Improved durability of the HeartMate XVE left ventricular assist device provides safe mechanical support up to 1 year but is associated with high risk of device failure in the second year.
BACKGROUND
Life-threatening device failure of the HeartMate VE due to biologic inflow valve incompetence or motor failure is a major drawback of long-term mechanical support when using this left ventricular assist device (LVAD). The new XVE model is the result of recent technical improvements. The aim of this study was to compare the clinical performance and durability of the new and earlier HeartMate versions.


METHODS
We analyzed the incidence of device failure and of other device-specific complications (infections, bleeding) in 9 VE and 17 XVE patients. Explanted pumps were examined and biologic valve damage classified according to a score ranging from 0 (no visible damage) to 3 (severe destruction).


RESULTS
Mean support time was 145 +/- 92 and 267 +/- 195 days in the VE and XVE groups, respectively (difference not significant [NS]). Survival was 89% (VE) vs 75% (XVE). The incidence of device failure requiring urgent heart transplantation or device replacement was 44% (VE) vs 31% (XVE) (NS). Device failure occurred significantly later in the XVE group (200 +/- 34 vs 487 +/- 53 days, p < 0.01). Causes of device failure were inflow valve incompetence (n = 6) and motor failure (n = 3). Acute device failure caused 1 death in the XVE group. One XVE patient has been on mechanical support for > 483 days. Macroscopic inflow valve damage score after explantation of the devices was 2.2 +/- 1.1 in the VE group and 2.0 +/- 0.8 in the XVE group (NS).


CONCLUSIONS
The novel HeartMate XVE offers greater durability and provides reliable mechanical support in the first year. However, there is a high risk of life-threatening device failure in the second year. Further technical refinements are necessary to meet the challenges of safe long-term circulatory assistance.
Martin
Juergen
J
Department of Cardiovascular Surgery, Albert-Ludwigs-University Medical Center, Freiburg, Germany. juergen.martin@jksdl.de
Friesewinkel
Ortwin
O
Benk
Christoph
C
Sorg
Stephan
S
Schultz
Susanne
S
Beyersdorf
Friedhelm
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D005858:Germany; D006333:Heart Failure / Q000601:surgery*; D016027:Heart Transplantation; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D013997:Time Factors