Incremental value of ABI and CAC beyond traditional risk markers in long-term prediction of cardiovascular disease incidence in participants with diabetes and impaired fasting glucose: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Subclinical atherosclerosis (SA) diagnosis is key to primary prevention of atherosclerotic cardiovascular disease (ASCVD). SA is common among diabetics. Ankle brachial index (ABI) and coronary artery calcium (CAC) are markers of SA. This study examined whether adding ABI and CAC to diabetic individuals improved ASCVD risk prediction beyond established risk factors.

METHODS

MESA is an observational cohort of 6814 participants without clinical cardiovascular disease. All participants with diabetes and impaired fasting glucose were included in the analysis. The association between CAC, ABI, and incident ASCVD, and all-cause mortality was examined using Cox proportional hazard regression. The risk prediction models including ABI and/or CAC in addition to standard risk factors alone were compared.

RESULTS

Of the 1719 participants, 55% were male and average age was 64 (±9.6) years old. Participants with diabetes or impaired fasting glucose with higher CAC and lower ABI had higher ASCVD and all-cause mortality. ABI and CAC enhanced ASCVD discrimination over standard risk factors, with C-index (95% CI) of 0.689 (0.66, 0.718) for risk factors alone, 0.696 (0.668, 0.724) for ABI, 0.719 (0.691, 0.747) for CAC, and 0.721 (0.693, 0.749) for CAC + ABI. Similarly, for all-cause mortality, both CAC and ABI improved risk discrimination in addition to standard risk factors alone.

CONCLUSIONS

In a large population-based study of individuals with diabetes or impaired fasting glucose, the addition of ABI and CAC to conventional risk factors improved 10-year ASCVD risk prediction. ABI and CAC are non-invasive and cost-effective tests; therefore, these markers should be included into ASCVD risk stratification for primary prevention in the diabetic and impaired fasting glucose population.

Racial Disparities in Incident and Recurrent Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis

Most prior studies of cardiovascular (CVD) events have focused on incident events. We analyzed differences by race/ethnicity in incident and recurrent CVD events in the Multi-Ethnic Study of Atherosclerosis from baseline in 2000-2002 through 2019 using joint and multivariable adjusted Cox proportional hazards modeling. Among 6,814 men and women aged 45-85 years without known CVD at enrollment, during median follow up of 17.7 years, 1206 incident and 695 recurrent CVD events were observed; 891 individuals with a non-fatal incident event were at risk for recurrent events. Rates of combined incident and recurrent CVD events among Black, White, Chinese, and Hispanic participants were 16.8, 18.6, 13.3, and 19.3 per 1000 person-years, respectively. First recurrent CVD event rates in Black, White, Chinese, and Hispanic participants were 87.7, 68.7, 78.1, and 80.7 per 1000 person-years, respectively. Revascularization rates were lower in Black versus White participants (3.8 vs 6.4 per 1000 person-years, p<0.0001). Adjusted hazard for CVD mortality was higher for Black vs. White participants (hazard ratio 1.85; 95% CI: 1.03, 3.29). In this multi-ethnic cohort, Black participants had a lower or similar rate of incident and recurrent CVD events, lower rate of revascularization, and higher rate of fatal CVD compared to White participants.

Abstract 598: Carotid Artery Ultrasound Texture, Cardiovascular Risk Factors, and Subclinical Arterial Disease: The Multi-Ethnic Study of Atherosclerosis (Mesa)

Background: Ultrasound texture “contrast” can be used to characterize the arterial wall non-invasively. Texture contrast provides information about the distribution and gray level differences of the pixels in the arterial wall and may describe early changes related to arterial injury. We determined if ultrasound texture contrast was associated with cardiovascular disease (CVD) risk factors and subclinical arterial disease.

Methods: We evaluated ultrasound images of the distal right common carotid artery from a convenience sample of 151 participants from the first examination of the Multi-Ethnic Study of Atherosclerosis, a population-based cohort of individuals without clinical CVD. Images were digitized, normalized, and standardized to a pixel density of 20/mm. Plaque texture analysis software (LifeQ Medical, Cyprus) used the gray level difference statistics method to determine the contrast of the far wall of the carotid intima-media complex. Multivariable linear regression models (adjusted for age, sex and race/ethnicity) were used to examine relationships between contrast, CVD risk factors (age, BMI, total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol, triglycerides, hypertension, diabetes mellitus, smoking, glomerular filtration rate, C-reactive protein, interleukin-6, D-dimer, fibrinogen, alcohol consumption, education level, physical activity level, statin use), carotid intima-media thickness (IMT), coronary artery calcium (CAC), and CVD risk score.

Results: The 151 participants were mean (standard deviation) 68.1 (9.2) years old (54% female; 31% Hispanic, 28% Black, 10% Chinese, and 31% White). In models that included age, sex, and race, contrast was associated independently with age (beta [standard error] -0.9 [0.4] per year; p=0.02), HDL-C (0.6 [0.2] per mg/dL; p=0.02), C-reactive protein (-2.3 [0.9] per mg/L; p=0.02), and carotid IMT (-1.3 [0.4] microns; p=0.001). Other CVD risk factors and CAC were not associated independently with contrast.

Conclusions: Lower contrast, an ultrasound texture feature, is associated with increasing age, lower HDL-C, higher CRP, and higher carotid IMT, supporting its potential use for evaluating arterial injury and CVD risk.

Semi-parametric Estimation of Biomarker Age Trends with Endogenous Medication Use in Longitudinal Data

In cohort studies, non-random medication use can pose barriers to estimation of the natural history trend in a mean biomarker value-namely, the association between a predictor of interest and a biomarker outcome that would be observed in the total absence of biomarker-specific treatment. Common causes of treatment and outcomes are often unmeasured, obscuring our ability to easily account for medication use with assumptions commonly invoked in causal inference such as conditional ignorability. Further, without a high degree of confidence in the availability of a variable satisfying the exclusion restriction, use of instrumental variable approaches may be difficult to justify. Heckman's hybrid model with structural shift (sometimes referred to less specifically as the treatment effects model) can be used to correct endogeneity bias via a homogeneity assumption (i.e., that average treatment effects do not vary across covariates) and parametric specification of a joint model for the outcome and treatment. In recent work, we relaxed the homogeneity assumption by allowing observed covariates to serve as treatment effect modifiers. While this method has been shown to be reasonably robust in settings of cross-sectional data, application of this methodology to settings of longitudinal data remains unexplored. We demonstrate how the assumptions of the treatment effects model can be extended to accommodate clustered data arising from longitudinal studies. Our proposed approach is semi-parametric in nature in that valid inference can be obtained without the need to specify any component of the longitudinal correlation structure. As an illustrative example, we use data from the Multi-Ethnic Study of Atherosclerosis to evaluate trends in low-density lipoprotein by age and gender. Results from a collection of simulation studies, as well as our illustrative example, confirm that our generalization of the treatment effects model can serve as a useful tool to uncover natural history trends in longitudinal data that are obscured by endogenous treatment.

Associations of Abdominal Muscle Density and Area and Incident Cardiovascular Disease, Coronary Heart Disease, and Stroke: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Muscle density is inversely associated with all-cause mortality, but associations with cardiovascular disease (CVD) risk are not well understood. This study evaluated the association between muscle density and muscle area and incident total CVD, coronary heart disease (CHD), and stroke in diverse men and women.

METHODS AND RESULTS

Adult participants (N=1869) in the Multi-Ethnic Study of Atherosclerosis Ancillary Body Composition Study underwent computer tomography scans of the L2-L4 region of the abdomen. Muscle was quantified by density (Hounsfield units) and area in cm2. Sex-stratified Cox proportional hazard models assessed associations between incident total CVD, incident CHD, and incident stroke across sex-specific percentiles of muscle area and density, which were entered simultaneously into the model. Mean age for men and women at baseline were 64.1 and 65.1 years, respectively, and median follow-up time was 10.3 years. For men, associations between muscle density and incident CVD were inverse but not significant in fully adjusted models (P trend=0.15). However, there was an inverse association between density and CHD (P trend=0.02; HR, 0.26 for 95th versus 10th percentile), and no association with stroke (P trend=0.78). Conversely, for men, there was a strong positive association between muscle area and incident CVD (HR, 4.19 for 95th versus 10th percentile; P trend<0.001). Associations were stronger for CHD (HR, 6.18 for 95th versus 10th percentile; P trend<0.001), and null for stroke (P trend=0.67). Associations for women were mostly null.

CONCLUSIONS

For men, abdominal muscle density is associated with lower CHD risk, whereas greater muscle area is associated with markedly increased risk of CHD.

Pulmonary arterial hypertension treatment: an individual participant data network meta-analysis

BACKGROUND AND AIMS

Effective therapies that target three main signalling pathways are approved to treat pulmonary arterial hypertension (PAH). However, there are few large patient-level studies that compare the effectiveness of these pathways. The aim of this analysis was to compare the effectiveness of the treatment pathways in PAH and to assess treatment heterogeneity.

METHODS

A network meta-analysis was performed using individual participant data of 6811 PAH patients from 20 Phase III randomized clinical trials of therapy for PAH that were submitted to the US Food and Drug Administration. Individual drugs were grouped by the following treatment pathways: endothelin, nitric oxide, and prostacyclin pathways.

RESULTS

The mean (±standard deviation) age of the sample was 49.2 (±15.4) years; 78.4% were female, 59.7% had idiopathic PAH, and 36.5% were on background PAH therapy. After covariate adjustment, targeting the endothelin + nitric oxide pathway {β: 43.7 m [95% confidence interval (CI): 32.9, 54.4]}, nitric oxide pathway [β: 29.4 m (95% CI: 22.6, 36.3)], endothelin pathway [β: 25.3 m (95% CI: 19.8, 30.8)], and prostacyclin pathway [oral/inhaled β: 19.1 m (95% CI: 14.2, 24.0), intravenous/subcutaneous β: 24.4 m (95% CI: 15.1, 33.7)] significantly increased 6 min walk distance at 12 or 16 weeks compared with placebo. Treatments also significantly reduced the likelihood of having clinical worsening events. There was significant heterogeneity of treatment effects by age, body mass index, hypertension, diabetes, and coronary artery disease.

CONCLUSIONS

Drugs targeting the three traditional treatment pathways significantly improve outcomes in PAH, with significant treatment heterogeneity in patients with some comorbidities. Randomized clinical trials are warranted to identify the most effective treatment strategies in a personalized approach.

Predictors of outcome after endovascular treatment of cerebral vasospasm

BACKGROUND AND PURPOSE

Angioplasty and intra-arterial papaverine are promising treatments for severe symptomatic vasospasm after subarachnoid hemorrhage (SAH), but there is little information on the clinical factors that predict treatment outcome. We sought to determine variables for predicting functional outcome in this setting.

METHODS

We reviewed 81 consecutive patients with symptomatic cerebral vasospasm from aneurysmal SAH treated with percutaneous balloon angioplasty or selective intra-arterial papaverine infusion between 1990 and 2000 (105 procedures). Logistic regression analysis was used to assess the effect of various clinical and angiographic factors on outcome.

RESULTS

Mean patient age was 54 years (range, 29-88 years). Twenty-nine patients (36%) presented with poor-grade (World Federation of Neurologic Surgeons [WFNS] grade IV or V) SAH. Clinical deficits were global in 55 patients (70%), and angiographic vasospasm was diffuse in 53 (65%). Endovascular treatment consisted of transluminal angioplasty alone (18 procedures, 17%), intra-arterial papaverine infusion (65 procedures, 62%), or both (22 procedures, 21%). Unequivocal arterial dilatation was achieved in all but two patients, and major complications occurred in 2% of the procedures. Ten patients (12%) died in the hospital, and 36 (44%) recovered poorly. Permanent deficits attributable to cerebral vasospasm were present in 37 patients (52% of survivors). On multivariate logistic regression analysis, advanced age and poor WFNS grade at presentation were predictive of poor clinical outcome.

CONCLUSION

Advanced age and poor clinical status at the time of SAH onset are predictive of poor clinical outcome despite endovascular treatment with angioplasty or intra-arterial papaverine in patients with symptomatic vasospasm.

Risk factor associations with individual myocardial infarction subtypes and acute non-ischemic myocardial injury in the Multi-Ethnic Study of Atherosclerosis (MESA): Design and rationale

BACKGROUND

Despite different prevalence, pathobiology, and prognosis between etiologically distinct myocardial infarction (MI) subtypes, prospective study of risk factor for MI in large NHLBI-sponsored cardiovascular cohorts is limited to acute MI as a singular entity. Therefore, we sought to utilize the Multi-Ethnic Study of Atherosclerosis (MESA), a large prospective primary prevention cardiovascular study, to define the incidence and risk factor profile of individual myocardial injury subtypes.

METHODS

We describe the rationale and design of re-adjudicating 4,080 events that occurred over the first 14 years of follow-up in MESA for the presence and subtype of myocardial injury as defined by the Fourth Universal Definition of MI: MI type 1 to 5, acute non-ischemic myocardial injury, and chronic myocardial injury. The project utilizes a 2-physician adjudication process via examination of medical records, abstracted data collection forms, cardiac biomarker results, and electrocardiograms of all relevant clinical events. Comparison of the magnitude and direction of associations between baseline traditional and novel cardiovascular risk factors with incident and recurrent acute MI subtypes and acute non-ischemic myocardial injury events will be made.

CONCLUSIONS

This project will result in one of the first large prospective cardiovascular cohort with modern classification of acute MI subtypes, as well as a full accounting of non-ischemic myocardial injury events, with implications for numerous ongoing and future studies in MESA. By creating precise MI phenotypes, and defining their epidemiology, this project will allow for discovery of novel pathobiology-specific risk factors, allow for development of more accurate risk prediction, and suggest more targeted preventive strategies.

Heterogeneity of treatment effects by risk in pulmonary arterial hypertension

BACKGROUND

It is currently unknown if disease severity modifies response to therapy in pulmonary arterial hypertension (PAH). We aimed to explore if disease severity, as defined by established risk-prediction algorithms, modified response to therapy in randomised clinical trials in PAH.

METHODS

We performed a meta-analysis using individual participant data from 18 randomised clinical trials of therapy for PAH submitted to the United States Food and Drug Administration to determine if predicted risk of 1-year mortality at randomisation modified the treatment effect on three outcomes: change in 6-min walk distance (6MWD), clinical worsening at 12 weeks and time to clinical worsening.

RESULTS

Of 6561 patients with a baseline US Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL 2.0) score, we found that individuals with higher baseline risk had higher probabilities of clinical worsening but no difference in change in 6MWD. We detected a significant interaction of REVEAL 2.0 risk and treatment assignment on change in 6MWD. For every 3-point increase in REVEAL 2.0 score, there was a 12.49 m (95% CI 5.86-19.12 m; p=0.001) greater treatment effect in change in 6MWD. We did not detect a significant risk by treatment interaction on clinical worsening with most of the risk-prediction algorithms.

CONCLUSIONS

We found that predicted risk of 1-year mortality in PAH modified treatment effect as measured by 6MWD, but not clinical worsening. Our findings highlight the importance of identifying sources of treatment heterogeneity by predicted risk to tailor studies to patients most likely to have the greatest treatment response.

Discrimination, Smoking, and Cardiovascular Disease Risk: A Moderated Mediation Analysis With MESA

BACKGROUND

Carotid intima-media thickness (cIMT) and carotid plaque are reliable indicators of cardiovascular disease risk, and research highlights that racial and ethnic minority individuals generally exhibit higher cIMT and carotid plaque than White individuals. At present, the mechanisms driving these disparities among different racial and ethnic and biological sex groups are poorly understood.

METHODS AND RESULTS

Data came from the baseline examination of MESA (Multi-Ethnic Study of Atherosclerosis). A total of 6814 participants aged 45 to 84 years free of clinical cardiovascular disease completed assessments on health behavior and perceived discrimination. Four sex-stratified moderated mediation models examined associations between discrimination, cigarette smoking, and mean cIMT and plaque. We hypothesized that cigarette use would mediate the association between discrimination and carotid artery disease features, and that these would differ by race and ethnicity. Indirect effects of discrimination on plaque were observed among Hispanic women such that discrimination was associated with cigarette use and, in turn, higher plaque (β=0.04 [95% CI, 0.01-0.08]). Indirect effects of discrimination on mean cIMT were found among Hispanic (β=0.003 [95% CI, 0.0001-0.007]) and White men (β=0.04 [95% CI, 0.01-0.08]) such that discrimination was associated with cigarette use and, in turn, higher cIMT. Finally, a positive indirect effect of discrimination on plaque was observed among Hispanic men (β=0.03 [95% CI, 0.004-0.07]). No other racial and ethnic differences were observed.

CONCLUSIONS

To understand and address social determinants of cardiovascular disease, researchers must incorporate an intersectional framework that will allow us to understand the complex nature of discrimination and cardiovascular disease risk for individuals of varying intersecting identities and social positions.

Cardiovascular Risks and Outcomes Among Chinese American Immigrants: Insights From the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Immigrants experience changes in cardiovascular risk factors and racial disparities in both cardiovascular health prevention and outcomes upon immigration. We aimed to examine cardiovascular risk factors and outcomes among Chinese American immigrants enrolled in the MESA (Multi-Ethnic Study of Atherosclerosis) cohort.

METHODS AND RESULTS

We analyzed data from 746 Chinese American immigrants in the MESA study with a median follow-up period of 17.8 years. The mean age of the cohort was 62.3 years, with 52.7% being women. Kaplan-Meier curves and Cox proportional hazards models were used to assess the association of immigration history, geographic location, biomarkers, and cardiac imaging parameters with cardiovascular risk factors and cardiovascular outcomes. The Cox hazards models were adjusted for known family history of heart disease, education level, sex, diabetes, hypertension, age, and body mass index. Although immigration history categorized as earlier (<20 years) versus later (≥20 years) showed no association with cardiovascular outcomes, the duration of residence in the United States emerged as a strong predictor for an increased risk of cardiovascular disease death (hazard ratio 1.39 [95% CI, 1.07-1.8]; P=0.012). All-cause mortality differed significantly between the Chinese immigrants from Los Angeles and those from Chicago, with higher survival probability in Chicago (log-rank test, P=0.018). Furthermore, elevated levels of N-terminal pro-brain natriuretic peptide levels, left ventricular mass, and coronary artery calcium scores were associated with the risk of cardiovascular disease among Chinese immigrants.

CONCLUSIONS

Within the MESA cohort, the duration of residence and geographic location were associated with the risk of cardiovascular disease outcomes among Chinese immigrants.

Deep phenotyping of dementia in a multi-ethnic cardiovascular cohort: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Our understanding of the specific aspects of vascular contributions to dementia remains unclear.

OBJECTIVES

We aim to identify the correlates of incident dementia in a multi-ethnic cardiovascular cohort.

METHODS

A total of 6806 participants with follow-up data for incident dementia were included. Probable dementia diagnoses were identified using hospitalization discharge diagnoses according to the International Classification of Diseases Codes (ICD). We used Random Forest analyses to identify the correlates of incident dementia and cognitive function from among 198 variables collected at the baseline MESA exam entailing demographic risk factors, medical history, anthropometry, lab biomarkers, electrocardiograms, cardiovascular magnetic resonance imaging, carotid ultrasonography, coronary artery calcium and liver fat content. Death and stroke were considered competing events.

RESULTS

Over 14 years of follow-up, 326 dementia events were identified. Beyond age, the top correlates of dementia included coronary artery calcification, high sensitivity troponin, common carotid artery intima to media thickness, NT-proBNP, physical activity, pulse pressure, tumor necrosis factor-α, history of cancer, and liver to spleen attenuation ratio from computed tomography. Correlates of cognitive function included income and physical activity, body size, serum glucose, glomerular filtration rate, measures of carotid artery stiffness, alcohol use, and inflammation indexed as IL-2 and TNF soluble receptors and plasmin-antiplasmin complex.

CONCLUSION

In a deeply phenotyped cardiovascular cohort we identified the key correlates of dementia beyond age as subclinical atherosclerosis and myocyte damage, vascular function, inflammation, physical activity, hepatic steatosis, and history of cancer.

Incidental Coronary Artery Calcium on Chest CT in Persons Without Known Atherosclerotic Cardiovascular Disease

This cross-sectional study examines the expected prevalence of coronary artery calcium (CAC) on chest computed tomography (CT) in people without clinical atherosclerotic cardiovascular disease (ASCVD) by age, sex, and race and ethnicity.

Density of Calcified Coronary Artery Plaque and Risk of Incident Atrial Fibrillation (from the Multiethnic Study of Atherosclerosis)

Elevated coronary artery calcium (CAC) score, as assessed by the Agatston method, is associated with incident atrial fibrillation (AF). We aimed to evaluate the associations of CAC volume and density with incident AF. Participants from the Multiethnic Study of Atherosclerosis without baseline AF and CAC &amp;gt;0 were included. The associations between baseline and progression (average annual change) of CAC measures and incident AF were evaluated using Cox proportional hazards models. CAC volume and Agatston scores were natural log (ln)-transformed, and hazard ratios (HRs) were calculated per standard deviation increment. The baseline analysis included 3,332 participants; 2,643 were included in the progression analysis. In multivariable models adjusted for cardiovascular risk factors, volume (HR 1.24, 95% confidence interval [CI] 1.14 to 1.36), density (HR 1.14, 95% CI 1.05 to 1.25), and Agatston score (HR 1.24, 95% CI 1.14 to 1.35) were associated with increased risk of incident AF. In models including both volume and density, the magnitude of association between volume and incident AF was unchanged, whereas the density association was eliminated (HR 0.99, 95% CI 0.89 to 1.11). Median time to follow-up CAC assessment was 1.9 (interquartile range 1.3, 3.0) years. Similar results were observed for the association of incident AF with annual change in volume and Agatston score. CAC volume, but not density, is associated with risk for incident AF when adjusting for both. In conclusion, our findings suggest that, although CAC may be a risk marker for AF, the association between CAC and AF appears to be independent of plaque density.

Impact of Nonalcoholic Hepatic Steatosis on the Warranty Period of a Coronary Artery Calcium Score of 0: Results From the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

For individuals with a coronary artery calcium (CAC) score of 0, CAC rescans at appropriate timings are recommended, depending on individual risk profiles. Although nonalcoholic fatty liver disease, recently redefined as metabolic-associated fatty liver disease, is a risk factor for atherosclerotic cardiovascular disease events, its relationship with the warranty period of a CAC score of 0 has not been elucidated.

METHODS

A total of 1944 subjects from the MESA (Multi-Ethnic Study of Atherosclerosis) with a baseline CAC score of 0, presence or absence of nonalcoholic hepatic steatosis, and at least 1 follow-up computed tomography scan were included. Nonalcoholic hepatic steatosis was defined using nonenhanced computed tomography and liver/spleen attenuation ratio <1. The association between nonalcoholic hepatic steatosis and new CAC incidence (CAC score >0) was evaluated using a Weibull survival model.

RESULTS

Nonalcoholic hepatic steatosis was identified in 268 (14%) participants. Participants with nonalcoholic hepatic steatosis had higher CAC incidence than those without nonalcoholic hepatic steatosis. Nonalcoholic hepatic steatosis was independently associated with new CAC incidence after adjustment for atherosclerotic cardiovascular disease risk factors (hazard ratio, 1.28 [95% CI, 1.05-1.57]; P=0.015). Using a 25% testing yield (25% of participants with zero CAC at baseline would be expected to have developed a CAC score >0), the warranty period of a CAC score of 0 in participants with nonalcoholic hepatic steatosis was shorter than in those without nonalcoholic hepatic steatosis (4.7 and 6.3 years). This association was consistent regardless of sex, race/ethnicity, age, and 10-year atherosclerotic cardiovascular disease risk.

CONCLUSIONS

Nonalcoholic hepatic steatosis had an impact on the warranty period of a CAC score of 0. The study suggests that the time period until a CAC rescan should be shorter in those with nonalcoholic hepatic steatosis and a CAC score of 0.

The value of additional risk factors for improving 10-year cardiovascular risk prediction in apparently healthy people

Background

In clinical practice, factors known to be associated with cardiovascular disease (CVD) like albuminuria, education level, or coronary calcium score are not directly incorporated in cardiovascular risk prediction models. The aim of the current study was to quantify the added value of potential risk modifying characteristics when added to the SCORE2 algorithm for individuals without diabetes mellitus (DM) or prior CVD.

Methods and results

Individuals without previous CVD or DM were included from the ARIC, MESA, EPIC-NL and HNR studies (n=46,285) in whom 2,177 CVD events and 2,062 non-cardiovascular deaths were observed over exactly 10.0 years of follow-up. The effect of each possible risk modifying characteristic was derived using Fine and Gray models that included an offset term for the SCORE2 linear predictor. The risk modifying characteristics were applied to individual predictions using the “naïve approach”, which modifies predicted risks based on the population prevalence and the SHR of the relevant predictor. Subdistribution hazard ratios are presented in the table. External validation was performed in the CPRD cohort (UK, n=518,015, 12,675 CVD events). In the external validation, adjustment of SCORE2 predicted risks with both single and with all available risk modifiers did not negatively affect calibration (see figure) and led to a modest increase in discrimination (C-index 0.742 [95% CI 0.737–0.746] versus unimproved SCORE2 risk C-index 0.737 [95% CI 0.732–0.741]). The net reclassification index or adding all these predictors was +0.032 (95% CI 0.025; 0.028) for future events and −0.008 (95% CI −0.009; −0.007) for future non-events. The coronary calcium score was found to the single strongest added predictor.

Interpretation

The current analysis presents a method on how to integrate possible risk modifying characteristics that are not included in existing CVD risk models for the prediction of CVD event risk in apparently healthy people. This flexible methodology improves the accuracy of predicted risks and increases applicability of prediction models for individuals with additional risk known modifiers

Funding Acknowledgement

Type of funding sources: None.

The Association of Upper Airway Anatomy with Brain Structure: The Multi-Ethnic Study of Atherosclerosis

Sleep apnea, affecting an estimated 1 in 4 American adults, has been reported to be associated with both brain structural abnormality and impaired cognitive function. Obstructive sleep apnea is known to be affected by upper airway anatomy. To better understand the contribution of upper airway anatomy to pathways linking sleep apnea with impaired cognitive function, we investigated the association of upper airway anatomy with structural brain abnormalities. Based in the Multi-Ethnic Study of Atherosclerosis, a longitudinal cohort study of community-dwelling adults, a comprehensive sleep study and an MRI of the upper airway and brain were performed on 578 participants. Machine learning models were used to select from 74 upper airway measures those measures most associated with selected regional brain volumes and white matter hyperintensity volume. Linear regression assessed associations between the selected upper airway measures, sleep measures, and brain structure. Maxillary divergence was positively associated with hippocampus volume, and mandible length was negatively associated with total white and gray matter volume. Both coefficients were small (coefficients per standard deviation 0.063 mL, p = 0.04, and - 7.0 mL, p < 0.001 respectively), and not affected by adjustment for sleep study measures. Self-reported snoring >2 times per week was associated with larger hippocampus volume (coefficient 0.164 mL, p = 0.007), and higher percentage of time in the N3 sleep stage was associated with larger total white and gray matter volume (4.8 mL, p = 0.004). Despite associations of two upper airway anatomy measures with brain volume, the evidence did not suggest that these upper airway and brain structure associations were acting primarily through the pathway of sleep disturbance.

Pre-diagnostic predictors of mortality in patients with heart failure: The multi-ethnic study of atherosclerosis

Background

There are multiple predictive factors for cardiovascular (CV) mortality measured at, or after heart failure (HF) diagnosis. However, the predictive role of long-term exposure to these predictors prior to HF diagnosis is unknown.

Objectives

We aim to identify predictive factors of CV mortality in participants with HF, using cumulative exposure to risk factors before HF development.

Methods

Participants of Multi-Ethnic Study of Atherosclerosis (MESA) with incident HF were included. We used stepwise Akaike Information Criterion to select CV mortality predictors among clinical, biochemical, and imaging markers collected prior to HF. Using the AUC of B-spline-corrected curves, we estimated cumulative exposure to predictive factors from baseline to the last exam before HF. The prognostic performance for CV mortality after HF was evaluated using competing risk regression with non-CV mortality as the competing risk.

Results

Overall, 375 participants had new HF events (42.9% female, mean age: 74). Over an average follow-up of 4.7 years, there was no difference in the hazard of CV death for HF with reduced versus preserved ejection fraction (HR = 1.27, p = 0.23). The selected predictors of CV mortality in models with the least prediction error were age, cardiac arrest, myocardial infarction, and diabetes, QRS duration, HDL, cumulative exposure to total cholesterol and glucose, NT-proBNP, left ventricular mass, and statin use. The AUC of the models were 0.72 when including the latest exposure to predictive factors and 0.79 when including cumulative prior exposure to predictive factors (p = 0.20).

Conclusion

In HF patients, besides age and diagnosed diabetes or CVD, prior lipid profile, NT-proBNP, LV mass, and QRS duration available at the diagnosis time strongly predict CV mortality. Implementing cumulative exposure to cholesterol and glucose, instead of latest measures, improves predictive accuracy for HF mortality, though not reaching statistical significance.

Plasma proteoforms of apolipoproteins C-I and C-II are associated with plasma lipids in the Multi-Ethnic Study of Atherosclerosis

Apolipoproteins (apo) C-I and C-II are key regulators of triglyceride and HDL metabolism. Both exist as full-size native and truncated (apoC-I'; apoC-II') posttranslational proteoforms. However, the determinants and the role of these proteoforms in lipid metabolism are unknown. Here, we measured apoC-I and apoC-II proteoforms by mass spectrometry immunoassay in baseline and 10-year follow-up plasma samples from the Multi-Ethnic Study of Atherosclerosis. We found that baseline total apoC-I (mean = 9.2 mg/dl) was lower in African Americans (AA), Chinese Americans (CA), and Hispanics (by 1.8; 1.0; 1.0 mg/dl vs. whites), higher in women (by 1.2 mg/dl), and positively associated with plasma triglycerides and HDL. Furthermore, we observed that the truncated-to-native apoC-I ratio (apoC-I'/C-I) was lower in CA, negatively associated with triglycerides, and positively associated with HDL. We determined that total apoC-II (8.8 mg/dl) was lower in AA (by 0.8 mg/dl) and higher in CA and Hispanics (by 0.5 and 0.4 mg/dl), positively associated with triglycerides, and negatively associated with HDL. In addition, apoC-II'/C-II was higher in AA and women, negatively associated with triglycerides, and positively associated with HDL. We showed that the change in triglycerides was positively associated with changes in total apoC-I and apoC-II and negatively associated with changes in apoC-I'/C-I and apoC-II'/C-II, whereas the change in HDL was positively associated with changes in total apoC-I and apoC-II'/C-II and negatively associated with change in total apoC-II. This study documents racial/ethnic variation in apoC-I and apoC-II plasma levels and highlights apolipoprotein posttranslational modification as a potential regulator of plasma lipids.