Background: After left ventricular assist device (LVAD) for end-stage heart failure, cognitive function should improve due to increased cerebral perfusion. However, stroke (a well-known LVAD complication) and even subclinical cerebral ischemia may also occur and manifest as transient or permanent cognitive decline. We sought to describe the incidence and predictors of cognitive decline after LVAD using a valid, sensitive assessment tool.
Methods: As part of the INTERMACS registry, cognitive function was assessed before LVAD and at each follow-up with the Trailmaking B Test (TBT), where a subject is timed connecting 25 dots labeled with alternating, consecutive numbers and letters (1, A, 2, B, etc.). The TBT can detect several forms of cognitive impairment, including subclinical stroke. Longer times are worse, and cognitive decline was defined as a clinically important increase from baseline to highest follow-up score using Cohen’s D Effect Size (0.2*baseline SD = 13 s). Patients who completed baseline and at least 1 follow-up TBT were included. Multivariable logistic regression was used to examine the association between patient characteristics and cognitive decline after LVAD.
Results: Among 1151 LVAD patients, median age was 60-69, 19% were female, and 40% were INTERMACS profile 1-2 (cardiogenic shock or declining despite inotropes) at implant. Among patients with 12-mo follow-up, mean TBT score improved from 126 at baseline to 123 at 1 yr. In the total cohort, 333 (29%) patients had significant cognitive decline within 12 mo of LVAD placement. Increasing age, chronic renal disease, better baseline TBT score (shorter time), and higher INTERMACS profiles (≥ 3; less severe heart failure) were significantly associated with greater odds of cognitive decline (Figure).
Conclusion: In a large LVAD registry, cognitive decline occurred in over a quarter of patients in the year after LVAD and was associated with older age, renal disease, higher baseline cognitive function, and more stable heart failure at implant. These results define the frequency of an important adverse event and provide new insights regarding outcomes after LVAD. Future studies are needed to explore the association of transient and permanent cognitive decline with subsequent stroke, health status, and mortality in patients after LVAD placement.