Helena Lau

Recurrent vascular events in lacunar stroke patients with metabolic syndrome and/or diabetes

Objectives: We used a prospective clinical trial to examine the risks conferred by metabolic syndrome (METS) and diabetes mellitus (DM) to recurrent strokes in the Secondary Prevention of Small Subcortical Strokes (SPS3) study cohort. Methods: The SPS3 trial enrolled 3,020 patients with lacunar strokes. Participants were stratified into groups of METS only, DM only, both, or neither using American Heart Association/National Heart, Lung, and Blood Institute and World Health Organization guidelines. Annualized event rates of strokes, myocardial infarction (MI), and all-cause mortality were calculated, and hazard ratios (HRs) referencing the “neither” group were computed, controlling for significantly associated baseline characteristics. Results: Among 2,999 participants, 25% had METS only, 6% had DM only, 32% had both conditions, and 37% had neither. Over a median of 3.8 years of follow-up, there were 274 recurrent strokes (240 ischemic, 34 hemorrhagic) and 74 MIs; among the 240 ischemic strokes, 134 (56%) were lacunar. The rates of any recurrent stroke (HR 1.7, 95% confidence interval [CI] 1.3–2.3) or lacunar stroke (HR 2.4, 95% CI 1.5–3.7) were significantly higher for those with concurrent METS and DM compared with those who had neither. Risk of incident MI was higher in participants with DM (HR 2.8, 95% CI 1.1–7.0) or concurrent DM and METS (HR 2.6, 95% CI 1.4–4.9). Conclusion: METS and DM were significant comorbid conditions in lacunar stroke patients and they were associated with stroke recurrence. In patients with lacunar infarcts, a vigilant approach to prevent development of DM in those with METS may be a potential strategy to reduce recurrent strokes.

Can Blood Pressure Be Lowered Safely in Older Adults with Lacunar Stroke? The Secondary Prevention of Small Subcortical Strokes Study Experience

To determine safety and tolerability of lowering blood pressure in older adults with lacunar stroke.

High Prevalence of Cerebral Microbleeds in Inner City Young Stroke Patients

BACKGROUND Data on cerebral microbleeds (CMBs) in younger populations are lacking, particularly in young stroke patients. We sought to characterize CMBs in an inner city cohort of young adults with stroke. METHODS CMB presence, count, and topography were assessed on magnetic resonance imaging (MRI) scans of 104 young stroke patients (≤49 years) presenting to Boston Medical Center between January 2006 and February 2010. Subsequent MRIs were assessed for the occurrence of new microbleeds in 29 patients. We performed cross-sectional analysis comparing baseline characteristics between patients with and without microbleeds, and between predefined microbleed burden and topography categories. We performed additional analysis to assess the determinants of new microbleeds on repeat MRI. RESULTS Microbleeds were present in 17% of the sample. Male sex (odds ratio [OR] 5.7, 95% confidence interval [CI] 1.0-32.6, P = .049), hypertension (OR 6.2, 95% CI 1.2-32, P = .03), moderate-severe white matter hyperintensities on MRI (OR 5.8, 95% CI 1.6-29.0, P = .01), and intracerebral hemorrhage (ICH; OR 5.0, 95% CI 1.2-20, P = .03) were over-represented in patients with microbleeds. Patients who developed new microbleeds on repeat MRI (14%) had higher microbleed counts on baseline MRI (50% versus 0% ≥ 3 CMBs, P = .02), history of illicit drug use (75% versus 24%, P = .08), positive serum toxicology for cocaine (67% versus 13%, P = .11), ICH as their presenting stroke subtype (50% versus 8%, P = .08), and over-representation of moderate-severe white matter hyperintensities (75% versus 20%, P = .05). CONCLUSIONS Results from this inner city cohort suggest that microbleeds are prevalent in young stroke patients and are largely associated with modifiable risk factors.

Larger A1/M1 Diameter Ratio Predicts Embolic Anterior Cerebral Artery Territorial Stroke

Background and Purpose— In contrast to middle cerebral artery territory strokes, anterior cerebral artery strokes (ACAS) occur rarely. The low frequency of ACAS, in relation to middle cerebral artery territory strokes, may be explained by differences in ACA and middle cerebral artery anatomy influencing their respective flow-directed embolism rates. We aimed to determine whether variability in ACA anatomy, and in particular A1 segment diameter, is associated with embolic ACAS. Methods— Consecutive patients admitted to Boston Medical Center with embolic ACAS were reviewed. Ipsilateral and contralateral A1 diameters, M1 diameters, and terminal internal carotid artery bifurcation angles were measured from computed tomographic angiography and MRI angiography images. We compared these measurements between cases of ACAS and consecutive cases of embolic middle cerebral artery territory strokes. Results— The study comprised 55 individuals (27 ACAS, 28 middle cerebral artery territory strokes) with mean age of 69 years. In multivariate regression analysis, larger ipsilateral A1 diameters (odds ratio per 1 mm increment: 8.5; 95% confidence interval, 1.4–53.3) and ipsilateral A1/M1 diameter ratio (odds ratio per 10% increment: 1.8; 95% confidence interval, 1.2–2.9) were associated with ACAS, whereas larger ipsilateral M1 diameters was protective for ACAS (odds ratio per 1 mm increment: 0.8; 95% confidence interval, 0.0–0.9). Conclusions— Larger ipsilateral A1 diameters and A1/M1 diameter ratio are associated with embolic ACAS. These findings suggest that A1 diameters and M1 diameters are important in determining the path of emboli that reach the terminal internal carotid artery.