Incidence and significance of pacemaker and implantable cardioverter-defibrillator lead masses discovered during transesophageal echocardiography

Background: Pacemaker and implantable cardioverter-defibrillator device infections are feared complications. The finding of a lead-associated mass on transesophageal echocardiogram (TEE) raises concern for endocarditis. However, the incidence and clinical importance of lead masses is not currently known. Methods: Consecutive patients with transvenous leads undergoing TEE from July 1, 2003, to June 30, 2005, were identified and assessed for a clinical diagnosis of endocarditis. An echocardiographer blinded to clinical information reviewed all TEEs. Results: Of 177 TEEs performed on 153 patients, a visible mass on a device lead was observed in 25 (14%), including 11 TEEs showing a lead vegetation, 13 TEEs showing lead strands, and one study showing both. Seventeen patients were adjudicated to have endocarditis, of which eight had a mass seen on a lead during TEE. Thus, 72% of patients (18 of 25) with a lead-associated mass did not have evidence of an infection. In TEEs performed for indications other than to rule out endocarditis, lead masses were seen in 13 of 136 studies (10%), with only one patient adjudicated to clinically have an infected device. Conclusion: During this 2-year study of consecutive patients with a tranvenous lead undergoing TEE, lead-associated masses were found in 14% of patients. In 72% of patients, the mass did not prove to be secondary to infectious causes. Thus, masses attached to a device lead should be interpreted in the overall clinical context and, in the absence of concomitant evidence of endocarditis, should not mandate device and lead removal.