A New Vision at the Interface of Atrial Fibrillation and Stroke

Effect of atrial fibrosis on clot burden score and physicochemical properties of thrombus in patients with ischaemic stroke occurring in non-valvular atrial fibrillation

Background

To investigate the effect of the degree of atrial fibrosis on the clot burden score (CBS) and physicochemical properties in patients with acute ischaemic stroke (AIS) due to non-valvular atrial fibrillation (NVAF).

Methods

A total of 117 patients with AIS in NVAF attending the Department of Cardiovascular Medicine and the Cerebrovascular Diagnostic and Treatment Centre between August 2021 and May 2024 were included in the study. Baseline clinical data, biochemical indexes, and imaging data of the patients were collected, and the patients were divided into 93 cases of the CBS (score of 0-6) group and 24 cases of the CBS (score of 7-10) group according to the CBS. CBS (score of 0-6) signifies higher clot burden. The enzyme-linked immunosorbent assay was used to measure the concentration of galactaglutinin-3 (gal-3) and transforming growth factor (TGF-β1) in the serum of the patients, and the PTFV1 were collected by 12-lead electrocardiogram, and the differences in the degree of atrial fibrosis between different groups and the risk factors of CBS (score of 0-6) were analysed. To analyse the effect of atrial fibrosis on the collateral circulation of stroke, the patients were divided into 31 cases with good collateral circulation (grade 3-4) and 86 cases with poor collateral circulation (grade 0-2) according to the digital subtraction angiography (DSA) images. The cerebral thrombus was collected from 60 AIS patients who underwent mechanical thrombectomy. The content of erythrocyte, fibrin/platelets and leukocytes in the thrombus was analysed by Mathew's scarlet blue staining, and the density of thrombus was measured by computed tomography (CT).

Results

A total of 117 patients were included in this study, and the proportion of hypertensive patients, proportion of chronic atrial fibrillation (CAF), B-type natriuretic peptide (BNP), neutrophil/lymphocyte ratio (NLR), D-dimer, uric acid concentration, proportion of patients with PTFV1 < -0.03 mm s, gal-3, and TGF-β1 were higher in the CBS (score of 0-6) group as compared to the CBS (score of 7-10) group (P-value < 0.05). Hypertension, proportion of CAF, homocysteine, NLR, D-dimer, uric acid, PTFV1 < -0.03 mm s, gal-3, and TGF-β1, were risk factors for the development of high CBS in atrial fibrillation (AF), and hypertension and CAF were the most important factors for the occurrence of AF in the independent risk factors for stroke combined with high clot burden. gal-3 and TGF-β1 were risk factors for poor collateral circulation, atrial fibrosis indexes were not associated with thrombus pathological composition and thrombus density.

Conclusions

Atrial fibrosis increases clot burden in patients with AIS due to NVAF but does not significantly correlate with the physicochemical properties and density of the thrombus.

Markers of Atrial Myopathy in the General Population: Prevalence, Predictors, and Inter-Relations

BACKGROUND

Atrial myopathy refers to structural and functional cardiac abnormalities associated with atrial fibrillation and stroke, but appropriate diagnostic criteria are lacking.

OBJECTIVES

This study aimed to assess prevalence, clinical correlates, and overlap between potential atrial myopathy markers.

METHODS

The population-based SCAPIS (Swedish CArdioPulmonary bioImage Study) prospectively included 6,013 subjects without atrial fibrillation with 24-hour electrocardiograms. Resting electrocardiograms measuring P-wave indices were collected at 1 screening site (n = 1,201), and a random sample (n = 385) had echocardiographic left atrial volume index (LAVi). Atrial myopathy markers were defined as ≥500 premature atrial complexes/24 h, LAVi ≥34 mL/m2, P-wave duration >120 milliseconds, or P-wave terminal force in V1 >4,000 ms·s. Clinical correlates included age, sex, body mass index, height, smoking, physical activity, coronary artery disease, diabetes, systolic blood pressure, antihypertensive medication, and low education.

RESULTS

Atrial myopathy was common; 42% of the sample with all diagnostic modalities available had ≥1 atrial myopathy marker, but only 9% had 2 and 0.3% had ≥3. Only P-wave duration and LAVi were correlated (ρ = 0.10; P = 0.04). Clinical correlates of premature atrial complexes, P-wave indices, and LAVi differed; current smoking (34% increase; P < 0.001), systolic blood pressure (4%/mm Hg increase; P = 0.01), diabetes (35% increase; P = 0.001), and coronary artery disease (71% increase; P = 0.003) were associated with premature atrial complexes, physical activity ≥2 h/wk was associated with increased LAVi (β-coefficient = 3.1; P < 0.0001) and body mass index was associated with P-wave duration (β-coefficient = 0.4/kg/m2; P < 0.0001).

CONCLUSIONS

In the general population, indirect markers of atrial myopathy are common but only weakly correlated, and their risk factor patterns are different. More studies are needed to accurately identify individuals with atrial myopathy with diagnostic methods.

Stroke in patients with heart failure and reduced or preserved ejection fraction

AIMS

Stroke is an important problem in patients with heart failure (HF), but the intersection between the two conditions is poorly studied across the range of ejection fraction. The prevalence of history of stroke and related outcomes were investigated in patients with HF.

METHODS AND RESULTS

Individual patient meta-analysis of seven clinical trials enrolling patients with HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). Of the 20 159 patients with HFrEF, 1683 (8.3%) had a history of stroke, and of the 13 252 patients with HFpEF, 1287 (9.7%) had a history of stroke. Regardless of ejection fraction, patients with a history of stroke had more vascular comorbidity and worse HF. Among those with HFrEF, the incidence of the composite of cardiovascular death, HF hospitalization, stroke, or myocardial infarction was 18.23 (16.81-19.77) per 100 person-years in those with prior stroke vs. 13.12 (12.77-13.48) in those without [hazard ratio 1.37 (1.26-1.49), P < 0.001]. The corresponding rates in patients with HFpEF were 14.16 (12.96-15.48) and 9.37 (9.06-9.70) [hazard ratio 1.49 (1.36-1.64), P < 0.001]. Each component of the composite was more frequent in patients with stroke history, and the risk of future stroke was doubled in patients with prior stroke. Among patients with prior stroke, 30% with concomitant atrial fibrillation were not anticoagulated, and 29% with arterial disease were not taking statins; 17% with HFrEF and 38% with HFpEF had uncontrolled systolic blood pressure (≥140 mmHg).

CONCLUSION

Heart failure patients with a history of stroke are at high risk of subsequent cardiovascular events, and targeting underutilization of guideline-recommended treatments might be a way to improve outcomes in this high-risk population.

Correlation of microembolism risk factors with age in the ischemic stroke recovery period

Identification of the age-related features of interaction between the risk factors of microembolism can improve understanding of the mechanisms underlying the development of ischemic stroke (IS). The study was aimed to assess the effects of age and other risk factors of stroke on the biophysical characteristics of microembolic signals (MES) recorded during the ischemic stroke recovery period. Transcranial Doppler ultrasound (TCD) involving microembolus detection (MED) was performed in 515 people, the data of 28 patients having a history of ischemic stroke, among them 9 women (32%) and 19 men (68%) aged 33–78 (average age 58 ± 13 years), were included in the study. Using the mixed-effects linear model it was found that age and interaction between age and atrial fibrillation affected the power of MES. The increase in the power of the recorded MES with age is observed, that is especially evident in patients with atrial fibrillation (р < 0.0005). As for cardioembolic IS variant, the power and duration of MES turn out to be significantly higher in elderly patients (p < 0.0005). The power of MES gradually increases with age in patients with no atherosclerosis and gradually decreases in patients with atherosclerosis, while MES power in patients with atherosclerosis in general (all age groups) is significantly higher (р < 0.0005) than that observed in patients with no atherosclerosis.