Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation.

OBJECTIVES: Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet). METHODS: We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use. RESULTS: A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (adjusted hazard ratio [aHR] = 2.74, 95% confidence interval = 1.76-4.26) and ischemic stroke (aHR = 1.29, 95% confidence interval = 1.04-1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleed burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2 to 4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥ 11 microbleeds (94 vs 48 per 1,000 patient-years). INTERPRETATION: Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. ANN NEUROL 2023;94:61-74.

Stroke Risk and Antithrombotic Treatment During Follow-up of Patients With Ischemic Stroke and Cortical Superficial Siderosis.

BACKGROUND AND OBJECTIVES: In patients with ischemic stroke (IS) or transient ischemic attack (TIA) and cortical superficial siderosis (cSS), there are few data regarding the risk of future cerebrovascular events and also about the benefits and safety of antithrombotic drugs for secondary prevention. We investigated the associations of cSS and stroke risk in patients with recent IS or TIA. METHODS: We retrospectively analyzed the Microbleeds International Collaborative Network (MICON) database. We selected patients with IS or TIA from cohorts who had MRI-assessed cSS, available data on antithrombotic treatments, recurrent cerebrovascular events (intracranial hemorrhage [ICrH], IS, or any stroke [ICrH or IS]), and mortality. We calculated incidence rates (IRs) and performed univariable and multivariable Cox regression analyses. RESULTS: Of 12,669 patients (mean age 70.4 ± 12.3 years, 57.3% men), cSS was detected in 273 (2.2%) patients. During a mean follow-up of 24 ± 17 months, IS was more frequent than ICrH in both cSS (IR 57.1 vs 14.6 per 1,000 patient-years) and non-cSS (33.7 vs 6.3 per 1,000 patient-years) groups. Compared with the non-cSS group, cSS was associated with any stroke on multivariable analysis {IR 83 vs 42 per 1,000 patient-years, adjusted hazard ratio [HR] for cSS 1.62 (95% CI: 1.14-2.28; p = 0.006)}. This association was not significant in subgroups of patients treated with antiplatelet drugs (n = 6,554) or with anticoagulants (n = 4,044). Patients with cSS who were treated with both antiplatelet drugs and anticoagulants (n = 1,569) had a higher incidence of ICrH (IR 107.5 vs 4.9 per 1,000 patient-years, adjusted HR 13.26; 95% CI: 2.90-60.63; p = 0.001) and of any stroke (IR 198.8 vs 34.7 per 1,000 patient-years, adjusted HR 5.03; 95% CI: 2.03-12.44; p < 0.001) compared with the non-cSS group. DISCUSSION: Patients with IS or TIA with cSS are at increased risk of stroke (ICrH or IS) during follow-up; the risk of IS exceeds that of ICrH for patients receiving antiplatelet or anticoagulant treatment alone, but the risk of ICrH exceeds that of IS in patients receiving both treatments. The findings suggest that either antiplatelet or anticoagulant treatment alone should not be avoided in patients with cSS, but combined antithrombotic therapy might be hazardous. Our findings need to be confirmed by randomized clinical trials.

Comparison of Clinical Characteristics of COVID-19-Related and Unrelated Acute Stroke Patients During the COVID-19 Pandemic in Turkey.

Objectives: Data on the co-occurrence of stroke and coronavirus disease 2019 (COVID-19) infection are limited and need to be improved. In our study, we aimed to evaluate the clinical and laboratory characteristics of COVID-19-related patients admitted to our center with acute stroke and compare them with acute stroke patients without COVID-19 infection during the same period. Methods: One hundred and eighty-four patients admitted with acute stroke from March 11, 2020, to May 11, 2020, were included in the study. Demographic and clinical characteristics, work-up studies, and clinical scales including National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS) scores were examined retrospectively. All patients diagnosed with acute stroke who were also evaluated for COVID-19 before hospitalization were divided into two groups: COVID-19-related and unrelated cases. Results: COVID-19-related and unrelated acute stroke patients had similar characteristics in terms of age, gender, and stroke risk factors. The admission NIHSS (mean NIHSS: 9.8 vs. 5.9) scores and the discharge mRS values (mean mRS: 3.9 vs. 2.4) were significantly higher in the COVID-19-related stroke group (p=0.002 and p=0.001, respectively). The prognosis of the COVID-19-related stroke group was significantly worse (69.6% vs. 39.8%) and the mortality rate (39.1% vs. 6.2%) was significantly higher than the COVID-19-unrelated stroke group (p=0.007 vs. p=0.000, respectively). The proportion of patients with large infarcts in the COVID-19-related acute ischemic stroke group was significantly higher than the one in the COVID-19-unrelated acute ischemic stroke group (57.9% vs. 21.9%, p=0.003). Conclusion: This is the first comparative study to evaluate the clinical presentation and outcome of COVID-19-related acute ischemic and hemorrhagic stroke patients in Turkey. Our results suggest that COVID-19-related acute stroke is associated with more severe clinical presentation and worse outcome. This seems to be linked to the coagulation abnormalities induced by COVID-19 infection.