Stroke incidence & continuous- flow left ventricular assisted device 

CF-LVAD have lead to improve survival of heart failure patients. However 10% of patients have stroke. Luckily the incidence of stroke with current generation (Heartmate III) is less now compare to previous generations of device.

Patients with CF-LVAD can have both ischemic and hemorrhagic stroke (51 vs 49% in one study).

What are the cause of the stroke?

1) Hypertension from LVAD

2) Pump thrombosis

3) Atrial fibriillation 

4) Mycotic aneurysm

5) Acquired von Willebrand Syndrome

6) Microembolic events during CF-LVAD support

Why patients with CF-LVAD have hypertension is multifactorial. They have sympathetic overdrive increase total peripheral vascular resistance and contributes to development or worsening hypertension.  The result of neurohumoral activation appears to be acheived through unloading of the arterial baroreceptors as a result of a reduction in pulsatility. They have high mean arterial pressure but low pulse pressure. 

Patient can have pump thrombosis about 5% in the first year and 8% in the second year. They can develop embolic stroke from that. Hypertension increase the risk of pump thrombosis 3 times. 

Atrial fibrillation (AF) is very common in congestive heart failure patients (25%). Patients with CF-LVAD & AF developed stroke with higher than INR that no LVAD patients. 

Device related infection can happen about 25% therefore increase the risk of blood stream infection and the risk of mycotic aneurysm. 

CF-LVAD has been associated with acquired (vWF) syndrome due to cleavage of large multimers by a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13) which predisposes these patients to bleeding. 

Currently we do not have data of microembolic events of the current use device. Previous pulsatile and CF-LVAD are associated with high prevalence of microembolic signals. 

Reference:

1) Stroke 2019;50:542-548