Framingham Stroke Risk Function in a Large Population-Based Cohort of Elderly People

Non-coding RNAs in acute ischemic stroke: from brain to periphery

Acute ischemic stroke is a clinical emergency and a condition with high morbidity, mortality, and disability. Accurate predictive, diagnostic, and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined. With innovations in high-throughput gene sequencing analysis, many aberrantly expressed non-coding RNAs (ncRNAs) in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models. Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes, leading to neuroprotection or deterioration, thus ncRNAs can serve as therapeutic targets in acute ischemic stroke. Moreover, distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. In particular, ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke. In this review, we consolidate the latest progress of research into the roles of ncRNAs (microRNAs, long ncRNAs, and circular RNAs) in the pathological processes of acute ischemic stroke-induced brain damage, as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

Brain artery diameters and risk of dementia and stroke

INTRODUCTION

We tested the association of brain artery diameters with dementia and stroke risk in three distinct population-based studies using conventional T2-weighted brain magnetic resonance imaging (MRI) images.

METHODS

We included 8420 adults > 40 years old from three longitudinal population-based studies with brain MRI scans. We estimated and meta-analyzed the hazard ratios (HRs) of the brain and carotids and basilar diameters associated with dementia and stroke.

RESULT

Overall and carotid artery diameters > 95th percentile increased the risk for dementia by 1.74 (95% confidence interval [CI], 1.13-2.68) and 1.48 (95% CI, 1.12-1.96) fold, respectively. For stroke, meta-analyses yielded HRs of 1.59 (95% CI, 1.04-2.42) for overall arteries and 2.11 (95% CI, 1.45-3.08) for basilar artery diameters > 95th percentile.

DISCUSSION

Individuals with dilated brain arteries are at higher risk for dementia and stroke, across distinct populations. Our findings underline the potential value of T2-weighted brain MRI-based brain diameter assessment in estimating the risk of dementia and stroke.

Stroke risk in older British men: Comparing performance of stroke-specific and composite-CVD risk prediction tools

Stroke risk is currently estimated as part of the composite risk of cardiovascular disease (CVD). We investigated if composite-CVD risk prediction tools QRISK3 and Pooled Cohort Equations-PCE, derived from middle-aged adults, are as good as stroke-specific Framingham Stroke Risk Profile-FSRP and QStroke for capturing the true risk of stroke in older adults. External validation for 10y stroke outcomes was performed in men (60-79y) of the British Regional Heart Study. Discrimination and calibration were assessed in separate validation samples (FSRP n = 3762, QStroke n = 3376, QRISK3 n = 2669 and PCE n = 3047) with/without adjustment for competing risks. Sensitivity/specificity were examined using observed and clinically recommended thresholds. Performance of FSRP, QStroke and QRISK3 was further compared head-to-head in 2441 men free of a range of CVD, including across age-groups. Observed 10y risk (/1000PY) ranged from 6.8 (hard strokes) to 11 (strokes/transient ischemic attacks). All tools discriminated weakly, C-indices 0.63-0.66. FSRP and QStroke overestimated risk at higher predicted probabilities. QRISK3 and PCE showed reasonable calibration overall with minor mis-estimations across the risk range. Performance worsened on adjusting for competing non-stroke deaths. However, in men without CVD, QRISK3 displayed relatively better calibration for stroke events, even after adjustment for competing deaths, including in oldest men. All tools displayed similar sensitivity (63-73 %) and specificity (52-54 %) using observed risks as cut-offs. When QRISK3 and PCE were evaluated using thresholds for CVD prevention, sensitivity for stroke events was 99 %, with false positive rate 97 % suggesting existing intervention thresholds may need to be re-examined to reflect age-related stroke burden.

Socioeconomic inequalities in dementia risk among a French population-based cohort: quantifying the role of cardiovascular health and vascular events

This study aimed to investigate the role of cardiovascular health (CVH) and vascular events as potential contributors to socioeconomic inequalities in dementia using causal mediation analyses. We used data from the Three-City Cohort, a French population-based study with 12 years of follow-up, with active search of dementia cases and validated diagnosis. Individual socioeconomic status was assessed using education, occupation and income. A CVH score as defined by the American Heart Association and incident vascular events were considered separately as mediators. We performed multi-level Cox proportional and Aalen additive hazard regression models to estimate the total effects of socioeconomic status on dementia risk. To estimate natural direct and indirect effects through CVH and vascular events, we applied two distinct weighting methods to quantify the role of CVH and vascular events: Inverse Odds Ratio Weighting (IORW) and Marginal Structural Models (MSM) respectively. Among 5581 participants, the risk of dementia was higher among participants with primary education (HR 1.60, 95%CI 1.44–1.78), blue-collar workers (HR 1.62, 95%CI 1.43–1.84) and with lower income (HR 1.23, 95%CI 1.09–1.29). Using additive models, 571 (95% CI 288–782) and 634 (95% CI 246–1020) additional cases of dementia per 100 000 person and year were estimated for primary education and blue-collar occupation, respectively. Using IORW, the CVH score mediate the relationship between education or income, and dementia (proportion mediated 17% and 26%, respectively). Yet, considering vascular events as mediator, MSM generated indirect effects that were smaller and more imprecise. Socioeconomic inequalities in dementia risk were observed but marginally explained by CVH or vascular events mediators.

A systematic review of the status and methodological considerations for estimating risk of first ever stroke in the general population

AIMS

The methodological quality of development, validation, and modification of those models have not been evaluated via a thoroughly literature review. This study aims to describe the overall status and evaluate the methodological quality of risk prediction models for stroke incidence in the general population.

METHODS

We searched the database of EMBASE and MEDLINE by the combination of subject words and key words to collect the research on stroke risk prediction model in the general population. The retrieval time was from the establishment of the database to September 2019. It should be mentioned that risk of bias for each model was assessed, and data on population characteristics and model performance was also extracted.

RESULTS

The search screened 11,386 peer-reviewed publications and 57 citation searching, of which 48 were included in the review, describing the development of 51 prediction models, 47 external validation models, and 12 modification models. Among 51 development models, the predicted outcome concentrated on fatal or non-fatal stroke (n = 37, 73%). Thirty-nine development models (76%) were without internal validation. C-statistic or AUC was adopted for discrimination in 80% models, and Hosmer-Lemeshow test (n = 25, 49%) was also performed for calibration. Twenty-six development models (53%) were externally validated, among which only 2 (8%) were validated by independent researchers. Risk prediction performance was improved when models were modified by adding novel risk factors, such as the internal carotid artery plaque and intima-media thickness.

CONCLUSION

Models for predicting stroke occurrence need further external validation, recalibration, or modification in different populations, to help interpret those models in the practice of stroke prevention.

MicroRNA: An Emerging Predictive, Diagnostic, Prognostic and Therapeutic Strategy in Ischaemic Stroke

Stroke continues to be the third-leading cause of death and disability worldwide. The limited availability of diagnostic tools approved therapeutics and biomarkers that help monitor disease progression or predict future events remain as the major challenges in the field of stroke medicine. Hence, attempts to discover safe and efficacious therapeutics and reliable biomarkers are of paramount importance. MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in regulating gene expression. Since miRNAs also play important roles in key mechanisms associated with the pathogenesis of stroke, including energy failure, inflammation and cell death, it is possible that miRNAs may serve as reliable blood-based markers for risk prediction, diagnosis and prognosis of ischaemic stroke. Discovery of better neurological outcome and smaller cerebral infarcts in animal models of ischaemic stroke treated with miRNA agomirs or antagomirs indicate that miRNAs may also play a cerebrovascular protective role after an ischaemic stroke. Nonetheless, further evidences on the optimum time for treatment and route of administration are required before effective translation of these findings into clinical practice. Bearing these in mind, this paper reviews the current literature discussing the involvement of miRNAs in major pathologies associated with ischaemic stroke and evaluates their value as reliable biomarkers and therapeutics for ischaemic stroke.

Essen Stroke Risk Score Predicts Carotid Atherosclerosis in Chinese Community Populations

BACKGROUND

Carotid atherosclerosis (CA) is closely related to stroke, and Framingham Risk Score (FRS) has been used for CA risk evaluation. However, FRS could only be used for subjects of up to 74 years old. The present study was to determine if Essen Stroke Risk Score (ESRS) could be used to estimate CA risk in community populations without age limits.

METHODS

In the present prospective multi-community screening study, we evaluated the prevalence of CA using high-resolution ultrasound in 521 males and 1039 females (35 to 91 years old). Both FRS and ESRS were calculated for the subjects. Multivariate logistic regression analysis was used to determine the predictive values of FRS and ESRS for CA in these subjects.

RESULTS

Ultrasound data showed that CA was present in 56.2% of the participants (total of 1560). Multivariate logistic regression analysis showed that ESRS was associated with CA with odds ratio (OR): 1.34 (95% confidence interval (CI), 1.12-1.60, p=0.001). Central obesity (OR: 1.40, CI: 1.07-1.83, p=0.015), female (OR: 0.55, CI: 0.39-0.77, p <0.001) and age (OR: 2.63, CI: 2.27-3.06, p <0.001) were also associated with CA. Based on the estimated area under curve (AUC), FRS (AUC 0.775) was better than ESRS (AUC 0.693) (z statistic 6.774, p <0.001) for CA prediction for individuals of ≤74 years old. However, receiver operating characteristic analysis showed ESRS was a good CA predictor for all subjects (AUC of 0.715).

CONCLUSION

ESRS could be used as an alternative to FRS to predict CA in community population of all age.

Validation of 10-Year Stroke Prediction Scores in a Community-Based Cohort of Chinese Older Adults

A stroke prediction model based on the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project was developed. We compared its predictive ability with the revised Framingham Stroke Risk Score (R-FSRS) for 5-year stroke incidence in a community cohort of Chinese adults, namely the Beijing Longitudinal Study of Aging (BLSA). Calibration, discrimination, and recalibration were used to compare the predictive ability between the two prediction models. Category-less net reclassification improvement (NRI) and integrated discrimination improvement (IDI) values were also assessed. During a mean follow-up duration of 5.1 years, 106 incidents of fatal or non-fatal strokes occurred among 1,203 participants aged 55–84 years. The R-FSRS applied to our cohort underestimated the 5-year risk for stroke in men and women. China-PAR performed better than the R-FSRS in terms of calibration (men, R-FSRS: χ²-value 144.2 [P < 0.001], China-PAR: 10.4 [P = 0.238]; women, R-FSRS: 280.1 [P < 0.001], China-PAR: 12.5 [P = 0.129]). In terms of discrimination, R-FSRS and China-PAR models performed modestly in our cohort (C-statistic 0.603 [95% CI: 0.560–0.644] for men using China-PAR and 0.568 [95% CI: 0.524–0.610] using the R-FSRS; the corresponding numbers for women were 0.602 [95% CI: 0.564–0.639] and 0.575 [95% CI: 0.537–0.613). The recalibrated China-PAR model significantly improved the discrimination in C statistics and produced higher category-less NRI and IDI for stroke incidence than the R-FSRS. Although China-PAR fairly estimated stroke risk in our cohort, it did not sufficiently identify adults at high risk of stroke. Caution would be exercised by practitioners in applying the original China-PAR to Chinese older adults. Further studies are needed to develop an adequate prediction model based on the recalibrated China-PAR or to find new risk markers which could upgrade this model.

Independent ischemic stroke risk factors in older Americans: a systematic review

The Framingham Stroke Risk Profile (FSRP) is a validated model for predicting 10-year ischemic stroke risk in middle-aged adults, yet has not been demonstrated to consistently translate in older populations. This is a systematic review of independent risk factors measured among > 65 year olds, with subsequent first ischemic stroke, using PRISMA guidelines. We appraised peer-reviewed publications that included participants > 65 years old at risk assessment. Combined with other criteria, results were abstracted from 28 papers reporting six types of stroke risk factors: Serologic/Diagnostic, Conventional, Psychosocial, Genetic, Cognitive, and Antibiotic use. These studies demonstrated levels of serum androgens, C-reactive protein, and advanced glycation endproducts; thrombin generation; left ventricular mass; depressive symptoms; phosphodiesterase 4D single nucleotide polymorphisms; coagulation factor XII gene; peak thrombus generation; and lower cognitive functioning were independent risk factors for ischemic stroke in older adults. Plasma adipokines, free fatty acids and antibiotic use did not predict ischemic stroke. Purpose in life and APOEε2 allele were protective for ischemic stroke. This systematic review provides evidence of risk and protective factors for ischemic stroke in older cohorts that are not included in the FSRP. Further studies are needed to understand whether these factors are important enough to comprise a risk score.

Machine learning provides evidence that stroke risk is not linear: The non-linear Framingham stroke risk score

Current stroke risk assessment tools presume the impact of risk factors is linear and cumulative. However, both novel risk factors and their interplay influencing stroke incidence are difficult to reveal using traditional additive models. The goal of this study was to improve upon the established Revised Framingham Stroke Risk Score and design an interactive Non-Linear Stroke Risk Score. Leveraging machine learning algorithms, our work aimed at increasing the accuracy of event prediction and uncovering new relationships in an interpretable fashion. A two-phase approach was used to create our stroke risk prediction score. First, clinical examinations of the Framingham offspring cohort were utilized as the training dataset for the predictive model. Optimal Classification Trees were used to develop a tree-based model to predict 10-year risk of stroke. Unlike classical methods, this algorithm adaptively changes the splits on the independent variables, introducing non-linear interactions among them. Second, the model was validated with a multi-ethnicity cohort from the Boston Medical Center. Our stroke risk score suggests a key dichotomy between patients with history of cardiovascular disease and the rest of the population. While it agrees with known findings, it also identified 23 unique stroke risk profiles and highlighted new non-linear relationships; such as the role of T-wave abnormality on electrocardiography and hematocrit levels in a patient’s risk profile. Our results suggested that the non-linear approach significantly improves upon the baseline in the c-statistic (training 87.43% (CI 0.85–0.90) vs. 73.74% (CI 0.70–0.76); validation 75.29% (CI 0.74–0.76) vs 65.93% (CI 0.64–0.67), even in multi-ethnicity populations. The clinical implications of the new risk score include prioritization of risk factor modification and personalized care at the patient level with improved targeting of interventions for stroke prevention.

A Multi-Center Competing Risks Model and Its Absolute Risk Calculation Approach

In the competing risks frame, the cause-specific hazard model (CSHM) can be used to test the effects of some covariates on one particular cause of failure. Sometimes, however, the observed covariates cannot explain the large proportion of variation in the time-to-event data coming from different areas such as in a multi-center clinical trial or a multi-center cohort study. In this study, a multi-center competing risks model (MCCRM) is proposed to deal with multi-center survival data, then this model is compared with the CSHM by simulation. A center parameter is set in the MCCRM to solve the spatial heterogeneity problem caused by the latent factors, hence eliminating the need to develop different models for each area. Additionally, the effects of the exposure factors in the MCCRM are kept consistent for each individual, regardless of the area they inhabit. Therefore, the coefficient of the MCCRM model can be easily explained using the scenario of each model for each area. Moreover, the calculating approach of the absolute risk is given. Based on a simulation study, we show that the estimate of coefficients of the MCCRM is unbiased and precise, and the area under the curve (AUC) is larger than that of the CSHM when the heterogeneity cannot be ignored. Furthermore, the disparity of the AUC increases progressively as the standard deviation of the center parameter (SDCP) rises. In order to test the calibration, the expected number (E) of strokes is calculated and then compared with the corresponding observed number (O). The result is promising, so the SDCP can be used to select the most appropriate model. When the SDCP is less than 0.1, the performance of the MCCRM and CSHM is analogous, but when the SDCP is equal to or greater than 0.1, the performance of the MCCRM is significantly superior to the CSHM. This suggests that the MCCRM should be selected as the appropriate model.

When are the cardiovascular and stroke risks too high? Pharmacotherapy for stroke prophylaxis

INTRODUCTION

Stroke is a significant source of morbidity and mortality in developed countries. Cardioembolic strokes represent approximately 15-30% of all ischemic strokes. They are frequently related to atrial fibrillation (AF) and have a worse prognosis and high recurrence rates when compared to other causes (e.g. atherosclerosis).

AREAS COVERED

This review includes a summary of general and specific scores to assess cardiovascular and stroke risks, with a focus on specific scores available in AF. Recommendations for antithrombotic therapy are also reviewed.

EXPERT OPINION

Several scores are available for the evaluation of stroke risk. They are useful to identify the risk factors that trigger the need for medical interventions. Integrated risk scores with visual interfaces showing the risk of events, with and without the proposed interventions, can aid decision-making. The risk of stroke can definitely be considered too high in those patients with a history of stroke/transient ischemic attack, who need antiplatelet therapy (after a non-cardioembolic stroke) or anticoagulant therapy (after a cardioembolic stroke). For primary prevention of stroke, antiplatelet therapy is not usually recommended, while anticoagulation should be considered if the patient has concomitant AF and at least one additional risk factor unrelated to sex.

Revised Framingham Stroke Risk Score, Nontraditional Risk Markers, and Incident Stroke in a Multiethnic Cohort

BACKGROUND AND PURPOSE

Limited data exist on the performance of the revised Framingham Stroke Risk Score (R-FSRS) and the R-FSRS in conjunction with nontraditional risk markers. We compared the R-FSRS, original FSRS, and the Pooled Cohort Equation for stroke prediction and assessed the improvement in discrimination by nontraditional risk markers.

METHODS

Six thousand seven hundred twelve of 6814 participants of the MESA (Multi-Ethnic Study of Atherosclerosis) were included. Cox proportional hazard, area under the curve, net reclassification improvement, and integrated discrimination increment analysis were used to assess and compare each stroke prediction risk score. Stroke was defined as fatal/nonfatal strokes (hemorrhagic or ischemic).

RESULTS

After mean follow-up of 10.7 years, 231 of 6712 (3.4%) strokes were adjudicated (2.7% ischemic strokes). Mean stroke risks using the R-FSRS, original FSRS, and Pooled Cohort Equation were 4.7%, 5.9%, and 13.5%. The R-FSRS had the best calibration (Hosmer-Lemeshow goodness-of-fit, χ2=6.55; P=0.59). All risk scores were predictive of incident stroke. C statistics of R-FSRS (0.716) was similar to Pooled Cohort Equation (0.716), but significantly higher than the original FSRS (0.653; P=0.01 for comparison with R-FSRS). Adding nontraditional risk markers individually to the R-FSRS did not improve discrimination of the R-FSRS in the area under the curve analysis, but did improve category-less net reclassification improvement and integrated discrimination increment for incident stroke. The addition of coronary artery calcium to R-FSRS produced the highest category-less net reclassification improvement (0.36) and integrated discrimination increment (0.0027). Similar results were obtained when ischemic strokes were used as the outcome.

CONCLUSIONS

The R-FSRS downgraded stroke risk but had better calibration and discriminative ability for incident stroke compared with the original FSRS. Nontraditional risk markers modestly improved the discriminative ability of the R-FSRS, with coronary artery calcium performing the best.

Development and Validation of a 10-Year Mortality Prediction Model: Meta-Analysis of Individual Participant Data From Five Cohorts of Older Adults in Developed and Developing Countries

Background

Existing mortality prediction models for older adults have been each developed using a single study from the United States or Western Europe. We aimed to develop and validate a 10-year mortality prediction model for older adults using data from developed and developing countries.

Methods

We used data from five cohorts, including data from 16 developed and developing countries: ELSA (English Longitudinal Study of Aging), HRS (Health and Retirement Study), MHAS (Mexican Health and Aging Study), SABE-Sao Paulo (The Health, Well-being and Aging), and SHARE (Survey on Health, Ageing and Retirement in Europe). 35,367 older adults were split into training (two thirds) and test (one third) data sets. Baseline predictors included age, sex, comorbidities, and functional and cognitive measures. We performed an individual participant data meta-analysis using a sex-stratified Cox proportional hazards model, with time to death as the time scale. We validated the model using Harrell's C statistic (discrimination) and the estimated slope between observed and predicted 10-year mortality risk across deciles of risk (calibration).

Results

During a median of 8.6 years, 8,325 participants died. The final model included age, sex, diabetes, heart disease, lung disease, cancer, smoking, alcohol use, body mass index, physical activity, self-reported health, difficulty with bathing, walking several blocks, and reporting date correctly. The model showed good discrimination (Harrell's C = 0.76) and calibration (slope = 1.005). Models for developed versus developing country cohorts performed equally well when applied to data from developing countries.

Conclusion

A parsimonious mortality prediction model using data from multiple cohorts in developed and developing countries can be used to predict mortality in older adults in both settings.

Revised Framingham Stroke Risk Profile to Reflect Temporal Trends

BACKGROUND

Age-adjusted stroke incidence has decreased over the past 50 years, likely as a result of changes in the prevalence and impact of various stroke risk factors. An updated version of the Framingham Stroke Risk Profile (FSRP) might better predict current risks in the FHS (Framingham Heart Study) and other cohorts. We compared the accuracy of the standard (old) and of a revised (new) version of the FSRP in predicting the risk of all-stroke and ischemic stroke and validated this new FSRP in 2 external cohorts, the 3C (3 Cities) and REGARDS (Reasons for Geographic and Racial Differences in Stroke) studies.

METHODS

We computed the old FSRP as originally described and a new model that used the most recent epoch-specific risk factor prevalence and hazard ratios for individuals ≥55 years of age and for the subsample ≥65 years of age (to match the age range in REGARDS and 3C studies, respectively) and compared the efficacy of these models in predicting 5- and 10-year stroke risks.

RESULTS

The new FSRP was a better predictor of current stroke risks in all 3 samples than the old FSRP (calibration χ2 of new/old FSRP: in men: 64.0/12.1, 59.4/30.6, and 20.7/12.5; in women: 42.5/4.1, 115.4/90.3, and 9.8/6.5 in FHS, REGARDS, and 3C, respectively). In the REGARDS, the new FSRP was a better predictor among whites compared with blacks.

CONCLUSIONS

A more contemporaneous, new FSRP better predicts current risks in 3 large community samples and could serve as the basis for examining geographic and racial differences in stroke risk and the incremental diagnostic utility of novel stroke risk factors.

High Level of Depressive Symptoms at Repeated Study Visits and Risk of Coronary Heart Disease and Stroke over 10 Years in Older Adults: The Three-City Study

BACKROUND

Baseline depressive symptoms have been consistently associated with the onset of cardiovascular disease (CVD).

OBJECTIVES

Since depressive symptoms vary over time in elderly persons, and to help clarify whether or not depression is an etiological factor for CVD, we quantified the association between the course of depressive symptoms and occurrence of first coronary heart disease (CHD) and stroke events in older adults.

DESIGN

A population-based prospective observational study.

SETTING

Participants were randomly selected from the electoral rolls of three large French cities.

PARTICIPANTS

A total of 9,294 participants were examined at baseline between 1999 and 2001, and thereafter at repeated study visits over 10 years.

MEASUREMENTS

High levels of depressive symptoms (HLDS) were defined as a score≥16 on the 20-item Center for Epidemiologic Studies Depression Scale. The number of study visits with HLDS was used as a time dependent variable in Cox proportional hazard models.

RESULTS

There were 7,313 participants (36.6% males) aged 73.8±5.4 years with no history of CHD, stroke or dementia at baseline. After a median follow-up of 8.4 years (SD 2.3 years), 629 first CHD or stroke events occurred. After adjustment for sociodemographic characteristics and vascular risk factors, the risk of CHD and stroke combined increased 1.15-fold (95% CI: 1.06 to 1.25) per each additional study visit with HLDS. The results remained unchanged when accounting for the presence of disability and antidepressant intake at baseline and during follow-up.

CONCLUSION

Elderly persons exposed to HLDS at several occasions over 10 years showed substantial increased risk of coronary heart disease and stroke events.

Field Synopsis of the Role of Sex in Stroke Prediction Models

Background

Guidelines for stroke prevention recommend development of sex‐specific stroke risk scores. Incorporating sex in Clinical Prediction Models (CPMs) may support sex‐specific clinical decision making. To better understand their potential to guide sex‐specific care, we conducted a field synopsis of the role of sex in stroke‐related CPMs.

Methods and Results

We identified stroke‐related CPMs in the Tufts Predictive Analytics and Comparative Effectiveness CPM Database, a systematic summary of cardiovascular CPMs published from January 1990 to May 2012. We report the proportion of models including the effect of sex on stroke incidence or prognosis, summarize the directionality of the predictive effects of sex, and explore factors influencing the inclusion of sex. Of 92 stroke‐related CPMs, 30 (33%) contained a coefficient for sex or presented sex‐stratified models. Only 12/58 (21%) CPMs predicting outcomes in patients included sex, compared to 18/30 (60%) models predicting first stroke (P<0.0001). Sex was most commonly included in models predicting stroke among a general population (69%). Female sex was consistently associated with reduced mortality after ischemic stroke (n=4) and higher risk of stroke from arrhythmias or coronary revascularization (n=5). Models predicting first stroke versus outcomes among patients with stroke (odds ratio=5.75, 95% CI 2.18–15.14, P<0.001) and those developed from larger versus smaller sample sizes (odds ratio=4.58, 95% CI 1.73–12.13, P=0.002) were significantly more likely to include sex.

Conclusions

Sex is included in a minority of published CPMs, but more frequently in models predicting incidence of first stroke. The importance of sex‐specific care may be especially well established for primary prevention.

Carotid plaque as a predictor of dementia in older adults: the Three-City Study

BACKGROUND

The contribution of carotid atherosclerosis to incident dementia remains unclear. We examined the association between carotid plaques (CP) and common carotid intima media thickness (CCA-IMT) with incident dementia and its subtypes, and their added value for dementia risk prediction.

METHODS

At baseline, 6025 dementia-free subjects aged 65-86 years underwent bilateral carotid ultrasonography measures of CP and plaque-free CCA-IMT. Subjects were followed-up over 7 years for the detection of dementia.

RESULTS

After a mean 5.4 years of follow-up, 421 subjects developed dementia including 272 Alzheimer's disease and 83 vascular/mixed dementia (VaD). Only CP were independently related to VaD (HR(≥2 sites with plaques) = 1.92; 95% confidence interval or CI = 1.13-3.22) and improved VaD risk prediction (continuous Net Reclassification Index = 30.1%; 95% CI = 8.4-51.7) beyond known dementia risk factors. Accounting for stroke or competing risk by death marginally modified the results.

CONCLUSION

In older adults, CP are independent predictors of incident VaD and may improve VaD risk prediction.

The Stroke Riskometer(TM) App: validation of a data collection tool and stroke risk predictor

Background

The greatest potential to reduce the burden of stroke is by primary prevention of first-ever stroke, which constitutes three quarters of all stroke. In addition to population-wide prevention strategies (the ‘mass’ approach), the ‘high risk’ approach aims to identify individuals at risk of stroke and to modify their risk factors, and risk, accordingly. Current methods of assessing and modifying stroke risk are difficult to access and implement by the general population, amongst whom most future strokes will arise. To help reduce the burden of stroke on individuals and the population a new app, the Stroke Riskometer™, has been developed. We aim to explore the validity of the app for predicting the risk of stroke compared with current best methods.

Methods

752 stroke outcomes from a sample of 9501 individuals across three countries (New Zealand, Russia and the Netherlands) were utilized to investigate the performance of a novel stroke risk prediction tool algorithm (Stroke Riskometer™) compared with two established stroke risk score prediction algorithms (Framingham Stroke Risk Score [FSRS] and QStroke). We calculated the receiver operating characteristics (ROC) curves and area under the ROC curve (AUROC) with 95% confidence intervals, Harrels C-statistic and D-statistics for measure of discrimination, R² statistics to indicate level of variability accounted for by each prediction algorithm, the Hosmer-Lemeshow statistic for calibration, and the sensitivity and specificity of each algorithm.

Results

The Stroke Riskometer™ performed well against the FSRS five-year AUROC for both males (FSRS = 75·0% (95% CI 72·3%–77·6%), Stroke Riskometer™ = 74·0(95% CI 71·3%–76·7%) and females [FSRS = 70·3% (95% CI 67·9%–72·8%, Stroke Riskometer™ = 71·5% (95% CI 69·0%–73·9%)], and better than QStroke [males – 59·7% (95% CI 57·3%–62·0%) and comparable to females = 71·1% (95% CI 69·0%–73·1%)]. Discriminative ability of all algorithms was low (C-statistic ranging from 0·51–0·56, D-statistic ranging from 0·01–0·12). Hosmer-Lemeshow illustrated that all of the predicted risk scores were not well calibrated with the observed event data (P < 0·006).

Conclusions

The Stroke Riskometer™ is comparable in performance for stroke prediction with FSRS and QStroke. All three algorithms performed equally poorly in predicting stroke events. The Stroke Riskometer™ will be continually developed and validated to address the need to improve the current stroke risk scoring systems to more accurately predict stroke, particularly by identifying robust ethnic/race ethnicity group and country specific risk factors.

Carotid artery stenosis: cost-effectiveness of assessment of cerebrovascular reserve to guide treatment of asymptomatic patients

PURPOSE

To project and compare the lifetime health benefits, health care costs, and incremental cost-effectiveness of a decision rule based on assessment of cerebrovascular reserve (CVR) compared with medical therapy and immediate revascularization in asymptomatic patients with carotid artery stenosis for prevention of stroke.

MATERIALS AND METHODS

The three strategies compared included immediate revascularization (carotid endarterectomy) and ongoing medical therapy (with antiplatelet, statin, and antihypertensive agents plus lifestyle modification), medical therapy-based treatment with revascularization only for patients who progressed, and use of a CVR-based decision rule for treatment in which patients with CVR impairment undergo immediate revascularization and all others receive medical therapy. A decision analytic model was developed to project lifetime quality-adjusted life years (QALYs) and costs for asymptomatic patients with carotid stenosis with 70%-89% carotid luminal narrowing at presentation. Risks of clinical events, costs, and quality-of-life values were estimated on the basis of those in published sources. The analysis was conducted from a health care system perspective, with health and cost outcomes discounted at 3%. Results Total costs per person and lifetime QALYs were lowest for the medical therapy-based strategy ($14 597, 9.848 QALYs), followed by CVR testing ($16 583, 9.934 QALYs) and immediate revascularization ($20 950, 9.940 QALYs). The incremental cost-effectiveness ratio for the CVR-based strategy compared with the medical therapy-based strategy was $23 000 per QALY and for the immediate revascularization versus the CVR-based strategy was $760 000 per QALY.

RESULTS

were sensitive to variations in model inputs for revascularization costs and complication risks and baseline stroke risk.

CONCLUSION

CVR testing can be a cost-effective tool to identify asymptomatic patients with carotid stenosis who are most likely to benefit from revascularization.

Separate prediction of intracerebral hemorrhage and ischemic stroke

OBJECTIVES

To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) and ischemic stroke (IS).

METHODS

We used data on 27,493 participants from 3 population-based cohort studies: the Atherosclerosis Risk in Communities Study, median age 54 years, 45% male, median follow-up 20.7 years; the Rotterdam Study, median age 68 years, 38% male, median follow-up 14.3 years; and the Cardiovascular Health Study, median age 71 years, 41% male, median follow-up 12.8 years. Among these participants, 325 ICH events, 2,559 IS events, and 9,909 nonstroke deaths occurred. We developed 10-year cumulative incidence functions for ICH and IS using stratified Cox regression and competing risks analysis. Basic models including only established nonlaboratory risk factors were extended with diastolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, body mass index, waist-to-hip ratio, and glomerular filtration rate. The cumulative incidence functions' performances were cross-validated in each cohort separately by Harrell C-statistic and calibration plots.

RESULTS

High total cholesterol/high-density lipoprotein cholesterol ratio decreased the ICH rates but increased IS rates (p for difference across stroke types <0.001). For both the ICH and IS models, C statistics increased more by model extension in the Atherosclerosis Risk in Communities and Cardiovascular Health Study cohorts. Improvements in C statistics were reproduced by cross-validation. Models were well calibrated in all cohorts. Correlations between 10-year ICH and IS risks were moderate in each cohort.

CONCLUSIONS

We developed and cross-validated cumulative incidence functions for separate prediction of 10-year ICH and IS risk. These functions can be useful to further specify an individual's stroke risk.

Guidelines for the prevention of stroke in women: a statement for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

The aim of this statement is to summarize data on stroke risk factors that are unique to and more common in women than men and to expand on the data provided in prior stroke guidelines and cardiovascular prevention guidelines for women. This guideline focuses on the risk factors unique to women, such as reproductive factors, and those that are more common in women, including migraine with aura, obesity, metabolic syndrome, and atrial fibrillation.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council's Scientific Statement Oversight Committee and the AHA's Manuscript Oversight Committee. The panel reviewed relevant articles on adults using computerized searches of the medical literature through May 15, 2013. The evidence is organized within the context of the AHA framework and is classified according to the joint AHA/American College of Cardiology and supplementary AHA Stroke Council methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive AHA internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

We provide current evidence, research gaps, and recommendations on risk of stroke related to preeclampsia, oral contraceptives, menopause, and hormone replacement, as well as those risk factors more common in women, such as obesity/metabolic syndrome, atrial fibrillation, and migraine with aura.

CONCLUSIONS

To more accurately reflect the risk of stroke in women across the lifespan, as well as the clear gaps in current risk scores, we believe a female-specific stroke risk score is warranted.

External validation of the 2008 Framingham cardiovascular risk equation for CHD and stroke events in a European population of middle-aged men. The PRIME study

OBJECTIVE

To test the applicability of the sex-specific 2008 Framingham general cardiovascular risk equation for coronary heart disease (CHD) and stroke in European middle-aged men from Ireland and France.

METHODS

In the PRIME study, 9638 healthy middle-aged men recruited in France and Ireland were surveyed for 10 years for the occurrence of first CHD and stroke events. The original Framingham equation, the partially calibrated Framingham equation (using the PRIME baseline survival at 10 years), and the completely calibrated Framingham equation (additionally using risk factor means calculated in PRIME) were assessed. Model fit (expected versus observed events) and discrimination ability were assessed using a modified Hosmer-Lemeshow Chi-square statistic and Harrell's c-index respectively.

RESULTS

The original (uncalibrated) Framingham equation overestimated by 1.94-fold the risk of CHD and stroke combined in PRIME, and by 2.23 and 1.42-fold in PRIME-France and PRIME-Ireland respectively. Adequate fit was found after complete calibration. However, discrimination ability of the Framingham equation was poor as shown by Harrell's c-index lower than 0.70.

CONCLUSION

The (completely) calibrated 2008 Framingham equation predicted accurate number of CHD and stroke events but discriminated poorly individuals at higher from those at lower event risk in a European population of middle-aged men.

Depressive symptoms, antidepressants and disability and future coronary heart disease and stroke events in older adults: the Three City Study

To investigate the association between baseline depressive symptoms and first fatal and non fatal coronary heart disease (CHD) and stroke in older adults, taking antidepressants and disability into account. In the Three City Study, a community-based prospective multicentric observational study cohort, 7,308 non-institutionalized men and women aged ≥65 years with no reported history of CHD, stroke or dementia, completed the 20-item Center for Epidemiologic Studies depression scale (CESD) questionnaire. First CHD and stroke events during follow-up were adjudicated by an independent expert committee. Hazard ratios (HRs) were estimated by Cox proportional hazard model. After a median follow-up of 5.3 years, 338 subjects had suffered a first non-fatal CHD or stroke event, and 82 had died from a CHD or stroke. After adjustment for study center, baseline socio-demographic characteristics, and conventional risk factors, depressive symptoms (CESD ≥ 16) were associated with fatal events only: fatal CHD plus stroke (HR = 2.50; 95% CI 1.57-3.97), fatal CHD alone (n = 57; HR = 2.21 ; 95%CI 1.27-3.87), and fatal stroke alone (n = 25; HR = 3.27; 95% CI 1.42-7.52). These associations were even stronger in depressed subjects receiving antidepressants (HR = 4.17; 95% CI 1.84-9.46) and in depressed subjects with impaired Instrumental Activities of Daily Living (HR = 8.93; 95% CI 4.60-17.34). By contrast, there was no significant association with non fatal events (HR for non-fatal CHD or stroke = 0.94; 95% CI 0.66-1.33). In non-institutionalized elderly subjects without overt CHD, stroke or dementia, depressive symptoms were selectively and robustly associated with first fatal CHD or stroke events.

[Treatment of type 2 diabetes in the elderly]

Treatment of type 2 diabetes in the elderly represents a major challenge both in terms of clinical management and public health. Aging is causing a marked increase in the pandemic of diabetes in elderly people. However, scientific evidence to support the most appropriate treatment for diabetes in the elderly is scarce. Given the heterogeneity of the elderly population, which includes subjects with very different functional and cognitive capacities, co-morbidities, and life expectancy, it is critical to make a comprehensive assessment from a biopsychosocial perspective, to address the vascular risk factors integrally, and to establish individually tailored targets for glycemic control. In frail elderly or individuals with a short life expectancy, it may be reasonable to maintain HbA1c between 7.6%-8.5%. The therapeutic strategy for elderly patients with type 2 diabetes should be individualized and agreed with the patient and their caregivers, according to the objective. Improving quality of life, assuring patient safety and avoiding the adverse effects of antidiabetic treatment should be prioritized. Given the increased susceptibility of the elderly to severe hypoglycemia and its consequences, antidiabetic therapies that minimize the risk of hypoglycemic events should be selected.

Birth cohort differences in hypertension control in a Brazilian population of older elderly: the Bambuí Cohort Study of Aging (1997 and 2008)

We examined for cohort differences in hypertension control between participants in the Bambuí Cohort Study of Aging of aging born 1916-1926 and 1927-1937. Participants included hypertensive elderly aged 71-81 at baseline (n = 313) and at 11th wave follow up (n = 484). Prevalence of hypertension awareness (70.9% and 81.2%, respectively), median medical appointments in previous 12 months (2 and 3, respectively) and antihypertensive drug use (74.4% and 90.7% respectively) increased significantly from older to younger cohort. However, prevalence of appropriately controlled hypertension among those treated (< 140/< 90 mmHg) was similar in both cohorts (44.6% and 40.1%, p = 0.255). Multivariate analysis returned schooling as the only factor independently associated with appropriately controlled hypertension. Despite increased medical appointments and drug use in the recent cohort, the prevalence of appropriately controlled hypertension remained as low as in the older cohort.

Self-rated health compared with objectively measured health status as a tool for mortality risk screening in older adults: 10-year follow-up of the Bambuí Cohort Study of Aging

Interest in self-rated health (SRH) as a tool for use in disease and mortality risk screening is increasing. The authors assessed the discriminatory ability of baseline SRH to predict 10-year mortality rates compared with objectively measured health status. Principal component analysis was used to create a health score that included systolic blood pressure, presence of diabetes mellitus, body mass index, electrocardiographic parameters, B-type natriuretic peptide, and other biochemical and hematologic measures. From 1997 to 2007, a total of 474 of the 1,388 baseline participants died and 81 were lost to follow-up, yielding 11,833 person-years of observation. The adjusted hazard ratio for death was 1.74 (95% confidence interval (CI): 1.32, 2.29) for persons reporting poor health versus those reporting good health. When combined with age and sex, SRH had a C statistic to predict death equal to 0.69 (95% CI: 0.67, 0.71), which was comparable to that of the inclusive health score (C = 0.69, 95% CI: 0.67, 0.72). The addition of other parameters, such as lifestyle, physical functioning, mental symptoms, and physical symptoms, had little effect on these 2 predictive models (C = 0.71 (95% CI: 0.69, 0.73) and C = 0.71 (95% CI: 0.69, 0.74), respectively). The abilities of the SRH and the health score models to predict death decreased in parallel fashion over time. These results suggest that older adults who report poor health warrant particular attention as persons who have accumulated biologic markers of disease.

Computed tomography detection of carotid calcium and subclinical carotid atherosclerosis

Computed tomography (CT) detection of coronary calcium has become a popular technique for assessing coronary atherosclerosis. Whether CT detection of carotid calcium could similarly assess carotid atherosclerosis is unknown. We thus performed a study evaluating the feasibility of carotid calcium scoring by CT. We also looked for an association between carotid calcium and subclinical carotid atherosclerosis. Subjects (n = 876) underwent non-contrast CT scanning of their carotid arteries. Carotid calcium was quantified by the Agatston method. Stenoses were detected by subsequent CT angiography. Significant subclinical atherosclerosis was defined by the presence of a ≥30% carotid stenosis. The frequency of a ≥30% carotid stenosis was then analyzed as a function of carotid calcium scores and various cardiovascular risk factors. CT detection of carotid calcium was feasible, robust, and reliable. Significant univariate associations for a ≥30% carotid stenosis included age (P < 0.001), diabetes (P = 0.02), hypertension (P = 0.01), and the carotid calcium score (P < 0.001). Those with a ≥30% carotid stenosis exhibited a median (25th, 75th percentile) carotid calcium score of 153 (19, 489), while those without a ≥30% carotid stenosis had a median (25th, 75th percentile) carotid calcium score of 0 (0, 89). Conversely, when no carotid calcium was detected, there was a low (1%) frequency of significant carotid atherosclerosis. The frequency of a ≥30% carotid stenosis increased as the carotid calcium score increased (P < 0.001 for trend). This association remained significant after adjustment for age, hypertension, diabetes, hyperlipidemia, and tobacco use. CT detection of carotid calcium can assess the burden of carotid atherosclerosis.

The effectiveness of personalized coronary heart disease and stroke risk communication

BACKGROUND

Current guidelines recommend global risk assessment to guide vascular risk factor management; however, most provider-patient communication focuses on individual risk factors in isolation. We sought to evaluate the impact of personalized coronary heart disease and stroke risk communication on patients' knowledge, beliefs, and health behavior.

METHODS

We conducted a randomized controlled trial testing personalized risk communication based on Framingham stroke and coronary heart disease risk scores compared with a standard risk factor education. A total of 89 patients were recruited from primary care clinics and followed up for 3 months. Outcomes included the following: risk perception and worry, risk factor knowledge, risk reduction preferences and decision conflict, medication adherence, health behaviors, and blood pressure.

RESULTS

Participants had a very low understanding of numeric information, high perceived risk for stroke or myocardial infarction, and high proportion of medication nonadherence. Patients' ability to identify vascular risk factors increased with personalized risk communication (mean 1.8 additional risk factors, 95% CI 1.3-2.2) and standard risk factor education (mean 1.6 additional risk factors, 95% CI 1.1-2.1) immediately after the intervention but was not sustained at 3 months. Patients in the personalized group had less decision conflict than the standard risk factor education group over intended risk reduction strategies (5.9 vs 10.1, P = .003). There was no appreciable impact of either communication strategy on medication adherence, exercise, smoking cessation, or blood pressure.

CONCLUSIONS

Personalized risk communication was preferred by patients and had a small impact on risk reduction preferences and decision conflict but had no impact on patient beliefs or behavior compared with standard risk factor education.

Predictive accuracy of the 'Framingham's general CVD algorithm' in a Middle Eastern population: Tehran Lipid and Glucose Study

AIMS

To examine the performance of 'the Framingham's general CVD algorithm' in estimating 5-year risk of cardiovascular disease (CVD) and coronary heart disease (CHD) in an adult Middle Eastern community.

METHODS

In a population-based prospective cohort, the Tehran Lipid and Glucose Study (TLGS), CVD risk estimates were calculated for 3838 individuals (2183 women) free of CVD at baseline.

RESULTS

Over 8.6 years, there were 119 CVD (106 CHD) events among women, and 164 (137) among men aged ≥ 30 years. Standard risk factors [age, systolic blood pressure (SBP), antihypertensive treatment, total and high-density lipoprotein cholesterol, smoking and diabetes mellitus], measured at baseline, were significantly related to the incidence of CVD. The only exception, lack of significance for coefficients of SBP among women, was attributable to collinearity between age and SBP. For most risk factors, hazard ratios (HRs) for CVD were similar for the TLGS and the Framingham cohorts' participants. Few exceptions were lower HR for SBP among TLGS' women and lower HR for age among TLGS' men. The Framingham equations quite correctly discriminated participants [C statistic: CVD, 0.818 (women) and 0.774 (men); CHD: 0.822 (women) and 0.751 (men)] with good calibration (all calibration χ(2) values < 15, ps > 0.1).

DISCUSSION AND CONCLUSIONS

The Framingham's CVD algorithm was effective at ranking individuals and could be used to quantify risk and to guide preventive care in Iranian adults. For regions without established cohort, recalibration using risk factors and CVD (CHD) rates may be an effective method to develop CVD (CHD) risk prediction algorithms for local practice.

Predicting CHD risk in France: a pooled analysis of the D.E.S.I.R., Three City, PRIME, and SU.VI.MAX studies

BACKGROUND

We aimed to develop and validate a simple coronary heart disease (CHD) risk algorithm applicable to asymptomatic men and women in France, and to compare its accuracy with that of the last published version of the Framingham risk function for cardiovascular disease.

DESIGN

A pooled analysis of four French prospective general-population studies.

METHODS

The baseline and follow-up data from D.E.S.I.R., PRIME, Three City, and SU.VI.MAX studies were used. The 10-year CHD risk was estimated by the Cox proportional hazards model with candidate variables including age, gender, body mass index, waist circumference, family history of coronary heart disease, smoking status, diabetes status, systolic blood pressure, and total and high-density lipoprotein (HDL) cholesterol.

RESULTS

The study population included 22,256 subjects (61.4% men) aged (SD) 56.0 years (8.3) without a personal history of CHD at baseline. After a mean follow-up of 8.0 years (2.3), 788 first CHD events occurred, 726 in men and 62 in women. The final model included age, gender, age × gender interaction, current smoking status, diabetes status, systolic blood pressure, total and HDL cholesterol. Using this model, the number of predicted coronary events fitted that given by the 10-year Kaplan-Meier survival estimates within each decile of estimated risk (calibration). This model had fair discrimination: Harrell C-index, 0.7831 (95% CI: 0.7704-0.7957). For comparison, the recalibrated Framingham risk function had equivalent performances compared to the French risk equation.

CONCLUSION

Our 10-year French CHD risk equation based on traditional risk factors performed at least as well as the recalibrated Framingham cardiovascular disease risk function.

Impact of microalbuminuria on incident stroke: a meta-analysis

BACKGROUND AND PURPOSE

Microalbuminuria, a marker of both kidney disease and endothelial dysfunction, may be associated with global vascular risk, but the nature and magnitude of the link between microalbuminuria and incident stroke has not been clearly defined. The purpose of this study was to assess the consistency and strength of the association of microalbuminuria with risk of stroke in prospective studies using meta-analysis.

METHODS

We conducted a systematic search of electronic databases and bibliographies for studies reporting a multivariate-adjusted estimate, represented as relative risk with 95% CI, of the association between microalbuminuria and stroke risk. Studies were excluded if a majority of study participants had established kidney disease or pre-eclampsia. Estimates were combined using a random-effect model.

RESULTS

We identified 12 studies, with a total of 48 596 participants and 1263 stroke events. Overall, presence of microalbuminuria was associated with greater stroke risk (relative risk, 1.92; 95% CI, 1.61 to 2.28; P < 0.001) after adjustment for established cardiovascular risk factors. There was evidence of significant heterogeneity in the magnitude of the association across studies (P for heterogeneity < 0.001, I² = 68%), which was partially explained by differences in study population, microalbuminuria definition, and different microalbuminuria-related risk among stroke subtypes. However, in stratified analyses, microalbuminuria was associated with increased risk of subsequent stroke in all subgroups (general population, diabetics, those with known stroke).

CONCLUSIONS

Microalbuminuria is strongly and independently associated with incident stroke risk. Future studies should explore whether microalbuminuria is just a risk marker or a modifiable risk factor for stroke.