Posted on 11/04/2010

Baltimore, MD--Implantable defibrillator leads are more likely to be dislodged from the myocardium if the patient has comorbidities or if the implanter is not a trained electrophysiologist, data from the National Cardiovascular Data Registry (NCDR) show.

Dr Alan Cheng (Johns Hopkins University, Baltimore, MD) and colleagues analyzed 2,628 cases of implantable cardioverter defibrillator (ICD) lead dislodgement in 226,764 patients treated between 2006 and 2008 in the Implantable Cardioverter-Defibrillator Registry part of the NCDR. Results of their analysis are published in the November 9, 2010 issue of the Journal of the American College of Cardiology.

Univariate analysis shows older age, female sex, atrial fibrillation, chronic lung disease, cerebrovascular disease, nonischemic cardiomyopathy, and lower ejection fractions are variables associated with higher rates of lead dislodgement. Multivariate adjustment analysis found that lead dislodgement was more common in patients with NYHA functional class 4 heart failure, atrial fibrillation or flutter, or a cardiac resynchronization therapy defibrillator (CRT-D) device.

"That's helpful to know, because when you're counseling patients and you're preparing yourself for doing these procedures, you can go in with your eyes wide open," Cheng said in an interview with HeartWire.

Risk-adjusted analysis also found that patients who had suffered an acute dislodgement were at higher risk for adverse events later on. Patients suffering a lead dislodgement were, on average, 5.62 times more likely to have a cardiac arrest, tamponade, pneumothorax, or infection than those who did not and were 2.66 times as likely to die in the hospital.

"We tend to think of lead dislodgements as, arguably, not a really big deal," Cheng said. Prior to this study, "we didn't have a good sense of whether people are dying from these things or having other downstream sequelae that are bad. . . . It shouldn't be brushed aside as a trivial event; it could be potentially a sentinel event for something more ominous to come."