Carotid artery structure and hemodynamics and their association with adverse vascular events in left ventricular assist device patients

Abstract

Left ventricular assist devices (LVADs) are associated with major vascular complications including stroke and gastrointestinal bleeding (GIB). These adverse vascular events may be the result of widespread vascular dysfunction resulting from pre-LVAD abnormalities or continuous flow during LVAD therapy. We hypothesized that pre-existing large artery atherosclerosis and/or abnormal blood flow as measured in carotid arteries using ultrasonography are associated with a post-implantation composite adverse outcome including stroke, GIB, or death. We retrospectively studied 141 adult HeartMate II patients who had carotid ultrasound duplex exams performed before and/or after LVAD surgery. Structural parameters examined included plaque burden and stenosis. Hemodynamic parameters included peak-systolic, end-diastolic, and mean velocity as well as pulsatility index. We examined the association of these measures with the composite outcome as well as individual subcomponents such as stroke. After adjusting for established risk factors, the composite adverse outcome was associated with pre-operative moderate-to-severe carotid plaque (OR 5.08, 95% CI 1.67–15.52) as well as pre-operative internal carotid artery stenosis (OR 9.02, 95% CI 1.06–76.56). In contrast, altered hemodynamics during LVAD support were not associated with the composite outcome. Our findings suggest that pre-existing atherosclerosis possibly in combination with LVAD hemodynamics may be an important contributor to adverse vascular events during mechanical support. This encourages greater awareness of carotid morphology pre-operatively and further study of the interaction between hemodynamics, pulsatility, and structural arterial disease during LVAD support.