Test Predicts Patients at Risk for Complication After Open-Heart Surgery

After 5/9/98:
Bob Szafranski
312/558-1770

Embargoed for Release Until After 11 a.m. PDT, Thursday, May 7

TEST PREDICTS PATIENTS AT RISK

FOR COMPLICATION AFTER OPEN-HEART SURGERY

SAN DIEGO -- A common side effect of open-heart surgery may be predicted with a simple test, according to research being presented here today at the 19th Annual Scientific Sessions of the North American Society of Pacing and Electrophysiology (NASPE).

One-third of coronary artery bypass surgery patients develop a heart rhythm problem called atrial fibrillation, which is associated with an increased risk of stroke, as well as an increase in the length and cost of hospitalization. An estimated 573,000 coronary artery bypass procedures were performed in 1995, according to the National Center for Health Statistics.

"Post-cardiac surgery atrial fibrillation is a common and expensive problem," said Rod S. Passman, M.D., a fellow in cardiac electrophysiology at the Hospital of the University of Pennsylvania, Philadelphia. "But you don't want to give prophylactic agents to everyone before surgery because they do have side effects. You want to identify people who really need them."

Patients at risk for the condition tend to be older than 65 and have intra-atrial conduction delay (IACD), meaning it takes the electrical impulse longer to get from one upper chamber of the heart to the other. IACD can be identified by using a computer program to interpret an electrocardiogram (commonly known as an EKG). Using the test and the patient's age, physicians can determine who is at higher risk of developing atrial fibrillation after open-heart surgery. Patients who are at risk can take one of several anti-arrhythmic drugs before surgery to combat the problem.

"A physician needs to weigh the risk of the therapy with the patient's risk of developing the condition," said Dr. Passman. "Clearly, if prophylactic therapies are associated with side effects, you want to give the therapy to people with a 90 percent chance of developing the condition, not a 10 percent chance."

Open-heart surgery patients who develop atrial fibrillation stay in the hospital an average of two days longer, which can add from $2,000 to $10,000 to the hospital bill, said Dr. Passman. Treatment with Sotalol Before Open-Heart Surgery May Prevent Atrial Fibrillation

In related research, a randomized, controlled study found patients treated with an anti- arrhythmic drug called sotalol before open-heart surgery (coronary artery bypass, valve replacement or both) were associated with a 73 percent decrease in risk for developing atrial fibrillation.

Four of the 40 patients (10 percent) who received sotalol developed atrial fibrillation, versus 16 of the 42 patients (38 percent) who received the placebo.

"We need to try this with a bigger patient population, but this is very exciting," said John H. Ip, M.D., a cardiac electrophysiologist at Thoracic Cardiovascular Institute, Lansing, Mich. "This is the first study to show anything that works this well."

Although sotalol has been tried before with less than impressive results, it was always given immediately before surgery, said Dr. Ip.

"In our study, patients received the drug twice a day for 48 hours before surgery, and I believe that's the difference," he said. While an anti-arrhythmic drug called amiodarone is also often prescribed for the problem, it can take up to two weeks to get enough of that drug in a patient's system to provide protection, said Dr. Ip.

Dr. Passman's co-authors of a paper on the pre-operative EKG as a predictor of atrial fibrillation are: John F. Beshai, M.D.; Marc A. Scheiner, M.D.; Behzad B. Pavri, M.D.; Luis Seijo, M.D.; Eric Grubman, M.D.; and Stephen Kimmel, M.D., M.S.

Co-authors of a paper on the sotalol study being presented by Dr. Ip are: Denise L. Grimes, R.N.; Temsian Etikerentse, M.D.; Franceso Santoni, M.D.; Davendra Mehta, M.D.; Elena Pe, R.N.; and J. Anthony Gomes, M.D.

Based in Natick, Mass., the North American Society of Pacing and Electrophysiology is a professional organization of physicians, scientists and allied professionals throughout the world dedicated to the study and management of cardiac arrhythmias. Its mission is to improve the care of patients by promoting research, education and training, and providing leadership towards optimal policies and standards.

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[Editors note: For more information, contact the NASPE Web site at www.naspe.org.]