Test Predicts Patients At Risk For Complication After Open-Heart Surgery

May 07, 1998

Philadelphia, PA -- Researchers at the University of Pennsylvania Medical Center have designed a novel test that effectively predicts a patient's risk for developing a common life-threatening heart-rhythm abnormality following coronary-artery bypass surgery (CABS). The abnormality -- known as atrial fibrillation, or AF -- occurs in approximately one-third of all bypass surgery patients, and is associated with an increased risk of stroke, as well as an increase in the length and cost of hospitalization. According to the test's designers, pre-surgical identification of high-risk AF patients can be used by physicians to treat those patients prophylactically with anti-arrhythmic medications. The Penn investigators will report their findings today at the annual conference of the North American Society of Pacing and Electrophysiology (NASPE), being held in San Diego, California.

The test, called the "Prediction Rule," is a mathematically-derived assessment of post-operative AF risk based on a patient's age plus two pre-surgical clinical factors. The clinical factors -- both of which are exacting measurements of electrical-impulse activity within the heart muscle -- can be extrapolated from the results of a patient's diagnostic electrocardiogram, commonly known as an EKG. The electrical-impulse data include a PR interval measurement, which notes the time it takes an electrical impulse to travel from the top chambers of the heart to the bottom ones; and a P-wave duration, which identifies the time required for an impulse to move between the two upper chambers. Basically, the longer the travel time, the greater the risk.

"We determined that patients who are older than 65 and have specific elevated travel-time factors have a 74% chance of developing post-operative atrial fibrillation," notes lead author Rod S. Passman, MD, a fellow in the Division of Cardiology at the University of Pennsylvania Medical Cancer. "These high-risk patients should be considered for treatment prophylactically to prevent the onset of atrial fibrillation after open-heart surgery." On the other hand, Passman and his colleagues found that patients with no risk factors -- i.e., those under age 65 with low-level impulse travel-time factors -- have only a 12% chance of suffering AF post-surgically.

"Because of their side effects, anti-arrhythmic medications should not be given to all patients before surgery," explains Passman, who also holds a fellowship appointment in Penn's Center for Clinical Epidemiology and Biostatistics. "Instead, they should be given only to those patients who really need them -- which means those deemed at-risk of developing AF."

In addition to the test's clear clinical benefit to patients, the test is useful for managing healthcare costs. According to Passman, the development of AF post-surgically increases a patient's length-of-stay in the hospital by an average of two days -- which can add anywhere from $2,000 to $10,000 to the hospital bill.

The inexpensive, non-invasive test was developed from a retrospective study of the EKG-test results from 152 patients who received CABG surgery at the Hospital of the University of Pennsylvania in 1996. "Although we believe we've designed a useful tool for risk-stratifying patients for post-operative AF, more research needs to be done to assess the overall clinical effectiveness of our test," adds Passman. "Meanwhile, I predict that our test, or a similar predictive model, will eventually become a standard-of-care component in managing CABG patients in the future."

Co-authors of the Penn study included John F. Beshai, MD, Marc A. Scheiner, MD, Behzad B. Pavri, MD, Luis Siejo, MD, Eric Grubman, MD, and Stephen E. Kimmel, MD.

University of Pennsylvania School of Medicine

Related Atrial Fibrillation Articles from Brightsurf:

Atrial fibrillation less deadly than it used to be, but still cause for concern: BU study
A first-of-its-kind study by researchers from the Boston University School of Public Health (BUSPH) shows a decline in deaths related to atrial fibrillation (irregular heartbeat) over the last 45 years.

Postoperative atrial fibrillation does not impact on overall survival after esophagectomy
Volume 11, Issue 25 of Oncotarget reported that Administration of landiolol hydrochloride was found to be associated with reduced incidence of atrial fibrillation after esophagectomy for esophageal cancer in our previous randomized controlled trial.

People with atrial fibrillation live longer with exercise
More than 100,000 Norwegians have atrial fibrillation. They should be actively exercising for their health.

Atrial fibrillation among overweight people is not due to fat
In a recently published study, researchers from Aarhus University document that the risk of atrial fibrillation is not linked to the amount of body fat, but instead to large muscle mass, or more precisely, a high fat-free weight

Eating more protein could help ward off atrial fibrillation in women
Women who ate slightly more than the recommended daily amount of protein were significantly less likely to develop atrial fibrillation (AFib), a dangerous heart rhythm disorder that can lead to stroke and heart failure, when compared with those who consumed less protein, according to research being presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC).

Zebrafish teach researchers more about atrial fibrillation
Genetic research in zebrafish at the University of Copenhagen has surprised the researchers behind the study.

Personalized medicine for atrial fibrillation
The study, published in Europace, uses signals from implantable devices -- pacemakers and defibrillators -- to analyze electrical signals in the heart during episodes of atrial fibrillation.

Prescribing anticoagulants in the ED for atrial fibrillation increases long-term use by 30%
Patients prescribed anticoagulants after a diagnosis of atrial fibrillation in the emergency department are more likely to continue long-term use of medications to treat the condition, according to research published in CMAJ (Canadian Medical Association Journal).

Anticoagulant benefits for atrial fibrillation decrease with age
The net clinical benefit of anticoagulants for atrial fibrillation (AF) -- one of the most important causes of irregular heartbeats and a leading cause of stroke -- decreases with age, as the risk of death from other factors diminishes their benefit in older patients, according to a study led by researchers at UC San Francisco.

Research improves understanding of mechanism of atrial fibrillation
Mouse model studies show that noncoding DNA regions linked to atrial fibrillation risk can display long-range regulatory functions directed at Pitx2 gene and in this way predispose to the condition.

Read More: Atrial Fibrillation News and Atrial Fibrillation Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.