Percutaneous lead dysfunction in the HeartMate II left ventricular assist device.
BACKGROUND
The incidence of percutaneous lead failure among patients supported with a HeartMate II left ventricular assist device is unknown.


METHODS
All HeartMate II left ventricular assist device driveline dysfunctions reported to Thoratec Corporation were retrospectively reviewed. The location and severity of driveline failures and their association with adverse clinical outcomes were examined. Also, the effect of design modifications was evaluated.


RESULTS
Between 2004 and October 2012, 12,969 HeartMate II pumps were implanted worldwide. The incidence of percutaneous lead dysfunction was 1,418 events occurring in 1,198 pumps (9.2% of pumps) over a cumulative support period of 13,932 patient-years (maximum, 8 years). Lead failure was mostly in the externalized part of the cable (87.2%). Lead dysfunction was managed by clamshell reinforcement of the external connector strain relief or by tape or silicone cable reinforcement in 76% of cases. Mortality or significant morbidity, including pump exchange or urgent transplant, or more complex cable repair occurred in 2.3% of all implanted pumps. The cumulative incidence of lead failures leading to major adverse clinical events has decreased with two lead design revisions: at 18 months postimplantation, the incidence was 6.2%±1.2% for the original design versus 2.2%±0.5% for the latest design change introduced in 2010 (log-rank p<0.001).


CONCLUSIONS
Lead failures remain an important factor in the durability of left ventricular assist devices during long-term support. Most lead failures in the HeartMate II occurred in the externalized portion of the driveline, suggesting lead fatigue. The incidence of both internal and external lead failures has diminished since 2004 with improvements in lead design.
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio.
Dimitri
D
Kalavrouziotis
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio.
Michael Z
MZ
Tong
Department of Cardiovascular Medicine, Cleveland Clinic, Ohio.
Randall C
RC
Starling
Department of Biomedical Engineering, Cleveland Clinic, Ohio.
Alex
A
Massiello
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio.
Edward
E
Soltesz
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio.
Nicholas G
NG
Smedira
Thoratec Corporation, Pleasanton, California.
Robert
R
Fryc
Thoratec Corporation, Pleasanton, California.
Gerald
G
Heatley
Thoratec Corporation, Pleasanton, California.
David J
DJ
Farrar
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio; Department of Biomedical Engineering, Cleveland Clinic, Ohio. Electronic address: moazamn@ccf.org.
Nader
N
Moazami
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004566:Electrodes; D005260:Female; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012189:Retrospective Studies; D055815:Young Adult