Resistin and risks of incident heart failure subtypes and cardiac fibrosis: the Multi-Ethnic Study of Atherosclerosis.

AIMS: Resistin is a circulating inflammatory biomarker that is associated with cardiovascular disease. We investigated the associations of resistin and incident heart failure (HF) and its subtypes, as well as specific measures of subclinical HF (myocardial fibrosis and relevant biomarkers). METHODS: We analysed data from 1968 participants in the Multi-Ethnic Study of Atherosclerosis with measurements of plasma resistin levels at clinic visits from 2002 to 2005. Participants were subsequently followed for a median of 10.5 years for HF events. The associations between resistin levels and incident HF, HF with reduced ejection fraction (HFrEF), and HF with preserved ejection fraction (HFpEF) were examined using multivariable Cox proportional hazards models. Linear regression models assessed the associations between resistin levels and myocardial fibrosis from cardiac magnetic resonance imaging, as well as hs-cTnT and NT-proBNP. RESULTS: The mean age of the cohort was 64.7 years, and 50.0% were female. Seventy-four participants (4%) developed incident HF during follow-up. In a Cox proportional hazards model adjusted for age, gender, education level, race/ethnicity, and traditional risk factors, higher resistin levels were significantly associated with incident HF (HR 1.44, CI 1.18-1.75, P = 0.001) and HFrEF (HR 1.47, CI 1.07-2.02, P = 0.016), but not with HFpEF (HR 1.25, CI 0.89-1.75, P = 0.195). Resistin levels showed no significant associations with myocardial fibrosis, NT-proBNP, or hs-cTnT levels. CONCLUSIONS: In a multi-ethnic cohort free of cardiovascular disease at baseline, elevated resistin levels were associated with incident HF, more prominently with incident HFrEF than HFpEF, but not with subclinical myocardial fibrosis or biomarkers of HF.

Association of inflammatory markers and lipoprotein particle subclasses with progression of coronary artery calcium: The multi-ethnic study of atherosclerosis.

BACKGROUND AND AIMS: Atherosclerosis is a complex phenomenon manifesting several features typical of chronic inflammation and disorders of lipid metabolism. We assessed association of nuclear magnetic resonance (NMR) lipid variables and inflammatory markers with incident coronary artery calcium (CAC) and CAC progression among participants with baseline CAC ≥0. METHODS: MESA is a longitudinal cohort study of 6,814 participants (aged 45-85). 3,115 had CAC = 0 and 2,896 had CAC>0 at baseline. Repeat CAC measurements were obtained (mean duration of follow up, 6.5 years). RESULTS: IL-6 (log pg/mL) and fibrinogen (50 mg/dL) were associated with a higher relative risk (RR) of incident CAC (HU) (RR = 1.09, p=0.010 & RR 1.05, p=0.004, respectively). Small LDL (100 nmol/L) (RR = 1.03, p<0.001) and log large VLDL (log nmol/L) (RR = 1.06, p=0.001) were associated with higher risks, whereas large HDL (µmol/L) was associated with an inverse risk of incident CAC (RR = 0.97, p< 0.001) in a model adjusted for follow up time, age, gender and race. Among participants with baseline CAC>0, progression of CAC was positively associated with hsCRP (log mg/L) (ß = 1.99), IL-6 (log pg/mL) (ß = 2.9), fibrinogen (50 mg/dL) (ß = 1.0), large VLDL (log nmol/L) (ß = 2.2), and small LDL (100 nmol/L) (ß = 0.36) (all p values < 0.05) in a model adjusted for scanner type, age, gender and race. Relationships with inflammatory markers and NMR lipoprotein particles lost significance after adjustment for traditional risk factors and statin use. Traditional risk factors were strongly associated with both CAC incidence and progression with the exception of cholesterol parameters not associated with CAC progression in adjusted model. CONCLUSIONS: Inflammatory markers and lipoprotein particles were associated with CAC incidence and progression in minimally adjusted models, but not after adjustment for traditional risk factors.

Cholesterol mass efflux capacity and risk of peripheral artery disease: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: We aimed to assess the relationship of HDL (high-density lipoprotein)-mediated cholesterol mass efflux capacity (CMEC) with risk of incident peripheral artery disease (PAD). METHODS: CMEC was measured in 1458 Multi-Ethnic Study of Atherosclerosis participants between 2000 and 2002 as part of a case-control study matched for incident cardiovascular disease and progression of carotid plaque by ultrasound. Incident clinical PAD, adjudicated on the basis of a positive history for the presence of disease-related symptoms or treatment, was ascertained through 2015 in 1419 individuals without clinical PAD at baseline. Subclinical PAD, defined as an ankle-brachial index (ABI) ≤1.0, was assessed among 1255 individuals with a baseline ABI >1.0 and at least one follow-up ABI measurement 3-10 years later. Cox proportional hazards and relative risk regression modeling per SD increment of CMEC were used to determine the association of CMEC with clinical and subclinical PAD, respectively. RESULTS: There were 38 clinical PAD and 213 subclinical PAD events that occurred over a mean follow-up of 6.0 and 6.5 years respectively. After adjustment for age, gender, and race, higher CMEC levels were not associated with clinical PAD (hazard ratio 1.25; 95% CI 0.89, 1.75) or subclinical PAD (risk ratio 1.02; 95% CI, 0.94, 1.11). CONCLUSIONS: These findings suggest that HDL-mediated cholesterol efflux is not significantly associated with incident clinical and subclinical PAD.

Virtual-Reality Guided Versus Fluoroscopy-Guided Transseptal Puncture in a Cardiac Phantom.

OBJECTIVES: We compared virtual-reality guided versus fluoroscopy-guided transseptal puncture by novice and experienced operators in a cardiac phantom. Outcome measures included accuracy, time, transseptal path distance, and a survey of the operator experience. METHODS: A transseptal simulator was created using a Plexiglas case and a 3D-printed cardiac phantom with a replaceable fossa ovalis, a customized support, and an electromagnetic tracking system. A precisely registered virtual-reality rendering was constructed. To display the transseptal instruments in virtual reality, we attached electromagnetic sensors to standard transseptal instruments, including the needle, dilator, and sheath. Each subject completed 6 simulated transseptal punctures (3 fluoroscopy-guided and 3 virtual-reality guided). We measured the distance traversed by the transseptal needle, accuracy, and time for each simulated transseptal puncture. Operators were then surveyed regarding their experience. RESULTS: A total of 8 subjects (6 faculty, 2 fellows) completed the trial. We found that virtual-reality guidance resulted in significantly more accurate puncture site selection and, subjectively, was more intuitive for the operator, particularly for novices. None of the participants experienced negative symptoms in virtual reality that required cessation of the procedure. CONCLUSIONS: Virtual reality compared with fluoroscopic guidance for transseptal puncture shows considerable promise, particularly for novice trainees, where it could lessen the learning curve. Current barriers to widespread implementation are discussed.

Current work hours and coronary artery calcification (CAC): The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Long work hours may be associated with adverse outcomes, including cardiovascular disease. We investigated cross-sectional associations of current work hours with coronary artery calcification (CAC). METHODS: Participants (n = 3046; 54.6% men) were from the Multi-Ethnic Study of Atherosclerosis. The number of hours worked in all jobs was obtained by questionnaire and CAC from computed tomography. The probability of a positive CAC score was modeled using log-binomial regression. Positive scores were modeled using analysis of covariance and linear regression. RESULTS: Sixteen percent of the sample worked over 50 hours per week. The overall geometric mean CAC score was 5.2 ± 10.0; 40% had positive scores. In fully-adjusted models, prevalence ratios were less than 40 hours: 1.00 (confidence interval [CI]: 0.88-1.12), 40:(ref), 41 to 49:1.13 (CI: 0.99-1.30), and ≥50:1.07 (CI: 0.94-1.23) and longer current work hours were not associated with higher mean CAC scores (<40:56.0 [CI: 47.3-66.3], 40:57.8 [CI: 45.6-73.3], 41 to 49:59.2 [CI: 45.2-77.6], ≥50:51.2 [CI: 40.5-64.8]; P = .686). CONCLUSIONS: Current work hours were not independently associated with CAC scores.

Assessment of rejection risk following subtherapeutic calcineurin inhibitor levels after pediatric heart transplantation.

CNIs are the mainstay of immunosuppressive therapy after pediatric HTx. While regular laboratory surveillance is performed to ensure blood levels are within targeted range, the risk of acute rejection associated with subtherapeutic CNI levels has never been quantified. This is a retrospective single-center review of 8413 CNI trough levels in 138 pediatric HTx recipients who survived >1 year after HTx. Subtherapeutic CNI levels were defined as <50% of the lower limit of target range. The risk of acute, late (>12 months post-transplant) rejection following recipients' subtherapeutic CNI levels was assessed using time-varying multivariable Cox proportional hazards analysis. We found that 79 of 138 recipients (57%) had at least one subtherapeutic CNI level on routine surveillance laboratories during a mean follow-up of 5.5 ± 3.6 years. Following an episode of subtherapeutic levels, 17 recipients (22%) had biopsy-proven rejection within the next 3 months; the majority (9/17) within the first 2 weeks. After presenting with subtherapeutic CNI levels, recipients incurred a 6.1 times increased risk of acute rejection in the following 3 months (HR = 6.11 [2.41, 15.51], P = <.001). Age at HTx, HLA sensitization, or positive crossmatch were not associated with acute late rejection, but rejection in the first post-transplant year was (HR 2.61 [1.27, 5.35], P = .009). Thus, maintaining therapeutic CNI levels is the most important factor in preventing acute rejection in recipients who are >12 months after pediatric HTx. Recipients who present with subtherapeutic CNI levels on surveillance monitoring are 6.1 times more likely to develop rejection in the following 3 months.

What have we learned in the last 20 years? A comparison of a modern era pediatric and congenital catheter ablation registry to previous pediatric ablation registries.

BACKGROUND: Since the onset of pediatric catheter ablation, the pediatric electrophysiology community has reported outcomes via various registries (PAPCA [Prospective Assessment After Pediatric Cardiac Ablation], PCAR [Pediatric Catheter Ablation Registry]). Most recently, a modern era pediatric and congenital ablation registry (MAP-IT [Multicenter Pediatric and Congenital EP Quality Initiative]) was developed for eventual incorporation into the National Cardiovascular Data Registry (NCDR) IMPACT (Improving Pediatric and Adult Congenital Treatment) registry. OBJECTIVE: The purpose of this study was to describe initial findings from the MAP-IT pilot registry and to compare these findings to earlier registries. METHODS: Before entering the NCDR IMPACT registry, MAP-IT was active at 12 centers (11 in the United States) between October 2014 and April 2016. All electrophysiological studies for patients younger than 21 years and for patients of all ages with structural congenital heart disease were included. We compared the acute success, fluoroscopy and procedural times, and frequency of complications between MAP-IT and the earlier registries. RESULTS: Acute success rates have improved from the initial PCAR registry for both accessory and slow pathway substrates. Both fluoroscopy and procedural times have significantly decreased across the time periods (fluoroscopy time 47.6 ± 40 minutes to 7.0 ± 9.2 minutes; P <.001; procedural time 257 ± 157 minutes to 166 ± 84 minutes; P <.001). CONCLUSION: Acute success rates and fluoroscopy and procedural times in pediatric ablation all have improved over the last 25 years.

Cholesterol Mass Efflux Capacity, Incident Cardiovascular Disease, and Progression of Carotid Plaque.

Objective- To assess the role of HDL (high-density lipoprotein)-mediated cholesterol mass efflux capacity (CMEC) in incident cardiovascular disease and carotid plaque progression. Approach and Results- We measured CMEC in 2 cohorts aged 45 to 84 years at baseline derived from the MESA (Multi-Ethnic Study of Atherosclerosis). Cohort 1 comprised 465 cases with incident cardiovascular disease events during 10 years of follow-up and 465 age- and sex-matched controls; cohort 2 comprised 407 cases with progression of carotid plaque measured by ultrasonography at 2 exams >10 years and 407 similarly matched controls. Covariates and outcome events were ascertained according to the MESA protocol. CMEC level was modestly correlated with HDL cholesterol ( R=0.13; P<0.001) but was not associated with age, sex, race/ethnicity, body mass index, diabetes mellitus, alcohol use, smoking status, or statin use. Higher CMEC level was significantly associated with lower odds of cardiovascular disease (odds ratio, 0.82 per SD of CMEC [95% CI, 0.69-0.98; P=0.031] in the fully adjusted model) in cohort 1 but higher odds of carotid plaque progression (odds ratio, 1.24 per SD of CMEC [95% CI, 1.04-1.48; P=0.018] in the fully adjusted model) in cohort 2 but without dose-response effect. In subgroup analysis within cohort 1, higher CMEC was associated with lower risk of incident coronary heart disease events (odds ratio, 0.72 per SD of CMEC (95% CI, 0.5-0.91; P=0.007) while no association was found with stroke events. Conclusions- These findings support a role for HDL-mediated cholesterol efflux in an atheroprotective mechanism for coronary heart disease but not stroke.

Use of coronary artery calcium testing to improve coronary heart disease risk assessment in a lung cancer screening population: The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Assessment of coronary artery calcium (CAC) during lung cancer screening chest computed tomography (CT) represents an opportunity to identify asymptomatic individuals at increased coronary heart disease (CHD) risk. We determined the improvement in CHD risk prediction associated with the addition of CAC testing in a population recommended for lung cancer screening. METHODS: We included 484 out of 6814 Multi-Ethnic Study of Atherosclerosis (MESA) participants without baseline cardiovascular disease who met U.S. Preventive Service Task Force CT lung cancer screening criteria and underwent gated CAC testing. 10 year-predicted CHD risks with and without CAC were calculated using a validated MESA-based risk model and categorized into low (<5%), intermediate (5%-10%), and high (≥10%). The net reclassification improvement (NRI) and change in Harrell's C-statistic by adding CAC to the risk model were subsequently determined. RESULTS: Of 484 included participants (mean age = 65; 39% women; 32% black), 72 (15%) experienced CHD events over the course of follow-up (median = 12.5 years). Adding CAC to the MESA CHD risk model resulted in 17% more participants classified into the highest or lowest risk categories and a NRI of 0.26 (p = 0.001). The C-statistic improved from 0.538 to 0.611 (p = 0.01). CONCLUSIONS: CHD event rates were high in this lung cancer screening eligible population. These individuals represent a high-risk population who merit consideration for CHD prevention measures regardless of CAC score. Although overall discrimination remained poor with inclusion of CAC scores, determining whether those reclassified to an even higher risk would benefit from more aggressive preventive measures may be important.

Association of lipoprotein-associated phospholipase A2 and risk of incident atrial fibrillation: Findings from 3 cohorts.

BACKGROUND: Multiple prospective studies have established an association between inflammation and higher risk of atrial fibrillation (AF), but the association between lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity and incident AF has not been extensively evaluated. METHODS: Using data from 10,794 Atherosclerosis Risk In Communities (ARIC) study participants aged 53-75 years, 5,181 Cardiovascular Health Study (CHS) participants aged 65 to 100 years, and 5,425 Multi-Ethnic Study of Atherosclerosis (MESA) participants aged 45-84 years, we investigated the association between baseline Lp-PLA2 levels and the risk of developing AF. Incident AF was identified in each cohort by follow-up visit electrocardiograms, hospital discharge coding of AF, or Medicare claims data. RESULTS: Over a mean of 13.1, 11.5, and 10.0 years of follow-up, 1,439 (13%), 2,084 (40%), and 615 (11%) incident AF events occurred in ARIC, CHS, and MESA, respectively. In adjusted analyses, each SD increment in Lp-PLA2 activity was associated with incident AF in both ARIC (hazard ratio [HR] 1.13, 95% CI 1.06-1.20) and MESA (HR 1.24, 95% CI 1.05-1.46). Each SD increment in Lp-PLA2 mass was also associated with incident AF in MESA (HR 1.25, 95% CI 1.11-1.41). No significant associations were observed among CHS participants. CONCLUSIONS: Although higher Lp-PLA2 mass and activity were associated with development of AF in ARIC and MESA, this relationship was not observed in CHS, a cohort of older individuals.

Outcome of antibody-mediated rejection compared to acute cellular rejection after pediatric heart transplantation.

Outcomes of ACR after pediatric HTx have been well described, but less has been reported on outcomes of AMR. We compared the clinical characteristics and cardiovascular outcomes (composite end-point of death, retransplantation, or allograft vasculopathy) of pediatric HTx recipients with AMR, ACR, and no rejection in a retrospective single-center study of 104 recipients. Twenty were treated for AMR; 15 were treated for ACR. Recipients with AMR had an increased frequency of congenital heart disease (90% vs ACR 67% vs no rejection 59%, P = .03), homograft (68% vs 7% vs 18%, P < .001), HLA sensitization (45% vs 13% vs 13%, P = .008), and positive cross-match (30% vs 7% vs 9%, P = .046). AMR caused hemodynamic compromise more often than ACR (39% vs 4%, P = .02). AMR recipients had worse cardiovascular outcome than recipients with ACR or no rejection (40% vs 20% vs 8.6%, P = .003). In bivariate Cox analysis, AMR (HR 4.1, CI 1.4-12.0, P = .009) and ischemic time (HR 1.6, CI 1.1-2.3, P = .02) were associated with worse cardiovascular outcome; ACR was not. In summary, pediatric HTx recipients who develop AMR have worse cardiovascular outcome than recipients who develop only ACR or experience no rejection at all.

Pediatric Appropriate Use Criteria for Outpatient Echocardiography: Practice Variations among Pediatric Cardiologists, Noncardiologist Subspecialists, and Primary Care Providers.

BACKGROUND: The first pediatric appropriate use criteria (AUC) address the use of initial transthoracic echocardiography in outpatients by all ordering providers. The aim of this study was to appraise the performance of the AUC across pediatric cardiologists, noncardiologist subspecialists, and primary care providers (PCPs). A further aim was to describe the variations in ordering patterns of different groups of practitioners, which could serve as the basis for targeted quality improvement activities. METHODS: Electronic health records for Seattle Children's Hospital and its four regional sites were retrospectively reviewed for initial transthoracic echocardiographic studies performed on patients aged ≤18 years. A sample of 1,000 consecutive studies and a sample of 1,514 studies in which studies ordered by noncardiologists were enriched were reviewed. The ordering provider type, study indication, and findings (normal, incidental, or abnormal) were classified. Indications mapped to three categories: appropriate (A), may be appropriate (M), and rarely appropriate (R). If multiple indications were documented, the highest level of appropriateness was used. RESULTS: In the consecutive sample, pediatric cardiologists ordered 81%, noncardiologist subspecialists 13%, and PCPs 5% of the total studies. In the enriched sample, only 4% were unclassifiable by the AUC. Abnormal findings were identified in 23% of A, 13% of M, and 9% of R studies (P = .03). Appropriateness varied among the three groups of providers (P < .001). For pediatric cardiologists, 67% of studies were indication category A, 13% M, and 14% R. Noncardiologist subspecialists ordered the highest percentage of A studies (88%) and the lowest percentage of R studies (1%). PCPs had the highest percentage of R indications (18%), and 23% could not be fully classified, because of insufficient order information. Yield of abnormal findings was highest for subspecialists (23%), intermediate for cardiologists (19%), and lowest for PCPs (15%; P = .03). CONCLUSIONS: The AUC performed well across all provider types, as measured by the low percentage of unclassifiable indications and the observed relationship between greater appropriateness and higher yield of abnormal findings. The three provider types differed in appropriateness rates and had distinct ordering patterns, which could form the basis for future targeted quality improvement efforts.

Feasibility and interpretation of global longitudinal strain imaging in pediatric heart transplant recipients.

Evaluation of myocardial mechanics after heart transplant is important in monitoring allograft function and identifying rejection. Speckle tracking global longitudinal strain (GLS) may be more sensitive to early regional changes from rejection. This study aimed to determine feasibility of GLS in pediatric hearts during surveillance echocardiograms, compare their GLS to published norms (-18% to -22%), and assess association of GLS with other indices of graft function. Retrospective review of transplant echocardiograms from 2013 to 2014. Philips QLAB was used for post-acquisition GLS analysis. Multiple linear regression was used to assess the association of GLS with echocardiographic/catheterization indices, and B-type natriuretic peptide (BNP). Forty-seven patients (84 studies) were included. Calculation of GLS was feasible in 82 studies (97%) with inter- and intra-observer variability of 0.71 and 0.69. Patients (n=9) with rejection had GLS of -16.4% (SD=3.5%) compared to those without [-16.8% (SD=3.7%)]. GLS worsened linearly with increasing Ln(BNP) (P=<.001), left ventricular volume in diastole (P=<.001), septal a' wave (P=<.001), and pulmonary capillary wedge pressure (P=<.001). Speckle tracking-based GLS is feasible and reproducible in pediatric heart recipients and is reduced at baseline. The role of GLS and BNP in detecting early systolic dysfunction warrants further investigation.

Lipoprotein-associated phospholipase A2 and risk of incident peripheral arterial disease in a multi-ethnic cohort: The Multi-Ethnic Study of Atherosclerosis.

Prospective studies supporting a relationship between elevated lipoprotein-associated phospholipase A2 (Lp-PLA2) and incident peripheral arterial disease (PAD) are limited. We evaluated the association of Lp-PLA2 with incident PAD in a multi-ethnic cohort without clinical cardiovascular disease. A total of 4622 participants with measurement of Lp-PLA2 mass and Lp-PLA2 activity and an ankle-brachial index (ABI) between 0.9 and 1.4 were followed for the development of PAD (median follow-up = 9.3 years), defined as an ABI ⩽0.9 and decline from baseline ⩾0.15. There were 158 incident PAD events during follow-up. In adjusted logistic regression models, each higher standard deviation of both Lp-PLA2 activity and mass did not confer an increased risk of developing PAD [odds ratios, (95% confidence intervals)]: 0.92 (0.66-1.27) for Lp-PLA2 activity and 1.06 (0.85-1.34) for mass. Additionally, no significant interaction was found according to ethnicity: p=0.43 for Lp-PLA2 activity and p=0.55 for Lp-PLA2 mass. We found no evidence of an association between Lp-PLA2 and incident PAD.

Socioeconomic Status and Poor Health Outcome at 10 Years of Follow-Up in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND/OBJECTIVES: Predictors of healthy aging have not been well-studied using longitudinal data with demographic, clinical, subclinical, and genetic information. The objective was to identify predictors of poor health outcome at 10 years of follow-up in the Multi-Ethnic Study of Atherosclerosis (MESA). DESIGN: Prospective cohort study. SETTING: Population-based sample from 6 U.S. communities. PARTICIPANTS: 4,355 participants In the MESA Study. MEASUREMENTS: Poor health outcome at 10 years of follow-up was defined as having died or having clinical cardiovascular disease, depression, cognitive impairment, chronic obstructive pulmonary disease, or cancer other than non-melanoma skin cancer. Absolute risk regression was used to estimate risk differences in the outcome adjusting for demographic variables, clinical and behavioral risk factors, subclinical cardiovascular disease, and ApoE genotype. Models were weighted to account for selective attrition. RESULTS: Mean age at 10 years of follow-up was 69.5 years; 1,480 participants had a poor health outcome, 2,157 participants were in good health, and 718 were unknown. Older age, smoking, not taking a statin, hypertension, diabetes, and higher coronary calcium score were associated with higher probability of poor health outcome. After multivariable adjustment, participants in the lowest income and educational categories had 7 to 14% greater absolute risk of poor health outcome at 10 years of follow-up compared to those in the next highest categories of income or education (P = 0.002 for both). Those in the lowest categories of both income and education had 21% greater absolute risk of poor health outcome compared to those in the highest categories of both income and education. CONCLUSIONS: Low income and educational level predict poor health outcome at 10 years of follow-up in an aging cohort, independent of clinical and behavioral risk factors and subclinical cardiovascular disease.

Association between Heat Shock Protein-60 and Development of Atrial Fibrillation: Results from the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: During atrial fibrillation (AF), a high rate of myocyte activation causes cellular stress and initiates the process of atrial remodeling, which further promotes persistence of AF. Although heat shock proteins (HSPs) have been shown to prevent atrial remodeling and suppress the occurrence of AF in cellular and animal experimental models, increased levels of HSP-60 have been observed in patients with postoperative AF, likely reflecting a response to cellular stress. To better understand the role of HSP-60 in relation to AF, we examined the association of HSP-60 levels in relation to the future development of AF in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: MESA is a cohort study that recruited 6,814 participants aged 45-84 years and free of known cardiovascular disease at baseline (2000-2002) from six field centers. We investigated 983 participants, selected at random from the total cohort, who had HSP-60 measured and were free of AF at baseline. We tested the association of HSP-60 levels with the incidence of AF using multivariate Cox models after adjustment for demographics, clinical characteristics, and biomarkers. RESULTS: During an average of 10.6 years of follow-up, 77 participants developed AF. We did not observe a significant association between the log-transformed HSP-60 levels and development of AF on either unadjusted or multivariate analysis (adjusted hazard ratio: 1.02 per unit difference on natural log scale, 95% confidence interval: 0.77-1.34 ln (ng/mL). CONCLUSION: Contrary to the findings from the preclinical studies, which demonstrated an important role of HSP-60 in the pathogenesis of AF, we did not observe a significant association between HSP-60 and occurrence of AF.

10-Year Coronary Heart Disease Risk Prediction Using Coronary Artery Calcium and Traditional Risk Factors: Derivation in the MESA (Multi-Ethnic Study of Atherosclerosis) With Validation in the HNR (Heinz Nixdorf Recall) Study and the DHS (Dallas Heart Study).

BACKGROUND: Several studies have demonstrated the tremendous potential of using coronary artery calcium (CAC) in addition to traditional risk factors for coronary heart disease (CHD) risk prediction. However, to date, no risk score incorporating CAC has been developed. OBJECTIVES: The goal of this study was to derive and validate a novel risk score to estimate 10-year CHD risk using CAC and traditional risk factors. METHODS: Algorithm development was conducted in the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective community-based cohort study of 6,814 participants age 45 to 84 years, who were free of clinical heart disease at baseline and followed for 10 years. MESA is sex balanced and included 39% non-Hispanic whites, 12% Chinese Americans, 28% African Americans, and 22% Hispanic Americans. External validation was conducted in the HNR (Heinz Nixdorf Recall Study) and the DHS (Dallas Heart Study). RESULTS: Inclusion of CAC in the MESA risk score offered significant improvements in risk prediction (C-statistic 0.80 vs. 0.75; p < 0.0001). External validation in both the HNR and DHS studies provided evidence of very good discrimination and calibration. Harrell's C-statistic was 0.779 in HNR and 0.816 in DHS. Additionally, the difference in estimated 10-year risk between events and nonevents was approximately 8% to 9%, indicating excellent discrimination. Mean calibration, or calibration-in-the-large, was excellent for both studies, with average predicted 10-year risk within one-half of a percent of the observed event rate. CONCLUSIONS: An accurate estimate of 10-year CHD risk can be obtained using traditional risk factors and CAC. The MESA risk score, which is available online on the MESA web site for easy use, can be used to aid clinicians when communicating risk to patients and when determining risk-based treatment strategies.

Long-term exposure to air pollution and markers of inflammation, coagulation, and endothelial activation: a repeat-measures analysis in the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Air pollution is associated with cardiovascular disease, and systemic inflammation may mediate this effect. We assessed associations between long- and short-term concentrations of air pollution and markers of inflammation, coagulation, and endothelial activation. METHODS: We studied participants from the Multi-Ethnic Study of Atherosclerosis from 2000 to 2012 with repeat measures of serum C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, D-dimer, soluble E-selectin, and soluble Intercellular Adhesion Molecule-1. Annual average concentrations of ambient fine particulate matter (PM2.5), individual-level ambient PM2.5 (integrating indoor concentrations and time-location data), oxides of nitrogen (NOx), nitrogen dioxide (NO2), and black carbon were evaluated. Short-term concentrations of PM2.5 reflected the day of blood draw, day prior, and averages of prior 2-, 3-, 4-, and 5-day periods. Random-effects models were used for long-term exposures and fixed effects for short-term exposures. The sample size was between 9,000 and 10,000 observations for CRP, IL-6, fibrinogen, and D-dimer; approximately 2,100 for E-selectin; and 3,300 for soluble Intercellular Adhesion Molecule-1. RESULTS: After controlling for confounders, 5 µg/m increase in long-term ambient PM2.5 was associated with 6% higher IL-6 (95% confidence interval = 2%, 9%), and 40 parts per billion increase in long-term NOx was associated with 7% (95% confidence interval = 2%, 13%) higher level of D-dimer. PM2.5 measured at day of blood draw was associated with CRP, fibrinogen, and E-selectin. There were no other positive associations between blood markers and short- or long-term air pollution. CONCLUSIONS: These data are consistent with the hypothesis that long-term exposure to air pollution is related to some markers of inflammation and fibrinolysis.

Evidence of heterogeneity by race/ethnicity in genetic determinants of QT interval.

BACKGROUND: QT interval (QT) prolongation is an established risk factor for ventricular tachyarrhythmia and sudden cardiac death. Previous genome-wide association studies in populations of the European descent have identified multiple genetic loci that influence QT, but few have examined these loci in ethnically diverse populations. METHODS: Here, we examine the direction, magnitude, and precision of effect sizes for 21 previously reported SNPs from 12 QT loci, in populations of European (n = 16,398), African (n = 5,437), American Indian (n = 5,032), Hispanic (n = 1,143), and Asian (n = 932) descent as part of the Population Architecture using Genomics and Epidemiology (PAGE) study. Estimates obtained from linear regression models stratified by race/ethnicity were combined using inverse-variance weighted meta-analysis. Heterogeneity was evaluated using Cochran's Q test. RESULTS: Of 21 SNPs, 7 showed consistent direction of effect across all 5 populations, and an additional 9 had estimated effects that were consistent across 4 populations. Despite consistent direction of effect, 9 of 16 SNPs had evidence (P < 0.05) of heterogeneity by race/ethnicity. For these 9 SNPs, linkage disequilibrium plots often indicated substantial variation in linkage disequilibrium patterns among the various racial/ethnic groups, as well as possible allelic heterogeneity. CONCLUSIONS: These results emphasize the importance of analyzing racial/ethnic groups separately in genetic studies. Furthermore, they underscore the possible utility of trans-ethnic studies to pinpoint underlying casual variants influencing heritable traits such as QT.

Multiancestral analysis of inflammation-related genetic variants and C-reactive protein in the population architecture using genomics and epidemiology study.

BACKGROUND: C-reactive protein (CRP) is a biomarker of inflammation. Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) associated with CRP concentrations and inflammation-related traits such as cardiovascular disease, type 2 diabetes mellitus, and obesity. We aimed to replicate previous CRP-SNP associations, assess whether these associations generalize to additional race/ethnicity groups, and evaluate inflammation-related SNPs for a potentially pleiotropic association with CRP. METHODS AND RESULTS: We selected and analyzed 16 CRP-associated and 250 inflammation-related GWAS SNPs among 40 473 African American, American Indian, Asian/Pacific Islander, European American, and Hispanic participants from 7 studies collaborating in the Population Architecture using Genomics and Epidemiology (PAGE) study. Fixed-effect meta-analyses combined study-specific race/ethnicity-stratified linear regression estimates to evaluate the association between each SNP and high-sensitivity CRP. Overall, 18 SNPs in 8 loci were significantly associated with CRP (Bonferroni-corrected P<3.1×10(-3) for replication, P<2.0×10(-4) for pleiotropy): Seven of these were specific to European Americans, while 9 additionally generalized to African Americans (1), Hispanics (5), or both (3); 1 SNP was seen only in African Americans and Hispanics. Two SNPs in the CELSR2/PSRC1/SORT1 locus showed a potentially novel association with CRP: rs599839 (P=2.0×10(-6)) and rs646776 (P=3.1×10(-5)). CONCLUSIONS: We replicated 16 SNP-CRP associations, 10 of which generalized to African Americans and/or Hispanics. We also identified potentially novel pleiotropic associations with CRP for two SNPs previously associated with coronary artery disease and/or low-density lipoprotein-cholesterol. These findings demonstrate the benefit of evaluating genotype-phenotype associations in multiple race/ethnicity groups and looking for pleiotropic relationships among SNPs previously associated with related phenotypes.