VA Study Shows Beta-Blockers Linked to Heart Attacks After Surgery

VA STUDY SHOWS COMMONLY-USED BETA-BLOCKERS LINKED TO HEART ATTACKS AFTER SURGERY
  
Beta-blockers linked to heart attacks after surgery

by Elizabeth Cooney

Patients who were taking drugs to lower their blood pressure before, during, and after operations unrelated to their hearts had higher rates of heart attacks and death than similar patients who were not taking the drugs, a study shows. The new findings add to an already complex picture of the best way to protect patients from heart complications after non-cardiac surgery.

A team led by Dr. Haytham M. S. Kaafarani and Dr. Kamal M.F. Itani of the Veterans Affairs Boston Health Care System reports in the Archives of Surgery on patients who took beta-blockers such as atenolol or metoprolol around the time that they had surgery at a Houston VA hospital in 2000.

Preventing cardiac complications in patients with coronary artery disease or risk factors for it has been the focus of intense research, they write, and guidelines from the American College of Cardiology and the American Heart Association recommend beta-blockers for high-risk patients having surgery, particularly vascular procedures. The authors set out to explore the effect of beta-blockers among patients at all levels of cardiac risk.

Reviewing the records of more than 1,200 patients who had vascular surgery, hernia repair, orthopedic procedures, or other kinds of surgery, the researchers ranked the patients as at low, intermediate, or high risk of heart problems. They also noted their heart rates before and after surgery, based on previous work in the field showing that an elevated heart rate preceded stroke, heart attack, and death.

Among the 238 patients in the retrospective study who were already taking beta-blockers or who received them around the time of their surgery, there was a higher rate of heart attacks and death – 2.94 percent compared with 0.74 percent — in the 30 days after surgery than among the 408 patients in a control group matched by age, sex, heart or procedure risk, smoking status, and kidney health. None of the patients who died had been classified as at high risk.

The patients who took beta-blockers and later died had higher heart rates before surgery – 86 compared to 70 beats per minute — than the patients on beta-blockers who survived. The differences in the death rate disappeared by one year after surgery.

The study raises questions about the safety of using beta-blockers in low-risk or intermediate-risk patients, the authors say. They also suggest that achieving a low heart rate before surgery may be essential for beta-blockers to protect against heart attacks.

“Our study adds to the controversy regarding the optimal use of perioperative beta-blockers in patient populations at various levels of cardiac risk,” they write. “Overall, our data found worse perioperative cardiovascular outcome and worse overall mortality associated with the use of beta-blockers.”

In a critique appearing with the article, Dr. Todd E. Rasmussen of Wilford Hall US Air Force Hospital in San Antonio, Texas, wonders whether taking beta-blockers is a sign of being at risk for heart complications, including death. He also questions how the patients were stratified according to their cardiac risk.

"It is conceivable, if not likely, that patients in the beta-blocker group were indeed at higher risk, having been identified as candidates for beta-blocker therapy," he writes. "Despite these limitations, the authors are to be commended for a significant undertaking and an insightful study. I would encourage them now to turn their energy and expertise to a contemporary cohort using more powerful and complete methods."