Effects of pulsatile- and continuous-flow left ventricular assist devices on left ventricular unloading.
BACKGROUND
In patients with end-stage heart failure, the use of left ventricular assist devices (LVADs) has improved clinical outcomes. Although newer continuous-flow devices have significant advantages, the effect of continuous flow on left ventricular unloading and hemodynamics is less well established. The aim of this investigation was to compare the effects of pulsatile- vs continuous-flow LVADs on left ventricular reverse remodeling and hemodynamic indices.


METHODS
Thirty-five patients undergoing implantation with a pulsatile volume displacement pump operating at fixed speed (n = 15; HeartMate XVE; Thoratec Corp., Pleasanton, CA) or a continuous-flow rotary pump with an axial design operating at a fixed rotor speed (n = 20; HeartMate II; Thoratec) were evaluated. Right heart catheterization and echocardiography were performed pre-operatively, and at 1- and 6-month follow-up intervals.


RESULTS
Thirty-five of 40 eligible patients with end-stage heart failure were included in this study. When used at fixed speed, use of both devices led to a substantial reduction in left ventricular volumes and dimensions at 1 month (p < 0.01). A marked and sustained reduction in filling pressures was also noted with both devices at 1 and 6 months (p < 0.01). The volume and pressure unloading effects of the HeartMate XVE were not superior to those with the HeartMate II (all p-values not statistically significant).


CONCLUSIONS
Substantial left ventricular unloading and hemodynamic improvement is achieved with the HeartMate XVE and the HeartMate II. We conclude that continuous-flow LVADs are as effective as pulsatile-flow LVADs with regard to degree of left ventricular unloading and cardiac hemodynamics.
Garcia
Santiago
S
Department of Cardiology, University of Minnesota, Minneapolis, Minnesota 55455, USA. garci205@umn.edu
Kandar
Forum
F
Boyle
Andrew
A
Colvin-Adams
Monica
M
Lliao
Kenneth
K
Joyce
Lyle
L
John
Ranjit
R
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*; D020521:Stroke / Q000209:etiology / Q000503:physiopathology; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology*