Transvenous defibrillation leads: high incidence of failure during long-term follow-up.
BACKGROUND
Patients with implantable cardioverter defibrillators (ICD) critically depend on correct functioning of their system. The aim of this study was to determine the incidence and clinical presentation of transvenous ICD lead failures during long-term follow-up.


RESULTS
The study group consisted of 261 consecutive patients who received Medtronic right ventricular polyurethane transvenous leads (models 6884, 6966, 6936) between 1990 and 1998 as part of an abdominal (n = 70) or pectoral (n = 191) ICD system. During mean follow-up of 4.0 +/- 2.6 years, 31 patients (12%) developed a lead-related sensing failure with oversensing of artifacts. All failures except two were compatible with an insulation defect and occurred late after ICD placement (6.0 +/- 1.8 years after implant). Lead survival decreased from 98% at 4-year follow-up to only 62% at 8-year follow-up. Lead survival was not related to patient age, sex, venous lead implantation route, or device implantation site. In 26 (87%) of 31 patients, a sensing defect resulted in inappropriate detection of ventricular fibrillation and subsequent delivery of 3 +/- 3 (range 1-11) inappropriate shocks in 19 (61%) of 31 patients. Device interrogation showed artifacts classified as nonsustained ventricular tachycardia in 21 patients, 40 +/- 43 days before clinically relevant failure of the system. One patient with a subclavian crush syndrome required resuscitation because of undersensing of true ventricular fibrillation.


CONCLUSIONS
Transvenous polyurethane ICD leads showed a high rate of lead insulation failure late after implantation with frequent inappropriate shock deliveries. Close follow-up is mandatory in patients with these leads. Automated device control features with patient alert function integrated into new devices may contribute to early detection of lead failure.
Dorwarth
Uwe
U
Department of Medicine I, University of Munich, Munich, Germany. uwe.dorwarth@med1.med.uni-muenchen.de
Frey
Bernhard
B
Dugas
Martin
M
Matis
Tomas
T
Fiek
Michael
M
Schmoeckel
Michael
M
Remp
Thomas
T
Durchlaub
Ilka
I
Gerth
Andrea
A
Steinbeck
Gerhard
G
Hoffmann
Ellen
E
D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use; D017147:Defibrillators, Implantable; D004554:Electric Countershock; D017097:Electric Impedance; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011140:Polyurethanes / Q000627:therapeutic use; D013318:Stroke Volume / Q000502:physiology; D013350:Subclavian Vein / Q000601:surgery; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000628:therapy; D013995:Time; D017211:Treatment Failure; D014683:Vena Cava, Superior / Q000601:surgery; D014693:Ventricular Fibrillation / Q000401:mortality / Q000628:therapy
D020099:Coated Materials, Biocompatible; D011140:Polyurethanes