Only half of eligible heart failure patients receive implantable devices

Study results: devices are used in half of patients eligible under current guidelines

A study of heart failure patients who meet national guidelines for devices that stabilize and strengthen the heart's electrical system found that only half of eligible patients received the devices. The study, which is the first to examine the management of heart failure patients in outpatient cardiology practices throughout the United States, also found wide, unexplained variations in the use of the devices, known as implantable cardioverter-defibrillators (ICDs). The study is published in the December 2009 issue of the journal HeartRhythm.

Certain heart failure patients with weakened pumping ability and those who develop a condition called left ventricular systolic dysfunction after a heart attack are at risk for an irregular heart rhythm that can lead to sudden cardiac death. The heart suddenly stops beating after an electrical disturbance causes the heart to beat rapidly or chaotically. Extensive clinical trial experience and national guidelines recommend the placement of ICDs in patients with either of these conditions as a preventive measure.

"These patients have not had a major heart arrhythmia, but they are at high risk for a rhythm abnormality and therefore meet the criteria for device-based treatment," says the study's lead author, Mandeep R. Mehra, M.B.B.S., professor of medicine, head of the Division of Cardiology at the University of Maryland School of Medicine in Baltimore and chief of cardiology at the University of Maryland Medical Center. "The device is implanted in order to be available if needed. For every 14 patients implanted with an ICD, one patient will experience a rhythm disorder that will trigger the device within two years."

The guidelines for device-based therapy of cardiac rhythm abnormalities were developed by the American College of Cardiologists, the American Heart Association and the Heart Rhythm Society. These guidelines are Class One recommendations, which Dr. Mehra says are must-do, based on tight evidence or clear consensus in the field that they should be done.