Background:Cerebral microbleeds (CMBs) have been observed in healthy elderly people undergoing systematic brain magnetic resonance imaging. The potential role of acute triggers on the appearance of CMBs remains unknown. We aimed to describe the incidence of new CMBs after transcatheter aortic valve replacement (TAVR) and to identify clinical and procedural factors associated with new CMBs including hemostatic measures and anticoagulation management.Methods:We evaluated a prospective cohort of patients with symptomatic aortic stenosis referred for TAVR for CMBs (METHYSTROKE [Identification of Epigenetic Risk Factors for Ischemic Complication During the TAVR Procedure in the Elderly]). Standardized neurologic assessment, brain magnetic resonance imaging, and analysis of hemostatic measures including von Willebrand factor were performed before and after TAVR. Numbers and location of microbleeds on preprocedural magnetic resonance imaging and of new microbleeds on postprocedural magnetic resonance imaging were reported by 2 independent neuroradiologists blinded to clinical data. Measures associated with new microbleeds and postprocedural outcome including neurologic functional outcome at 6 months were also examined.Results:A total of 84 patients (47% men, 80.9±5.7 years of age) were included. On preprocedural magnetic resonance imaging, 22 patients (26% [95% CI, 17%–37%]) had at least 1 microbleed. After TAVR, new microbleeds were observed in 19 (23% [95% CI, 14%–33%]) patients. The occurrence of new microbleeds was independent of the presence of microbleeds at baseline and of diffusion-weighted imaging hypersignals. In univariable analysis, a previous history of bleeding (P=0.01), a higher total dose of heparin (P=0.02), a prolonged procedure (P=0.03), absence of protamine reversion (P=0.04), higher final activated partial thromboplastin time (P=0.05), lower final von Willebrand factor high-molecular-weight:multimer ratio (P=0.007), and lower final closure time with adenosine–diphosphate (P=0.02) were associated with the occurrence of new postprocedural microbleeds. In multivariable analysis, a prolonged procedure (odds ratio, 1.22 [95% CI, 1.03–1.73] for every 5 minutes of fluoroscopy time; P=0.02) and postprocedural acquired von Willebrand factor defect (odds ratio, 1.42 [95% CI, 1.08–1.89] for every lower 0.1 unit of high-molecular-weight:multimer ratio; P=0.004) were independently associated with the occurrence of new postprocedural microbleeds. New CMBs were not associated with changes in neurologic functional outcome or quality of life at 6 months.Conclusions:One out of 4 patients undergoing TAVR has CMBs before the procedure and 1 out of 4 patients develops new CMBs. Procedural or antithrombotic management and persistence of acquired von Willebrand factor defect were associated with the occurrence of new CMBs.Registration:URL: https://www.clinicaltrials.gov; Unique identifier: NCT02972008.

中文翻译：

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经导管主动脉瓣置换术期间的脑微出血：前瞻性磁共振成像队列

背景：在接受系统脑磁共振成像的健康老年人中观察到脑微出血（CMB）。急性触发因素对 CMB 出现的潜在作用仍然未知。我们的目的是描述经导管主动脉瓣置换术 (TAVR) 后新发 CMB 的发生率，并确定与新发 CMB 相关的临床和程序因素，包括止血措施和抗凝管理。 CMB 的 TAVR（METHYSTROKE [确定老年人 TAVR 手术期间缺血并发症的表观遗传风险因素]）。标准化神经系统评估、脑磁共振成像、在 TAVR 前后对包括 von Willebrand 因子在内的止血措施进行了分析。2 名对临床数据不知情的独立神经放射学家报告了术前磁共振成像微出血的数量和位置以及术后磁共振成像新微出血的数量和位置。还检查了与新微出血和术后结果（包括 6 个月时的神经功能结果）相关的措施。结果：总共包括 84 名患者（47% 男性，80.9±5.7 岁）。在术前磁共振成像中，22 名患者 (26% [95% CI, 17%–37%]) 有至少 1 次微出血。TAVR 后，在 19 名 (23% [95% CI, 14%–33%]) 患者中观察到新的微出血。新微出血的发生与基线微出血和弥散加权成像超信号的存在无关。在单变量分析中，既往出血史（P =0.01)，较高的肝素总剂量 ( P =0.02)，延长的手术时间 ( P =0.03)，无鱼精蛋白逆转 ( P =0.04)，较高的最终活化部分凝血活酶时间 ( P =0.05)，较低的最终von Willebrand 因子高分子量：多聚体比率 ( P = 0.007) 和使用二磷酸腺苷的较短最终闭合时间 ( P = 0.02) 与新的术后微出血的发生有关。在多变量分析中，每 5 分钟透视时间的延长程序（比值比为 1.22 [95% CI，1.03–1.73]；P=0.02) 和术后获得性 von Willebrand 因子缺陷（优势比，1.42 [95% CI，1.08–1.89] 每降低 0.1 个单位的高分子量：多聚体比率；P =0.004）与新的术后微出血。新的 CMB 与 6 个月时神经功能结果或生活质量的变化无关。结论：接受 TAVR 的 4 名患者中有 1 名在手术前有 CMB，4 名患者中有 1 名出现新的 CMB。程序或抗血栓管理以及获得性 von Willebrand 因子缺陷的持续存在与新 CMB 的发生有关。注册：URL：https://www.clinicaltrials.gov；唯一标识符：NCT02972008。