The relationship between the HeartMate II left ventricular assist device (LVAD) position and pump thrombosis has been reported. However, further clinical implications of device position are unknown. This study aimed to investigate optimal device position for better left ventricular (LV) unloading and patient prognosis. Patients undergoing a ramp test with right heart catheterization after HeartMate II LVAD implantation were enrolled to this study. Device position was quantified from the chest X-ray obtained at the time of the ramp test: (1) inflow cannula angle relative to horizontal line, (2) pump angle relative to spine, (3) pump depth, (4) angle between inflow cannula and pump, and (5) angle between pump and outflow graft. LV unloading was assessed by pulmonary capillary wedge pressure at set LVAD speed. Fifty-four patients (60 years old and 34 male [63%]) were enrolled. Nobody experienced device malfunction during the study period. Increased LV unloading (i.e., lower pulmonary capillary wedge pressure) was associated with a narrower inflow cannula angle relative to horizontal line. Inflow cannula angle <75° was associated with higher 1 year heart failure readmission-free survival rate (p < 0.05, hazards ratio 7.56 [95% confidence interval 2.32–24.7]). In conclusion, HeartMate II LVAD inflow cannula position was associated with LV unloading and patient prognosis. Prospective studies to ensure optimal device positioning and target better clinical outcomes are warranted.
From the *Department of Medicine, University of Chicago Medical Center, Chicago, Illinois
†Department of Surgery, University of Chicago Medical Center, Chicago, Illinois
‡Houston Methodist Hospital, Houston, Texas
§Columbia University Medical Center, and Cardiovascular Research Foundation, New York, New York.
Submitted for consideration November 2017; accepted for publication in revised form March 2018.
Teruhiko Imamura receives financial funding from Postdoctoral Fellowship for Research Abroad of Japan Society for the Promotion of Science. Nir Uriel receives grant support from Abbott and Medtronic. Valluvan Jeevanandam receives consultant fee from Abbott. Daniel Burkhoff receives consultant fee from Medtronic, Corvia Medical, Sensible Medical, Impulse Dynamics, Cardiac Implants, and educational grant support from Abiomed. Gabriel Sayer received consultant fee from Medtronic.
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Correspondence: Nir Uriel, Department of Medicine, University of Chicago Medical Center, 5841 South Maryland Avenue, Chicago, IL 60637. Email: firstname.lastname@example.org.