Reduced regional cerebral blood flow in patients with heart failure

Abstract

Aims: Heart failure (HF) patients show significant lateralized neural injury, accompanied by autonomic, mood and cognitive deficits. Both gray and white matter damage occurs and probably develops from altered cerebral blood flow (CBF), a consequence of impaired cardiac output. However, the distribution of regional CBF changes in HF patients is unknown, but is an issue in determining mechanisms of neural injury. Our aim was to compare regional CBF changes in HF with CBF in control subjects using non-invasive pseudo-continuous arterial spin labelling (ASL) procedures.

Methods and results: We collected pseudo-continuous ASL data from 19 HF patients [mean age 55.5 ± 9.1 years; mean body mass index 27.7 ± 5.3 kg/m² ; 13 male) and 29 control subjects (mean age 51.4 ± 5.3 years; mean body mass index 25.7 ± 3.6 kg/m² ; 18 male), using a 3.0-Tesla magnetic resonance imaging (MRI) scanner. Whole-brain CBF maps were calculated, normalized to a common space, smoothed and compared between groups using ANCOVA (covariates; age, gender and gray matter volume). Reduced CBF appeared in multiple sites in HF patients in comparison with controls, with principally lateralized lower flow in temporal, parietal and occipital regions. Areas with decreased CBF included the bilateral prefrontal, frontal, temporal and occipital cortex, thalamus, cerebellum, corona radiate, corpus callosum, hippocampus and amygdala.

Conclusions: Heart failure patients showed lower, and largely lateralized, CBF in multiple autonomic, mood and cognitive regulatory sites. The reduced CBF is likely to contribute to the lateralized brain injury, leading to the autonomic and neuropsychological deficits found in the condition.

Keywords: Arterial spin labelling; Brain imaging; Cerebral blood flow; Cognition; Magnetic resonance imaging.

Figure 1

Lateralized CBF changes in HF subjects. 3D views (A–D) of brain with decreased regional CBF in HF compared to control subjects, with arrows pointing to widespread sites suggesting lateralized CBF changes. Clusters are overlaid onto a 3D whole-brain cortical surface for structural identification (L = Left; R = Right). Color bar indicates t-statistic values.

Figure 2

Brain regions with reduced CBF in HF over control subjects. These sites with reduced CBF included the bilateral anterior cerebellar cortex (a, b), left posterior cerebellar cortex (c), right amygdala (d), cerebellar vermis (e), left anterior corpus callosum (f) bilateral mid-dorsal temporal white matter (g, h), and bilateral dorsal hippocampus (i, j). All images are in neurological convention (L = Left; R = Right). Color bar indicates t-statistic values.

Figure 3

Brain sites with lower CBF values in HF over control subjects. Decreased CBF values appeared in the bilateral pre-frontal cortex (a, k), frontal white matter (b, c), occipital cortex (d, e), anterior thalamus (f), right superior parietal cortex (g), right corona radiata (h), and bilateral mid-temporal cortex (i, j). Figure conventions are same as in Figure 2.