Physical activity and vascular brain lesions in elderly VHF patients

Swiss-AF is a prospective observational study conducted throughout Switzerland at a total of 14 centers investigating the relationship between atrial fibrillation and impaired brain performance. A substudy analyzed whether there was an association between atrial fibrillation, regular physical activity, and vascular brain lesions. The
Results were published in the European Journal of Neurology .

Atrial fibrillation (VHF) is the most common cardiac arrhythmia worldwide and is associated with an increased risk of morbidity and mortality [1]. Furthermore, VHF is associated with a decrease in brain performance and quality of life. There is increasing evidence that VHF is associated with cognitive decline and dementia [2–4]. The increased risk of stroke in AF partly explains this association, but covert cerebral infarcts and white matter hyperintensities ( WMH), which are presumed to be of vascular origin, may also lead to cognitive impairment in VHF patients without a history of clinically manifest stroke [3–5]. As studies have shown, increased incidence or greater severity of WMH in the elderly is associated with cognitive impairment, gait and balance problems, incontinence, and depression [6]. Treatment of WMH is currently limited to preventive lifestyle changes and management of risk factors [7].

Large sample of average 72-year-old VHF patients.

Between 2014 and 2017, the Swiss-AF study recruited a total of 2415 patients with documented AF [1]. Most of them were over 65 years old. However, in order to evaluate sociodemographic aspects, approximately 10% of participants under 65 years of age were also included. The substudy of the Swiss-AF cohort, which investigated possible associations between physical activity and vascular brain lesions, as well as brain volume and cognitive function in elderly VCF patients, included 1490 patients with MRI examination of the brain (bMRI) and available data on physical activity ( PA) and neurocognitive function. The average age was 72 ± 9 years. 26% of the patients were female. Among all study participants, 46% had paroxysmal AF, 31% had persistent AF, and 23% had permanent AF.

MRI brain scans and standardized recording of physical activity.

The following lesions were detected on bMRI [4]: large non-cortical and cortical infarcts (LNCCI), including FLAIR – an MRI sequence that can distinguish between free and tissue-bound fluid. FLAIR enables the identification of lesions that would otherwise not be clearly delineated due to homogeneously bright MR signals. Small noncortical infarcts (SNCI) are hyperintense lesions detectable in FLAIR consistent with an ischemic infarct in the area of a perforating arteriole (in the white matter, internal or external capsule, deep brain nuclei, thalamus, or brainstem) [4]. For the present analysis, the prevalence and volume of LNCCI and SNCI were combined and scored as ischemic infarction. Cerebral microbleeds have been defined as round, small areas (usually 2-5 mm in diameter; but up to 10 mm in some cases) with loss of signal in the vessel (so-called signal void), which can be seen on T2-weighted MRI images and elsewhere [6]. Cerebral microbleeds and WMH are considered markers of microangiopathic injury.

Regular physical activity (regular exercise, RE) was considered to be a once-weekly moderately strenuous exercise session (e.g., examples of jogging, Nordic walking, cycling, aerobics, or ball sports). The validated International Physical Activity Questionnaire ( IPAQ) was used to more specifically assess the amount and intensity of weekly PA [8,9]. As a quantitative measure of weekly PA, metabolic equivalent of activity (MET) (box) per week was calculated as an index of energy expenditure based on information collected with the IPAQ (MET-min/week). In addition, MET intensity was adjusted for age according to the American College of Sports Medicine (MET-min/week age-adjusted) [10].

Fewer vascular lesions with regular physical activity

Patients with regular physical activity (RE) achieved a median of 4343 age-adjusted MET-min/week (IQR**=2195-7862), whereas patients without RE activities achieved a median of 2540 age-adjusted MET-min/week (IQR=987-6389) [1]. Patients who performed RE activities were younger and tended to have fewer cardiovascular risk factors, such as diabetes or hypertension, took fewer cardiovascular medications, and had higher educational attainment than patients who reported no RE activities. The mean _CHA2DS2-VASc score of the entire analyzed population was 3.2 ± 1.7. (The _CHA2DS2-VASc score is used to estimate the risk of stroke in atrial fibrillation.) Overall, patients with regular daily physical activity were less likely to have ischemic infarcts (33% vs. 42%), and less likely to have cerebral microbleeds (19% vs. 24%) or moderate-to-severe WMH (48% vs. 58%) than patients with little or no physical activity ( Fig. 1) .

** IQR = interquartile range

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HAUSARZT PRAXIS 2023; 18(3): 38-39