Fusion of Aortic Valve Commissures in Patients Supported by a Continuous Axial Flow Left Ventricular Assist Device

Background: Left ventricular assist devices (LVADs) are an important therapy for selected individuals with advanced heart failure unable to wait for a suitable donor for transplantation. Pulsatile LVADs are associated with commissural fusion of the aortic valve, yet little is known about this association with newer generation continuous axial flow LVADs. Methods: We retrospectively reviewed pathologic samples from 9 patients enrolled in the HeartMate II Bridge to Transplantation Trial. Echocardiograms at 1, 6 and 12 months after device placement were evaluated for aortic valve opening and aortic insufficiency. At the time of transplantation, explanted hearts were examined for gross pathologic valvular abnormalities and histologic analysis. Results: All but 1 explant had evidence of commissural fusion of the native aortic valve leaflets. Over time there was a decreasing prevalence of aortic valve opening and an increasing prevalence of mild to moderate aortic insufficiency independent of pump speed. All patients had improvements in their functional status and were successfully bridged to orthotopic heart transplantation. Conclusions: Commissural fusion of the native aortic valve leaflets occurs frequently with an increasing prevalence of aortic insufficiency during continuous flow LVAD support. With the potential broader use of non-pulsatile LVADs and the prospect of using LVADs as means to assist in myocardial recovery, special attention should be given to evaluating aortic valve function during LVAD support.