P-wave terminal force in lead V1 and atrial fibrillation burden in cryptogenic stroke with implantable loop recorders

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.

Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke

BACKGROUND

Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM).

METHODS

We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS2 score.

RESULTS

Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P<0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively.

CONCLUSIONS

The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.

Atrial Fibrillation Detection and Ischemic Stroke Recurrence in Cryptogenic Stroke: A Retrospective, Multicenter, Observational Study

BACKGROUND

Atrial fibrillation (AF) is known to be a strong risk factor for stroke. However, the risk of stroke recurrence in patients with cryptogenic stroke with AF detected after stroke by an insertable cardiac monitor (ICM) is not well known. We sought to evaluate the risk of ischemic stroke recurrence in patients with cryptogenic stroke with and without ICM-detected AF.

METHODS AND RESULTS

We retrospectively reviewed patients with cryptogenic stroke who underwent ICM implantation at 8 stroke centers in Japan. Cox regression models were developed using landmark analysis and time-dependent analysis. We set the target sample size at 300 patients based on our estimate of the annualized incidence of ischemic stroke recurrence to be 3% in patients without AF detection and 9% in patients with AF detection. Of the 370 patients, 121 were found to have AF, and 110 received anticoagulation therapy after AF detection. The incidence of ischemic stroke recurrence was 4.0% in 249 patients without AF detection and 5.8% in 121 patients with AF detection (P=0.45). In a landmark analysis, the risk of ischemic stroke recurrence was not higher in patients with AF detected ≤90 days than in those without (hazard ratio, 1.47 [95% CI, 0.41-5.28]). In a time-dependent analysis, the risk of ischemic stroke recurrence did not increase after AF detection (hazard ratio, 1.77 [95% CI, 0.70-4.47]).

CONCLUSIONS

The risk of ischemic stroke recurrence in patients with cryptogenic stroke with ICM-detected AF, 90% of whom were subsequently anticoagulated, was not higher than in those without ICM-detected AF.

Left atrial appendage flow velocity predicts occult atrial fibrillation in cryptogenic stroke: a CRYPTON-ICM registry

BACKGROUND

An insertable cardiac monitor (ICM) and transesophageal echocardiography (TEE) are useful for investigating potential embolic sources in cryptogenic stroke, of which atrial fibrillation (AF) is a critical risk factor for stroke recurrence. The association of left atrial appendage flow velocity (LAA-FV) on TEE with ICM-detected AF is yet to be elucidated.

METHODS

CRYPTON-ICM (CRYPTOgenic stroke evaluation in Nippon using ICM) is a multicenter registry of cryptogenic stroke with ICM implantation, and patients whose LAA-FV was evaluated on TEE were enrolled. The primary outcome was the detection of AF (> 2 min) on ICM. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off of LAA-FV, and factors associated with ICM-detected AF were assessed.

RESULTS

A total of 307 patients (age 66.6 ± 12.3 years; 199 males) with median follow-up of 440 (interquartile range 169-726) days were enrolled; AF was detected in 101 patients. The lower-tertile LAA-FV group had older age, more history of congestive heart failure, and higher levels of B-type natriuretic peptide (BNP) or N-terminal proBNP (all P < 0.05). On ROC analysis, LAA-FV < 37.5 cm/s predicted ICM-detected AF with sensitivity of 26.7% and specificity of 92.2%. After adjustment for covariates, the lower tertile of LAA-FV (hazard ratio [HR], 1.753 [1.017-3.021], P = 0.043) and LAA-FV < 37.5 cm/s (HR 1.987 [1.240-3.184], P = 0.004) predicted ICM-detected AF.

CONCLUSIONS

LAA-FV < 37.5 cm/s predicts AF. TEE is useful not only to evaluate potential embolic sources, but also for long-term detection of AF on ICM by measuring LAA-FV in cryptogenic stroke. http://www.umin.ac.jp/ctr/ (UMIN000044366).