A Review of the Complex Landscape of Stroke in Left Ventricular Assist Device Trials

Despite innovations in left ventricular assist device (LVAD) technology, stroke remains a leading cause of morbidity and mortality in this population. Major clinical trials of LVAD have used various definitions and approaches to measuring stroke outcomes, which may limit comparison of stroke risk between different devices.

Data from the five major LVAD randomized, controlled, trials were abstracted to compare definitions of stroke (composite, ischemic, hemorrhagic, and disabling) and stroke event rates across trials. Methodologic limitations and suggestions to improve research and clinical practices for stroke and LVAD were identified.

Comparison of stroke events across LVAD clinical trials is confounded by methodologic variability, including heterogeneity in stroke definitions, nonstandardized evaluation of stroke etiology, oversimplification of stroke severity classification, and inconsistent event rate reporting due to data censoring at the time of death or transplant. Variability in the study of stroke in LVAD patients limits the ability to compare devices and design prevention strategies to mitigate stroke risk.

Based on this review, we propose that future clinical trials (1) utilize standardized stroke definitions and define stroke subtypes; (2) ensure that neurologists are integrated in study design and event adjudication; (3) include more thorough evaluations of stroke etiology using multimodality techniques; and (4) adopt the National Institutes of Health Stroke Scale to define stroke severity.