Stroke incidence and survival among middle-aged adults: 9-year follow-up of the Atherosclerosis Risk in Communities (ARIC) cohort

Thyroid Function, Cardiovascular Risk Factors, and Incident Atherosclerotic Cardiovascular Disease: The Atherosclerosis Risk in Communities (ARIC) Study

CONTEXT

Cardiovascular outcomes in mild thyroid dysfunction (treatment controversial) and moderate or severe dysfunction (treatment standard) remain uncertain.

OBJECTIVE

To examine cross-sectional and prospective associations of thyroid function with cardiovascular risk factors and events.

DESIGN

In the Atherosclerosis Risk in Communities Study, we measured concentrations of thyrotropin, free thyroxine, and total triiodothyronine (T3) in stored serum samples originally collected in 1990-1992. We used multivariable linear regression to assess cross-sectional associations of thyroid function with cardiovascular risk factors and Cox regression to assess prospective associations with cardiovascular events. Follow-up occurred through 31 December 2014.

SETTING

General community.

PARTICIPANTS

Black and white men and women from the United States, without prior myocardial infarction (MI), stroke, or heart failure.

MAIN OUTCOMES AND MEASURES

Cross-sectional outcomes were blood pressure, glycemic markers, and blood lipids. Prospective outcomes were adjudicated fatal and nonfatal MI and stroke.

RESULTS

Among 11,359 participants (57 ± 6 years, 58% women), thyroid function was more strongly associated with blood lipids than blood pressure or glycemic measures. Mean adjusted differences in low-density lipoprotein cholesterol were +15.1 (95% confidence interval: 10.5 to 19.7) and +3.2 (0.0 to 6.4) mg/dL in those with moderate/severe and mild chemical hypothyroidism, relative to euthyroidism; an opposite pattern was seen in hyperthyroidism. Similar differences were seen in triglycerides and non-high-density lipoprotein cholesterol. With a 22.5-year median follow-up, 1102 MIs and 838 strokes occurred, with similar outcomes among baseline thyroid function groups and by T3 concentrations.

CONCLUSIONS

Hypothyroidism is associated with hyperlipidemia, but the magnitude is small in mild chemical hypothyroidism, and cardiovascular outcomes are similar between thyroid function groups.

Blood Pressure and Risk of Cardiovascular Events in Patients on Chronic Hemodialysis: The CRIC Study (Chronic Renal Insufficiency Cohort)

We recently reported a linear association between higher systolic blood pressure (SBP) and risk of mortality in hemodialysis patients when SBP is measured outside of the dialysis unit (out-of-dialysis-unit-SBP), despite there being a U-shaped association between SBP measured at the dialysis unit (dialysis-unit-SBP) with risk of mortality. Here, we explored the relationship between SBP with cardiovascular events, which has important treatment implications but has not been well elucidated. Among 383 hemodialysis participants enrolled in the prospective CRIC study (Chronic Renal Insufficiency Cohort), multivariable splines and Cox models were used to study the association between SBP and adjudicated cardiovascular events (heart failure, myocardial infarction, ischemic stroke, and peripheral artery disease), controlling for differences in demographics, cardiovascular disease risk factors, and dialysis parameters. Dialysis-unit-SBP and out-of-dialysis-unit-SBP were modestly correlated (r=0.34; P<0.001). We noted a U-shaped association of dialysis-unit-SBP and risk of cardiovascular events, with the nadir risk between 140 and 170 mm Hg. In contrast, there was a linear stepwise association between out-of-dialysis-unit-SBP with risk of cardiovascular events. Participants with out-of-dialysis-unit-SBP ≥128 mm Hg (top 2 quartiles) had >2-fold increased risk of cardiovascular events compared with those with out-of-dialysis-unit-SBP ≤112 mm Hg (3rd SBP quartile: adjusted hazard ratio, 2.08 [95% confidence interval, 1.12-3.87] and fourth SBP quartile: adjusted hazard ratio, 2.76 [95% confidence interval, 1.42-5.33]). In conclusion, among hemodialysis patients, although there is a U-shaped (paradoxical) association of dialysis-unit-SBP and risk of cardiovascular disease, there is a linear association of out-of-dialysis-unit-SBP with risk of cardiovascular disease. Out-of-dialysis-unit blood pressure provides key information and may be an important therapeutic target.

Abnormal P-Wave Axis and Ischemic Stroke: The ARIC Study (Atherosclerosis Risk In Communities)

BACKGROUND AND PURPOSE

Abnormal P-wave axis (aPWA) has been linked to incident atrial fibrillation and mortality; however, the relationship between aPWA and stroke has not been reported. We hypothesized that aPWA is associated with ischemic stroke independent of atrial fibrillation and other stroke risk factors and tested our hypothesis in the ARIC study (Atherosclerosis Risk In Communities), a community-based prospective cohort study.

METHODS

We included 15 102 participants (aged 54.2±5.7 years; 55.2% women; 26.5% blacks) who attended the baseline examination (1987-1989) and without prevalent stroke. We defined aPWA as any value outside 0 to 75° using 12-lead ECGs obtained during study visits. Each case of incident ischemic stroke was classified in accordance with criteria from the National Survey of Stroke by a computer algorithm and adjudicated by physician review. Multivariable Cox regression was used to estimate hazard ratios and 95% confidence intervals for the association of aPWA with stroke.

RESULTS

During a mean follow-up of 20.2 years, there were 657 incident ischemic stroke cases. aPWA was independently associated with a 1.50-fold (95% confidence interval, 1.22-1.85) increased risk of ischemic stroke in the multivariable model that included atrial fibrillation. When subtyped, aPWA was associated with a 2.04-fold (95% confidence interval, 1.42-2.95) increased risk of cardioembolic stroke and a 1.32-fold (95% confidence interval, 1.03-1.71) increased risk of thrombotic stroke.

CONCLUSIONS

aPWA is independently associated with ischemic stroke. This association seems to be stronger for cardioembolic strokes. Collectively, our findings suggest that alterations in atrial electric activation may predispose to cardiac thromboembolism independent of atrial fibrillation.

Correlates of Dementia and Mild Cognitive Impairment in Patients With Atrial Fibrillation: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

BACKGROUND

Atrial fibrillation (AF) has been associated with faster cognitive decline and increased dementia risk. Factors associated with dementia in patients with AF have been seldom studied.

METHODS AND RESULTS

We studied 6432 individuals from the ARIC-NCS (Atherosclerosis Risk in Communities Neurocognitive Study). In 2011 to 2013, participants underwent a physical exam, echocardiography, detailed cognitive assessments, and a subset, brain magnetic resonance imaging. Dementia and mild cognitive impairment (MCI), as well as etiology of MCI/dementia, Alzheimer's disease-related or vascular, were adjudicated by an expert panel. AF was defined by study ECGs and past hospitalizations. We used logistic regression to estimate odds ratios and 95% CI of MCI/dementia by AF status and to assess cross-sectional correlates of MCI/dementia in patients with AF. Among 6432 participants, 611 (9.5%) had prevalent AF. AF was associated with increased odds of dementia and MCI (odds ratio, 95% CI, 2.25, 1.64-3.10, and 1.28, 1.04-1.56, respectively). Prevalence of Alzheimer's disease-related MCI/dementia and vascular MCI/dementia were higher in participants with AF than without AF (odds ratio, 95% CI, 1.29, 1.04-1.61, and 1.50, 0.99-2.25, respectively). In multivariable analyses, older age, lower body mass index, diabetes mellitus, stroke, and APOE genotype were associated with dementia prevalence in participants with AF. In models evaluating MCI/dementia subtypes, diabetes mellitus was associated with Alzheimer's disease-related MCI/dementia, whereas male sex and stroke were risk factors for vascular MCI/dementia.

CONCLUSIONS

In a large, community-based study, AF was associated with higher prevalence of MCI and dementia. Controlling cardiometabolic risk factors is a potential target for prevention of adverse cognitive outcomes in AF patients.

Joint Effects of GWAS SNPs in Coagulation System Confer Risk to Hypertensive Intracerebral Hemorrhage

Recent genome-wide association studies (GWAS) have identified numerous single nucleotide polymorphisms (SNPs) associated with coagulation system, including hemostatic factors and hematological phenotypes. However, few articles described the relationships between these SNPs and the risk of hemorrhagic stroke. The aim of our study was to evaluate the roles of these SNPs as risk factors and survival predictors for hemorrhagic stroke. Thirteen SNPs from GWAS in coagulation system were genotyped in a Chinese Han population including 1000 patients with hemorrhagic stroke (intracerebral hemorrhage, ICH = 743; subarachnoid hemorrhage, SAH = 257) and 1044 population-based controls. The associations between the genetics risk score (GRS) and risk of hemorrhagic stroke as well as post-stroke adverse outcomes were determined. No individual SNP was associated with the risk of hemorrhagic stroke. The GRS was calculated by summing the number of risk alleles of each SNP, and a total of 13 SNPs were included. Meanwhile, the GRS cutoffs values were defined to be close to quartiles or tertiles in control subjects. For quartiles, individuals with GRS about 8-9, 10-11, ≥12 had 1.28 (OR 1.28, 95% CI 0.98-1.68, p = 0.067)-, 1.36 (OR 1.36, 95% CI 1.04-1.79, p = 0.026)-, 1.53 (OR 1.53, 95% CI 1.13-2.07, p = 0.006)-fold increase in ICH risk compared to those with GRS ≤7, respectively; for tertiles, individuals with GRS about GRS 9-10, ≥11 had 0.98 (OR 0.98, 95% CI 0.78-1.23, p = 0.067)- and 1.26 (OR 1.26, 95% CI 1.00-1.59, p = 0.048)-fold increase in ICH risk compared to those with GRS ≤8, respectively. Further stratification analyses indicated that this association was only found in hypertensive ICH subjects. However, no statistical difference was found in the volume of hematoma, activities of daily living scale as well as hospital death in the ICH patients based on GRS values. Joint effects of SNPs associated with low coagulation factor levels might confer risk to ICH patients with hypertension. However, the clinical value on risk stratification and survival prediction was limited.

Proposed Standardized Neurological Endpoints for Cardiovascular Clinical Trials: An Academic Research Consortium Initiative

Surgical and catheter-based cardiovascular procedures and adjunctive pharmacology have an inherent risk of neurological complications. The current diversity of neurological endpoint definitions and ascertainment methods in clinical trials has led to uncertainties in the neurological risk attributable to cardiovascular procedures and inconsistent evaluation of therapies intended to prevent or mitigate neurological injury. Benefit-risk assessment of such procedures should be on the basis of an evaluation of well-defined neurological outcomes that are ascertained with consistent methods and capture the full spectrum of neurovascular injury and its clinical effect. The Neurologic Academic Research Consortium is an international collaboration intended to establish consensus on the definition, classification, and assessment of neurological endpoints applicable to clinical trials of a broad range of cardiovascular interventions. Systematic application of the proposed definitions and assessments will improve our ability to evaluate the risks of cardiovascular procedures and the safety and effectiveness of preventive therapies.

Predictive value of stroke discharge diagnoses in the Danish National Patient Register

AIMS

To determine the positive predictive values for stroke discharge diagnoses, including subarachnoidal haemorrhage, intracerebral haemorrhage and cerebral infarction in the Danish National Patient Register.

METHODS

Participants in the Danish cohort study Diet, Cancer and Health with a stroke discharge diagnosis in the National Patient Register between 1993 and 2009 were identified and their medical records were retrieved for validation of the diagnoses.

RESULTS

A total of 3326 records of possible cases of stroke were reviewed. The overall positive predictive value for stroke was 69.3% (95% confidence interval (CI) 67.8-70.9%). The predictive values differed according to hospital characteristics, with the highest predictive value of 87.8% (95% CI 85.5-90.1%) found in departments of neurology and the lowest predictive value of 43.0% (95% CI 37.6-48.5%) found in outpatient clinics.

CONCLUSIONS

The overall stroke diagnosis in the Danish National Patient Register had a limited predictive value. We therefore recommend the critical use of non-validated register data for research on stroke. The possibility of optimising the predictive values based on more advanced algorithms should be considered.

Low-level inorganic arsenic exposure and neuropsychological functioning in American Indian elders

BACKGROUND

Inorganic arsenic at high and prolonged doses is highly neurotoxic. Few studies have evaluated whether long-term, low-level arsenic exposure is associated with neuropsychological functioning in adults.

OBJECTIVES

To investigate the association between long-term, low-level inorganic arsenic exposure and neuropsychological functioning among American Indians aged 64-95.

METHODS

We assessed 928 participants in the Strong Heart Study by using data on arsenic species in urine samples collected at baseline (1989-1991) and results of standardized tests of global cognition, executive functioning, verbal learning and memory, fine motor functioning, and speed of mental processing administered during comprehensive follow-up evaluations in 2009-2013. We calculated the difference in neuropsychological functioning for a 10% increase in urinary arsenic with adjustment for sex, age, education, and study site.

RESULTS

The sum of inorganic and methylated arsenic species (∑As) in urine was associated with limited fine motor functioning and processing speed. A 10% increase in ∑As was associated with a .10 (95% CI -.20, -.01) decrease on the Finger Tapping Test for the dominant hand and a .13 decrease (95% CI -.21, -.04) for the non-dominant hand. Similarly, a 10% increase in ∑As was associated with a .15 (95% CI -.29, .00) decrease on the Wechsler Adult Intelligence Scale-Fourth Edition Coding Subtest. ∑As was not associated with other neuropsychological functions.

CONCLUSIONS

Findings indicate an adverse association between increased urinary arsenic fine motor functioning and processing speed, but not with other neuropsychological functioning, among elderly American Indians.

Refining Stroke Prediction in Atrial Fibrillation Patients by Addition of African-American Ethnicity to CHA2DS2-VASc Score

BACKGROUND

Prior studies show that African-American patients have a higher risk of stroke compared with Caucasians.

OBJECTIVES

This study hypothesized addition of African-American ethnicity to CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke, vascular disease, age 65 to 74, and female sex) score might improve stroke prediction in patients with atrial fibrillation (AF).

METHODS

Medicare claims from January 2010 to December 2012 identified patients with newly diagnosed AF. The CHA2DS2-VASc was calculated on the basis of diagnoses in claims incurred during 12 months before first AF diagnosis. Ethnicity was identified from the Beneficiary Summary File. CHA2DS2-VASc-R score was calculated by giving 1 additional point for African-American ethnicity. The primary outcome was stroke, defined by primary diagnosis on acute inpatient admissions after the initial AF diagnosis. We used proportional hazards regression to determine the relationship between stroke and the CHA2DS2-VASc or a revised CHA2DS2-VASc-R score.

RESULTS

Of 460,417 patients with AF, 390,590 (85%) were non-Hispanic whites, 31,702 (7%) were non-Hispanic African Americans, and the remainder were other non-white ethnicities. Mean age was 79.2 ± 8.0 years, with 60% females. Overall, 16,703 stroke events occurred, and 151,441 (32.7%) patients died during a mean follow-up period of 18.0 months. Compared with CHA2DS2-VASc, CHA2DS2-VASc-R score improved the fit of the model significantly as measured by the log likelihood ratio statistic (p < 0.001). Among individual risk factors in CHA2DS2-VASc-R score, only prior stroke, age ≥75 years, and female sex had a stronger association with incident stroke than African-American ethnicity.

CONCLUSIONS

In patients >65 years of age with newly diagnosed AF, the addition of ethnicity to CHA2DS2-VASc score significantly improved stroke prediction.

Increased Proximal Aortic Diameter is Associated With Risk of Cardiovascular Events and All-Cause Mortality in Blacks The Jackson Heart Study

BACKGROUND

Enlargement of the proximal aorta is associated with aortic wall tissue remodeling, including fragmentation of the elastin fibers, increased synthesis of collagen, and calcification, all of which are associated with aortic wall stiffening. We hypothesized that the proximal aortic diameter (AoD) is associated with cardiovascular events in a community-based cohort of blacks.

METHODS AND RESULTS

We investigated the associations between AoD and cardiovascular events among 3018 black participants (mean age, 55.9 years; 69% women) without past history of cardiovascular disease in the Jackson Heart Study. AoD was measured using echocardiography at the level of the sinuses of Valsalva at end diastole. Cardiovascular event was defined as incident myocardial infarction, fatal coronary artery disease, stroke, or heart failure hospitalization. Cox proportional hazards regression models were used to evaluate the association between baseline AoD and cardiovascular events. Over a median follow-up of 8.3 years, there were 258 cardiovascular events (incident rate, 10.5 per 1000 person-years). After adjustment for traditional risk factors, increased AoD was significantly associated with cardiovascular events (hazard ratio per 1-cm increase, 1.72; 95% CI, 1.10-2.69; P<0.05). Participants in the top AoD quintile had a higher incidence of cardiovascular events compared to those not in the top quintile (hazard ratio, 1.47; 95% CI, 1.11-1.94; P<0.005) after adjustment for risk factors.

CONCLUSIONS

Greater AoD was associated with an increased risk of cardiovascular events in a community-based cohort of blacks. AoD may be useful as a predictor of incident cardiovascular events and further investigation is warranted.

Ethnicity and the first diagnosis of a wide range of cardiovascular diseases: Associations in a linked electronic health record cohort of 1 million patients

BACKGROUND

While the association of ethnic group with individual cardiovascular diseases has been studied, little is known about ethnic differences in the initial lifetime presentation of clinical cardiovascular disease in contemporary populations.

METHODS AND RESULTS

We studied 1,068,318 people, aged ≥30 years and free from diagnosed CVD at baseline (90.9% White, 3.6% South Asian and 2.9% Black), using English linked electronic health records covering primary care, hospital admissions, acute coronary syndrome registry and mortality registry (CALIBER platform). During 5.7 years median follow-up between 1997-2010, 95,224 people experienced an incident cardiovascular diagnosis. 69.9% (67.2%-72.4%) of initial presentation in South Asian <60 yrs were coronary heart disease presentations compared to 47.8% (47.3%-48.3%) in White and 40.1% (36.3%-43.9%) in Black patients. Compared to White patients, Black patients had significantly lower age-sex adjusted hazard ratios (HRs) for initial lifetime presentation of all the coronary disease diagnoses (stable angina HR 0.80 (95% CI 0.68-0.93); unstable angina- 0.75 (0.59-0.97); myocardial infarction 0.49 (0.40-0.62)) while South Asian patients had significantly higher HRs (stable angina- 1.67 (1.52-1.84); unstable angina 1.82 (1.56-2.13); myocardial infarction- 1.67 (1.49-1.87). We found no ethnic differences in initial presentation with heart failure (Black 0.97 (0.79-1.20); S Asian 1.04(0.87-1.26)). Compared to White patients, Black patients were more likely to present with ischaemic stroke (1.24 (0.97-1.58)) and intracerebral haemorrhage (1.44 (0.97-2.12)). Presentation with peripheral arterial disease was less likely for Black (0.63 (0.50-0.80)) and South Asian patients (0.70 (0.57-0.86)) compared with White patients.

DISCUSSION

While we found the anticipated substantial predominance of coronary heart disease presentations in South Asian and predominance of stroke presentations in Black patients, we found no ethnic differences in presentation with heart failure. We consider the public health and research implications of our findings.

TRIAL REGISTRATION

NCT02176174, www.clinicaltrials.gov.

Relationship Between Midlife Cardiovascular Health and Late-Life Physical Performance: The ARIC Study

OBJECTIVES

To examine the association between midlife cardiovascular health and physical performance 25 years later.

DESIGN

Cohort study (Atherosclerosis Risk in Communities Study); multinomial logistic and logistic regression adjusted for demographic characteristics and clinical measures.

SETTING

Four U.S. communities: Forsyth County, North Carolina; Washington County, Maryland; Minneapolis, Minnesota; and Jackson, Mississippi.

PARTICIPANTS

Individuals aged 54.2 ± 5.8 at baseline (N = 15,744; 55% female, 27% black).

MEASUREMENTS

Cardiovascular health was measured at baseline using the American Heart Association's Life's Simple 7 (LS7) score (0-14) and LS7 component categories (poor, intermediate, ideal) for each risk factor. The Short Physical Performance Battery (SPPB) was used to quantify physical function as ordinal (0-12) and categorical (low (0-6), fair (7-9), good (10-12) outcomes.

RESULTS

Mean baseline LS7 score was 7.9 ± 2.4; 6,144 (39%) individuals returned 25 years later for the fifth ARIC examination, at which point the SPPB was administered. Of 5,916 individuals who completed the SPPB, 3,288 (50%) had good physical performance. Each 1-unit increase in LS7 score was associated with a 17% higher SPPB score (rate ratio (RR) = 1.17, 95% confidence interval (CI) = 1.15-1.19) and a 29% greater chance of having a late-life SPPB score of 10 or greater compared to SPPB score of less than 10 (RR = 1.29, 95% CI = 1.25-1.34). Ideal baseline glucose (RR = 2.53, 95% CI = 2.24-2.87), smoking (RR = 1.97, 95% CI = 1.81-2.15), blood pressure (RR = 1.70, 95% CI = 1.54-1.88), body mass index (RR = 1.51, 95% CI = 1.37-1.66), and physical activity (RR = 1.31, 95% CI = 1.20-1.43) had the strongest associations with late-life SPPB score, adjusting for other LS7 components.

CONCLUSION

Better cardiovascular health during midlife may lead better physical functioning in older age.

Statistical evaluation of adding multiple risk factors improves Framingham stroke risk score

BACKGROUND

Framingham Stroke Risk Score (FSRS) is the most well-regarded risk appraisal tools for evaluating an individual's absolute risk on stroke onset. However, several widely accepted risk factors for stroke were not included in the original Framingham model. This study proposed a new model which combines an existing risk models with new risk factors using synthesis analysis, and applied it to the longitudinal Atherosclerosis Risk in Communities (ARIC) data set.

METHODS

Risk factors in original prediction models and new risk factors in proposed model had been discussed. Three measures, like discrimination, calibration and reclassification, were used to evaluate the performance of the original Framingham model and new risk prediction model.

RESULTS

Modified C-statistics, Hosmer-Lemeshow Test and classless NRI, class NRI were the statistical indices which, respectively, denoted the performance of discrimination, calibration and reclassification for evaluating the newly developed risk prediction model on stroke onset. It showed that the NEW-STROKE (new stroke risk score prediction model) model had higher modified C-statistics, smaller Hosmer-Lemeshow chi-square values after recalibration than original FSRS model, and the classless NRI and class NRI of the NEW-STROKE model over the original FSRS model were all significantly positive in overall group.

CONCLUSION

The NEW-STROKE integrated with seven literature-derived risk factors outperformed the original FSRS model in predicting the risk score of stroke. It illustrated that seven literature-derived risk factors contributed significantly to stroke risk prediction.

Local Ancestry and Clinical Cardiovascular Events Among African Americans From the Atherosclerosis Risk in Communities Study

BACKGROUND

Local ancestry in relation to clinical cardiovascular events (CVEs) among African Americans can provide insight into their genetic susceptibility to the disease.

METHODS AND RESULTS

We examined local European ancestry (LEA) association with CVEs among 3000 African Americans from the Atherosclerosis Risk in Communities Study (ARIC). We estimated LEA using Local Ancestry Inference in adMixed Populations using Linkage Disequilibrium (LAMP-LD) and examined its association with myocardial infarction, stroke, coronary heart disease and its composite and cardiovascular disease composite using logistic regression. Genome-wide significance was achieved by 121 LEA regions in relation to myocardial infarction and 2 in relation to the cardiovascular disease composite. The LEA region downstream of 4q32.1 was significantly associated with 2 times higher odds of myocardial infarction (P=1.45×10^-6). The LEA region upstream of 6q11.1 was associated with 0.37 times lower odds of fatal coronary heart disease (P=7.34×10^-4), whereas the LEA region downstream of 21q21.1 was associated with 1.55 times higher odds of composite coronary heart disease (P=3.45×10^-4). Association of LEA with stroke was observed in the region upstream of 6p22.3 with a 1.57 times higher odds of stroke (P=9.69×10^-4). Likewise, the LEA region on 4q32.3 was associated with a 1.53 times higher odds of composite cardiovascular disease (P=3.04×10^-4). We also found 20 of the LEA regions at previously significant cardiovascular disease single-nucleotide polymorphisms to be associated with CVE in our study.

CONCLUSIONS

Future studies are needed to replicate and/or determine the causal variants driving our associations and explore clinical applications for those consistently associated with CVEs.

Stroke in Indigenous Africans, African Americans, and European Americans: Interplay of Racial and Geographic Factors

BACKGROUND AND PURPOSE

The relative contributions of racial and geographic factors to higher risk of stroke in people of African ancestry have not been unraveled. We compared stroke type and contributions of vascular risk factors among indigenous Africans (IA), African Americans (AA), and European Americans (EA).

METHODS

SIREN (Stroke Investigative Research and Educational Network) is a large multinational case-control study in West Africa-the ancestral home of 71% AA-whereas REGARDS (Reasons for Geographic and Racial Differences in Stroke) is a cohort study including AA and EA in the United States. Using harmonized assessments and standard definitions, we compared data on stroke type and established risk factors for stroke in acute stroke cases aged ≥55 years in both studies.

RESULTS

There were 811 IA, 452 AA, and 665 EA stroke subjects, with mean age of 68.0±9.3, 73.0±8.3, and 76.0±8.3 years, respectively (P<0.0001). Hemorrhagic stroke was more frequent among IA (27%) compared with AA (8%) and EA (5.4%; P<0.001). Lacunar strokes were more prevalent in IA (47.1%), followed by AA (35.1%) and then EA (21.0%; P<0.0001). The frequency of hypertension in decreasing order was IA (92.8%), followed by AA (82.5%) and then EA (64.2%; P<0.0001) and similarly for diabetes mellitus IA (38.3%), AA (36.8%), and EA (21.0%; P<0.0001). Premorbid sedentary lifestyle was similar in AA (37.7%) and EA (34.0%) but lower frequency in IA (8.0%).

CONCLUSIONS

Environmental risk factors such as sedentary lifestyle may contribute to the higher proportion of ischemic stroke in AA compared with IA, whereas racial factors may contribute to the higher proportion of hypertension and diabetes mellitus among stroke subjects of African ancestry.

Circulating ceruloplasmin, ceruloplasmin-associated genes, and the incidence of atrial fibrillation in the atherosclerosis risk in communities study

BACKGROUND

Ceruloplasmin (CP) may promote structural changes in the atrium making it more arrhythmogenic. We assessed the associations between CP, CP-associated genetic variants, and incident atrial fibrillation (AF) in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS AND RESULTS

We studied 10,059 men and women without prevalent AF aged 53 to 75years in 1996-1998 and followed through 2012. Circulating CP was measured in stored blood samples obtained in 1996-1998. Polymorphisms rs11708215 and rs13072552, previously associated with CP concentrations, were measured in 10,059 and 8829 participants respectively. AF was ascertained from study electrocardiograms, hospital discharge codes, and death certificates. Multivariable Cox models were run to study the association between circulating CP, CP-associated polymorphisms, and the incidence of AF. Over 10.5years of mean follow-up, 1357 cases of AF were identified. After adjusting for traditional risk factors and biomarkers, higher levels of circulating CP were associated with incident AF (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.11, 1.61 comparing top to bottom quartiles). Both rs11708215 and rs13072552 were significantly associated with CP levels. Presence of the CP-increasing alleles in rs11708215 and rs13072552, however, were significantly associated with lower risk of AF in whites (HR 0.84, 95%CI 0.76, 0.94, p=0.002 and HR 0.83; 95%CI 0.69, 0.99, p=0.043 respectively per CP-increasing allele in the final adjusted model) but not in African Americans.

CONCLUSIONS

Even though higher CP concentrations were associated with increased AF risk, genetic variants associated with higher CP decreased the risk of AF in whites. Our results suggest that circulating CP levels may not be causally related to risk of incident AF.

Tale of 2 Health-care Systems: Disparities in Demographic and Clinical Characteristics between 2 Ischemic Stroke Populations in Los Angeles County

BACKGROUND

Individuals who present to the emergency departments of safety-net systems often have poorly controlled risk factors due to lack of primary care. Little is known about potential differences in presenting characteristics, discharge medications, and discharge destinations of patients with acute ischemic stroke (AIS) who present to safety-net settings versus university medical centers (UMCs).

METHODS

Demographic characteristics, medical history, premorbid medication use, stroke severity, discharge medications, and discharge destination were assessed among consecutive admissions for AIS over a 2-year period at a UMC (n = 385) versus 2 university-affiliated safety-net hospitals (SNHs) (n = 346) in Los Angeles County.

RESULTS

Compared with patients presenting to the UMC, individuals admitted to the SNHs were younger, more frequently male, nonwhite, current smokers, hypertensive, and diabetic; they were less likely to take antithrombotics and statins before admission, and had worse serum lipid and glycemic markers (all P < .05). Patients admitted to the UMC trended toward more cardioembolic strokes and had higher stroke severity scores (P < .0001). At discharge, patients admitted to the SNHs were more likely to receive antihypertensive medications than do patients admitted to the UMC (P < .001), but there were no differences in prescription of antiplatelet medications or statins.

CONCLUSIONS

Individuals with AIS admitted to SNHs in Los Angeles County are younger and have poorer vascular risk factor control than their counterparts at a UMC. Discharge treatment does not vary considerably between systems. Early and more vigorous efforts at primary vascular risk reduction among patients seen at SNHs may be warranted to reduce disparities.

Lipidomic analysis of plasma in patients with lacunar infarction using normal-phase/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry

Stroke is a major cause of mortality and long-term disability worldwide. The study of biomarkers and pathogenesis is vital for early diagnosis and treatment of stroke. In the present study, a continuous-flow normal-phase/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (NP/RP 2D LC-QToF/MS) method was employed to measure lipid species in human plasma, including healthy controls and lacunar infarction (LI) patients. As a result, 13 lipid species were demonstrated with significant difference between the two groups, and a "plasma biomarker model" including glucosylceramide (38:2), phosphatidylethanolamine (35:2), free fatty acid (16:1), and triacylglycerol (56:5) was finally established. This model was evaluated as an effective tool in that area under the receiver operating characteristic curve reached 1.000 in the discovery set and 0.947 in the validation set for diagnosing LI patients from healthy controls. Besides, the sensitivity and specificity of disease diagnosis in validation set were 93.3% and 96.6% at the best cutoff value, respectively. This study demonstrates the promising potential of NP/RP 2D LC-QToF/MS-based lipidomics approach in finding bio-markers for disease diagnosis and providing special insights into the metabolism of stroke induced by small vessel disease. Graphical abstract Flow-chart of the plasma biomarker model establishment through biomarker screening and validation.

Sex Differences in the Association Between Insulin Resistance and Incident Coronary Heart Disease and Stroke Among Blacks Without Diabetes Mellitus: The Jackson Heart Study

Background

Studies exploring the association between insulin resistance (IR) and cardiovascular disease in blacks have not been conclusive, especially for coronary heart disease (CHD). The McAuley index and homeostasis model assessment of IR (HOMA‐IR) perform differently in predicting cardiovascular disease. We investigated this association in the Jackson Heart Study, a large longitudinal cohort of blacks.

Methods and Results

IR was estimated for 3565 participants without diabetes mellitus and cardiovascular disease at baseline using the McAuley index and HOMA‐IR, and their associations with incident CHD and stroke (composite outcome) were compared. A lower McAuley index and higher HOMA‐IR are indicative of IR. Cox regression analysis was used to estimate adjusted hazard ratios for incident CHD and/or stroke. There were 158 events (89 CHD‐only, 58 stroke‐only, and 11 CHD/stroke) over a median follow‐up of 8.4 years. After adjustment for demographic factors, the risk of the composite outcome decreased with each SD increase in the McAuley index (hazard ratio 0.80; 95% CI: 0.67–0.96), with no attenuation after further accounting for CHD and stroke risk factors. When considered individually, McAuley index and HOMA‐IR were associated with CHD (hazard ratio 0.71, 95% CI: 0.55–0.92 and hazard ratio 1.33, 95% CI: 1.03–1.72, respectively), but not stroke risk. The logHOMA‐IR and CHD association was present in men, but not in women (P_interaction=0.01).

Conclusions

Both HOMA‐IR and the McAuley index demonstrate strong associations with CHD but not stroke risk in blacks. The logHOMA‐IR and CHD association was present in men, but not in women.

Prehospital Systolic Hypertension and Outcomes in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

It is well known that hematoma volume and expansion is associated with poor outcomes in patients with spontaneous intracerebral hemorrhage (sICH). The factors associated with hematoma volume and possible expansion include the use of anticoagulant medications, autoimmune or bacterial diseases that reduce platelet production, and genetic defects of Von Willebrand factor causing inhibition or reduction of platelet aggregation. However, little is known about the role of elevated systolic blood pressure (SBP) on hematoma volume and its ultimate role on sICH when identified in the prehospital setting. Our objectives were to determine the prevalence of elevated SBP among diagnosed sICH patients transported by emergency medical services (EMS), and to explore possible associations between prehospital elevated SBP and hematoma volume.

METHODS

This is a hypothesis-generating study for which we used a retrospective observational design. The subjects included 243 adult patients who were seen and treated for sICH in an emergency department serving a county hospital in a large metropolitan city. Elevated SBP in the setting of sICH was defined as ≥140 mm Hg. A univariate analysis was performed to investigate associations between patient demographics, elevated SBP, and sICH characteristics with the pre-determined outcome of hematoma volume. We then performed a multivariable logistic regression model to determine if elevated prehospital SBP remained associated with hematoma volume.

RESULTS

The number of subjects with a hospital-based diagnosis of sICH was 243. Of those, 193 (79%) were transported by an ambulance. Among those transported by ambulance, 180 (93%) had a documented prehospital SBP; out of those patients with a documented SBP, 173 (96%) showed an elevated SBP of ≥140 mm Hg, and 82 (46%) had a hematoma volume of ≥30 mL. Our univariate analysis showed that sICH patients with an elevated prehospital SBP of ≥140 mm Hg were associated with hematoma volume. The multivariable regression model showed that elevated prehospital SBP (≥140 mm Hg) was associated with larger hematoma volumes (odds ratio (OR) 3.86 95% confidence interval (CI) 1.02-4.60).

CONCLUSIONS

Prehospital elevated SBP is associated with larger hematoma volume in patients with sICH. Future studies should confirm these findings in a larger cohort of patients.

Usefulness of Maintaining a Normal Electrocardiogram Over Time for Predicting Cardiovascular Health

We hypothesized that maintaining a normal electrocardiogram (ECG) status over time is associated with low cardiovascular (CV) disease in a dose-response fashion and subsequently could be used to monitor programs aimed at promoting CV health. This analysis included 4,856 CV disease-free participants from the Atherosclerosis Risk in Communities study who had a normal ECG at baseline (1987 to 1989) and complete electrocardiographic data in subsequent 3 visits (1990 to 1992, 1993 to 1995, and 1996 to 1998). Participants were classified based on maintaining their normal ECG status during these 4 visits into "maintained," "not maintained," or "inconsistent" normal ECG status as defined by the Minnesota ECG classification. CV disease events (coronary heart disease, heart failure, and stroke) were adjudicated from Atherosclerosis Risk in Communities visit-4 through 2010. Over a median follow-up of 13.2 years, 885 CV disease events occurred. The incidence rate of CV disease events was lowest among study participants who maintained a normal ECG status, followed by those with an inconsistent pattern, and then those who did not maintain their normal ECG status (trend p value <0.001). Similarly, the greater the number of visits with a normal ECG status, the lower was the incidence rate of CV disease events (trend p value <0.001). Maintaining (vs not maintaining) a normal ECG status was associated with a lower risk of CV disease, which was lower than that observed in those with inconsistent normal ECG pattern (trend p value <0.01). In conclusion, maintaining a normal ECG status over time is associated with low risk of CV disease in a dose-response fashion, suggesting its potential use as a monitoring tool for programs promoting CV health.

Understanding Neurologic Complications Following TAVR

Transcatheter aortic valve replacement is a groundbreaking treatment modality for severe, symptomatic aortic stenosis. Despite the rapid progression in indications to include intermediate-risk patients, the risk of peri-procedural stroke remains, with a higher incidence rate than previously reported. Accurate assessment of peri-procedural stroke rates requires selection of careful and meaningful trial endpoints during evaluation of neuroprotective devices. In this article, we review recommendations and stroke definitions from academic research consortiums along with device trial results.

Trajectories of Cardiovascular Risk Factors and Incidence of Atrial Fibrillation Over a 25-Year Follow-Up: The ARIC Study (Atherosclerosis Risk in Communities)

BACKGROUND

Timing and trajectories of cardiovascular risk factor (CVRF) development in relation to atrial fibrillation (AF) have not been described previously. We assessed trajectories of CVRF and incidence of AF over 25 years in the ARIC study (Atherosclerosis Risk in Communities).

METHODS

We assessed trajectories of CVRF in 2456 individuals with incident AF and 6414 matched control subjects. Subsequently, we determined the association of CVRF trajectories with the incidence of AF among 10 559 AF-free individuals (mean age, 67 years; 52% men; 20% blacks). Risk factors were measured during 5 examinations between 1987 and 2013. Cardiovascular events, including incident AF, were ascertained continuously. We modeled the prevalence of risk factors and cardiovascular outcomes in the period before and after AF diagnosis and the corresponding index date for control subjects using generalized estimating equations. Trajectories in risk factors were identified with latent mixture modeling. The risk of incident AF by trajectory group was examined with Cox models.

RESULTS

The prevalence of stroke, myocardial infarction, and heart failure increased steeply during the time close to AF diagnosis. All CVRFs were elevated in AF cases compared with controls >15 years before diagnosis. We identified distinct trajectories for all the assessed CVRFs. In general, individuals with trajectories denoting long-term exposure to CVRFs had increased AF risk even after adjustment for single measurements of the CVRFs.

CONCLUSIONS

AF patients have increased prevalence of CVRF many years before disease diagnosis. This analysis identified diverse trajectories in the prevalence of these risk factors, highlighting their different roles in AF pathogenesis.

Ischemic stroke subtypes and migraine with visual aura in the ARIC study

OBJECTIVE

To investigate the association among migraine, ischemic stroke, and stroke subtypes in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS

In this ongoing, prospective, longitudinal community-based cohort study, participants were given an interview ascertaining migraine history in 1993-1995, and were followed for all vascular events, including stroke. All stroke events over the subsequent 20 years were adjudicated and classified into stroke subtypes by standard definitions. Cox proportional hazards models adjusted for stroke risk factors were used to study the relationship between migraine and ischemic stroke, overall, as well as stroke subtypes (cardioembolic, lacunar, or thrombotic).

RESULTS

We identified 1,622 migraineurs among 12,758 participants. Mean age of the study population at the 3rd clinical visit was 59 years. When compared to nonheadache participants, there was a significant association between migraine with visual aura and ischemic stroke (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.6, p = 0.008). Migraine without visual aura was not significantly associated with ischemic stroke (HR 1.2, CI 1.0-1.8, p = 0.28) when compared to nonheadache participants. Among the 3 subtypes of ischemic stroke evaluated, migraine with visual aura was significantly associated only with cardioembolic stroke (HR 3.7, 95% CI 1.6-8.7, p = 0.003).

CONCLUSION

In participants with migraine with visual aura in late middle age, increased risk of cardioembolic stroke was observed. Migraine with visual aura was linked to increased stroke risk, while migraine without visual aura was not, over the period of 20 years. These results are specific to older migraineurs.

Prospective associations of plasma phospholipids and mild cognitive impairment/dementia among African Americans in the ARIC Neurocognitive Study

Introduction

The objective of this study was to investigate whether 10 phospholipids/metabolites previously identified as prospectively predictive of mild cognitive impairment (MCI) or dementia in whites would also be predictive in a mostly African-American cohort.

Methods

We repeatedly measured 188 phospholipids/metabolites in plasma samples of 221 participants of the Atherosclerosis Risk in Communities study, 97% African American, who were followed between 2004–2006 and 2011–2013.

Results

After a mean follow-up of 7.3 years, 77 were classified as having MCI and 18 as having dementia. Our study failed to replicate previous findings in this mostly African American cohort, in that the 10 phospholipids/metabolites only achieved a C statistic/AUC of 0.609 in predicting development of MCI or dementia (compared to 0.96) and 0.607 in distinguishing normal from MCI or dementia at the follow-up visit.

Conclusion

A panel of 10 phospholipids/metabolites previously associated with incident dementia was not predictive of MCI or dementia in an independent cohort.

Association Between Endogenous Testosterone and Cerebrovascular Disease in the ARIC Study (Atherosclerosis Risk in Communities)

BACKGROUND AND PURPOSE

Epidemiological studies in men suggest a relationship between endogenous testosterone and ischemic vascular events. We hypothesized that low testosterone is independently associated with ischemic stroke and ischemic brain changes.

METHODS

In 1558 male participants (mean [SD] age, 63.1 [5.6] years; body mass index, 28.2 [4.3] kg/m²) from visit 4 (1996-1998) of the ARIC study (Atherosclerosis Risk in Communities) without cardiovascular disease, stroke, and previous testosterone therapy, we measured plasma total testosterone by liquid chromatography mass spectrometry using morning samples and divided levels into tertiles (median [25th-75th percentile], 377.6 [288.4-480.1] ng/dL). General linear models, for cross-sectional analyses, and proportional hazards regression, for time-to-event analysis, examined the association of testosterone with participant characteristics and incident stroke through 2011. Linear and logistic regression models examined the association of testosterone with percentage white matter hyperintensities and prevalent infarcts in participants (n=257) who underwent brain magnetic resonance imaging at visit 5 (2011-2013). Analyses were adjusted for age, race, and ARIC center, body mass index, waist circumference, smoking status, diabetes mellitus, hypertension, low-density lipoprotein, and high-density lipoprotein.

RESULTS

Lower testosterone was significantly associated with higher body mass index, greater waist circumference, diabetes mellitus, hypertension, lower high-density lipoprotein, and never smoking. After adjustment, no association of testosterone with incident stroke was found (hazard ratios [95% confidence intervals] for tertile 1 or 3 versus 2, 1.47 [0.83-2.61], 1.15 [0.62-2.14]; median follow-up, 14.1 years), nor with percentage white matter hyperintensities, cortical infarcts, or subcortical infarcts.

CONCLUSIONS

After controlling for atherosclerotic risk factors, there was no association between endogenous testosterone and incident clinical stroke or ischemic brain changes in community-dwelling men.

Comparative Cost-Effectiveness of Hypertension Treatment in Non-Hispanic Blacks and Whites According to 2014 Guidelines: A Modeling Study

BACKGROUND

We compared the cost-effectiveness of hypertension treatment in non-Hispanic blacks and non-Hispanic whites according to 2014 US hypertension treatment guidelines.

METHODS

The cardiovascular disease (CVD) policy model simulated CVD events, quality-adjusted life years (QALYs), and treatment costs in 35- to 74-year-old adults with untreated hypertension. CVD incidence, mortality, and risk factor levels were obtained from cohort studies, hospital registries, vital statistics, and national surveys. Stage 1 hypertension was defined as blood pressure 140-149/90-99mm Hg; stage 2 hypertension as ≥150/100mm Hg. Probabilistic input distribution sampling informed 95% uncertainty intervals (UIs). Incremental cost-effectiveness ratios (ICERs) < $50,000/QALY gained were considered cost-effective.

RESULTS

Treating 0.7 million hypertensive non-Hispanic black adults would prevent about 8,000 CVD events annually; treating 3.4 million non-Hispanic whites would prevent about 35,000 events. Overall 2014 guideline implementation would be cost saving in both groups compared with no treatment. For stage 1 hypertension but without diabetes or chronic kidney disease, cost savings extended to non-Hispanic black males ages 35-44 but not same-aged non-Hispanic white males (ICER $57,000/QALY; 95% UI $15,000-$100,000) and cost-effectiveness extended to non-Hispanic black females ages 35-44 (ICER $46,000/QALY; $17,000-$76,000) but not same-aged non-Hispanic white females (ICER $181,000/QALY; $111,000-$235,000).

CONCLUSIONS

Compared with non-Hispanic whites, cost-effectiveness of implementing hypertension guidelines would extend to a larger proportion of non-Hispanic black hypertensive patients.

Ideal Cardiovascular Health and Incident Cardiovascular Events: The Jackson Heart Study

INTRODUCTION

The epidemiology of American Heart Association ideal cardiovascular health (CVH) metrics has not been fully examined in African Americans. This study examines the associations of CVH metrics with incident cardiovascular disease (CVD) in the Jackson Heart Study, a longitudinal cohort study of CVD in African Americans.

METHODS

Jackson Heart Study participants without CVD (n=4,702) were followed prospectively between 2000 and 2011. Incidence rates and Cox proportional hazard ratios estimated risks for incident CVD (myocardial infarction, stroke, cardiac procedures, and CVD mortality) associated with seven CVH metrics by sex. Analyses were performed in 2015.

RESULTS

Participants were followed for a median of 8.3 years; none had ideal health on all seven CVH metrics. The prevalence of ideal health was low for nutrition, physical activity, BMI, and blood pressure metrics. The age-adjusted CVD incidence rate (IR) per 1,000 person years was highest for individuals with the least ideal health metrics: zero to one (IR=12.5, 95% CI=9.7, 16.1), two (IR=8.2, 95% CI=6.5, 10.4), three (IR=5.7, 95% CI=4.2, 7.6), and four or more (IR=3.4, 95% CI=2.0, 5.9). Adjusting for covariates, individuals with four or more ideal CVH metrics had lower risks of incident CVD compared with those with zero or one ideal CVH metric (hazard ratio, 0.29; 95% CI=0.17, 0.52; p<0.001).

CONCLUSIONS

African Americans with more ideal CVH metrics have lower risks of incident CVD. Comprehensive preventive behavioral and clinical supports should be intensified to improve CVD risk for African Americans with few ideal CVH metrics.

Subarachnoid hemorrhage admissions retrospectively identified using a prediction model

OBJECTIVE

To create an accurate prediction model using variables collected in widely available health administrative data records to identify hospitalizations for primary subarachnoid hemorrhage (SAH).

METHODS

A previously established complete cohort of consecutive primary SAH patients was combined with a random sample of control hospitalizations. Chi-square recursive partitioning was used to derive and internally validate a model to predict the probability that a patient had primary SAH (due to aneurysm or arteriovenous malformation) using health administrative data.

RESULTS

A total of 10,322 hospitalizations with 631 having primary SAH (6.1%) were included in the study (5,122 derivation, 5,200 validation). In the validation patients, our recursive partitioning algorithm had a sensitivity of 96.5% (95% confidence interval [CI] 93.9-98.0), a specificity of 99.8% (95% CI 99.6-99.9), and a positive likelihood ratio of 483 (95% CI 254-879). In this population, patients meeting criteria for the algorithm had a probability of 45% of truly having primary SAH.

CONCLUSIONS

Routinely collected health administrative data can be used to accurately identify hospitalized patients with a high probability of having a primary SAH. This algorithm may allow, upon validation, an easy and accurate method to create validated cohorts of primary SAH from either ruptured aneurysm or arteriovenous malformation.

The Influence of Vascular Risk Factors and Stroke on Cognition in Late Life: Analysis of the NACC Cohort

OBJECTIVE

Vascular risk factors in mid-life predict late life cognitive decline in previously normal populations. We sought to investigate the contribution of vascular risk factors in late life to cognitive decline in a cohort of normal elderly individuals.

METHODS

Cognitively normal subjects were identified from the longitudinal cohort of participants in the National Alzheimer Coordinating Center (NACC) database (n=2975). The association between a composite score of vascular risk factors (based on the Framingham Stroke Risk Profile) and cognitive function was tested at baseline visit and estimated in longitudinal analyses using linear mixed-effects models.

RESULTS

Total vascular risk factor burden was associated with worse cognitive performance at baseline and faster decline longitudinally in univariate analyses but only with worse WAIS digit symbol performance in cross-sectional (estimate=-0.266 units/1 unit of Framingham Stroke Risk Profile Score; 95% confidence interval, -0.380 to -0.153; P<0.001) and longitudinal (estimate=-0.034 units/1 unit of Framingham Stroke Risk Profile Score/year; 95% confidence interval, -0.055 to -0.012; P=0.002) analyses after adjusting for age, education, and APOE genotype. Individuals with history of stroke performed significantly worse on the trails B, category fluency, and Boston naming tests in cross-sectional analyses and in delayed logical memory and digit span backwards in longitudinal analyses.

CONCLUSIONS

Although the modified Framingham Stroke Risk Profile in late-life predicts rate of decline on selective neurocognitive measures in previously normal elderly individuals, age appears to be the strongest risk factor for cognitive impairment in this population. History of stroke independently influences rate of cognitive decline in these individuals.

Cranial Magnetic Resonance Imaging in Elderly American Indians: Design, Methods, and Implementation of the Cerebrovascular Disease and Its Consequences in American Indians Study

The Cerebrovascular Disease and its Consequences in American Indians (CDCAI) Study recruited surviving members of a 20-year, longitudinal, population-based cohort of American Indians focused on cardiovascular disease, its risk factors, and its consequences. The goal of the CDCAI Study is to characterize the burden, risk factors, and manifestations of vascular brain injury identified on cranial MRI. The CDCAI Study investigators enrolled 1,033 participants aged 60 and older from 11 American Indian communities and tribes in the Northern Plains, Southern Plains, and Southwestern United States. In addition to cranial MRI performed according to standardized protocols, participants underwent extensive medical interview, clinical examination, neurocognitive testing, physical function evaluation, electrocardiogram, and provided blood and urine specimens. Participants also self-administered questionnaires covering demographics, quality of life, and medical history. This report describes the design, implementation, and some of the unique challenges of this study and data collection.

Risk prediction of major complications in individuals with diabetes: the Atherosclerosis Risk in Communities Study

AIMS

To develop a prediction equation for 10-year risk of a combined endpoint (incident coronary heart disease, stroke, heart failure, chronic kidney disease, lower extremity hospitalizations) in people with diabetes, using demographic and clinical information, and a panel of traditional and non-traditional biomarkers.

METHODS

We included in the study 654 participants in the Atherosclerosis Risk in Communities (ARIC) study, a prospective cohort study, with diagnosed diabetes (visit 2; 1990-1992). Models included self-reported variables (Model 1), clinical measurements (Model 2), and glycated haemoglobin (Model 3). Model 4 tested the addition of 12 blood-based biomarkers. We compared models using prediction and discrimination statistics.

RESULTS

Successive stages of model development improved risk prediction. The C-statistics (95% confidence intervals) of models 1, 2, and 3 were 0.667 (0.64, 0.70), 0.683 (0.65, 0.71), and 0.694 (0.66, 0.72), respectively (p < 0.05 for differences). The addition of three traditional and non-traditional biomarkers [β-2 microglobulin, creatinine-based estimated glomerular filtration rate (eGFR), and cystatin C-based eGFR] to Model 3 significantly improved discrimination (C-statistic = 0.716; p = 0.003) and accuracy of 10-year risk prediction for major complications in people with diabetes (midpoint percentiles of lowest and highest deciles of predicted risk changed from 18-68% to 12-87%).

CONCLUSIONS

These biomarkers, particularly those of kidney filtration, may help distinguish between people at low versus high risk of long-term major complications.

Diastolic Blood Pressure, Subclinical Myocardial Damage, and Cardiac Events: Implications for Blood Pressure Control

BACKGROUND

The optimal systolic blood pressure (SBP) treatment goal is in question, with SPRINT (Systolic Blood Pressure Intervention Trial) suggesting benefit for 120 mm Hg. However, achieving an SBP this low may reduce diastolic blood pressure (DBP) to levels that could compromise myocardial perfusion.

OBJECTIVES

This study sought to examine the independent association of DBP with myocardial damage (using high-sensitivity cardiac troponin-T [hs-cTnT]) and with coronary heart disease (CHD), stroke, or death over 21 years.

METHODS

The authors studied 11,565 adults from the ARIC (Atherosclerosis Risk In Communities) cohort, analyzing DBP and hs-cTnT associations as well as prospective associations between DBP and events.

RESULTS

Mean baseline age was 57 years, 57% of patients were female, and 25% were black. Compared with persons who had DBP between 80 to 89 mm Hg at baseline (ARIC visit 2), the adjusted odds ratio of having hs-cTnT ≥14 ng/l at that visit was 2.2 and 1.5 in those with DBP <60 mm Hg and 60 to 69 mm Hg, respectively. Low DBP at baseline was also independently associated with progressive myocardial damage on the basis of estimated annual change in hs-cTnT over the 6 years between ARIC visits 2 and 4. In addition, compared with a DBP of 80 to 89 mm Hg, a DBP <60 mm Hg was associated with incident CHD and mortality, but not with stroke. The DBP and incident CHD association was strongest with baseline hs-cTnT ≥14 ng/l (p value for interaction <0.001). Associations of low DBP with prevalent hs-cTnT and incident CHD were most pronounced among patients with baseline SBP ≥120 mm Hg.

CONCLUSIONS

Particularly among adults with an SBP ≥120 mm Hg, and thus elevated pulse pressure, low DBP was associated with subclinical myocardial damage and CHD events. When titrating treatment to SBP <140 mm Hg, it may be prudent to ensure that DBP levels do not fall below 70 mm Hg, and particularly not below 60 mm Hg.

Physical Activity, Parental History of Premature Coronary Heart Disease, and Incident Atherosclerotic Cardiovascular Disease in the Atherosclerosis Risk in Communities (ARIC) Study

Background

The effects of some atherosclerotic cardiovascular disease (ASCVD) risk factors vary according to whether an individual has a family history (FHx) of premature coronary heart disease (CHD). Physical activity (PA) is associated with reduced risk of ASCVD, but whether this association varies by FHx status is not well established.

Methods and Results

We evaluated 9996 participants free of ASCVD at baseline. FHx of premature CHD was defined as CHD occurring in a father before age 55 or mother before age 60. PA, assessed by a Baecke questionnaire, was converted into minutes/week of moderate or vigorous exercise and categorized per American Heart Association guidelines as recommended, intermediate, or poor. Incident ASCVD was defined as incident myocardial infarction, fatal CHD, or stroke. Multivariable‐adjusted Cox hazard models were used. The mean age was 54±6 years, 56% were women, and 21% of black race. Participants with and without a FHx of premature CHD reported similar levels of PA at baseline (423 versus 409 metabolic equivalents of task×min/week, respectively, P=0.852), and ≈40% of both groups met American Heart Association recommended PA levels. Over a mean follow−up of 20.9 years, there were 1723 incident ASCVD events. Compared to those with poor PA adherence to American Heart Association guidelines, participants who reported PA at recommended levels had significantly lower risk of incident ASCVD after adjustment for demographics and lifestyle factors (hazard ratio 0.84, 95% CI 0.74–0.94), but this association was not modified by FHx status (P−interaction=0.680).

Conclusions

PA was associated with a reduced risk of ASCVD among individuals with and without a FHx of premature CHD.

Advanced interatrial block and ischemic stroke: The Atherosclerosis Risk in Communities Study

OBJECTIVE

Given that recent reports have suggested left atrial disease to be an independent risk factor for ischemic stroke, we sought to examine if advanced interatrial block (aIAB) is an independent stroke risk factor.

METHODS

We examined the association between aIAB and incident ischemic stroke in 14,716 participants (mean age 54 ± 5.8 years; 55% female; 26% black) from the Atherosclerosis Risk in Communities Study (ARIC). Cases of aIAB were identified from digital ECGs recorded during the baseline ARIC visit (1987-1989) and the first 3 follow-up study visits (1990-1992, 1993-1995, and 1996-1998). Adjudicated ischemic stroke events were ascertained through December 31, 2010.

RESULTS

There were 266 (1.8%) participants who had evidence of aIAB. Over a median follow-up of 22 years, 916 (6.2%) ischemic stroke events were detected. The incidence rate (per 1,000 person-years) of ischemic stroke among those with aIAB (incidence rate 8.05, 95% confidence interval [CI] 5.7, 11.4) was more than twice the rate in those without aIAB (incidence rate 3.14, 95% CI 2.94, 3.35). In a multivariable Cox regression analysis adjusted for stroke risk factors and potential confounders, aIAB was associated with an increased risk of ischemic stroke (hazard ratio 1.63, 95% CI 1.13, 2.34). The results were consistent across subgroups of participants stratified by age, sex, and race.

CONCLUSIONS

In the ARIC, aIAB was associated with incident ischemic stroke, which strengthens the hypothesis that left atrial disease should be considered an independent stroke risk factor.

Association of injection drug use with incidence of HIV-associated non-AIDS-related morbidity by age, 1995-2014

OBJECTIVE

Incidence of HIV-associated non-AIDS (HANA) related comorbidities is increasing in HIV-infected individuals. Our objective was to estimate the risk of HANA comorbidity associated with history of injection drug use (IDU) correctly accounting for higher death rates among people who inject drugs (PWID).

DESIGN

We followed HIV-infected persons aged 25-59 years who enrolled in the Johns Hopkins HIV Clinical Cohort between 1995 and May 2014, from enrollment until HANA comorbidity diagnosis, death, age 60, or administrative censoring.

METHODS

We compared cumulative incidence ('risk'), by age, of validated diagnoses of HANA comorbidities among HIV-infected PWID and non-IDU; specifically, we considered end-stage renal disease (ESRD), end-stage liver disease (ESLD), myocardial infarction, stroke, and non-AIDS-defining cancer. We used competing risk methods appropriate to account for death, standardized to the marginal distribution of baseline covariates, and adjusted for potential differential loss-to-clinic.

RESULTS

Of 5490 patients included in this analysis, 37% reported IDU as an HIV transmission risk. By age 55 years, PWID had higher risk of ESLD [risk difference = 6.8, 95% confidence interval (CI): -1.9, 15.5] and ESRD (risk difference = 11.1, 95% CI: 1.2, 21.0) than did non-IDU. Risk of myocardial infarction and stroke were similar among PWID and non-IDU. Risk of non-AIDS-defining cancer was lower among PWID than among non-IDU (risk difference at 55 years: -4.9, 95% CI: -11.2, 1.3).

CONCLUSION

Not all HANA comorbidities occur with higher incidence in PWID compared with non-IDU. However, higher incidence of ESRD and ESLD among PWIDs highlights the importance of recognition and management of markers of these comorbidities in early stages among PWID.

Hospitalized Infection as a Trigger for Acute Ischemic Stroke: The Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

Acute triggers for ischemic stroke, which may include infection, are understudied, as is whether background cardiovascular disease (CVD) risk modifies such triggering. We hypothesized that infection increases acute stroke risk, especially among those with low CVD risk.

METHODS

Hospitalized strokes and infections were identified in the Atherosclerosis Risk in Communities (ARIC) cohort. A case-crossover design and conditional logistic regression were used to compare hospitalized infections among patients with stroke (14, 30, 42, and 90 days before stroke) with corresponding control periods 1 year and 2 years before stroke. Background CVD risk was assessed at both visit 1 and the visit most proximal to stroke, with risk dichotomized at the median.

RESULTS

A total of 1008 adjudicated incident ischemic strokes were included. Compared with control periods, hospitalized infection was more common within 2 weeks before stroke (14-day odds ratio [OR], 7.7; 95% CI, 2.1-27.3); the strength of association declined with increasing time in the exposure window before stroke (30-day OR, 5.7 [95% CI, 2.3-14.3]; 42-day OR, 4.5 [95% CI, 2.0-10.2]; and 90-day OR, 3.6 [95% CI, 2.1-6.5]). Stroke risk was higher among those with low compared with high CVD risk, with this interaction reaching statistical significance for some exposure periods.

CONCLUSIONS

These results support the hypothesis that hospitalized infection is a trigger of ischemic stroke and may explain some cryptogenic strokes. Infection control efforts may prevent strokes. CVD preventive therapies may prevent strokes if used in the peri-infection period, but clinical trials are needed.

Heart Rate Variability and Incident Stroke: The Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort.

METHODS

The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus.

RESULTS

Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus.

CONCLUSIONS

Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus.

Natriuretic Peptide and High-Sensitivity Troponin for Cardiovascular Risk Prediction in Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

Cardiovascular disease (CVD) is the major cause of morbidity and mortality in diabetes; yet, heterogeneity in CVD risk has been suggested in diabetes, providing a compelling rationale for improving diabetes risk stratification. We hypothesized that N-terminal prohormone brain natriuretic peptide (NTproBNP) and high-sensitivity troponin T may enhance CVD risk stratification beyond commonly used markers of risk and that CVD risk is heterogeneous in diabetes.

RESEARCH DESIGN AND METHODS

Among 8,402 participants without prevalent CVD at visit 4 (1996-1998) of the Atherosclerosis Risk in Communities (ARIC) study there were 1,510 subjects with diabetes (mean age 63 years, 52% women, 31% African American, and 60% hypertensive).

RESULTS

Over a median follow-up of 13.1 years, there were 540 incident fatal/nonfatal CVD events (coronary heart disease, heart failure, and stroke). Both troponin T ≥14 ng/L (hazard ratio [HR] 1.96 [95% CI 1.57-2.46]) and NTproBNP >125 pg/mL (1.61 [1.29-1.99]) were independent predictors of incident CVD events at multivariable Cox proportional hazard models. Addition of circulating cardiac biomarkers to traditional risk factors, abnormal electrocardiogram (ECG), and conventional markers of diabetes complications including retinopathy, nephropathy, and peripheral arterial disease significantly improved CVD risk prediction (net reclassification index 0.16 [95% CI 0.07-0.22]). Compared with individuals without diabetes, subjects with diabetes had 1.6-fold higher adjusted risk of incident CVD. However, participants with diabetes with normal cardiac biomarkers and no conventional complications/abnormal ECG (n = 725 [48%]) were at low risk (HR 1.12 [95% CI 0.95-1.31]), while those with abnormal cardiac biomarkers, alone (n = 186 [12%]) or in combination with conventional complications/abnormal ECG (n = 243 [16%]), were at greater risk (1.99 [1.59-2.50] and 2.80 [2.34-3.35], respectively).

CONCLUSIONS

Abnormal levels of NTproBNP and troponin T may help to distinguish individuals with high diabetes risk from those with low diabetes risk, providing incremental risk prediction beyond commonly used markers of risk.

Racial Differences in and Prognostic Value of Biomarkers of Hyperglycemia

OBJECTIVE

We compared levels and associations of traditional (fasting glucose, HbA1c) and nontraditional (fructosamine, glycated albumin, and 1,5-anhydroglucitol [1,5-AG]) biomarkers of hyperglycemia with incident cardiovascular disease (CVD), incident end-stage renal disease (ESRD), and prevalent retinopathy in black and white adults.

RESEARCH DESIGN AND METHODS

We included 10,373 participants without (8,096 white, 2,277 black) and 727 with diagnosed diabetes (425 white, 302 black) from the Atherosclerosis Risk in Communities (ARIC) Study. We used Cox proportional hazards models to compare hazards ratios of CVD and ESRD among blacks and whites from baseline (1990-1992) through 2012. We compared the odds ratios (from logistic regression) of retinopathy among blacks and whites. We tested for the interaction of each biomarker with race.

RESULTS

Median values of biomarkers were higher among blacks versus whites (all P < 0.001). Relative risks for each biomarker with incident CVD and ESRD, and odds ratios for each biomarker with prevalent retinopathy, were similar by race (all P values for interaction by race >0.10).

CONCLUSIONS

The prognostic value of HbA1c, fructosamine, glycated albumin, and 1,5-AG with incident CVD, incident ESRD, and prevalent retinopathy were similar by race. Our results support similar interpretation of HbA1c and nontraditional biomarkers of hyperglycemia among black and whites with respect to long-term complications.

Comparison of Risk Factor between Lacunar Stroke and Large Artery Atherosclerosis Stroke: A Cross-Sectional Study in China

Background

Stroke is the second most common cause of mortality in China. Although most subtypes of ischemic stroke share similar risk factors, they have different etiologies. Our study aimed to evaluate the different risk factor profiles between the stroke subtypes, lacunar infarcts (LI) and large-artery atherosclerosis (LAA), and clarify the characteristics of current acute ischemic stroke in China.

Methods

In this cross-sectional study, we analyzed the clinical characteristics of 1982 patients with acute ischemic stroke who were admitted to the neurology department at the Peking University First Hospital between 2007 and 2014. Ischemic stroke was further classified into LAA, LI, cardioembolism (CE) and undetermined causes of infarction (UDI) according to TOAST classification. Demographic characteristics, risk factors, as well as the findings of laboratory and imaging tests of 1773 patients with LAA and LI, were analyzed by univariate and multivariate logistic analysis.

Results

Of the 1982 ischemic stroke patients included in this study, 1207 were diagnosed with LAA, 566 with LI, 173 with cardioembolism (CE) and 36 with undetermined causes of infarction (UDI). By comparing the risk factors in multivariate logistic regression analysis, hypertension [odds ratio (OR) = 1.832] and white matter leukoaraiosis (WML) (OR = 1.865) were found to be more strongly correlated with LI than LAA. Low density lipoprotein- cholesterol (LDL-c) (OR = 0.774) were more strongly related to LAA than LI.

Conclusions

This study found that hypertension and WML were more strongly correlated with LI than LAA. LDL-c was more strongly related to LAA than LI.

Age dependency of ischaemic stroke subtypes and vascular risk factors in western Norway: the Bergen Norwegian Stroke Cooperation Study

OBJECTIVES

Age dependency of acute ischaemic stroke aetiology and vascular risk factors have not been adequately evaluated in stroke patients in Norway. Aims of this study were to evaluate how stroke subtypes and vascular risk factors vary with age in a western Norway stroke population.

MATERIALS AND METHODS

Patients aged 15-100 years consecutively admitted to our neurovascular centre with acute ischaemic stroke between 2006 and 2012 were included. The study population was categorized as young (15-49 years), middle-aged (50-74 years) or elderly (≥ 75 years). Stroke aetiology was defined by TOAST criteria. Risk factors and history of cardiovascular disease were recorded.

RESULTS

In total, 2484 patients with acute cerebral infarction were included: 1418 were males (57.3%). Mean age was 70.8 years (SD ± 14.9), 228 patients were young, 1126 middle-aged, and 1130 were elderly. The proportion of large-artery atherosclerosis and of small-vessel occlusion was highest among middle-aged patients. The proportion of cardioembolism was high at all ages, especially among the elderly. The proportion of stroke of other determined cause was highest among young patients. Some risk factors (diabetes mellitus, active smoking, angina pectoris, prior stroke and peripheral artery disease) decreased among the elderly. The proportions of several potential causes increased with age.

CONCLUSION

The proportion of stroke subtypes and vascular risk factors are age dependent. Age 50-74 years constitutes the period in life where cardiovascular risk factors become manifest and stroke subtypes change.

Association of Smoking, Alcohol, and Obesity with Cardiovascular Death and Ischemic Stroke in Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study and Cardiovascular Health Study (CHS)

Atrial fibrillation (AF) is associated with an increased risk of ischemic stroke and cardiovascular (CV) death. Whether modifiable lifestyle risk factors are associated with these CV outcomes in AF is unknown. Among Atherosclerosis Risk in Communities (ARIC) study and Cardiovascular Health Study (CHS) participants with incident AF, we estimated the risk of composite endpoint of ischemic stroke or CV death associated with candidate modifiable risk factor (smoking, heavy alcohol consumption, or high body mass index [BMI]), and computed the C-statistic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) of incorporating each factor into the CHA₂DS₂-VASc. Among 1222 ARIC (mean age: 63.4) and 756 CHS (mean age: 79.1) participants with incident AF, during mean follow-up of 6.9 years and 5.7 years, there were 332 and 335 composite events respectively. Compared with never smokers, current smokers had a higher incidence of the composite endpoint in ARIC [HR: 1.65 (1.21–2.26)] but not in CHS [HR: 1.05 (0.69–1.61)]. In ARIC, the addition of current smoking did not improve risk prediction over and above the CHA₂DS₂-VASc. No significant associations were observed with alcohol consumption or BMI with CVD outcomes in AF patients from either cohort. Smoking is associated with an increased risk of ischemic stroke or CV death in ARIC, which comprised mostly middle-aged to young-old (65–74 years), but not in CHS, which comprised mostly middle-old or oldest-old (≥75 years) adults with AF. However, addition of smoking to the CHA₂DS₂-VASc score did not improve risk prediction of these outcomes.

Association of 1,5-Anhydroglucitol With Cardiovascular Disease and Mortality

In diabetes, low concentrations of the biomarker 1,5-anhydroglucitol (1,5-AG) reflect hyperglycemic excursions over the prior 1-2 weeks. To the extent that hyperglycemic excursions are important in atherogenesis, 1,5-AG may provide independent information regarding cardiovascular risk. Nonetheless, few studies have evaluated associations of 1,5-AG with long-term cardiovascular outcomes in a population-based setting. We measured 1,5-AG in 11,106 participants in the Atherosclerosis Risk in Communities (ARIC) study without cardiovascular disease at baseline (1990-1992) and examined prospective associations with coronary heart disease (n = 1,159 events), ischemic stroke (n = 637), heart failure (n = 1,553), and death (n = 3,120) over 20 years of follow-up. Cox proportional hazards models were adjusted for demographic and cardiovascular risk factors. Compared with persons with 1,5-AG ≥6 μg/mL and no history of diabetes, persons with diabetes and 1,5-AG <6.0 μg/mL had an increased risk of coronary heart disease (HR 3.85, 95% CI 3.11-4.78), stroke (HR 3.48, 95% CI 2.66-4.55), heart failure (HR 3.50, 95% CI 2.93-4.17), and death (HR 2.44, 95% CI 2.11-2.83). There was a threshold effect, with little evidence for associations at "nondiabetic" concentrations of 1,5-AG (e.g., >10 μg/mL). Associations remained but were attenuated with additional adjustment for fasting glucose or HbA1c. These data add to the growing evidence for the prognostic value of 1,5-AG for long-term complications in the setting of diabetes.

Individual components of the Romhilt-Estes left ventricular hypertrophy score differ in their prediction of cardiovascular events: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

It has been recently reported that the Romhilt-Estes (R-E) score, originally proposed for detection of left ventricular hypertrophy from the electrocardiogram, is a strong predictor of all-cause mortality. Whether the R-E score is also predictive of cardiovascular disease (CVD) and whether its individual components differ in their ability to predict different CVD outcomes are not well established.

METHODS

This analysis includes 13,261 participants from the ARIC study who were free of CVD at baseline (1987-1989). Incident CVD, coronary heart disease (CHD), heart failure (HF), and stroke were ascertained by an adjudication committee through December 2010. The R-E left ventricular hypertrophy score was measured from automatically processed baseline electrocardiogram data. Cox proportional hazard models were used to examine the association between baseline the R-E overall score (overall) and each of its 6 individual components separately, with each of the CVD outcomes.

RESULTS

During a median follow-up of 21.8 years, 3,579, 2,205, 1,814, and 731 CVD, CHD, HF, and stroke events, respectively, occurred. In multivariable adjusted models, R-E score ≥4 points (compared with 0 points) was associated with increased risk of CVD, CHD, HF, and stroke (hazard ratio [95% CI] 1.66 [1.41-1.96], 1.66 [1.34-2.07], 1.97 [1.60-2.43], and 1.49 [1.07-2.07], respectively). The 6 component of the R-E score varied in their relationship to different CVD outcomes.

CONCLUSIONS

The R-E score is predictive of CVD outcomes. The 6 R-E score components differ in their associations with different CVD outcomes, indicating that they may be electrical biomarkers of different physiological events within the myocardium.