Cerebral Microbleeds With Atrial Fibrillation After Ablation Therapy.

Akihiro Shindo,Maki Umino,Natsuko Kato,Hidekazu Tomimoto,Mariko Shiga,Naoko Nakamura,Keita Matsuura,Hajime Sakuma,Yuichiro Ii,Masayuki Maeda,Kaoru Dohi,Ryota Kogue,Ken-Ichi Tabei,Masayuki Satoh,Satoshi Fujita,Yoshihiko Kagawa,Yoshinori Hirata,Tomoyuki Fukuma,Kanako Muraga

doi:10.3389/fncel.2022.818288

Abstract

BackgroundThe prevalence of cerebral microbleeds (CMBs) is significantly higher in patients with atrial fibrillation (AF) than in those without AF. CMBs in patients with AF have been reported to be primarily of the lobar type, but the exact cause of this remains unknown. We investigated the possibility that hemorrhagic transformation of embolic microinfarction can account for de novo lobar CMBs.MethodsA total of 101 patients who underwent ablation therapy for AF were prospectively registered, and 72 patients completed the assessment with MRI 6 months after catheter ablation. Brain MRI, including diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI), were examined at 1–3 days (baseline) and 6 months after catheter ablation. We quantitatively evaluated the spatial and temporal distribution of embolic microinfarctions and de novo CMBs.ResultsOf the 101 patients, 68 were enrolled in this study. Fifty-nine patients (86.8%) showed embolic microinfarctions on baseline DWI immediately after catheter ablation. There were 137 CMBs in SWI, and 96 CMBs were of the lobar type. Six months later, there were 208 CMBs, including 71 de novo CMBs, and 60 of 71 (84.5%) were of the lobar type. Of the 71 de novo CMBs, 56 (78.9%) corresponded to the location of previous embolic microinfarctions found on baseline DWI. The platelet count was significantly lower and hematocrit/hemoglobin and Fazekas score were higher in the group with de novo CMBs than in the group without de novo CMBs.ConclusionDe novo CMBs frequently appeared after catheter ablation therapy. Our results suggest that embolic microinfarction can cause lobar CMBs.

Highlights

Cerebral microbleeds (CMBs) are small perivascular accumulations of hemosiderin-containing macrophages as a result of extravasation of erythrocytes from cerebral small vessels on histopathological examinations
De novo cerebral microbleeds (CMBs) frequently appeared after catheter ablation therapy
Our results suggest that embolic microinfarction can cause lobar CMBs

Summary

Introduction

Cerebral microbleeds (CMBs) are small perivascular accumulations of hemosiderin-containing macrophages as a result of extravasation of erythrocytes from cerebral small vessels on histopathological examinations. CMBs are classified into two types according to their location (deep and lobar CMBs), and histopathological analysis reveals mainly two types of vascular pathological changes, hypertensive vasculopathy and cerebral amyloid angiopathy (CAA), respectively. The lobar CMBs are mostly considered to be caused by CAA and are found frequently in patients with Alzheimer’s disease (Yates et al, 2014; Selim and Diener, 2017), whereas the non-lobar, deep or infratentorial, and mixed types of CMBs are considered to be due to hypertensive vasculopathy (Matsuyama et al, 2017). One plausible cause of dementia with AF is the presence of cerebral infarctions (Graff-Radford et al, 2016) and the other mechanism may be the existence of CMBs which have been suggested to be associated with cognitive dysfunction (Poels et al, 2012). The prevalence of cerebral microbleeds (CMBs) is significantly higher in patients with atrial fibrillation (AF) than in those without AF.

Results

Discussion

Conclusion