Clinical differences between continuous flow ventricular assist devices: a comparison between HeartMate II and HeartWare HVAD

Abstract

Background: The HeartWare ventricular assist device (HVAD) is a new generation centrifugal flow VAD recently introduced in Canada. The objective of this study was to compare the HVAD device to the HeartMate II (HMII) axial flow device. Very few studies have compared clinical outcomes between newer generation VADs.

Methods: All perioperative and follow-up data on LVAD recipients were collected prospectively in our institutional database. Between January 2006 and April 2012, 46 consecutive patients underwent implantation of either an HVAD (n=13) or a HMII (n=33) device. Pre-implant demographics, perioperative and postoperative clinical outcomes were reviewed between groups.

Results: Overall, the baseline characteristics, demographics, co-morbidities and laboratory values were comparable between the two groups. The majority of the patients were Interagency Registry for Mechanical Assisted Circulatory Support 3-4 (92% in both groups) and most of the patients were bridge to transplant (75% in HMII vs. 79% in HVAD). Survival and the incidence of perioperative bleeding, renal dysfunction, liver dysfunction, and infection were similar between the groups. However, HVAD devices had a significantly higher incidence of gastrointestinal (GI) bleeding (31% vs. 0% in HMII patients, p<0.01) and stroke (44% vs. 10% in HMII patients, at one year p=0.04). Hemorrhagic strokes were more frequent in patients with HVAD (three of the five episodes vs. one of the three episodes in HMII patients, p=0.06).

Conclusion: While device complications were comparable, patients with HVAD experienced a significantly higher incidence of stroke and GI bleeding and therefore refinement in patients' management may decrease incidence of these complications.