Cilostazol for Secondary Stroke Prevention: History, Evidence, Limitations, and Possibilities

Cilostazol is a phosphodiesterase III inhibitor with a long track record of safety that is FDA and EMA approved for the treatment of claudication in patients with peripheral arterial disease. In addition, cilostazol has been approved for secondary stroke prevention in several Asian countries based on trials that have demonstrated a reduction in stroke recurrence among patients with non-cardioembolic stroke. The onset of benefit appears after 60–90 days of treatment, which is consistent with cilostazol’s pleiotropic effects on platelet aggregation, vascular remodeling, blood flow, and plasma lipids. Cilostazol appears safe and does not increase the risk of major bleeding when given alone or in combination with aspirin or clopidogrel. Adverse effects such as headache, gastrointestinal symptoms and palpitations, however, contributed to a 6% increase in drug discontinuation among patients randomized to cilostazol in a large secondary stroke prevention trial (CSPS.com). Due to limitations of prior trials, such as open label design, premature trial termination, large loss to follow-up, lack of functional or cognitive outcome data, and exclusive enrollment in Asia, the existing trials have not led to a change in clinical practice or guidelines in Western countries. These limitations could be addressed by a double-blind placebo-controlled randomized trial conducted in a broader population. If positive, it would increase the evidence in support of long-term treatment with cilostazol for secondary prevention in the millions of patients worldwide who have suffered a non-cardioembolic ischemic stroke

Clinical significance of cerebral microbleeds on MRI

__Background:__ Cerebral microbleeds can confer a high risk of intracerebral hemorrhage, ischemic stroke, death and dementia, but estimated risks remain imprecise and often conflicting. We investigated the association between cerebral microbleeds presence and these outcomes in a large meta-analysis of all published cohorts including: ischemic stroke/TIA, memory clinic, “high risk” elderly populations, and healthy individuals in population-based studies. __Methods:__ Cohorts (with > 100 participants) that assessed cerebral microbleeds presence on MRI, with subsequent follow-up (≥3 months) were identified. The association between cerebral microbleeds and each of the outcomes (ischemic stroke, intracerebral hemorrhage, death, and dementia) was quantified using random effects models of (a) unadjusted crude odds ratios and (b) covariate-adjusted hazard rations. Results: We identified 31 cohorts (n = 20,368): 19 ischemic stroke/TIA (n = 7672), 4 memory clinic (n = 1957), 3 high risk elderly (n = 1458) and 5 population-based cohorts (n = 11,722). Cerebral microbleeds were associated with an increased risk of ischemic stroke (OR: 2.14; 95% CI: 1.58–2.89 and adj-HR: 2.09; 95% CI: 1.71–2.57), but the relative increase in future intracerebral hemorrhage risk was greater (OR: 4.65; 95% CI: 2.68–8.08 and adj-HR: 3.93; 95% CI: 2.71–5.69). Cerebral microbleeds were an independent predictor of all-cause mortality (adj-HR: 1.36; 95% CI: 1.24–1.48). In three population-based studies, cerebral microbleeds were independently associated with incident dementia (adj-HR: 1.35; 95% CI: 1.00–1.82). Results were overall consistent in analyses stratified by different populations, but with different degrees of heterogeneity. __Conclusions:__ Our meta-analysis shows that cerebral microbleeds predict an increased risk of stroke, death, and dementia and provides up-to-date effect sizes across different clinical settings. These pooled estimates can inform clinical decisions and trials, further supporting cerebral microbleeds role as biomarkers of underlying subclinical brain pathology in research and clinical settings

Oral anticoagulant re-initiation following intracerebral hemorrhage in non-valvular atrial fibrillation: Global survey of the practices of neurologists, neurosurgeons and thrombosis experts

<div><p>Background</p><p>While oral anticoagulants (OACs) are highly effective for ischemic stroke prevention in atrial fibrillation, intracerebral hemorrhage (ICH) remains the most feared complication of OAC. Clinical controversy remains regarding OAC resumption and its timing for ICH survivors with atrial fibrillation because the balance between risks and benefits has not been investigated in randomized trials.</p><p>Aims/Hypothesis</p><p>To survey the practice of stroke neurologists, thrombosis experts and neurosurgeons on OAC re-initiation following OAC-associated ICH.</p><p>Methods</p><p>An online survey was distributed to members of the International Society for Thrombosis and Haemostasis, Canadian Stroke Consortium, NAVIGATE-ESUS trial investigators (Clinicatrials.gov identifier NCT02313909) and American Association of Neurological Surgeons. Demographic factors and 11 clinical scenarios were included.</p><p>Results</p><p>Two hundred twenty-eight participants from 38 countries completed the survey. Majority of participants were affiliated with academic centers, and >20% managed more than 15 OAC-associated ICH patients/year. Proportion of respondents suggesting OAC anticoagulant resumption varied from 30% (for cerebral amyloid angiopathy) to 98% (for traumatic ICH). Within this group, there was wide distribution in response for timing of resumption: 21.4% preferred to re-start OACs after 1–3 weeks of incident ICH, while 25.3% opted to start after 1–3 months. Neurosurgery respondents preferred earlier OAC resumption compared to stroke neurologists or thrombosis experts in 5 scenarios (p<0.05 by Kendall’s tau).</p><p>Conclusions</p><p>Wide variations in current practice exist among management of OAC-associated ICH, with decisions influenced by patient- and provider-related factors. As these variations likely reflect the lack of high quality evidence, randomized trials are direly needed in this population.</p></div

Rivaroxaban versus aspirin for prevention of covert brain infarcts in patients with embolic stroke of undetermined source: NAVIGATE ESUS MRI substudy

Background: Covert brain infarcts are associated with important neurological morbidity. Their incidence in patients with embolic stroke of undetermined source (ESUS) is unknown. Aims: To assess the incidence of covert brain infarcts and cerebral microbleeds using MRI in a prospective substudy of the NAVIGATE ESUS randomized trial and to evaluate the effects of antithrombotic therapies. Methods: At 87 sites in 15 countries, substudy participants were randomly assigned to receive rivaroxaban 15 mg daily or aspirin 100 mg daily and underwent brain MRI near randomization and after study termination. The primary outcome was incident brain infarct (clinical ischemic stroke or covert brain infarct). Brain infarcts and microbleeds were ascertained centrally by readers unaware of treatment. Treatment effects were estimated using logistic regression. Results: Among the 718 substudy participants with interpretable, paired MRIs, the mean age was 67 years and 61% were men with a median of 52 days between the qualifying ischemic stroke and randomization and a median of seven days between randomization and baseline MRI. During the median (IQR) 11 (12) month interval between scans, clinical ischemic strokes occurred in 27 (4%) participants, while 60 (9%) of the remaining participants had an incident covert brain infarct detected by MRI. Assignment to rivaroxaban was not associated with reduction in the incidence of brain infarct (OR 0.77, 95% CI 0.49, 1.2) or of covert brain infarct among those without clinical stroke (OR 0.85, 95% CI 0.50, 1.4). New microbleeds were observed in 7% and did not differ among those assigned rivaroxaban vs. aspirin (HR 0.95, 95% CI 0.52–1.7). Conclusions: Incident covert brain infarcts occurred in twice as many ESUS patients as a clinical ischemic stroke. Treatment with rivaroxaban compared with aspirin did not significantly reduce the incidence of covert brain infarcts or increase the incidence of microbleeds, but the confidence intervals for treatment effects were wide. Registration: https://www.clinicaltrials.gov. Unique identifier: NCT 02313909

Cerebral amyloid angiopathy, cerebral microbleeds and implications for anticoagulation decisions:The need for a balanced approach

Cerebral amyloid angiopathy is a common hemorrhagic small vessel disease of the brain, often associated with high risk of spontaneous lobar intracerebral hemorrhage. When the suspicion of cerebral amyloid angiopathy is raised, clinicians are hesitant in prescribing oral anticoagulation in patients in whom it is otherwise indicated, including the case of non-valvular atrial fibrillation. This is one of the thorniest clinical dilemmas in the field currently. In this short Leading Opinion piece by an international panel of clinicians-researchers active in the field, we present our consistent approach and future outlook on oral anticoagulation post intracerebral hemorrhage and in the setting of clinical-radiologic evidence of cerebral amyloid angiopathy. We discuss recent advances and support a more balanced approach with implications for the wider neurological clinical community in regards to successful recruiting this patient population in ongoing and future randomized trials. </jats:p

Cerebral Microbleeds as Predictors of Mortality

Background and purposeCerebral microbleeds (CMB) represent a common magnetic resonance imaging marker of cerebral small vessel disease, increasingly recognized as a subclinical marker of stroke and dementia risk. CMB detection may reflect the cumulative effect of vascular risk burden and be a marker of higher mortality. We investigated the relation of CMB to risk of death in community dwelling participants free of stroke and dementia.MethodsWe evaluated 1963 Framingham Original and Offspring Cohort participants (mean age 67 years; 54% women) with available brain magnetic resonance imaging and mortality data. Using Cox proportional hazards models, we related CMB to all-cause, cardiovascular, and stroke-related mortality.ResultsParticipants with CMB (8.9%) had higher prevalence of cardiovascular risk factors and use of preventive medications. During a mean follow-up of 7.2±2.6 years, we observed 296 deaths. In age- and sex-adjusted analysis, CMB were associated with increased all-cause mortality (hazards ratio, 1.39; 95% confidence interval 1.03-1.88), a relation that was no longer significant after adjustment for cardiovascular risk and preventive medication use (hazards ratio, 1.15; 95% confidence interval, 0.82-1.63).ConclusionsCMBs may represent the deleterious effect of cardiovascular risk factors in the cerebral vasculature. Although their presence was associated with increased all-cause mortality, the effect was no longer present after accounting for vascular risk factors and preventive treatment use. Further studies are required to clarify the role of cardiovascular preventive therapies for prevention of mortality in persons with incidental detection of CMB

Inflammatory biomarkers, cerebral microbleeds, and small vessel disease

ObjectiveWe investigated the association between circulating biomarkers of inflammation and MRI markers of small vessel disease.MethodsWe performed a cross-sectional study relating a panel of 15 biomarkers, representing systemic inflammation (high-sensitivity C-reactive protein, interleukin-6, monocyte chemotactic protein-1, tumor necrosis factor α, tumor necrosis factor receptor 2, osteoprotegerin, and fibrinogen), vascular inflammation (intercellular adhesion molecule 1, CD40 ligand, P-selectin, lipoprotein-associated phospholipase A2 mass and activity, total homocysteine, and vascular endothelial growth factor), and oxidative stress (myeloperoxidase) to ischemic (white matter hyperintensities/silent cerebral infarcts) and hemorrhagic (cerebral microbleeds) markers of cerebral small vessel disease (CSVD) on MRI in 1,763 stroke-free Framingham offspring (mean age 60.2 ± 9.1 years, 53.7% women).ResultsWe observed higher levels of circulating tumor necrosis factor receptor 2 and myeloperoxidase in the presence of cerebral microbleed (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.1-4.1 and OR 1.5, 95% CI 1.1-2.0, respectively), higher levels of osteoprotegerin (OR 1.1, 95% CI 1.0-1.2), intercellular adhesion molecule 1 (OR 1.7, 95% CI 1.1-2.5), and lipoprotein-associated phospholipase A2 mass (OR 1.5, 95% CI 1.1-2.1), and lower myeloperoxidase (OR 0.8, 95% CI 0.7-1.0) in participants with greater white matter hyperintensity volumes and silent cerebral infarcts.ConclusionsOur study supports a possible role for inflammation in the pathogenesis of CSVD, but suggests that differing inflammatory pathways may underlie ischemic and hemorrhagic subtypes. If validated in other samples, these biomarkers may improve stroke risk prognostication and point to novel therapeutic targets to combat CSVD