Magnetic resonance imaging of the brain and haematological profile in adult cyanotic congenital heart disease without stroke

Adults with tetralogy of Fallot show specific features of cerebral small vessel disease: the BACH San Donato study

Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients grow older, they experience aging-related diseases more than their healthy peers. To better characterize this field, we launched the multi-disciplinary BACH (Brain Aging in Congenital Heart disease) San Donato study, that aimed at investigating signs of brain injury in ACHD. Twenty-three adults with repaired tetralogy of Fallot and 23 age- and sex-matched healthy controls were prospectively recruited and underwent brain magnetic resonance imaging. White matter hyperintensities (WMHs) were segmented using a machine-learning approach and automatically split into periventricular and deep. Cerebral microbleeds were manually counted. A subset of 14 patients were also assessed with an extensive neuropsychological battery. Age was 41.78 ± 10.33 years (mean ± standard deviation) for patients and 41.48 ± 10.28 years for controls (p = 0.921). Albeit not significantly, total brain (p = 0.282) and brain tissue volumes (p = 0.539 for cerebrospinal fluid, p = 0.661 for grey matter, p = 0.793 for white matter) were lower in ACHD, while total volume (p = 0.283) and sub-classes of WMHs (p = 0.386 for periventricular WMHs and p = 0.138 for deep WMHs) were higher in ACHD than in controls. Deep WMHs were associated with poorer performance at the frontal assessment battery (r = -0.650, p = 0.012). Also, patients had a much larger number of microbleeds than controls (median and interquartile range 5 [3–11] and 0 [0–0] respectively; p < 0.001). In this study, adults with tetralogy of Fallot showed specific signs of brain injury, with some clinical implications. Eventually, accurate characterization of brain health using neuroimaging and neuropsychological data would aid in the identification of ACHD patients at risk of cognitive deterioration.

Brain volumes in adults with congenital heart disease correlate with executive function abilities

Congenital heart disease is the most common birth defect, and patients are at risk for neurodevelopmental impairment and brain abnormalities. Yet, little is known about the link between brain volumes and cognitive function in adults with congenital heart disease. Forty-four patients and 53 controls between 18 and 32 years underwent brain magnetic resonance imaging and cognitive testing, assessed with an intelligence quotient and executive function global score. Associations between brain volumes and cognitive function were calculated using linear models. Cognitive function in patients was within the normal range (intelligence quotient: 97.74 (10.76)). Total brain volume was significantly smaller in patients compared to controls (1067.26 (113.53) vs 1113.04 (97.88) cm³, P < 0.01), irrespective of cardiac factors (heart defect complexity, cyanosis, cardiopulmonary bypass: all P > 0.4). After adjusting for total brain volume, only corpus callosum volume remained significantly smaller (P = 0.03). Smaller total brain volume was associated with poorer overall executive functioning (P = 0.02) and inhibition (P < 0.01), in both patients and controls. The association between total brain volume and overall executive functioning was moderated by parental socioeconomic status (lower socioeconomic status was associated with a stronger association between brain volume and EF; interaction P = 0.03). In adults with congenital heart disease, despite normal intelligence quotient, brain volume alterations persist into adulthood and are related to executive functioning, in particular inhibitory control. Adults coming from low socioeconomic background and with altered brain volumes are especially vulnerable and should thus be followed-up during adulthood to ensure optimal social and educational support.

Acute ischaemic stroke in secondary polycythaemia due to complex congenital cyanotic heart disease

A 65-year-old woman presented to the emergency department with an acute onset of left-sided hemiparesis and slurred speech for 6 hours. Physical examination was notable for clubbing and peripheral cyanosis. Brain MRI showed an acute infarct involving the right gangliocapsular region. Investigations showed an elevated haemoglobin level, a haematocrit level of >65% and thrombocytopaenia. Transthoracic echocardiography revealed tricuspid atresia, ventricular septal defect and atrial septal defect. A diagnosis of cyanotic congenital heart disease was made. Studies have indicated an association between raised haematocrit and vascular occlusive episodes in patients with polycythaemia vera. However, a relationship between raised haematocrit due to polycythaemia secondary to complex congenital heart disease and vascular thrombosis has not been reported. The improvement of neurological deficits in our patient coincided with a decline in haematocrit. The objective of this report was to highlight an association between elevated haematocrit and ischaemic stroke in patients with secondary polycythaemia due to complex congenital heart disease.

Brain vascular changes in adults with congenital heart disease: A systematic review

Less information is available on brain integrity in adults with congenital heart disease than on brain changes in newborns and children with heart defects. Nevertheless, the number of adults with congenital heart disease is increasing rapidly and it has been shown that adults with congenital heart disease develop dementia almost twice as frequently as adults in the general population.

In the context of a rapidly growing congenital heart disease population, neuroradiological-oriented investigations of biomarkers distinctive for vascular damage, brain aging, and possible cognitive impairment is a crucial challenge. We provide an overview of the existing literature on neuroimaging studies in adults with congenital heart disease and discuss methodology issues to further investigate this subject. Overall, we aim to raise awareness of the importance of brain health studies in adults with congenital heart disease given the likely increasing impact on social and healthcare systems.

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The number of adults with congenital heart disease is increasing rapidly.

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There is considerable concern regarding global health outcomes in this population.

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Evidence shows that patients with congenital heart disease are more prone to cerebrovascular accidents.

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Neuroimaging tools may aid the detection of subtle vascular brain changes before cognitive impairment occurs.

CEREBRAL BLOOD FLOW AND PREDICTORS OF WHITE MATTER LESIONS IN ADULTS WITH TETRALOGY OF FALLOT

Long-term outcomes for Tetralogy of Fallot (TOF) have improved dramatically in recent years, but survivors are still afflicted by cerebral damage. In this paper, we characterized the prevalence and predictors of cerebral silent infarction (SCI) and their relationship to cerebral blood flow (CBF) in 46 adult TOF patients. We calculated both whole brain and regional CBF using 2D arterial spin labeling (ASL) images, and investigated the spatial overlap between voxel-wise CBF values and white matter hyperintensities (WMHs) identified from T2-FLAIR images. SCIs were found in 83% of subjects and were predicted by the year of the patient's first cardiac surgery and patient's age at scanning (combined r² 0.44). CBF was not different in brain regions prone to stroke compared with healthy white matter.

Subclinical atherosclerosis in patients with cyanotic congenital heart disease

INTRODUCTION

Survival in patients with cyanotic congenital heart disease (CCHD) has improved dramatically. The result is an ageing population with risk of acquired heart disease. Previous small uncontrolled studies suggested that these patients are protected against the development of atherosclerosis. To test this hypothesis, we sought to determine the prevalence of subclinical atherosclerosis in a larger population of patients with CCHD.

METHOD

We compared the prevalence of subclinical atherosclerosis in adult CCHD patients from Denmark, Sweden, Norway and Australia, with that in age-, sex-, smoking status-, and body mass index matched controls. Coronary artery atherosclerosis was assessed on computed tomography with coronary artery calcification (CAC) score. Subclinical atherosclerosis was defined by CAC-score > 0. Carotid artery atherosclerosis was evaluated using ultrasound by measuring carotid plaque thickness (cPT-max) and carotid intima media thickness (CIMT). Lipid status was evaluated as an important atherosclerotic risk factor.

RESULTS

Seventy-four patients with CCHD (57% women, median age 49.5 years) and 74 matched controls (57% women, median age 50.0 years) were included. There were no differences between the groups in: CAC-score > 0 (21% vs. 19%, respectively; p = 0.8), carotid plaques (19% vs. 9%, respectively; p = 0.1), cPT-max (2.3 mm vs. 2.8 mm, respectively; p = 0.1) or CIMT (0.61 mm vs. 0.61 mm, respectively; p = 0.98). And further no significant differences in lipoprotein concentrations measured by ultracentrifugation.

CONCLUSION

Young adults with CCHD have similar cardiovascular risk factor profiles and measures of subclinical atherosclerosis, compared with controls. Given their increasing life expectancies, athero-preventive strategies should be an important part of their clinical management.

Does Tetralogy of Fallot affect brain aging? A proof-of-concept study

The impact of congenital heart disease on brain aging has not been extensively investigated. We evaluated cerebral microbleeds and white matter hyperintensities on brain magnetic resonance imaging in adult patients with tetralogy of Fallot (ToF). Ten ToF patients (6 women, 4 men; aged 21–58 years; New York Heart Association [NYHA] class 1–2) were prospectively enrolled and underwent a T1-weighted, a T2-weighted dark fluid, and a T2*-weighted scans. Ten age- and sex-matched controls were prospectively recruited and subjected to the same acquisition protocol. Cerebral microbleeds (CMBs) were manually counted while white matter hyperintensities (WMHs) were segmented using ITK-Snap. Wilcoxon signed-rank test, Spearman correlation, and Bland-Altman statistics were used. The median (interquartile range [IQR]) age was 45.0 (30.5–49.5) years in ToF patients and 46.0 (30.5–49.8) years in controls. The median (IQR) of the number of CMBs was 6.0 (4.0–7.8) in ToF patients and 0 (0.0–0.0) in controls (p = 0.002). The WMHs burden was 2,506 (1,557–2,900) mm³ for ToF patients and 2,212 (1,860–2,586) mm³ for controls (p = 0.160). Moreover, a positive significant correlation was found between the WMHs burden and the NYHA class (ρ = 0.80, p = 0.005). Inter-operator concordance rate for the presence/absence of CMBs was 90%; the reproducibility for the WMHs burden was 77%. In conclusion, we found more cerebral microbleeds and a higher WMHs burden in adult ToF patients than in controls. This preliminary comparison supports the hypothesis of an early brain aging in ToF patients. Larger studies are warranted.

Reduced cortical volume and thickness and their relationship to medical and operative features in post-Fontan children and adolescents

BACKGROUND

We compared brain cortical and subcortical gray matter volumes and cortical thickness between post-Fontan patients and healthy controls, and examined brain anatomical associations with operative and medical history characteristics.

METHODS

Post-Fontan (n = 128 volumes; n = 115 thickness) and control subjects (n = 48 volumes; n = 45 thickness) underwent brain MRI at ages 10-19 y. Subcortical and cortical volumes and cortical thicknesses were measured for intergroup comparison. Associations between brain measures and clinical measures were assessed in the Fontan group.

RESULTS

Widespread, significant reduction in brain volumes and thicknesses existed in the Fontan group compared to controls, spanning all brain lobes and subcortical gray matter. Fontan subjects treated with vs. without the Norwood procedure had smaller volumes in several terminal clusters, but did not differ in cortical thickness. Older age at first operation and increasing numbers of cardiac catheterizations, operative complications, and catheterization complications were associated with lower regional volumes and thicknesses. Increasing numbers of operative complications and cardiac catheterizations were associated with smaller regional volumes in the Norwood group.

CONCLUSION

The post-Fontan adolescent brain differs from the normal control brain. Some of these differences are associated with potentially modifiable clinical variables, suggesting that interventions might improve long-term neurocognitive outcome.

Brain volumetric, regional cortical thickness and radiographic findings in adults with cyanotic congenital heart disease

Background

Chronic cyanosis in adults with congenital heart disease (CHD) may cause structural brain changes that could contribute to impaired neurological functioning. The extent of these changes has not been adequately characterized.

Hypothesis

We hypothesized that adults with cyanotic CHD would have widespread changes including abnormal brain volumetric measures, decreased cortical thickness and an increased burden of small and large vessel ischemic changes.

Methods

Ten adults with chronic cyanosis from CHD (40 ± 4 years) and mean oxygen saturations of 82 ± 2% were investigated using quantitative MRI. Hematological and biochemical parameters were also assessed. All subjects were free from major physical or intellectual impairment. Brain volumetric results were compared with randomly selected age- and sex-matched controls from our database of normal subjects.

Results

Five of 10 cyanotic subjects had cortical lacunar infarcts. The white matter (WM) hyperintensity burden was also abnormally high (Scheltens Scale was 8 ± 2). Quantitative MRI revealed evidence of extensive generalized WM and gray matter (GM) volumetric loss; global GM volume was reduced in cyanosed subjects (630 ± 16 vs. 696 ± 14 mL in controls, p = 0.01) as was global WM volume (471 ± 10 vs. 564 ± 18 mL, p = 0.003). Ventricular cerebrospinal fluid volume was increased (35 ± 10 vs. 26 ± 5 mL, p = 0.002). There were widespread regions of local cortical thickness reduction observed across the brain. These changes included bilateral thickness reductions in the frontal lobe including the dorsolateral prefrontal cortex and precentral gyrus, the posterior parietal lobe and the middle temporal gyrus. Sub-cortical volume changes were observed in the caudate, putamen and in the thalamus (p ≤ 0.005 for all regions). Cortical GM volume negatively correlated with brain natriuretic peptide (R = − 0.89, p = 0.009), high sensitivity C-reactive protein (R = − 0.964, p < 0.0001) and asymmetric dimethylarginine (R = − 0.75, p = 0.026) but not with oxygen saturations, packed cell volume or viscosity.

Conclusions

We present the first comprehensive analysis of brain structure in adults with chronic neurocyanosis due to congenital heart disease. We demonstrate clear evidence for marked macro- and microvascular injury. Cyanotic patients show global evidence for reduced brain volume as well as specific foci of cortical thickness reduction. The GM volume loss correlated with hsCRP, BNP and ADMA suggesting that inflammation, neurohormonal activation and endothelial dysfunction may have important roles in its pathogenesis.

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A high burden of cerebral small and large vessel ischemic injury.

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Extensive white and gray matter (GM) volumetric loss.

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Regions of bilateral local cortical thickness reduction within the frontal, parietal and temporal lobes.