A review of a national registry found that more than 20 percent of patients who received implantable cardioverter-defibrillators (ICDs) did not meet evidence-based guidelines for the devices, putting them at a higher risk of in-hospital death than individuals who met criteria for the implants, according to a study in the Jan. 5 issue of the Journal of the American Medical Association.

Sana M. Al-Khatib, MD, of the Duke Clinical Research Institute, Durham, N.C., and colleagues noted that practice guidelines do not recommend use of an ICD for primary sudden cardiac death prevention in patients recovering from a heart attack or coronary artery bypass graft surgery and those with severe heart failure symptoms or a recent diagnosis of heart failure.

To determine compliance to guidelines, they analyzed cases submitted to the American College of Cardiology's National Cardiovascular Data Registry-ICD Registry between January 2006 and June 2009.

Out of more than 111,000 initial primary prevention ICD implants that occurred during the study period, more than 25,000 were for a non-evidence-based indication. Of these, 36 percent were in patients within 40 days of an MI and 62 percent were in patients with newly diagnosed heart failure.

The risk of in-hospital death for those who received a non-evidence-based device was 0.57 percent, compared with 0.18 percent for those who received an evidence-based device. The risk of any post-procedure complication also was significantly higher in the non-evidence-based group at 3.23 percent, compared with 2.41 percent in the evidence-based group.

"Although the absolute difference in complications between the two groups is modest, these complications could have significant effects on patients' quality of life and healthcare use, including length of hospital stay and costs. Importantly, these complications resulted from procedures that were not clearly indicated in the first place. While a small risk of complications is acceptable when a procedure has been shown to improve outcomes, no risk is acceptable if a procedure has no demonstrated benefit," the authors wrote.

Al-Khatib and colleagues found the non-evidence-based group had a three-day median hospital stay compared with one day for the other group. They also found that electrophysiologists performed the least amount of non-evidence-based implants (20.8 percent) compared with nonelectrophysiologists (24.8 percent for nonelectrophysiologist cardiologists; 36.1 percent for thoracic surgeons; and 24.9 percent for other specialties). During the period studied, researchers found no clear decrease in the rate of non-evidence-based ICDs.

In addition, investigators discovered substantial hospital variation in the use of non-evidence-based ICDs, "which at many sites constituted more than 40 percent of the overall number of implanted ICDs."

These data also confirmed previous findings that racial minorities are more likely to receive non-evidence-based therapy.

In an accompanying editorial, Alan Kadish, MD, and Jeffrey Goldberger, MD, of Northwestern University Feinberg School of Medicine in Chicago, praised the study while pointing out some considerations.

"Further information and specific data are needed to characterize some of the issues, such as how well the National Cardiovascular Data Registry captures some of the subtleties of ICD indications and whether reasons for deviations from the guidelines can be captured accurately. Once this is accomplished, it is possible that prospective data entry in an online system can be developed to provide immediate feedback regarding the presence or absence of an evidence-based indication for an individual patient prior to ICD implantation."