Prevalence and predictors of off-label use of cardiac resynchronization therapy in patients enrolled in the National Cardiovascular Data Registry Implantable Cardiac-Defibrillator Registry

Abstract

Objectives: The purpose of the study was to define the extent and nature of cardiac resynchronization therapy (CRT) device usage outside consensus guidelines using national data.

Background: Recent literature has shown that the application of CRT in clinical practice frequently does not adhere to evidence-based consensus guidelines. Factors underlying these practices have not been fully explored.

Methods: From the National Cardiovascular Data Registry's Implantable Cardiac-Defibrillator Registry, we defined a cohort of 45,392 cardiac resynchronization therapy-defibrillator (CRT-D) implants between January 2006 and June 2008 with a primary prevention indication. We defined "off-label" implants as those in which the ejection fraction was >35%, the New York Heart Association functional class was below III, or the QRS interval duration was <120 ms in the absence of a documented need for ventricular pacing. The relationships between patient, implanting physician, and hospital characteristics with off-label use were explored with multivariable hierarchical logistic regression models.

Results: Overall, 23.7% of devices were placed without meeting all 3 implant criteria, most often due to New York Heart Association functional class below III (13.1% of implants) or QRS interval duration <120 ms (12.0%). Atrial fibrillation/flutter, previous percutaneous coronary intervention, and the performance of an electrophysiology study before implant were independently associated with increased odds of off-label use, whereas diabetes mellitus, increasing age, and female sex were associated with decreased odds. Physician training and insurance payer were weakly associated with the likelihood of off-label use.

Conclusions: Nearly 1 in 4 patients receiving CRT devices in the study time frame did not meet guideline-based indications. Given the evolving evidence base supporting the use of CRT, these practices require careful scrutiny.