Pacemakers Do Not Help 40% of Heart Failure Patients
Up to 40 percent of heart failure patients who receive a three-lead pacemaker are not helped by the device, according to a new meta-analysis. This finding could change the current treatment guidelines for individuals who have heart failure.
Many pacemakers are unnecessary
Approximately 6 million people in the United States have heart failure, a condition in which the heart is unable to pump enough blood throughout the body. Heart failure can be caused by high blood pressure, diabetes, and coronary artery disease and can be treated with medication and implantation of a pacemaker.
The findings of the new study conducted by physicians at University Hospitals Case Medical Center and Case Western Reserve University (CWRU) School of Medicine indicate that many of the implanted pacemakers are unnecessary because they do not help patients.
The investigators evaluated the use of cardiac resynchronization therapy (CRT) in nearly 6,000 patients with heart failure from five randomized clinical trials. CRT involves the use of a special pacemaker, known as a biventricular pacemaker, that paces both ventricles of the heart as a way to restore synchronization during heart contractions.
Ilke Sipahi, MD, associate director of Heart Failure and Transplantation at UH Case Medical Center and assistant professor at CWRU School of Medicine, noted their analysis revealed “that pacemaker patients with less severe electrical disturbance in their hearts did not receive any benefit whatsoever from these expensive and potentially risky implants.”
Current treatment guidelines regarding pacemakers for heart failure patients are based on the presence of an abnormality seen on an electrocardiogram (EKG) called a QRS prolongation. It is recommended that individuals who have a QRS prolongation greater than 0.12 seconds receive the pacemaker.
The new study, however, indicates that the only heart failure patients who benefit from these pacemakers are those whose QRS prolongation is greater than 0.15 seconds. Currently, about 40 percent of patients who receive the implant have a QRS prolongation ranging from 0.12 to 0.15 seconds.
The meta-analysis also showed that patients with the pacemaker whose QRS prolongation was greater than 0.15 seconds had significant benefits associated with the device, including improvement in peak oxygen consumption, better survival, and a reduction in hospitalizations.
Based on the data showing no benefit from implantation of a pacemaker in certain heart failure patients, Dr. Sipahi concluded that “current treatment guidelines should be changed.” Co-author James Fang, MD, director, Clinical Cardiovascular Services at UH Case Medical Center and professor at CWRU School of Medicine, added that “this study may help to better select patients who are most likely to benefit from this effective but costly procedure.”
Sipahi I et al. Archives of Internal Medicine 2011 June; doi:10.1001/archinternmed.2011.247