Factors defining occurrence of ischemic and hemorrhagic strokes during continuous flow left ventricular assist device support.

Abstract

LVAD-related strokes occur at a much higher rate compared to traditional open heart surgery. The pathophysiology of ischemic and hemorrhagic strokes after LVAD implantation is not well defined. The aim of this study was to better describe the etiopathogenesis of strokes during continuous flow LVAD support based on our institutional experience. We performed a retrospective analysis of 200 patients, with and without stroke that underwent implantation of a continuous flow LVAD from 2011 to 2016. The incidences of stroke in our patient population were 13% (26/200), of which 50% (13/26) were ischemic and 50% hemorrhagic (13/26). Only 8% of strokes occurred within the first 48h from LVAD implantation, all of which were ischemic. The median duration of support was 148days for ischemic and 351days (p = 0.012) for hemorrhagic strokes. The average mean arterial pressure measurements at the time of hospital discharge were 89mmHg for patients who subsequently developed stroke and 72mmHg (p = 0.03) for stroke-free patients. The average outpatient pressure measurements were 96mmHg and 76mmHg (p = 0.02) for the stroke and stroke-free patients, respectively. The mean velocity index showed the potential impairment of cerebral autoregulation. Multivariate analysis demonstrated that INR, COPD, aortic cross clamping, previous stroke, and device infections were statistically significant risk factors for stroke occurrence after LVAD implantation. In addition to LVAD-related thrombogenicity, the subsequent need for anticoagulation, and an acquired von Willebrand syndrome, several clinical factors, such as deviation from the anticoagulation regimen, hypertension, COPD, device infections, and aortic cross clamping, appear to have an influence on the extremely high rate of postoperative ischemic and hemorrhagic strokes.