HTML clipboardMehran Attari, MD, a UC Health electrophysiologist, along with cardiologists around the world, found that the use of cardiac resynchronization therapy (CRT)—a device used to electrically synchronize the contractions of the heart’s two lower chambers—in patients who are in early stages of heart failure significantly decreased hospitalization and death.
These findings are being presented Sept. 1 at the European Society of Cardiology Congress 2009, scheduled for Aug. 29-Sept. 2 in Barcelona, Spain, and are being published in an advanced online edition of the New England Journal of Medicine.
In this study—called the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy, or MADIT-CRT—University Hospital was ranked 11th in the United States and tied for 22nd internationally for number of enrollees. There were 110 sites in 14 countries involved in the study.
“It is standard to deliver resynchronization therapy in heart failure patients with a New York Heart Association classification of III or more,” Attari says, noting that levels III and IV involve shortness of breath and chest pain during moderate activities or during rest. “It is proven to reduce mortality and hospitalization in these advanced heart failure patients.”
But Attari says the goal in this study was to focus on mild, asymptomatic heart failure patients who normally wouldn’t qualify for CRT.
“We looked at classes I—those with no symptoms whose heart issues were remedied with medications—and II—those who were mildly symptomatic,” he says.
Using a sample of 1,800, patients were split into two groups: those with only an implantable defibrillator—a device that delivers internal electric shocks to a patient’s heart whenever a life-threatening cardiac rhythm is detected—and those with a CRT defibrillator.
“Most defibrillators have two electrode wires—one in the right atrium and one in the right ventricle—to maintain the normal coordinated pumping relationship between the upper and lower chambers of the heart,” Attari says. “The CRT device has a third lead that is positioned in a vein on the surface of the left ventricle to simultaneously stimulate the left and right ventricles and restore a coordinated squeezing pattern.”
Both groups were evaluated every three months for a period of three years.
In class I and II heart failure patients, researchers found a 34 percent reduction in both mortality and hospitalization.
In addition, they found that CRT reduced the risk of heart failure events by 41 percent when compared to the defibrillator.
“This shows that by using the CRT device in patients with mild heart failure, we can prevent the progression of the disease and stop future problems, in addition to reducing hospital costs,” Attari says. “We hope that these findings lead to more effective treatments that will not only improve quality of life for our patients, but will also benefit in more cost-effective strategies for providers.”
Boston Scientific Corporation is the sole sponsor of MADIT-CRT. Attari cites no conflict of interest.