http://www.thoratec.com/downloads/heartmate-ii-pivotal-clinical-t...

http://www.thoratec.com/downloads/heartmate-ii-pivotal-clinical-trial-fact-sheet-111109.pdf

Thoractec BTT: As of July 2009, actuarial survival of 281 patients observed in a prospective, multi-center study (based on Kaplan-Meier analysis) was 82% at six months, 73% at 12 months, and 72% at 18 months. The conclusion: a continuous-flow LVAD provides effective hemodynamic support for at least 18 months in patients awaiting transplantation, with improved functional status and quality of life.

If I'm not wrong Heartware had a survival rate of 94% at 6 months with 240 patients?