Implantable cardioverter-defibrillators are often used for the primary prevention of sudden cardiac death in patients with advanced systolic heart failure. But a recent study found that 22.5% of the devices were implanted in patients who didn't meet the criteria for implantation set forth in current evidence-based practice guidelines. The study also found that the risks of both death while in the hospital and of complications were higher in recipients who didn't meet the criteria, compared with recipients who did.

Al-Khatib and colleagues analyzed data on implantations in the National Cardiovascular Data Registry's Implantable Cardioverter-Defibrillator Registry. The authors' analysis was based on 111,707 implantations performed as primary prevention of sudden cardiac death between January 1, 2006, and June 30, 2009.

A total of 25,145 (22.5%) were implanted in patients who didn't meet current criteria, including 9,257 (36.8%) who were within 40 days of an acute myocardial infarction, 814 (3.2%) who were within three months of coronary artery bypass graft surgery, 3,022 (12%) with New York Heart Association class IV symptoms (severe heart failure), and 15,604 (62.1%) who had a recent diagnosis of congestive heart failure.

In addition to having greater risks of death and complications, patients who didn't meet guidelines for device implantation had more comorbid conditions, such as heart failure, atrial fibrillation or flutter, ischemic heart disease, cerebrovascular disease, chronic lung disease, diabetes, and end-stage renal disease.

The researchers also found that electrophysiologists implanted fewer devices in patients not meeting the criteria than did other physicians, such as cardiologists without training in electrophysiology, thoracic surgeons, and "other" specialists (internists and general surgeons). In an accompanying editorial, Kadish and Goldberger stress the importance of formal training in cardiac electrophysiology to help physicians "understand the rationale for the guidelines and potential alternative approaches when a patient does not meet guidelines for [device] implantation." Through adherence to the guidelines, the editorialists write, the cardiovascular-care community "may improve practice patterns and outcomes, with the unique opportunity to do so while lowering health care costs."-Linda Wilson