Sex Differences in Plaque Composition and Morphology Among Symptomatic Patients With Mild-to-Moderate Carotid Artery Stenosis.

BACKGROUND AND PURPOSE: Incidence of ischemic stroke differs between men and women, with substantially higher rates in men. The underlying mechanism of this difference remains poorly understood but may be because of differences in carotid atherosclerosis. Using an in-depth imaging-based approach, we investigated differences between carotid plaque composition and morphology in male and female patients with stroke, taking into account differences in total plaque burden. Additionally, we investigated all possible within-artery combinations of plaque characteristics to explore differences between various plaque phenotypes. METHODS: We included 156 men and 68 women from the PARISK (Plaque At Risk) study, a prospective cohort study of patients with recent ischemic cerebrovascular symptoms and <70% ipsilateral carotid stenosis. Plaque characteristics (intraplaque hemorrhage [IPH], lipid-rich necrotic core [LRNC], calcifications, thin-or-ruptured fibrous cap, ulcerations, total plaque volume) were assessed with magnetic resonance imaging and multidetector-row computed tomography angiography. We used multivariable logistic and linear regression analyses to assess sex differences in plaque characteristics. RESULTS: We found significant difference in total plaque volume between men and women (ß=22.9 mm3 [95% CI, 15.4-30.5]; mean volume in men 1399±425 mm3, in women 1011±242 mm3). Additionally, men were more likely to have IPH (odds ratio [OR]=2.8 [95% CI, 1.3-6.3]; IPH proportion in men 49%, in women 16%) and LRNC (OR=2.4 [95% CI, 1.2-4.7]; LRNC proportion in men 73%, in women 41%) even after adjustment for total plaque volume. We found no sex-specific differences in plaque volume-corrected volumes of IPH, LRNC, and calcifications. In terms of coexistence of plaque characteristics, we found that men had more often a plaque with coexistence of calcifications, LRNC, and IPH (OR=2.7 [95% CI, 1.2-7.0]), with coexistence of thin-or-ruptured fibrous cap/ulcerations, LRNC, and IPH (OR=2.4 [95% CI, 1.1-5.9]), and with coexistence of all plaque characteristics (OR=3.0 [95% CI, 1.2-8.6]). CONCLUSIONS: In symptomatic patients with mild-to-moderate carotid stenosis, men are more likely to have a high-risk carotid plaque with IPH and LRNC than women, regardless of total plaque burden. Men also have more often a plaque with multiple vulnerable plaque components, which could comprise an even higher stroke risk. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01208025.

Prevalence, Clinical Management, and Natural Course of Incidental Findings on Brain MR Images: The Population-based Rotterdam Scan Study.

Purpose To present an updated prevalence estimate for incidental findings on brain magnetic resonance (MR) images and provide information on clinical relevance, including natural course, over a period of up to 9 years. Materials and Methods This study was approved by the institutional review board and all participants gave informed consent. In a prospective population-based setting, structural brain MR imaging was performed in 5800 participants (mean age, 64.9 years; 3194 women [55.1%]). Trained reviewers recorded abnormalities, which were subsequently evaluated by neuroradiologists. The prevalence with 95% confidence interval (CI) of incidental findings was determined, and clinical management of findings that required the attention of a medical specialist was followed. Follow-up imaging in the study context provided information on the natural course of findings that were not referred. Results In 549 of 5800 participants (9.5% [95% CI: 8.7%, 10.3%]), incidental findings were found, of which meningiomas (143 of 5800; 2.5% [95% CI: 2.1%, 2.9%]) and cerebral aneurysms (134 of 5800; 2.3% [95% CI: 2.0%, 2.7%]) were most common. A total of 188 participants were referred to medical specialists for incidental findings (3.2% [95% CI: 2.8%, 3.7%]). Of these, 144 (76.6% [95% CI: 70.1%, 82.1%]) either underwent a wait-and-see policy or were discharged after the initial clinical visit. The majority of meningiomas and virtually all aneurysms not referred or referred but untreated remained stable in size during follow-up. Conclusion Incidental findings at brain MR imaging that necessitate further diagnostic evaluation occur in over 3% of the general middle-aged and elderly population, but are mostly without direct clinical consequences. © RSNA, 2016.

Mid- to Late-Life Trajectories of Blood Pressure and the Risk of Stroke: The Rotterdam Study.

Hypertension is a major modifiable risk factor for stroke. Associations of blood pressure with incident stroke are mostly based on single or average blood pressure levels. However, this approach does not take into account long-term trajectories of blood pressure, which can vary considerably in the elderly. Within the population-based Rotterdam Study, we examined trajectories of systolic blood pressure in 6745 participants (60.0% women) over an age-range from 55 to 106 years and jointly modeled their risk of stroke and competing causes of death using joint latent class mixed modeling. Four trajectories were identified. Class 1 was characterized by blood pressure increasing gradually from on average 120 to 160 mm Hg over 5 decades (n=4938). Compared with this class, class 2, characterized by a similar midlife blood pressure, but a steep increase (n=822, increasing from 120 to 200 mm Hg), and class 4, characterized by a high midlife blood pressure (n=115; average 160 mm Hg) and had a higher risk of stroke and death. Class 3, characterized by a moderate midlife blood pressure (n=870; average 140 mm Hg), had a similar risk of death as class 1, but the highest risk of stroke. Assessing trajectories of blood pressure provides a more nuanced understanding of the associations between blood pressure, stroke, and mortality. In particular, high blood pressure and rapidly increasing blood pressure patterns are associated with a high risk of stroke and death, whereas moderately high blood pressure is only related to an increased risk of stroke. Future studies should explore the potential pathogenic significance of these patterns.

Hospital costs of ischemic stroke and TIA in the Netherlands.

OBJECTIVES: There have been no ischemic stroke costing studies since major improvements were implemented in stroke care. We therefore determined hospital resource use and costs of ischemic stroke and TIA in the Netherlands for 2012. METHODS: We conducted a retrospective cost analysis using individual patient data from a national diagnosis-related group registry. We analyzed 4 subgroups: inpatient ischemic stroke, inpatient TIA, outpatient ischemic stroke, and outpatient TIA. Costs of carotid endarterectomy and costs of an extra follow-up visit were also estimated. Unit costs were based on reference prices from the Dutch Healthcare Insurance Board and tariffs provided by the Dutch Healthcare Authority. Linear regression analysis was used to examine the association between hospital costs and various patient and hospital characteristics. RESULTS: A total of 35,903 ischemic stroke and 21,653 TIA patients were included. Inpatient costs were €5,328 ($6,845) for ischemic stroke and €2,470 ($3,173) for TIA. Outpatient costs were €495 ($636) for ischemic stroke and €587 ($754) for TIA. Costs of carotid endarterectomy were €6,836 ($8,783). Costs of inpatient days were the largest contributor to hospital costs. Age, hospital type, and region were strongly associated with hospital costs. CONCLUSIONS: Hospital costs are higher for inpatients and ischemic strokes compared with outpatients and TIAs, with length of stay (LOS) the most important contributor. LOS and hospital costs have substantially declined over the last 10 years, possibly due to improved hospital stroke care and efficient integrated stroke services.

Prediabetes in patients with stroke or transient ischemic attack: prevalence, risk and clinical management.

BACKGROUND: The prevalence of diabetes is emerging worldwide and is an important modifiable risk factor for stroke. People with prediabetes, an intermediate metabolic state between normal glucose metabolism and diabetes, have a tenfold increased risk of developing diabetes compared to those with a normal glucose metabolism. Prediabetes is comprised of impaired fasting glucose and/or impaired glucose tolerance and/or disturbed glycosylated hemoglobin levels. Prediabetes is highly prevalent in nondiabetic patients with transient ischemic attack (TIA) or ischemic stroke and nearly doubles their risk of stroke. This offers new options for secondary stroke prevention. SUMMARY: Several detection methods exist for identifying (pre)diabetes, including fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels. The concordance between these tests is not 100%, and they seem to be complementary. Screening for (pre)diabetes after stroke with fasting plasma glucose levels alone is insufficient, and 2-hour postload glucose and/or glycosylated hemoglobin levels should be determined as well. The prevalence of prediabetes in previously nondiabetic patients with a recent TIA or stroke ranges from 23 to 53%. This high prevalence in the acute phase after stroke can be transient or persistent, representing undiagnosed abnormal glucose metabolism. Impaired fasting glucose and impaired glucose tolerance have different pathophysiological mechanisms, including hepatic insulin resistance and muscle insulin resistance, respectively. Prediabetes seems to be a modest predictor for stroke, but doubles the risk for recurrent stroke. The relation between prediabetes after stroke and functional outcome is still unknown. However, it is most likely that prediabetes is a risk factor for a poor clinical outcome after stroke. There is a growing recognition that patients with prediabetes should be treated more aggressively. Both lifestyle and pharmacological interventions are possible treatment strategies. They are at least equally effective in preventing progression to diabetes. Lifestyle changes are difficult to maintain over a long period. The evidence of pharmacological interventions on stroke or other cardiovascular diseases is limited though and is still subject of several clinical trials. CONCLUSIONS: As the prevalence of prediabetes is growing rapidly, prediabetes might become one of the most important modifiable therapeutic targets in both primary and secondary prevention.

Modifiable etiological factors and the burden of stroke from the Rotterdam study: a population-based cohort study.

BACKGROUND: Stroke prevention requires effective treatment of its causes. Many etiological factors for stroke have been identified, but the potential gain of effective intervention on these factors in terms of numbers of actually prevented strokes remains unclear because of the lack of data from cohort studies. We assessed the impact of currently known potentially modifiable etiological factors on the occurrence of stroke. METHODS AND FINDINGS: This population-based cohort study was based on 6,844 participants of the Rotterdam Study who were aged ≥55 y and free from stroke at baseline (1990-1993). We computed population attributable risks (PARs) for individual risk factors and for risk factors in combination to estimate the proportion of strokes that could theoretically be prevented by the elimination of etiological factors from the population. The mean age at baseline was 69.4 y (standard deviation 6.3 y). During follow-up (mean follow-up 12.9 y, standard deviation 6.3 y), 1,020 strokes occurred. The age- and sex-adjusted combined PAR of prehypertension/hypertension, smoking, diabetes mellitus, atrial fibrillation, coronary disease, and overweight/obesity was 0.51 (95% CI 0.41-0.62) for any stroke; hypertension and smoking were the most important etiological factors. C-reactive protein, fruit and vegetable consumption, and carotid intima-media thickness in combination raised the total PAR by 0.06. The PAR was 0.55 (95% CI 0.41-0.68) for ischemic stroke and 0.70 (95% CI 0.45-0.87) for hemorrhagic stroke. The main limitations of our study are that our study population comprises almost exclusively Caucasians who live in a middle and high income area, and that risk factor awareness is higher in a study cohort than in the general population. CONCLUSIONS: About half of all strokes are attributable to established causal and modifiable factors. This finding encourages not only intervention on established etiological factors, but also further study of less well established factors. Please see later in the article for the Editors' Summary.

Assessment of cerebral small vessel disease predicts individual stroke risk.

BACKGROUND: Despite several known risk factors it is still difficult to foresee who will develop a stroke and who will not. Vascular brain damage, visualised with MRI, reflects how the brain tolerates the effects of vascular risk factors and may therefore be relevant in predicting individual stroke risk. OBJECTIVE: To examine whether the presence of small vessel disease on brain MRI could improve the prediction of stroke beyond the classic stroke risk factors from the 1991 Framingham Stroke Risk Function. METHODS: 1007 community-dwelling elderly people, free of stroke at baseline were included in the study. Small vessel disease--that is, the presence of silent brain infarcts (SBI) and white matter lesions (WML), was scored on MRI scans obtained in 1995-6. 10-Year stroke risk prediction was assessed by the C statistic and by reclassification adding SBI and WML to a risk model including the classic stroke risk factors. RESULTS: During 10-years of follow-up 99 strokes occurred. Individual stroke risk prediction significantly improved from 0.73 (95% CI 0.67 to 0.78) to 0.75 (0.69 to 0.80) in men and from 0.69 (0.64 to 0.75) to 0.77 (0.71 to 0.82) in women after inclusion of SBI and periventricular WML to the stroke risk factors. Reclassification occurred mainly in the intermediate stroke risk group (men 26%; women 61% reclassified). CONCLUSIONS: Assessment of small vessel disease with MRI beyond the classic stroke risk factors improved the prediction of subsequent stroke, especially in women with an intermediate stroke risk. These findings support the use of MRI as a possible tool for better identifying people at high risk of stroke.

Real-life costs and effects of an implementation program to increase thrombolysis in stroke.

OBJECTIVES: We have shown that a Breakthrough Series-based implementation program increases the number of patients with acute ischemic stroke treated with alteplase 4.5% in real-life settings. It is unclear whether such an implementation program is cost-effective. METHODS: The practice study includes 12 randomized hospitals and 5,515 patients. Its present cost-effectiveness analysis involves 1,657 patients with ischemic stroke admitted within 4 hours from onset. Defined primary outcomes are thrombolysis rate and actual health care costs up to 3 months, including additional implementation efforts. Secondary outcomes are lifetime quality-adjusted years (QALYs) and lifetime costs of individual trial patients, using a validated probabilistic, disability-stratified stroke life table. Differences in outcome include 95% confidence intervals (CI), adjusted for intracluster correlation. RESULTS: The thrombolysis rate in the intervention group was 44.3% vs 39.8% in the control group (difference 4.5%; 95% CI 3.1% to 5.9%. Mean costs per patient at 3 months (euros were converted to 2010 USD) were $9,192 USD in the intervention group and $9,647 USD in the control group (difference -$455 USD; 95% CI -$232 to -$679 USD). Lifetime QALYs in the intervention group were 3.89 and in the control group 3.84 (difference 0.05; 95% CI -0.04 to 0.14). The mean lifetime costs in the intervention group were $22,994 USD against $24,315 USD in the control group (difference -$1,321 USD; 95% CI -$1,722 to -$921 USD). CONCLUSIONS: A Breakthrough Series implementation program of thrombolysis increases thrombolysis. It saves short- and long-term health care costs due to lower hospital admission and residential costs, increasing stroke care efficiency.

Burden of atherosclerosis improves the prediction of coronary heart disease but not cerebrovascular events: the Rotterdam Study.

AIMS: Since atherosclerosis is a systemic process, risk prediction would benefit from targeting multiple components of cardiovascular disease simultaneously. To this end, it is useful to examine the predictive value of non-invasive measures of atherosclerosis in various vascular beds for both coronary heart disease (CHD) and cerebrovascular disease. METHODS AND RESULTS: Between September 2003 and February 2006, 2153 asymptomatic participants (69.6±6.6 years) from the Rotterdam Study underwent a multi-detector computed tomography scan. During a median follow-up of 3.5 years, 58 CHD events (myocardial infarction and CHD death) and 52 cerebrovascular events (TIA and stroke) occurred. Participants were classified into low (<5%), intermediate (5-10%), and high (>10%) 5-year risk categories based on a refitted Framingham risk model. The model was extended by coronary, aortic arch, or carotid calcium and reclassification percentages were calculated. For the outcome CHD, the C-statistic improved from 0.693 for the Framingham refitted model to 0.743, 0.740, and 0.749 by addition of coronary, aortic arch, and carotid calcium, respectively. Reclassification was most substantial in the intermediate risk group where addition of coronary calcium reclassified 56% of persons [net reclassification improvement (NRI): 15%; P<0.01)]. Adding aortic arch calcium led to a reclassification of 32% of persons (NRI: 8%; P=0.01) and adding carotid calcium reclassified 51% (NRI: 9%; P=0.02). In contrast, calcification in any of the three vascular beds did not improve cerebrovascular risk prediction. CONCLUSION: Coronary, aortic arch, and carotid artery calcification significantly improved risk prediction of CHD but not of cerebrovascular events.

Assessment of feasibility of endovascular treatment of ruptured intracranial aneurysms with 16-detector row CT angiography.

BACKGROUND: It is unclear whether 16-detector row CT angiography (CTA) can replace digital subtraction angiography (DSA) to assess the feasibility of endovascular treatment (EVT) in the acute phase after aneurysmal subarachnoid hemorrhage. METHODS: We studied 80 consecutive patients with aneurysmal subarachnoid hemorrhage, who underwent both CTA and DSA. Two interventional neuroradiologists independently scored CTA and, immediately thereafter, DSA with respect to feasibility of EVT. We determined whether CTA without DSA was sufficient for a definite judgment. We also assessed interobserver agreement. RESULTS: The 2 readers judged EVT to be feasible in 24 and 37 patients with CTA alone and not feasible in 34 and 20 patients. In these patients, DSA yielded additional information in 6 (reader 1) and 5 patients (reader 2), which did not affect treatment decision. In 19 and 7 patients, DSA was considered inferior to CTA. In the remaining patients (n = 22 and 23, respectively), feasibility of EVT could not be judged with CTA alone, and DSA results were required in addition for a treatment decision. Interobserver agreement on feasibility of EVT was just fair (kappa <0.40). CONCLUSIONS: In our series of patients, 16-detector row CTA was a reliable investigation to assess feasibility of EVT of ruptured intracranial aneurysms in most patients. Further, we found that interobserver disagreement on feasibility of EVT was considerable.