therapy."

SOURCE: Journal of the American College of Cardiology and Circulation, November 24, 2009