Incidence and predictors of cognitive decline in patients with left ventricular assist devices

After left ventricular assist device (LVAD) placement for advanced heart failure, increased cerebral perfusion should result in improved cognitive function. However, stroke (a well-known LVAD complication) and subclinical cerebral ischemia may result in transient or permanent cognitive decline. We sought to describe the incidence and predictors of cognitive decline after LVAD using a valid, sensitive assessment tool.

Among 4419 patients in the Interagency Registry for Mechanically Assisted Circulatory Support who underwent LVAD implantation between May 2012 and December 2013, cognitive function was assessed in 1173 patients with the Trail Making B Test before LVAD and at 3, 6, and 12 months. The test detects several forms of cognitive impairment, including subclinical stroke. Cognitive decline was defined as a clinically important increase during follow-up using a moderate Cohen d effect size of 0.5×baseline SD (32 s). The cumulative incidence of cognitive decline in the year after LVAD implantation, treating death and transplantation as competing risks, was 29.2%. In adjusted analysis, older age (≥70 versus <50 years; hazard ratio, 2.24; 95% confidence interval 1.46-3.44; P(trend)<0.001) and destination therapy (hazard ratio, 1.42; 95% confidence interval, 1.05-1.92) were significantly associated with greater risk of cognitive decline.

Cognitive decline occurs commonly in patients in the year after LVAD and is associated with older age and destination therapy. These results could have important implications for patient selection and improved communication of risks before LVAD implantation. Additional studies are needed to explore the association between cognitive decline and subsequent stroke, health status, and mortality in patients after LVAD.