From Cedars-Sinai Medical Center
Patients who need cardiac resynchronization therapy may be eligible for Cedars-Sinai clinical trials LOS ANGELES (March 8, 2002) -- Patients who suffer from advanced congestive heart failure and heart rhythm abnormalities may qualify to participate in one of two research trials now underway at Cedars-Sinai Medical Center.
One study is designed to determine whether certain patients who require an implantable defibrillator for life-threatening arrhythmias may enjoy a better quality of life and improved activity level through a combined defibrillator / biventricular pacemaker device.
The other study seeks to enroll patients who are current candidates for biventricular pacemaker therapy (advanced congestive heart failure with delayed impulse conduction) to determine whether cardiac resynchronization therapy alone or in combination with an implantable defibrillator will provide improved patient survival over existing medical therapies.
To be eligible for either study, patients must have advanced congestive heart failure as well as cardiac conduction abnormalities. These conduction abnormalities correlate with worsening congestive heart failure and result in discoordinated contraction of the left and right heart chambers, effectively reducing the forward flow of blood through the heart.
Cardiologists and heart surgeons at Cedars-Sinai Medical Center have offered cardiac resynchronization therapy (CRT) since the introduction of biventricular pacing devices several years ago. These devices, implanted using minimally invasive techniques, stimulate the left and right ventricles to activate in unison, effectively 'resynchronizing' the chambers to contract as they would in a normal heart. Based on already completed clinical trial data showing improvement in heart failure status and activity level, CRT has been approved by the Food and Drug Administration for patients with advanced heart failure and delayed impulse conduction.
Cardiac resynchronization therapy may not, however, prevent irregular heartbeats known as ventricular arrhythmias. Without warning, ventricular arrhythmias may cause sudden death if not detected and treated immediately. The implanted cardioverter defibrillator (ICD) has proven ability to detect these fatal rhythms and provide intervention in the form of a shock to restore normal rhythm. The ICD has demonstrated efficacy in reducing the incidence of death in patients with advanced congestive heart failure.
"We have been providing state-of-the-art defibrillator therapy and cardiac resynchronization therapy for some time. Through these trials, however, certain individuals may qualify to receive an investigational device that may be even better for their situation," said Walter Kerwin, M.D., co-investigator. Dr. Kerwin is a cardiologist/electrophysiologist at Cedars-Sinai and assistant clinical professor at the University of California Los Angeles School of Medicine.
The MIRACLE ICD (Multi-center InSync Randomized Clinical Evaluation) Study is based on an implanted cardioverter defibrillator called InSync-ICD, developed by Medtronic, Inc. Patients meeting current indications for an implantable defibrillator and who also have delayed impulse conduction will receive the InSync-ICD, which has combined biventricular pacing and defibrillator functions. The ICD will administer a potentially life-saving shock in the event of serious arrhythmia. The biventricular pacing function is expected to enhance the patient's quality of life and improve activity levels, which are to be measured throughout the study period.
The COMPANION trial is a multi-center, randomized clinical trial to assess whether patients meeting current indications for biventricular pacing (advanced heart failure and delayed impulse conduction) may live longer with cardiac resynchronization therapy compared to similar patients not receiving a device. Patients will be randomly assigned to receive one of three established therapies: 1) maximized medical therapy; 2) maximized medical therapy plus biventricular pacemaker; or 3) maximized medical therapy plus biventricular pacemaker combined with defibrillator function. Based on the randomized protocol, 80 percent of the patients will receive cardiac resynchronization capable devices, with half of these patients (40 percent) receiving the combined biventricular pacemaker-ICD (CONTAK-CD, a product of Guidant Inc.).
Steven Khan, M.D., principal investigator in the studies, serves as director of Cedars-Sinai's Congestive Heart Failure Program and director of Clinical Trials in the Division of Cardiology. He is also an associate professor at the UCLA School of Medicine.
Patients with advanced congestive heart failure may call the Cardiology Research Coordinator's Office at 310-423-6034 for more information about the studies and eligibility requirements.
Cedars-Sinai Medical Center is one of the largest non-profit academic medical centers in the Western United States. For the fifth straight two-year period, Cedars-Sinai has been named Southern California's gold standard in health care in an independent survey. Cedars-Sinai is internationally renowned for its diagnostic and treatment capabilities and its broad spectrum of programs and services, as well as breakthrough in biomedical research and superlative medical education. Named one of the 100 "Most Wired" hospitals in health care in 2001, the Medical Center ranks among the top 10 non-university hospitals in the nation for its research activities.