Sex differences in cognitive functioning in patients with heart failure

BACKGROUND: Cognitive impairment is common in patients with heart failure (HF) and impacts patients' life. Sex differences in HF-characteristics are well-established. We hypothesized that women and men with HF also differ in cognitive functioning and that this may be related to sex differences in HF-characteristics and vascular brain injury. METHODS: In the Heart-Brain Connection Study, 162 clinically stable HF patients (mean age 69.7 ± 10.0, 33 % women) underwent neuropsychological assessments and brain-MRI. Test results were standardized into z-scores for memory, language, attention/speed, executive functioning, and global cognition. Using linear models adjusted for age and education, we calculated sex differences (women-to-men: W-M∆) in cognitive functioning and examined effects of HF- and vascular brain injury-characteristics on these differences. RESULTS: Men more often had an ischemic cause of HF and lower NYHA-classes, whereas women more often had preserved left ventricular ejection fractions (LVEF). Women had a higher volume of white matter hyperintensities (WMHs) whereas non-lacunar infarcts and microbleeds were more prevalent in men. Women performed better on global cognition than men (W-M∆ in z-score 0.20, 95 %CI 0.03-0.37), predominantly on memory (0.40, 0.02-0.78). These differences were associated with ischemic HF-etiology, as adjustment attenuated these sex differences. After adjustment for non-lacunar infarcts, global cognition difference persisted, but the difference in memory functioning attenuated. Adjustments for NYHA-class, LVEF, WMHs, and microbleeds did not change the results. CONCLUSION: Women and men with HF differ in cognitive functioning, predominantly in memory functioning, these differences were related to some sex differences in HF-characteristics and vascular brain injury, but not to all.