Objective: Our goal was to determine the operative mortality of isolated implantation of the HeartMate II continuous flow LVAD and the impact of additional concurrent cardiac procedures on patient outcomes.
Methods: In a multicenter trial, 279 patients at 33 clinical sites underwent implantation of the HeartMate II continuous flow LVAD as a bridge to transplantation from March 2005 to March 2007. HeartMate II implantation (HM II) was the only procedure required in 172 patients while 80 patients required concurrent cardiac procedures in conjunction with LVAD implantation (HM II+CCP).
Results: Preoperative characteristics were similar, but central venous pressure (14.5 vs 11.6 mmHg) was greater for patients requiring concurrent cardiac procedures, suggesting worse right heart dysfunction. Mean cardiopulmonary bypass times increased from 97 to 120 minutes when a concurrent cardiac procedure was performed (p<0.001). Length of stay slightly increased from 23 to 26 days (p=0.17). Overall 30- and 180-day mortality was 5.8% and 13.3% for the HM II group, and 11.3% and 20.0% for the HM II+CCP group. Concurrent valvular procedures increased the risk to 8.5% and 19.1%. Patients who underwent an aortic valve replacement with cardioplegic arrest had a 30-day mortality of 25%, higher than for isolated concurrent mitral (0%) or tricuspid repair (3.3%). Other cardiac procedures were associated with a 30-day mortality of 27.8%. Survival at 180 days was 87% for HMII alone and 80% for HMII+CCP.
Conclusion: There is a low 5.8% operative mortality for patients requiring uncomplicated HeartMate II implantation, with no apparent increased risk for concurrent PFO closure, mitral or tricuspid repair. However, concurrent aortic valve and other cardiac procedures are associated with a significantly decreased survival. The increased risk of these procedures must be balanced against the negative impact of uncorrected aortic insufficiency during VAD support.
An Intra-Cycle Optimal Control Framework for Ventricular Assist Devices Based on Atrioventricular Plane Displacement Modeling