Aortic Valve Commissural Fusion During Continuous-Flow Left Ventricular Assist Device Support is Associated with Continuous Valve Closure; a Correlation Study Between Valve Histopathology and Clinical Patient Characteristics

Purpose Continuous-flow Left Ventricular Assist Devices (cf-LVADs) may induce commissural fusion of the aortic valve leaflets. The factors associated with this occurrence of commissural fusion are unknown. Therefore, the aim of this study was to examine the association between cf-LVAD-induced aortic valve commissural fusion and clinical characteristics. Methods and Materials Gross and histopathological examinations were performed on 15 hearts from patients supported by either Heartmate II (n=13) or Heartware (n=2) cf-LVADs and related to clinical characteristics (10 heart transplantation, 5 autopsy). Results 9/15 (60%) aortic valves showed fusion of single or multiple commissures (total fusion length 11 mm [2.5-24] (median [Interquartile range]) per valve, some leading to noticeable nodular displacements or considerable lumen diameter narrowing. Multiple fenestrations were observed in one valve. Histopathological examination confirmed commissural fusion, with minor and prominent changes in valve layer structure without evidence of inflammatory infiltration at the site of fusion. Commissural fusion was associated with continuous aortic valve closure during cf-LVAD support (p=0.05). LVAD-induced aortic valve insufficiency developed in all patients with commissural fusion and in 50% of patients without fusion. Age, duration of cf-LVAD support and aetiology of heart failure (ischemic versus dilatated cardiomypathy) were not associated with the amount of fusion. Conclusions Aortic valve commissural fusion is a non-inflammatory process, observed in 60% of cf-LVAD patients. Patients receiving full LVAD support without opening of the valve are most likely to develop commissural fusion. Aortic valve insufficiency is frequently observed in patients with commissural fusion, which might reduce long-term efficiency of cardiac support with cf-LVADs.