Prevalence of Cerebral Microbleeds in Patients With Continuous‐Flow Left Ventricular Assist Devices

Abstract

BackgroundThe prevalence of cerebral microbleeds (CMBs) in gradient echo T2*‐weighted brain MRI has a positive correlation with hemorrhagic stroke incidence. However, the prevalence of CMBs in patients with left ventricular assist devices (LVADs) has not been evaluated. We evaluated the prevalence of CMBs and the relationship with hemorrhagic stroke incidence in patients with LVADs.Method and ResultsWe analyzed results from brain MRI in prospective examinations of 35 consecutive patients who had undergone LVAD explantation for heart transplantation or recovery since 2011. The number and distribution of CMBs were counted, then the relationship between baseline characteristics and adverse events during LVAD support were analyzed. The mean age was 37.7±12.4 years and the mean LVAD duration was 2.43±1.08 years. Thirty‐four (97%) patients had at least one CMB. Nine (26%) developed hemorrhagic stroke during LVAD support, and patients with hemorrhagic stroke had a significantly greater number of CMBs compared with patients without hemorrhagic stroke (5 [interquartile range (IQR), 4–7] versus 9 [IQR, 5–23]; odds ratio 1.14 [95% Confidence Interval (CI), 1.02–1.32], P=0.05). There was no significant relationship between age, LVAD support duration, or systolic blood pressure during LVAD. However, patients who had at least one episode of bacteremia (9 [IQR, 4–16] versus 5 [IQR, 3–7], P=0.06) and pump pocket infection (14 [IQR, 4–27] versus 5 [IQR, 3–7], P=0.08) showed a trend toward a greater number of CMBs than patients without bacteremia.ConclusionsThirty‐four (97%) patients with continuous‐flow LVAD had at least one CMB, and the number of CMBs were more prevalent in patients with hemorrhagic stroke and in patients with LVAD‐related infection.

CrossTalk proposal: Blood flow pulsatility in left ventricular assist device patients is essential to maintain normal brain physiology

“…The high occurrence of bleeding events, such as GI bleeding and haemorrhagic strokes, indicates a primary problem with endothelial integrity. A recent study confirms elegantly that a staggering proportion of LVAD patients have cortical microbleeds in a pattern similar to cerebral amyloid angiopathy, a condition with high rates of arteriolar fragility (Yoshioka et al 2017). Furthermore, reduced pulsatility appears responsible for the marked reduction in endothelial nitric oxide bioavailability in CF-LVAD patients when compared to those on support with pulsatile device (Witman et al 2015), although this may be more relevant in the systemic circulation than in the brain (Zhang et al 2004).…”

“…A recent study confirms elegantly that a staggering proportion of LVAD patients have cortical microbleeds in a pattern similar to cerebral amyloid angiopathy, a condition with high rates of arteriolar fragility (Yoshioka et al . ). Furthermore, reduced pulsatility appears responsible for the marked reduction in endothelial nitric oxide bioavailability in CF‐LVAD patients when compared to those on support with pulsatile device (Witman et al .…”

Rebuttal from William K. Cornwell III, Takashi Tarumi, Justin Lawley and Amrut V. Ambardekar

“…() suggest that continuous‐flow circulatory support leads to reductions in nitric oxide (NO) bioavailability and endothelial dysfunction, which in turn increases the prevalence of cerebral microbleeds among individuals supported by CF‐LVAD (Yoshioka et al . ). However, in the study by Yoshioka et al ., CF‐LVAD patients who suffered from haemorrhagic stroke had a high rate of infection compared to those without haemorrhagic stroke.…”

Effect of Cerebral Flow Autoregulation Function on Cerebral Flow Rate Under Continuous Flow Left Ventricular Assist Device Support

“…Neurological complications in CF‐LVAD patients are the second‐leading highest risk after multi‐organ failure . The prevalence of cerebral micro‐bleeds which are positively correlated with hemorrhagic stroke is very common in CF‐LVAD patients . However, it should be noted that the causes of cerebral function problems still remain unclear and may be associated with preoperative and postoperative factors such as previous strokes, persistent malnutrition and inflammation, severity of heart failure, and post‐LVAD infections, reduced pulsatility or the anatomic configuration of LVAD outflow cannula‐ascending aorta anastomosis .…”