BACKGROUND: Heart failure (HF) and cognitive impairment often occur together in older adults. Although earlier studies have reported an association between blood pressure (BP) variability (BPV) and cognitive impairment, the underlying pathophysiology remains unclear in HF. In this study, the hypothesis that higher BPV is associated with cognitive impairment was evaluated in the elderly patients with acute decompensated HF (ADHF). METHODS: Day-to-day in-hospital BPV and cognitive function using a mini-mental state examination (MMSE) were assessed in 245 elderly patients (82.9 ± 6.0 years, 49.4% male) with ADHF. Based on the data of 7 days, day-to-day BPV (expressed as the standard deviation [SD], coefficient of variation [CV], maximum BP, minimum BP, and δ [maximum-minimum] BP) were measured. RESULTS: According to MMSE score quartiles, significant differences were observed in SD (8.2 vs 6.2 vs 6.7 mmHg, p<
0.001), CV (13.3 vs 9.94 vs 10.9 %, p<
0.001) and δ (22.8 vs 17.5 vs 18.6 mmHg, p<
0.001) in diastolic blood pressure (DBP) between three groups. In the logistic regression analysis adjusted for the confounders, SD (OR: 1.23, p<
0.01), CV (OR: 1.12, p<
0.01), maximum (OR: 1.13, p<
0.001) and δ (OR: 1.07, p<
0.01) in DBP were significantly associated with the lowest quartile of MMSE score. In the stratified analysis by HF phenotypes, significant associations of day-to-day DBP variability were found with the lowest quartile of MMSE score specifically in the HF with preserved ejection fraction group (HFpEF). CONCLUSIONS: Cognitive impairment in association with day-to-day BPV is increasingly prevalent in elderly patients presenting with ADHF, specifically in HFpEF.