Association of White Matter Hyperintensity Markers on MRI and Long-term Risk of Mortality and Ischemic Stroke: The SMART-MR Study.

OBJECTIVE: To determine whether white matter hyperintensity (WMH) markers on MRI are associated with long-term risk of mortality and ischemic stroke. METHODS: We included consecutive patients with manifest arterial disease enrolled in the Second Manifestations of Arterial Disease-Magnetic Resonance (SMART-MR) study. We obtained WMH markers (volume, type, and shape) from brain MRI scans performed at baseline using an automated algorithm. During follow-up, occurrence of death and ischemic stroke was recorded. Using Cox regression, we investigated associations of WMH markers with risk of mortality and ischemic stroke, adjusting for demographics, cardiovascular risk factors, and cerebrovascular disease. RESULTS: We included 999 patients (59 ± 10 years; 79% male) with a median follow-up of 12.5 years (range 0.2-16.0 years). A greater periventricular or confluent WMH volume was independently associated with a greater risk of vascular death (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.13-1.47) for a 1-unit increase in natural log-transformed WMH volume and ischemic stroke (HR 1.53, 95% CI 1.26-1.86). A confluent WMH type was independently associated with a greater risk of vascular (HR 1.89, 95% CI 1.15-3.11) and nonvascular death (HR 1.65, 95% CI 1.01-2.73) and ischemic stroke (HR 2.83, 95% CI 1.36-5.87). A more irregular shape of periventricular or confluent WMH, as expressed by an increase in concavity index, was independently associated with a greater risk of vascular (HR 1.20, 95% CI 1.05-1.38 per SD increase) and nonvascular death (HR 1.21, 95% CI 1.03-1.42) and ischemic stroke (HR 1.28, 95% CI 1.05-1.55). CONCLUSIONS: WMH volume, type, and shape are associated with long-term risk of mortality and ischemic stroke in patients with manifest arterial disease.

White matter hyperintensity load on stroke recurrence and mortality at 1 year after ischemic stroke.

OBJECTIVE: To define the role and risks associated with white matter hyperintensity (WMH) load in a stroke population with respect to recurrent stroke and mortality after ischemic stroke. METHODS: A total of 7,101 patients at a network of university hospitals presenting with ischemic strokes were followed up for 1 year. Multivariable Cox proportional hazards model and competing risk analysis were used to examine the independent association between quartiles of WMH load and stroke recurrence and mortality at 1 year. RESULTS: Overall recurrent stroke risk at 1 year was 6.7%/y, divided between 5.6%/y for recurrent ischemic and 0.5%/y for recurrent hemorrhagic strokes. There was a stronger association between WMH volume and recurrent hemorrhagic stroke by quartile (hazard ratio [HR] 7.32, 14.12, and 33.52, respectively) than for ischemic recurrence (HR 1.03, 1.37, and 1.61, respectively), but the absolute incidence of ischemic recurrence by quartile was higher (3.8%/y, 4.5%/y, 6.3%/y, and 8.2%/y by quartiles) vs hemorrhagic recurrence (0.1%/y, 0.4%/y, 0.6%/y, and 1.3%/y). All-cause mortality (10.5%) showed a marked association with WMH volume (HR 1.06, 1.46, and 1.60), but this was attributable to nonvascular rather than vascular causes. CONCLUSIONS: There is an association between WMH volume load and stroke recurrence, and this association is stronger for hemorrhagic than for ischemic stroke, although the absolute risk of ischemic recurrence remains higher. These data should be helpful to practitioners seeking to find the optimal preventive/treatment regimen for poststroke patients and to individualize risk-benefit ratios.

Cognitive Decline in Patients with Leukoaraiosis Within 5 Years after Initial Stroke.

BACKGROUND: Leukoaraiosis (LA) is closely associated with cognitive deficits. The association between LA and cognitive disorders, such as mild cognitive impairment (MCI) and dementia, after initial stroke has not been systematically studied. In this study, we sought to identify whether LA contributes to the occurrence of certain type of cognitive disorders after initial stroke. METHODS: Data from our Stroke Registry were examined, and 5-year follow-up data for LA and cognitive disorders were analyzed. We performed Kaplan-Meier analysis and log-rank test to assess the predictive value of LA for risk of cognitive decline and the Cox proportional hazards model to test the risk factors studied as independent determinants of cognitive impairment. RESULTS: The frequency of patients with normal cognitive function decreased significantly at 5 years compared with initial stroke (78% vs 70%; odds ratio, 1.51; 95% confidence interval, 1.41-1.62). Of 8784 patients, 1659 (19%) had dementia and 964 (11%) had MCI at the final analysis. After 5 years of follow-up, survival analysis showed that all patients with LA had an increased probability of MCI compared with those without LA (P < .0001). Patients with LA had an increased chance of dementia compared with those without LA (P < .0001) at the end of follow-up. Cognitive decline probability was significantly higher in patients with severe LA compared with those with mild/moderate LA (P < .0001). Cox regression analyses showed that recurrence of stroke (hazard ratio [HR], 3.92 [95% CI, 3.26-4.72]), hypertension (HR, 1.11 [95% CI, 1.0-1.22]), LA (HR, 1.15 [95% CI, 1.05-1.25]), age (HR, 1.05 [95% CI, 1.04-1.06]), hypercholesterolemia (HR, .86 [95% CI, .77-.95]), higher LDL cholesterol (HR, 1.21 [95% CI, 1.11-1.32]), lower HDL cholesterol (HR, .90 [95% CI, .83-.98]), coronary heart disease (HR, .85 [95% CI, .77-.94]), and National Institutes of Health Stroke Scale score at admission (HR, .77 [95% CI, .72-.82]) were also significantly associated with cognitive impairments. CONCLUSIONS: Our findings suggest that patients with LA may be at risk of developing new cognitive impairments at long-term period after initial stroke. The evaluation of the concomitant risk factors, besides providing insights about the possible mechanisms behind the cognitive dysfunction present in LA, may be of help for the prevention of cognitive impairments.

Association of leukoaraiosis with stroke recurrence within 5 years after initial stroke.

BACKGROUND: Leukoaraiosis (LA) is closely associated with stroke. Despite the fact that LA has consistently been shown to predict development of recurrent stroke, prior studies on the association of LA and stroke subtypes have been unsatisfactory. In this study, we sought to identify whether LA contributes to the recurrence of certain subtypes of stroke at long term. METHODS: Data from the Ege Stroke Registry were examined, and 5 years follow-up data for LA and stroke recurrence were analyzed. We performed survival curves using the Kaplan-Meier method (unadjusted) and log-rank tests in patients with stroke to determine the relationship between LA and recurrent stroke by stroke subtypes within a time period of 5 years. Multivariate survival analyses were undertaken using Cox proportional hazards models to determine the prognostic value of LA, stroke subtypes, and other vascular risk factors before recurrent stroke. RESULTS: Of 9522 patients with stroke, 1280 (26%) with LA and 901 (19%) without LA experienced a stroke recurrence within 5 years of follow-up (odds ratio, 1.53; 95% confidence interval, 1.39-1.69). After stratification by stroke subtypes, multivariable analysis revealed a significant association between LA and large artery disease (LAD; odds ratio [OR], 1.39; 95% confidence interval [CI], 1.18-1.64), small artery disease (SAD; OR, 1.57; 95% CI, 1.27-1.94), and intracerebral hemorrhage (ICH; OR, 1.88; 95% CI, 1.32-2.66), except cardioembolic stroke and "other" stroke subtypes at 5 years after stroke onset. The survival analysis showed that stroke recurrence was significantly higher in patients with severe LA compared with those with mild/moderate LA (log-rank test [Mantel-Cox], P < .001). CONCLUSIONS: Our results showed that LA is related to the recurrent strokes in patients with stroke within 5 years after stroke, specifically to the LAD, SAD and ICH.

Factors associated with severity of leukoaraiosis in first-ever lacunar stroke and atherosclerotic ischemic stroke patients.

BACKGROUND: Leukoaraiosis (LA) is an indicator of small vessel disease, but little is known about the relationship between the severity of LA and etiologic subtype of ischemic stroke. Our study aimed to investigate the factors associated with the severity of LA and the relationship between the severity of LA and etiologic subtype of ischemic stroke. METHODS: A total of 791 patients with first-ever ischemic stroke within 7 days were enrolled in our study. We evaluated cranial magnetic resonance imagings including severity of LA in periventricular and deep white matter, severity of silent lacunar infarcts (SLIs), etiologic subtype of ischemic stroke, and topographic patterns of acute cerebral infarcts. Severity of LA was graded as grade 0 when Fazekas scores = 0, grade 1 when Fazekas scores ranged from 1 to 2, and grade 2 when Fazekas scores were greater than or equal to 3. Multivariable ordinal logistic regression was used to analyze the factors associated with the severity of LA. RESULTS: A total of 748 patients (94.6%) had LA, the numbers and proportions of grade 0, grade 1, and grade 2 LA were 43 patients (5.4%), 413 patients (52.2%), and 335 patients (42.4%), respectively. In multivariable ordinal logistic regression analysis, increasing age, higher diastolic blood pressure, admission National Institutes of Health Stroke Scale scores less than or equal to 3, presence of SLIs, and small artery occlusion (SAO) subtype of ischemic stroke were found to be independently associated with higher grade of LA. CONCLUSIONS: LA is prevalent in first-ever ischemic stroke patients. Severe LA is more frequently associated with higher grades of SLIs and ischemic stroke due to SAO.

Leukoaraiosis is associated with short- and long-term mortality in patients with intracerebral hemorrhage.

BACKGROUND: There are few recent European studies of mortality after intracerebral hemorrhage (ICH), particularly long-term follow-up studies. No previous European studies have included information on leukoaraiosis. METHODS: We studied all consecutive patients hospitalized with a first-ever intracerebral hemorrhage between 2005 and 2009 in a well-defined area and assessed the prognostic value of various baseline clinical and radiologic factors. Leukoaraiosis was scored on the baseline computed tomographic (CT) scan as described by van Swieten et al, with an overall score from 0 to 4. RESULTS: One hundred thirty-four patients were followed up for a median of 4.7 years (interquartile range 2.5-6.6). Overall mortality was 23% at 2 days, 30% at 7 days, 37% at 30 days, 46% at 1 year, and 53% at 2 years. Factors independently associated with increased 30-day mortality were warfarin use, leukoaraiosis score, intraventricular hemorrhage, and Glasgow Coma Scale (GCS) score. Factors independently associated with long-term mortality in the 85 patients who survived the first 30 days were leukoaraiosis score, coronary heart disease, and initial GCS score. Recurrent ICH occurred in 4.5% and was significantly more frequent after lobar ICH than after ICH in other locations (11.1% v 0%; P = .025). CONCLUSIONS: In unselected patients in Southern Norway with first-ever ICH, severe leukoaraiosis is independently associated with both 30-day and long-term mortality in 30-day survivors. Warfarin is independently associated with 30-day mortality and coronary heart disease with long-term mortality in 30-day survivors. Recurrent ICH is more frequent after lobar ICH than after ICH in other locations.

White matter hyperintensities: age appropriate or risk indicator?

White matter hypertensity (WMH) is a term frequently seen in the MRI reports of insurance applicants. Its significance is often uncertain. There are different patterns and extent of WMH of variable clinical significance can be identified. Pathological correlates are varied with most pointing toward WMH as a reflection of small vessel ischemic burden. The predominant clinical associations are with stroke, cognitive impairment, dementia, general disability and death. This review examines the relationship of white matter hyperintensities to client morbidity, disability and mortality from an insurance medicine perspective.