The Correlation of Aortic Valve Opening Status and Stroke Risk in Patients Supported with HeartWare HVAD

Objectives: The estimated risk of stroke in patients with HeartWare HVAD System (HeartWare Inc., Framingham, MA) is 0.20 events per patient's year. It has been reported that the opening status of the aortic valve (AV) may affect the incidence of postoperative stroke in patients with ventricular assist device (VAD). We aimed to investigate the correlation of the AV opening status and the risk of stroke in patients supported with HeartWare HVAD.

Methods: Data of patients receiving HeartWare HVAD at single institution between 01.2010 and 09.2015 were analyzed. Inclusion criteria were patients with HeartWare HVAD who were discharged from hospital, had documented serial echocardiograms (echos) following the implant and at least 60 days of VAD support. The opening status of the AV was assessed using several available echos after the VAD implant and graded as no opening, intermittent opening (AV open or closed at different echos) or opening every beat. The cohort was then divided into two groups (“no or intermittent AV opening” versus “full AV opening”) and compared for risk of stroke.

Results: A total of 39 HeartWare patients with mean age of 57 ± 12 years met the inclusion criteria. The AV was persistently open in 25 patients, intermittently open in 10 patients and persistently closed in 4 patients. Over a median follow up of 521 days (57 years of support), stroke event occurred in 8 male patients (21%) after median support duration of 538 days (range 31- 929 days). No significant difference in patient's characteristics between patients with or without stroke was observed. The mean pump flow and blood pressure in patients with or without stroke was 4.6 ± 0.7 L/min versus 4.4 ± 0.6 L/min and 89 ± 10 mm Hg versus 86 ± 10 mm Hg, respectively (p = 0.50 and 0.46). The AV was graded as no or intermittent opening in 50% and 32% of patients with or without stroke (p = 0.424). No significant correlation between AV opening status and freedom from stroke was found (p = 0.442).

Conclusion: Unlike the risk of de Novo aortic valve insufficiency in LVAD supported patients, stroke events appear to occur in HeartWare HVAD patients regardless of the opening status of the AV.