Background The optimal time to commence anticoagulation in patients with atrial fibrillation (AF) after ischaemic stroke or transient ischaemic attack (TIA) is unclear, with guidelines differing in recommendations. A limitation of previous studies is the focus on clinically overt stroke, rather than radiologically obvious diffusion-weighted imaging ischaemic lesions. We aimed to quantify silent ischaemic lesions and haemorrhages on MRI at 1 month in patients commenced on early (<4 days) vs late (≥4 days) anticoagulation. We hypothesised that there would be fewer ischaemic lesions and more haemorrhages in the early anticoagulant group at 1-month MRI. Methods A prospective multicentre, observational cohort study was performed at 11 Australian stroke centres. Clinical and MRI data were collected at baseline and follow-up, with blinded imaging assessment performed by two authors. Timing of commencement of anticoagulation was at the discretion of the treating stroke physician. Results We recruited 276 patients of whom 208 met the eligibility criteria. The average age was 74.2 years (SD±10.63), and 79 (38%) patients were female. Median National Institute of Health Stroke Scale score was 5 (IQR 1–12). Median baseline ischaemic lesion volume was 5 mL (IQR 2–17). There were a greater number of new ischaemic lesions on follow-up MRI in patients commenced on anticoagulation ≥4 days after index event (17% vs 8%, p=0.04), but no difference in haemorrhage rates (22% vs 32%, p=0.10). Baseline ischaemic lesion volume of ≤5 mL was less likely to have a new haemorrhage at 1 month (p=0.02). There was no difference in haemorrhage rates in patients with an initial ischaemic lesion volume of >5 mL, regardless of anticoagulation timing. Conclusion Commencing anticoagulation <4 days after stroke or TIA is associated with fewer ischaemic lesions at 1 month in AF patients. There is no increased rate of haemorrhage with early anticoagulation. These results suggest that early anticoagulation after mild-to-moderate acute ischaemic stroke associated with AF might be safe, but randomised controlled studies are needed to inform clinical practice. Data are available on reasonable request. Study data are available on reasonable request to the corresponding author.

中文翻译：

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ATTUNE 研究表明，中风和房颤患者早期抗凝治疗与 1 个月时缺血性病变较少有关

背景 缺血性卒中或短暂性脑缺血发作（TIA）后心房颤动（AF）患者开始抗凝的最佳时间尚不清楚，各指南的建议也有所不同。先前研究的局限性在于关注临床明显的中风，而不是放射学上明显的弥散加权成像缺血性病变。我们的目的是量化开始早期（<4天）与晚期（≥4天）抗凝治疗的患者1个月时MRI上的无症状缺血性病变和出血情况。我们假设早期抗凝组在 1 个月的 MRI 中缺血性病变较少，出血较多。方法 在 11 个澳大利亚卒中中心进行了一项前瞻性多中心观察性队列研究。在基线和随访时收集临床和 MRI 数据，并由两位作者进行盲法成像评估。开始抗凝治疗的时间由治疗中风的医生决定。结果我们招募了 276 名患者，其中 208 名符合资格标准。平均年龄为 74.2 岁（SD±10.63），其中 79 名（38%）患者为女性。美国国立卫生研究院卒中量表评分中位数为 5 (IQR 1-12)。中位基线缺血性病变体积为 5 mL (IQR 2-17)。在指数事件发生后 ≥4 天开始抗凝治疗的患者中，随访 MRI 发现更多新的缺血性病变（17% vs 8%，p=0.04），但出血率没有差异（22% vs 32%， p=0.10）。基线缺血性病变体积≤5 mL 在 1 个月时出现新出血的可能性较小 (p=0.02)。无论抗凝时机如何，初始缺血病变体积> 5 mL的患者的出血率没有差异。结论 AF 患者中风或 TIA 后 4 天以内开始抗凝与 1 个月时缺血性病变较少相关。早期抗凝治疗不会增加出血率。这些结果表明，与房颤相关的轻至中度急性缺血性卒中后早期抗凝可能是安全的，但需要随机对照研究来指导临床实践。可根据合理要求提供数据。研究数据可根据合理要求向通讯作者提供。