New race-free creatinine- and cystatin C-based equations for the estimation of glomerular filtration rate and association with cardiovascular mortality in the AtheroGene study

Renal function is associated with cardiovascular outcomes and mortality. Among equations used to eGFR, CKD-EPI equations show more accurate association with cardiovascular risk and mortality than MDRD. Recently, new CKD-EPI equations were proposed which do not include race and would be considered sufficiently accurate to estimate eGFR in clinical practice. It is unknown if these new race-free equations are comparably well associated with cardiovascular outcomes in high-risk individuals. The analysis was performed in the AtheroGene Study cohort including patients at high cardiovascular risk. eGFR was determined using the established as well as the recently developed formulas which are calculated without the otherwise existing coefficient for black race. The outcome was cardiovascular death. Analyses included Cox-proportional hazard regression and area-under-the-curve calculation. The analysis included 2089 patients followed up for a median of 3.8 years with a maximum of 6.9 years, corresponding to an overall period of 7701 patient-years. Cardiovascular death occurred in 93 (4.45%), corresponding to an annualized rate of 1.2/100 person-years. In all Cox regression analyses, the estimated adjusted GFR was an independent predictor of cardiovascular death. The equations which included cystatin C showed higher C-index compared to those which did not include cystatin C (0.75-0.76 vs. 0.71, respectively). The equations for the estimation of eGFR which include cystatin C are better associated with cardiovascular death compared to the race-free equations which include only creatinine. This finding adds on the related literature which supports the elimination of race in GFR-estimating equations, and promotion of the use of cystatin C.

Calibrating machine learning approaches for probability estimation: A comprehensive comparison

Statistical prediction models have gained popularity in applied research. One challenge is the transfer of the prediction model to a different population which may be structurally different from the model for which it has been developed. An adaptation to the new population can be achieved by calibrating the model to the characteristics of the target population, for which numerous calibration techniques exist. In view of this diversity, we performed a systematic evaluation of various popular calibration approaches used by the statistical and the machine learning communities for estimating two-class probabilities. In this work, we first provide a review of the literature and, second, present the results of a comprehensive simulation study. The calibration approaches are compared with respect to their empirical properties and relationships, their ability to generalize precise probability estimates to external populations and their availability in terms of easy-to-use software implementations. Third, we provide code from real data analysis allowing its application by researchers. Logistic calibration and beta calibration, which estimate an intercept plus one and two slope parameters, respectively, consistently showed the best results in the simulation studies. Calibration on logit transformed probability estimates generally outperformed calibration methods on nontransformed estimates. In case of structural differences between training and validation data, re-estimation of the entire prediction model should be outweighted against sample size of the validation data. We recommend regression-based calibration approaches using transformed probability estimates, where at least one slope is estimated in addition to an intercept for updating probability estimates in validation studies.

Global Effect of Modifiable Risk Factors on Cardiovascular Disease and Mortality

BACKGROUND

Five modifiable risk factors are associated with cardiovascular disease and death from any cause. Studies using individual-level data to evaluate the regional and sex-specific prevalence of the risk factors and their effect on these outcomes are lacking.

METHODS

We pooled and harmonized individual-level data from 112 cohort studies conducted in 34 countries and 8 geographic regions participating in the Global Cardiovascular Risk Consortium. We examined associations between the risk factors (body-mass index, systolic blood pressure, non-high-density lipoprotein cholesterol, current smoking, and diabetes) and incident cardiovascular disease and death from any cause using Cox regression analyses, stratified according to geographic region, age, and sex. Population-attributable fractions were estimated for the 10-year incidence of cardiovascular disease and 10-year all-cause mortality.

RESULTS

Among 1,518,028 participants (54.1% of whom were women) with a median age of 54.4 years, regional variations in the prevalence of the five modifiable risk factors were noted. Incident cardiovascular disease occurred in 80,596 participants during a median follow-up of 7.3 years (maximum, 47.3), and 177,369 participants died during a median follow-up of 8.7 years (maximum, 47.6). For all five risk factors combined, the aggregate global population-attributable fraction of the 10-year incidence of cardiovascular disease was 57.2% (95% confidence interval [CI], 52.4 to 62.1) among women and 52.6% (95% CI, 49.0 to 56.1) among men, and the corresponding values for 10-year all-cause mortality were 22.2% (95% CI, 16.8 to 27.5) and 19.1% (95% CI, 14.6 to 23.6).

CONCLUSIONS

Harmonized individual-level data from a global cohort showed that 57.2% and 52.6% of cases of incident cardiovascular disease among women and men, respectively, and 22.2% and 19.1% of deaths from any cause among women and men, respectively, may be attributable to five modifiable risk factors. (Funded by the German Center for Cardiovascular Research (DZHK); ClinicalTrials.gov number, NCT05466825.).

Biomarker-based prediction of fatal and non-fatal cardiovascular outcomes in individuals with diabetes mellitus

AIMS

The role of biomarkers in predicting cardiovascular outcomes in high-risk individuals is not well established. We aimed to investigate benefits of adding biomarkers to cardiovascular risk assessment in individuals with and without diabetes.

METHODS AND RESULTS

We used individual-level data of 95 292 individuals of the European population harmonized in the Biomarker for Cardiovascular Risk Assessment across Europe consortium and investigated the prognostic ability of high-sensitivity cardiac troponin I (hs-cTnI), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP). Cox-regression models were used to determine adjusted hazard ratios of diabetes and log-transformed biomarkers for fatal and non-fatal cardiovascular events. Models were compared using the likelihood ratio test. Stratification by specific biomarker cut-offs was performed for crude time-to-event analysis using Kaplan-Meier plots. Overall, 6090 (6.4%) individuals had diabetes at baseline, median follow-up was 9.9 years. Adjusting for classical risk factors and biomarkers, diabetes [HR 2.11 (95% CI 1.92, 2.32)], and all biomarkers (HR per interquartile range hs-cTnI 1.08 [95% CI 1.04, 1.12]; NT-proBNP 1.44 [95% CI 1.37, 1.53]; hs-CRP 1.27 [95% CI 1.21, 1.33]) were independently associated with cardiovascular events. Specific cut-offs for each biomarker identified a high-risk group of individuals with diabetes losing a median of 15.5 years of life compared to diabetics without elevated biomarkers. Addition of biomarkers to the Cox-model significantly improved the prediction of outcomes (likelihood ratio test for nested models P < 0.001), accompanied by an increase in the c-index (increase to 0.81).

CONCLUSION

Biomarkers improve cardiovascular risk prediction in individuals with and without diabetes and facilitate the identification of individuals with diabetes at highest risk for cardiovascular events.

Risk prediction of atrial fibrillation and its complications in the community using hs troponin I

AIMS

Atrial fibrillation (AF) is becoming increasingly common. Traditional cardiovascular risk factors (CVRF) do not explain all AF cases. Blood-based biomarkers reflecting cardiac injury such as high-sensitivity troponin I (hsTnI) may help close this gap.

METHODS

We investigated the predictive ability of hsTnI for incident AF in 45,298 participants (median age 51.4 years, 45.0% men) across European community cohorts in comparison to CVRF and established biomarkers (C-reactive protein, N-terminal pro B-type natriuretic peptide).

RESULTS

During a median follow-up of 7.7 years, 1734 (3.8%) participants developed AF. Those in the highest hsTnI quarter (≥4.2 ng/L) had a 3.91-fold (95% confidence interval (CI) 3.30, 4.63; p < .01) risk for developing AF compared to the lowest quarter (<1.4 ng/L). In multivariable-adjusted Cox proportional hazards models a statistically significant association was seen between hsTnI and AF (hazard ratio (HR) per 1 standard deviation (SD) increase in log10(hsTnI) 1.08; 95% CI 1.01, 1.16; p = .03). Inclusion of hsTnI did improve model discrimination (C-index CVRF 0.811 vs. C-index CVRF and hsTnI 0.813; p < .01). Higher hsTnI concentrations were associated with heart failure (HR per SD 1.37; 95% CI 1.12, 1.68; p < .01) and overall mortality (HR per SD 1.24; 95% CI 1.09, 1.41; p < .01).

CONCLUSION

hsTnI as a biomarker of myocardial injury does not improve prediction of AF incidence beyond classical CVRF and NT-proBNP. However, it is associated with the AF-related disease heart failure and mortality likely reflecting underlying subclinical cardiovascular impairment.

Exploring the incremental utility of circulating biomarkers for robust risk prediction of incident atrial fibrillation in European cohorts using regressions and modern machine learning methods

AIMS

To identify robust circulating predictors for incident atrial fibrillation (AF) using classical regressions and machine learning (ML) techniques within a broad spectrum of candidate variables.

METHODS AND RESULTS

In pooled European community cohorts (n = 42 280 individuals), 14 routinely available biomarkers mirroring distinct pathophysiological pathways including lipids, inflammation, renal, and myocardium-specific markers (N-terminal pro B-type natriuretic peptide [NT-proBNP], high-sensitivity troponin I [hsTnI]) were examined in relation to incident AF using Cox regressions and distinct ML methods. Of 42 280 individuals (21 843 women [51.7%]; median [interquartile range, IQR] age, 52.2 [42.7, 62.0] years), 1496 (3.5%) developed AF during a median follow-up time of 5.7 years. In multivariable-adjusted Cox-regression analysis, NT-proBNP was the strongest circulating predictor of incident AF [hazard ratio (HR) per standard deviation (SD), 1.93 (95% CI, 1.82-2.04); P < 0.001]. Further, hsTnI [HR per SD, 1.18 (95% CI, 1.13-1.22); P < 0.001], cystatin C [HR per SD, 1.16 (95% CI, 1.10-1.23); P < 0.001], and C-reactive protein [HR per SD, 1.08 (95% CI, 1.02-1.14); P = 0.012] correlated positively with incident AF. Applying various ML techniques, a high inter-method consistency of selected candidate variables was observed. NT-proBNP was identified as the blood-based marker with the highest predictive value for incident AF. Relevant clinical predictors were age, the use of antihypertensive medication, and body mass index.

CONCLUSION

Using different variable selection procedures including ML methods, NT-proBNP consistently remained the strongest blood-based predictor of incident AF and ranked before classical cardiovascular risk factors. The clinical benefit of these findings for identifying at-risk individuals for targeted AF screening needs to be elucidated and tested prospectively.

Predicting cardiovascular risk factors from facial & full body photography using deep learning

Introduction

The early and easy detection of pathological cardiovascular phenotypes can lead to an early medical intervention and thus slow or limit the development of cardiovascular diseases. As full body photographs are easily obtainable without the need of medical expertise, this modality holds the potential to be viable for screening of populations.

Purpose

Utilizing data from a population-based study, we examined the possibility to detect cardiovascular risk factors from total body photographs using deep learning.

Methods

A population-based cohort study was utilized. The first data release provides facial and full body photographs in dermatologic standard poses of 6500 participants (median age 62.0 years, 49.6% men) and corresponding cardiovascular risk factors. Here, we focus on the most prevalent ones: smoking status (prevalence: 19.0%), hypertension (35.3%) and diabetes (8.2%). Here we employ a 2D-Convolutional Resnet-18 Neural Network for predicting the risk factors. It receives the full body image, the facial image and age and sex as input. We compare this to a logistic regression model only including sex and age. Logistic Regression and Neural Network are employed in a 5-fold validation scheme and t-tested for significance.

Results

Our model provided a good detection of arterial hypertension (AUC 0.711, CI 0.684–0.739), while a logistic regression on age and sex yielded a significantly worse prediction (AUC 0.681, CI 0.679– 0.683, p&lt;0.05). Additionally, it made a good detection of a positive smoking status (AUC 0.733, CI 0.711–0.754), being significantly better than a respective logistic regression on age and sex (AUC 0.598, CI 0.597–0.6, p&lt;0.001). Lastly, it classified diabetes well (AUC 0.744, CI 0.724–0.764, p&lt;0.001) in comparison to the logistic regression (AUC 0.681, CI 0.679–0.683, p&lt;0.001).

Conclusion

The presence of cardiovascular risk factors can be detected from a total body photograph. As total body photographs can be easily obtained with a majority of digital cameras, including smart phones, this model represents a potentially widely applicable diagnostic tool to easily screen large parts of the population for relevant cardiovascular risk factors, making an early medical intervention possible.

Funding Acknowledgement

Type of funding sources: None.

The Relationship Between Vitamin D and Postoperative Atrial Fibrillation: A Prospective Cohort Study

Background and Aims

The relationship between postoperative atrial fibrillation (POAF) and 25-hydroxyvitamin D [25(OH)D] concentration as well as vitamin D supplementation has been discussed controversially. The relation of pre-operative vitamin D status and POAF remains unclear.

Methods and Results

We analysed the risk of POAF in a prospective, observational cohort study of n = 201 patients undergoing coronary artery bypass graft surgery (CABG) with 25(OH)D concentration. The median age was 66.6 years, 15.4% were women. The median (25th/75th percentile) vitamin D concentration at baseline was 17.7 (12.6/23.7) ng/ml. During follow-up we observed 48 cases of POAF. In age, sex, and creatinine-adjusted analyses, 25(OH)D was associated with an increased risk of POAF, though with borderline statistical significance [odds ratio (OR) 1.85, 95% confidence interval (CI) 0.87–3.92, p-value 0.107], in further risk factor-adjusted analyses the results remained stable (OR 1.99, 95% CI 0.90–4.39, p-value 0.087). The subgroup with vitamin D supplementation at baseline showed an increased risk of POAF (OR 5.03, 95% CI 1.13–22.33, p-value 0.034).

Conclusion

In our contemporary mid-European cohort, higher 25(OH)D concentration did not show a benefit for POAF in CABG patients and may even be harmful, though with borderline statistical significance. Our data are in line with a recent randomised study in community-based adults and call for further research to determine both, the clinical impact of elevated 25(OH)D concentration and vitamin D supplementation as well as the possible underlying pathophysiological mechanisms.

Risk Factors, Subsequent Disease Onset, and Prognostic Impact of Myocardial Infarction and Atrial Fibrillation

Background Although myocardial infarction (MI) and atrial fibrillation (AF) are frequent comorbidities and share common cardiovascular risk factors, the direction and strength of the association of the risk factors with disease onset, subsequent disease incidence, and mortality are not completely understood. Methods and Results In pooled multivariable Cox regression analyses, we examined temporal relations of disease onset and identified predictors of MI, AF, and all-cause mortality in 108 363 individuals (median age, 46.0 years; 48.2% men) free of MI and AF at baseline from 6 European population-based cohorts. During a maximum follow-up of 10.0 years, 3558 (3.3%) individuals were diagnosed exclusively with MI, 1922 (1.8%) with AF but no MI, and 491 (0.5%) individuals developed both MI and AF. Association of sex, systolic blood pressure, antihypertensive treatment, and diabetes appeared to be stronger with incident MI than with AF, whereas increasing age and body mass index showed a higher risk for incident AF. Total cholesterol and daily smoking were significantly related to incident MI but not AF. Combined population attributable fraction of cardiovascular risk factors was >70% for incident MI, whereas it was only 27% for AF. Subsequent MI after AF (hazard ratio [HR], 1.68; 95% CI, 1.03-2.74) and subsequent AF after MI (HR, 1.75; 95% CI, 1.31-2.34) both significantly increased overall mortality risk. Conclusions We observed different associations of cardiovascular risk factors with both diseases indicating distinct pathophysiological pathways. Subsequent diagnoses of MI and AF significantly increased mortality risk.

Association of iron deficiency with incident cardiovascular diseases and mortality in the general population

Aims

Although absolute (AID) and functional iron deficiency (FID) are known risk factors for patients with cardiovascular (CV) disease, their relevance for the general population is unknown. The aim was to assess the association between AID/FID with incident CV disease and mortality in the general population.

Methods and results

In 12 164 individuals from three European population‐based cohorts, AID was defined as ferritin < 100 μg/L or as ferritin < 30 μg/L (severe AID), and FID was defined as ferritin < 100 μg/L or ferritin 100–299 μg/L and transferrin saturation < 20%. The association between iron deficiency and incident coronary heart disease (CHD), CV mortality, and all‐cause mortality was evaluated by Cox regression models. Population attributable fraction (PAF) was estimated. Median age was 59 (45–68) years; 45.2% were male. AID, severe AID, and FID were prevalent in 60.0%, 16.4%, and 64.3% of individuals. AID was associated with CHD [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.04–1.39, P = 0.01], but not with mortality. Severe AID was associated with all‐cause mortality (HR 1.28, 95% CI 1.12–1.46, P < 0.01), but not with CV mortality/CHD. FID was associated with CHD (HR 1.24, 95% CI 1.07–1.43, P < 0.01), CV mortality (HR 1.26, 95% CI 1.03–1.54, P = 0.03), and all‐cause mortality (HR 1.12, 95% CI 1.01–1.24, P = 0.03). Overall, 5.4% of all deaths, 11.7% of all CV deaths, and 10.7% of CHD were attributable to FID.

Conclusions

In the general population, FID was highly prevalent, was associated with incident CHD, CV death, and all‐cause death, and had the highest PAF for these events, whereas AID was only associated with CHD and severe AID only with all‐cause mortality. This indicates that FID is a relevant risk factor for CV diseases in the general population.

Age-specific atrial fibrillation incidence, attributable risk factors and risk of stroke and mortality: results from the MORGAM Consortium

Background

The main aim was to examine age-specific risk factor associations with incident atrial fibrillation (AF) and their attributable fraction in a large European cohort. Additionally, we aimed to examine risk of stroke and mortality in relation to new-onset AF across age.

Methods

We used individual-level data (n=66 951, 49.1% men, age range 40–98 years at baseline) from five European cohorts of the MOnica Risk, Genetics, Archiving and Monograph Consortium. The participants were followed for incident AF for up to 10 years and the association with modifiable risk factors from the baseline examinations (body mass index (BMI), hypertension, diabetes, daily smoking, alcohol consumption and history of stroke and myocardial infarction (MI)) was examined. Additionally, the participants were followed up for incident stroke and all-cause mortality after new-onset AF.

Results

AF incidence increased from 0.9 per 1000 person-years at baseline age 40–49 years, to 17.7 at baseline age ≥70 years. Multivariable-adjusted Cox models showed that higher BMI, hypertension, high alcohol consumption and a history of stroke or MI were associated with increased risk of AF across age groups (p<0.05). Between 30% and 40% of the AF risk could be attributed to BMI, hypertension and a history of stroke or MI. New-onset AF was associated with a twofold increase in risk of stroke and death at ages≥70 years (p≤0.001).

Conclusion

In this large European cohort aged 40 years and above, risk of AF was largely attributed to BMI, high alcohol consumption and a history MI or stroke from middle age. Thus, preventive measures for AF should target risk factors such as obesity and hypertension from early age and continue throughout life.

Noninvasive peripheral vascular function, incident cardiovascular disease, and mortality in the general population

Aims 

Evidence suggests that peripheral vascular function is related to cardiovascular disease (CVD) and mortality. We evaluated the associations of non-invasive measures of flow-mediated dilatation and peripheral arterial tonometry with incident CVD and mortality.

Methods and results 

In a post-hoc analysis of the community-based Gutenberg Health Study, median age 55 years (25th/75th percentile 46/65) and 49.5% women, we measured brachial artery flow-mediated dilatation (N=12 599) and fingertip peripheral arterial tonometry (N=11 125). After a follow-up of up to 11.7 years, we observed 595 incident CVD events, 106 cardiac deaths, and 860 deaths in total. Survival curves showed decreased event-free survival with higher mean brachial artery diameter and baseline pulse amplitude and better survival with higher mean flow-mediated dilatation and peripheral arterial tonometry ratio (all P_{log rank} <0.05). In multivariable-adjusted Cox regression analyses only baseline pulse amplitude was inversely related to mortality [hazard ratio (HR) per standard deviation increase, 0.86, 95% confidence interval (95% CI), 0.79–0.94; P=0.0009]. After exclusion of individuals with prevalent CVD the association was no longer statistically significant in multivariable-adjusted models (HR 0.91, 95% CI 0.81–1.02; P=0.11). None of the vascular variables substantially increased the C-index of a model comprising clinical risk factors.

Conclusions 

In our cohort, non-invasive measures of peripheral vascular structure and function did not reveal clinically relevant associations with incident CVD or mortality. Whether determination of pulse amplitude by peripheral arterial tonometry improves clinical decision-making in primary prevention needs to be demonstrated.

Association of Circulating Metabolites With Risk of Coronary Heart Disease in a European Population: Results From the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) Consortium

Importance

Risk stratification for coronary heart disease (CHD) remains challenging because of the complex causative mechanism of the disease. Metabolomic profiling offers the potential to detect new biomarkers and improve CHD risk assessment.

Objective

To evaluate the association between circulating metabolites and incident CHD in a large European cohort.

Design, Setting, and Participants

This population-based study used the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) case-cohort to measure circulating metabolites using a targeted approach in serum samples from 10 741 individuals without prevalent CHD. The cohort consisted of a weighted, random subcohort of the original cohort of more than 70 000 individuals. The case-cohort design was applied to 6 European cohorts: FINRISK97 (Finland), Monitoring of Trends and Determinants in Cardiovascular Diseases/Cooperative Health Research in the Region of Augsburg (MONICA/KORA; Germany), MONICA-Brianza and Moli-sani (Italy), DanMONICA (Denmark), and the Scottish Heart Health Extended Cohort (United Kingdom).

Main Outcomes and Measures

Associations with time to CHD onset were assessed individually by applying weighted and adjusted Cox proportional hazard models. The association of metabolites with CHD onset was examined by C indices.

Results

In 10 741 individuals (4157 women [38.7%]; median [interquartile range] age, 56.5 [49.2-62.2] years), 2166 incident CHD events (20.2%) occurred over a median (interquartile range) follow-up time of 9.2 (4.5-15.0) years. Among the 141 metabolites analyzed, 24 were significantly associated with incident CHD at a nominal P value of .05, including phosphatidylcholines (PCs), lysoPCs, amino acids, and sphingolipids. Five PCs remained significant after correction for multiple testing: acyl-alkyl-PC C40:6 (hazard ratio [HR], 1.13 [95% CI, 1.07-1.18]), diacyl-PC C40:6 (HR, 1.10 [95% CI, 1.04-1.15]), acyl-alkyl-PC C38:6 (HR, 1.11 [95% CI, 1.05-1.16]), diacyl-PC C38:6 (HR, 1.09 [95% CI, 1.04-1.14]) and diacyl-PC C38:5 (HR, 1.10 [95% CI, 1.05-1.16]). Lower levels of these metabolites were associated with increased risk of incident CHD. The strength of the associations competes with those of classic risk factors (C statistics: acyl-alkyl-PC C40:6, 0.756 [95% CI, 0.738-0.774], diacyl-PC C40:6, 0.754 [95% CI, 0.736-0.772], acyl-alkyl-PC C38:6, 0.755 [95% CI, 0.736-0.773], diacyl-PC C38:6, 0.754 [95% CI, 0.736-0.772]), diacyl-PC C38:5, 0.754 [95% CI, 0.736-0.772]). Adding metabolites to a base risk model including classic risk factors high-sensitivity C-reactive protein and high-sensitivity troponin I did not improve discrimination by C statistics.

Conclusions and Relevance

Five PCs were significantly associated with increased risk of incident CHD and showed comparable discrimination with individual classic risk factors. Although these metabolites do not improve CHD risk assessment beyond that of classic risk factors, these findings hold promise for an improved understanding of the pathophysiology of CHD.

Comparison of Cardiovascular Risk Factors in European Population Cohorts for Predicting Atrial Fibrillation and Heart Failure, Their Subsequent Onset, and Death

Background

Differences in risk factors for atrial fibrillation (AF) and heart failure (HF) are incompletely understood. Aim of this study was to understand whether risk factors and biomarkers show different associations with incident AF and HF and to investigate predictors of subsequent onset and mortality.

Methods and Results

In N=58 693 individuals free of AF/HF from 5 population‐based European cohorts, Cox regressions were used to find predictors for AF, HF, subsequent onset, and mortality. Differences between associations were estimated using bootstrapping. Median follow‐up time was 13.8 years, with a mortality of 15.7%. AF and HF occurred in 5.0% and 5.4% of the participants, respectively, with 1.8% showing subsequent onset. Age, male sex, myocardial infarction, body mass index, and NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) showed similar associations with both diseases. Antihypertensive medication and smoking were stronger predictors of HF than AF. Cholesterol, diabetes mellitus, and hsCRP (high‐sensitivity C‐reactive protein) were associated with HF, but not with AF. No variable was exclusively associated with AF. Population‐attributable risks were higher for HF (75.6%) than for AF (30.9%). Age, male sex, body mass index, diabetes mellitus, and NT‐proBNP were associated with subsequent onset, which was associated with the highest all‐cause mortality risk.

Conclusions

Common risk factors and biomarkers showed different associations with AF and HF, and explained a higher proportion of HF than AF risk. As the subsequent onset of both diseases was strongly associated with mortality, prevention needs to be rigorously addressed and remains challenging, as conventional risk factors explained only 31% of AF risk.

P6498Linkage analysis of transvalvular flow patterns, histopathology and target gene expression in aortic valve disease

Objectives

Recent studies have shown that shear stress can alter the integrity and gene expression of the aortic wall. We aim to analyze the link between jet dynamic, histological alterations, and gene expression patterns of the proximal aorta in patients with aortic valve disease.

Methods

We prospectively identified a total of 139 consecutive patients who were referred for aortic valve replacement (AVR) from January 2012 through December 2015. All patients underwent pre-operative MRI assessment to determine the maximal shear stress area of the proximal aorta. Depending of the aorta diameter we subdivided our study population in three subgroup (i.e., patients with a diameter ≤40mm, 41–49mm and ≥50mm). Based on the MRI results, two aortic wall tissue samples were collected during surgery. One sample were acquired from an area of low wall shear stress (WSS) and the second from the area of maximal WSS. The samples were graded in seven histopathologic features.

For RNA isolation the tissue was disrupted using a Tissue Lyser II (Qiagen). For the gene expression analysis of h18S, hCCL2, hCOL1A1, hVCAM1, and hELN reverse transcription of RNA was carried out using the High-capacity cDNA kit (life-technologies,USA). Therefore, 125 ng total RNA from tissue samples were reversely transcribed into cDNA.

Results

Regardless of the aortic valve functional lesion (i.e., stenosis or regurgitation), the maximal area of WSS was in the major curvature of the proximal aorta (73%, n=102). We observed that in both tissue samples just the orientation of vascular smooth muscle cell was strongly related to the diameter of the ascending aorta (p=0.004 vs. p=0.0032). In the whole study population any significant correlation was found between maximal cross-sectional aortic diameter and genes expression. However, in the subgroup analysis we identified that the tissue samples who were exposed to higher wall shear stress and presented a diameter ≥50mm, showed a statically significant gene over-expresion of COL1A1 (p=0.041) and ELN (p=0.01). In the tissue samples with a low WSS we also identified a significant over-expression of CCL2 (p=0.005) and COL1A1 (p=0.01).

Conclusions

Tissue samples from the slow WSS area with a proximal aortic diameter ≥50mm presented elevated levels of inflammatory response genes (i.e, CCL2). On the other hand, samples that were exposed to higher WSS demonstrated more relation to changes in the architecture of the connective fibres (i.e., elastin and collagen).

Acknowledgement/Funding

None

Sex differences in preformed panel-reactive antibody levels and outcomes in patients undergoing heart transplantation

BACKGROUND

Sex differences in panel-reactive antibody (PRA) levels in heart transplant recipients and their association with transplant-related outcomes are mostly unknown.

METHODS

In 20 181 (24.7% women) first-time heart transplant recipients included from July 2004 to March 2015 in the prospective Organ Procurement and Transplantation Network (OPTN), we studied sex differences in most recent (mr) and peak (p)PRA and outcomes (graft failure, rejection, cardiac allograft vasculopathy [CAV], retransplantation, and mortality). Median follow-up (all-cause mortality) was 6 years. Analyses are based on OPTN data (March 6, 2017).

RESULTS

MrPRA levels were associated with all-cause mortality (hazard ratio, 95% confidence interval: class I 1.03, 1.01-1.04, P < 0.001) and acute rejection (class II 1.08, 1.03-1.14, P = 0.0044). PPRA levels were associated with all-cause mortality (class I 1.02, 1.00-1.04, P = 0.015) and CAV (class II 1.03, 1.01-1.06, P = 0.020). Sex interactions were seen for the association of pPRA and graft failure with a higher risk in women, and for pPRA and CAV with a higher risk in men.

CONCLUSIONS

PRA were associated with different transplant-related outcomes in both sexes. However, women with elevated pPRA were shown to be at higher risk for graft failure, whereas higher levels of pPRA were more hazardous for men in developing CAV.

Symptom Burden of Atrial Fibrillation and Its Relation to Interventions and Outcome in Europe

Background

Little is known about the association of atrial fibrillation symptom burden with quality of life and outcomes.

Methods and Results

In the Prevention of Thromboembolic Events–European Registry in Atrial Fibrillation (n=6196 patients with atrial fibrillation; mean±SD age, 71.8±10.4 years; 39.7% women), we assessed European Heart Rhythm Association score symptoms and calculated correlations with the standardized health status questionnaire (EQ‐5D‐5L). Patients were followed up for atrial fibrillation therapies and outcomes (stroke/transient ischemic attack/arterial thromboembolism, coronary events, heart failure, and major bleeding) over 1 year. Most individuals (92%) experienced symptoms. Correlations with health status and quality of life were modest. In multivariable‐adjusted regression models, the dichotomized European Heart Rhythm Association score (intermediate/frequent versus never/occasional symptoms) was associated with cardioversions (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.01–1.45) and catheter ablation (OR, 1.97; 95% CI, 1.44–2.69), and inversely related with heart rate control (OR, 0.80; 95% CI, 0.70–0.92) and heart failure incidence (OR, 1.65; 95% CI, 1.16–2.34). Anxiety was inversely related with stroke/transient ischemic attack/arterial thromboembolism (OR, 0.55; 95% CI, 0.32–0.93), whereas chest pain related positively with coronary events (OR, 2.45; 95% CI, 1.42–4.22). Fatigue (OR, 1.84; 95% CI, 1.30–2.60), dyspnea (OR, 2.33; 95% CI, 1.63–3.33), and anxiety (OR, 1.72; 95% CI, 1.16–2.55) were associated with heart failure incidence. Palpitations were positively associated with cardioversion (OR, 1.32; 95% CI, 1.08–1.61) and ablation therapy (OR, 2.02; 95% CI, 1.48–2.76).

Conclusions

A higher symptom burden, in particular palpitations, predicted interventions to restore sinus rhythm. The score itself had limited predictive value, but its individual components were related to different and specific clinical events, and may thus be helpful to target patient management.

Atrial fibrillation patterns are associated with arrhythmia progression and clinical outcomes

OBJECTIVES

Determinants of atrial fibrillation (AF) patterns and of progression of earlier forms to permanent AF, and their relationship with outcome are still poorly understood.

METHODS

We examined AF patterns (paroxysmal, persistent and permanent), rate and predictors of AF progression, and outcomes in the PREFER (PREvention oF thromboembolic events-European Registry) in AF. The primary analysis was performed in the PREFER in AF prolongation dataset (n=3223 patients with AF with a complete 1-year follow-up, mean age 72±9 years, 40% women). Sensitivity analyses were performed using the PREFER in the AF study (n=6390 patients).

RESULTS

AF progressed to more persistent types in 506 patients (17%). Permanent AF was associated with development of heart failure at 1 year (OR 1.80, 95% CI 1.06 to 3.07, p=0.03) compared with paroxysmal AF, which was confirmed in the entire cohort. In multivariable-adjusted models, sinus rhythm at baseline, AF duration, cardioversion, hyperthyroidism, valvular heart disease, diabetes mellitus and heart failure were predictors of AF progression (area under the receiver operating characteristic curve 0.60, 95% CI 0.57 to 0.63). Results were similar when we restricted analyses to patients with AF duration <1 year. AF progression showed an association with coronary events over 1 year (OR 2.27, 95% CI 1.22 to 4.19, p=0.0074).

CONCLUSIONS

Permanent AF at baseline was associated with incident heart failure. A substantial proportion of well-managed patients with AF showed AF progression over 1 year. AF progression itself was not strongly related to outcome and may indicate the need to refine the current classification of AF types to enhance clinical utility.

Sex Differences and Similarities in Atrial Fibrillation Epidemiology, Risk Factors, and Mortality in Community Cohorts: Results From the BiomarCaRE Consortium (Biomarker for Cardiovascular Risk Assessment in Europe)

BACKGROUND

Atrial fibrillation (AF) is a common cardiac disease in aging populations with high comorbidity and mortality. Sex differences in AF epidemiology are insufficiently understood.

METHODS

In N=79 793 individuals without AF diagnosis at baseline (median age, 49.6 years; age range, 24.1-97.6 years; 51.7% women) from 4 community-based European studies (FINRISK, DanMONICA, Moli-sani Northern Sweden) of the BiomarCaRE consortium (Biomarker for Cardiovascular Risk Assessment in Europe), we examined AF incidence, its association with mortality, common risk factors, biomarkers, and prevalent cardiovascular disease, and their attributable risk by sex. Median follow-up time was 12.6 (to a maximum of 28.2) years.

RESULTS

Fewer AF cases were observed in women (N=1796; 4.4%), than in men (N=2465; 6.4%). Cardiovascular risk factor distribution and lipid profile at baseline were less beneficial in men than in women, and cardiovascular disease was more prevalent in men. Cumulative incidence increased markedly after the age of 50 years in men and after 60 years in women. The lifetime risk was similar (>30%) for both sexes. Subjects with incident AF had a 3.5-fold risk of death in comparison with those without AF. Multivariable-adjusted models showed sex differences for the association of body mass index and AF (hazard ratio per standard deviation increase, 1.18; 95% confidence interval [CI], 1.12-1.23 in women versus 1.31; 95% CI 1.25-1.38 in men; interaction P value of 0.001). Total cholesterol was inversely associated with incident AF with a greater risk reduction in women (hazard ratio per SD, 0.86; 95% CI, 0.81-0.90 versus 0.92; 95% CI, 0.88-0.97 in men; interaction P value of 0.023). No sex differences were seen for C-reactive protein and N-terminal pro B-type natriuretic peptide. The population-attributable risk of all risk factors combined was 41.9% in women and 46.0% in men. About 20% of the risk was observed for body mass index.

CONCLUSIONS

Lifetime risk of AF was high, and AF was strongly associated with increased mortality both in women and men. Body mass index explained the largest proportion of AF risk. Observed sex differences in the association of body mass index and total cholesterol with AF need to be evaluated for underlying pathophysiology and relevance to sex-specific prevention strategies.

Gender differences in clinical presentation and 1-year outcomes in atrial fibrillation

OBJECTIVES

Our objective was to examine gender differences in clinical presentation, management and prognosis of atrial fibrillation (AF) in a contemporary cohort.

METHODS

In 6412 patients, 39.7% women, of the PREvention oF thromboembolic events - European Registry in Atrial Fibrillation, we examined gender differences in symptoms, risk factors, therapies and 1-year incidence of adverse outcomes.

RESULTS

Men with AF were on average younger than women (mean±SD: 70.1±10.7 vs 74.1±9.7 years, p<0.0001). Women more frequently had at least one AF-related symptom at least occasionally compared with men (95.4% in women, 89.8% in men, p<0.0001). Prescription of oral anticoagulation was similar, with an increase of non-vitamin K antagonist oral anticoagulants from 5.9% to 12.6% in women and from 6.2% to 12.6% in men, p<0.0001 for both.Men were more frequently treated with electrical cardioversion and ablation (20.6% and 6.3%, respectively) than women (14.9% and 3.3%, respectively), p<0.0001. Women had 65% (OR: 0.35; 95% CI (0.22 to 0.56)) lower age-adjusted and country-adjusted odds of coronary revascularisation, 40% (OR: 0.60; (0.38 to 0.93)) lower odds of acute coronary syndrome and 20% (OR: 0.80; (0.68 to 0.96)) lower odds of heart failure at 1 year. There were no statistically significant gender differences in 1-year stroke/transient ischaemic attack/arterial thromboembolism and major bleeding events.

CONCLUSION

In a 'real-world' European AF registry, women were more symptomatic but less likely to receive invasive rhythm control therapy such as electrical cardioversion or ablation. Further study is needed to confirm that these differences do not disadvantage women with AF.

Relations of Metabolically Healthy and Unhealthy Obesity to Digital Vascular Function in Three Community-Based Cohorts: A Meta-Analysis

Background

Microvascular dysfunction is a marker of early vascular disease that predicts cardiovascular events. Whether metabolically healthy obese individuals have impaired microvascular function remains unclear. The aim of this study was to evaluate the relation of obesity phenotypes stratified by metabolic status to microvascular function.

Methods and Results

We meta‐analyzed aggregate data from 3 large cohorts (Brazilian Longitudinal Study of Adult Health, the Framingham Heart Study, and the Gutenberg Heart Study; n=16 830 participants, age range 19–90, 51.3% men). Regression slopes between cardiovascular risk factors and microvascular function, measured by peripheral arterial tonometry (PAT), were calculated. Individuals were classified as normal‐weight, overweight, or obese by body mass index (BMI) and stratified by healthy or unhealthy metabolic status based on metabolic syndrome using the ATP‐III criteria. Male sex, BMI, and metabolic risk factors were associated with higher baseline pulse amplitude and lower PAT ratio. There was stepwise impairment of vascular measures from normal weight to obesity in both metabolic status strata. Metabolically healthy obese individuals had more impaired vascular function than metabolically healthy normal‐weight individuals (baseline pulse amplitude 6.12±0.02 versus 5.61±0.01; PAT ratio 0.58±0.01 versus 0.76±0.01, all P<0.0001). Metabolically unhealthy obese individuals had more impaired vascular function than metabolically healthy obese individuals (baseline pulse amplitude 6.28±0.01 versus 6.12±0.02; PAT ratio 0.49±0.01 versus 0.58±0.01, all P<0.0001).

Conclusions

Metabolically healthy obese individuals have impaired microvascular function, though the degree of impairment is less marked than in metabolically unhealthy obese individuals. Our findings suggest that obesity is detrimental to vascular health irrespective of metabolic status.

Reference intervals of plasma homoarginine from the German Gutenberg Health Study

BACKGROUND

Low circulating homoarginine has been associated with adverse cardiovascular (CV) outcome and mortality in patients at risk and in the general population. The present study aimed to define plasma homoarginine reference intervals from a representative population sample to improve risk stratification between healthy individuals and individuals at risk.

METHODS

We determined age- and sex-specific reference intervals for circulating plasma homoarginine in a subgroup of 786 healthy participants (no CV disease or risk factors) of the Gutenberg Health Study. Homoarginine concentrations were measured using a validated liquid chromatography-tandem mass spectrometry method.

RESULTS

Median EDTA plasma homoarginine concentration was 1.88 [25th; 75th percentile, 1.47; 2.41] μmol/L, with lower concentrations in women (1.77 [1.38; 2.26] μmol/L) than in men (2.01 [1.61; 2.56] μmol/L; p<0.001). Sex-specific 2.5th and 97.5th percentiles of reference intervals were 0.84 and 3.89 μmol/L in women and 0.98 and 4.10 μmol/L in men, respectively. Homoarginine concentrations also depended on age and single nucleotide polymorphisms related to the L-arginine:glycine amidinotransferase gene.

CONCLUSIONS

We provide plasma homoarginine reference intervals in men and women of the general population. The determination of homoarginine levels might be favorable for individual risk stratification.

FEV1 and FVC predict all-cause mortality independent of cardiac function - Results from the population-based Gutenberg Health Study

BACKGROUND

Lung function has previously been related to increased mortality. Whether pulmonary impairment is associated with an increased mortality independent of cardiac dysfunction remains unclear.

METHODS

In 15010 individuals from the general population (age range 35-74years, 51% men) in the Gutenberg Health Study we performed spirometry and transthoracic echocardiography. N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and high-sensitive troponin I (hsTnI) were measured in all individuals. 1819 individuals with pulmonary diseases were excluded from further analysis.

RESULTS

The median for forced expiratory volume in 1s (FEV1) was 94.2% and for forced vital capacity (FVC) 94.2% as a percentage of their predicted values. The median FEV1/FVC ratio was 79.1%. In 13191 subjects, 335 deaths were verified from death certificate over a median follow-up of 5.5years. Multivariable-adjusted Cox regression analyses for common cardiovascular risk factors and heart failure revealed that an increase of one standard deviation (SD) of percent predicted (%pred.) FEV1 was associated with a 22% risk reduction (hazard ratio [HR] per SD 0.78 [95% confidence interval (CI): 0.70, 0.86]). The association remained statistically significant after additional adjustment for diastolic dysfunction, Nt-proBNP or hsTnI. Comparable results were seen for %pred. FVC. After adjustment, no association of FEV1/FVC ratio with mortality could be shown. No significant interaction by heart failure was observed.

CONCLUSIONS

The lung function parameters FEV1 and FVC, but not FEV1/FVC ratio, were related to all-cause mortality in individuals from the general population independent of cardiac function.

High-sensitivity troponin and novel biomarkers for the early diagnosis of non-ST-segment elevation myocardial infarction in patients with atrial fibrillation

AIMS

To evaluate the diagnostic performance of high-sensitivity troponin I (hsTnI) and other novel biomarkers for diagnosing non-ST-segment elevation myocardial infarction (NSTEMI) in patients with atrial fibrillation.

METHODS

In an acute chest pain cohort (N=1673), mean age 61.4±13.6 (34% female), we measured hsTnI and 13 established and novel biomarkers reflecting ischaemia, necrosis, inflammation, myocardial stress, angiogenesis on admission and after three hours in order to investigate their diagnostic accuracy for NSTEMI.

RESULTS

In atrial fibrillation patients (N=299) hsTnI on admission had the best discriminatory ability for NSTEMI (area under the curve 0.97) with only two novel biomarkers, copeptin and heart-type fatty acid binding protein, having area under the curve >0.70. Measured biomarkers showed comparable discriminatory ability in atrial fibrillation and non-atrial fibrillation patients. The combination of hsTnI on admission with additional biomarkers did not clinically significantly improve diagnostic performance. In atrial fibrillation patients, hsTnI concentrations ⩽21.7 ng/L (99th percentile in a healthy German cohort) on admission gave a negative predictive value of ~100% (95% confidence interval 97-100%). The combination of hsTnI on admission and absolute change of hsTnI concentration after three hours of ⩾40 ng/L resulted in a positive predictive value of 81.2% and sensitivity of 88.6%. Diagnostic accuracy was validated in an independent cohort (N=1076).

CONCLUSION

The diagnostic accuracy of hsTnI in patients with acute chest pain and atrial fibrillation is high and comparable to those without atrial fibrillation. Absolute change in hsTnI concentration enhanced diagnostic performance. No clinically relevant improvement was achieved by adding other biomarkers.

Comparison of Cox Model Methods in A Low-dimensional Setting with Few Events

Prognostic models based on survival data frequently make use of the Cox proportional hazards model. Developing reliable Cox models with few events relative to the number of predictors can be challenging, even in low-dimensional datasets, with a much larger number of observations than variables. In such a setting we examined the performance of methods used to estimate a Cox model, including (i) full model using all available predictors and estimated by standard techniques, (ii) backward elimination (BE), (iii) ridge regression, (iv) least absolute shrinkage and selection operator (lasso), and (v) elastic net. Based on a prospective cohort of patients with manifest coronary artery disease (CAD), we performed a simulation study to compare the predictive accuracy, calibration, and discrimination of these approaches. Candidate predictors for incident cardiovascular events we used included clinical variables, biomarkers, and a selection of genetic variants associated with CAD. The penalized methods, i.e., ridge, lasso, and elastic net, showed a comparable performance, in terms of predictive accuracy, calibration, and discrimination, and outperformed BE and the full model. Excessive shrinkage was observed in some cases for the penalized methods, mostly on the simulation scenarios having the lowest ratio of a number of events to the number of variables. We conclude that in similar settings, these three penalized methods can be used interchangeably. The full model and backward elimination are not recommended in rare event scenarios.

Subclinical impairment of lung function is related to mild cardiac dysfunction and manifest heart failure in the general population

BACKGROUND

Lung function impairment has previously been related to heart failure, although no overt cardiovascular or structural heart disease is present. The extent to which pulmonary function is related to subclinical left ventricular impairment in the general population remains to be investigated.

METHODS

15010 individuals from the general population (mean age 55±11years, 50.5% men) in the Gutenberg Health Study underwent spirometry, transthoracic echocardiography and biomarker measurement. Forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) in percent of the predicted value and FEV1/FVC ratio were associated with echocardiographic measures of cardiac structure, systolic and diastolic function, biomarkers of cardiac necrosis (high-sensitive troponin I, hsTnI) and stress (N-terminal pro-B-type natriuretic peptide, Nt-proBNP) and heart failure with preserved (HFpEF) and reduced ejection fraction (HFrEF).

RESULTS

Percent predicted FEV1 and FVC were significantly associated with hsTnI (P<0.001) and Nt-proBNP (P<0.001). Additionally, FEV1/FVC ratio was significantly related to hsTnI (P=0.0043) and Nt-proBNP (P<0.001). In the multivariable-adjusted linear regression analyses strongest associations were observed for percent predicted FEV1 and FVC with LVESD, E/e', SV and EF. FEV1/FVC ratio was significantly related with SV and EF. The three lung function parameters were significantly (P<0.001) associated with HFpEF and HFrEF. Associations remained statistically significant after exclusion of individuals with COPD.

CONCLUSIONS

FEV1, FVC and FEV1/FVC ratio were associated with systolic and diastolic function and manifest heart failure. Our observations could show, that subclinical lung function impairment is related to a measurable reduction of left ventricular filling and cardiac output in the general population.

Sex Differences in Correlates of Intermediate Phenotypes and Prevalent Cardiovascular Disease in the General Population

Background

There are marked sex differences in cardiovascular disease (CVD) manifestation. It is largely unknown how the distribution of CVD risk factors or intermediate phenotypes explain sex-specific differences.

Methods and Results

In 5000 individuals of the population-based Gutenberg Health Study, mean age 55 ± 11 years, 51% males, we examined sex-specific associations of classical CVD risk factors with intima-media thickness, ankle-brachial index, flow-mediated dilation, peripheral arterial tonometry, echocardiographic, and electrocardiographic variables. Intermediate cardiovascular phenotypes were related to prevalent CVD [coronary artery disease, heart failure, stroke, myocardial infarction, lower extremity artery disease (LEAD) N = 561].

We observed differential distributions of CVD risk factors with a higher risk factor burden in men. Manifest coronary artery disease, stroke, myocardial infarction, and LEAD were more frequent in men; the proportion of heart failure was higher in women. Intermediate phenotypes showed clear sex differences with more beneficial values in women. Fairly linear changes toward less beneficial values with age were observed in both sexes. In multivariable-adjusted regression analyses, age, systolic blood pressure, and body mass index were consistently associated with intermediate phenotypes in both sexes with different ranking according to random forests, maximum model R² 0.43. Risk factor-adjusted associations with prevalent CVD showed some differences by sex. No interactions by menopausal status were observed.

Conclusion

In a population-based cohort, we observed sex differences in risk factors and a broad range of intermediate phenotypes of non-invasive cardiovascular structure and function. Their relation to prevalent CVD differed markedly. Our results indicate the need of future investigations to understand sex differences in CVD manifestation.

Multiple biomarkers and atrial fibrillation in the general population

Background

Different biological pathways have been related to atrial fibrillation (AF). Novel biomarkers capturing inflammation, oxidative stress, and neurohumoral activation have not been investigated comprehensively in AF.

Methods and Results

In the population-based Gutenberg Health Study (n = 5000), mean age 56±11 years, 51% males, we measured ten biomarkers representing inflammation (C-reactive protein, fibrinogen), cardiac and vascular function (midregional pro adrenomedullin [MR-proADM], midregional pro atrial natriuretic peptide [MR-proANP], N-terminal pro-B-type natriuretic peptide [Nt-proBNP], sensitive troponin I ultra [TnI ultra], copeptin, and C-terminal pro endothelin-1), and oxidative stress (glutathioneperoxidase-1, myeloperoxidase) in relation to manifest AF (n = 161 cases). Individuals with AF were older, mean age 64.9±8.3, and more often males, 71.4%. In Bonferroni-adjusted multivariable regression analyses strongest associations per standard deviation increase in biomarker concentrations were observed for the natriuretic peptides Nt-proBNP (odds ratio [OR] 2.89, 99.5% confidence interval [CI] 2.14–3.90; P<0.0001), MR-proANP (OR 2.45, 99.5% CI 1.91–3.14; P<0.0001), the vascular function marker MR-proADM (OR 1.54, 99.5% CI 1.20–1.99; P<0.0001), TnI ultra (OR 1.50, 99.5% CI 1.19–1.90; P<0.0001) and. fibrinogen (OR 1.44, 99.5% CI 1.19–1.75; P<0.0001). Based on a model comprising known clinical risk factors for AF, all biomarkers combined resulted in a net reclassification improvement of 0.665 (99.3% CI 0.441–0.888) and an integrated discrimination improvement of >13%.

Conclusions

In conclusion, in our large, population-based study, we identified novel biomarkers reflecting vascular function, MR-proADM, inflammation, and myocardial damage, TnI ultra, as related to AF; the strong association of natriuretic peptides was confirmed. Prospective studies need to examine whether risk prediction of AF can be enhanced beyond clinical risk factors using these biomarkers.

Genome-wide association study of L-arginine and dimethylarginines reveals novel metabolic pathway for symmetric dimethylarginine

BACKGROUND

Dimethylarginines (DMA) interfere with nitric oxide formation by inhibiting nitric oxide synthase (asymmetrical DMA [ADMA]) and l-arginine uptake into the cell (ADMA and symmetrical DMA [SDMA]). In prospective clinical studies, ADMA has been characterized as a cardiovascular risk marker, whereas SDMA is a novel marker for renal function and associated with all-cause mortality after ischemic stroke. The aim of the current study was to characterize the environmental and genetic contributions to interindividual variability of these biomarkers.

METHODS AND RESULTS

This study comprised a genome-wide association analysis of 3 well-characterized population-based cohorts (Framingham Heart Study [FHS; n=2992], Gutenberg Health Study [GHS; n=4354], and Multinational Monitoring of Trends and Determinants in Cardiovascular Disease Study [MONICA]/Cooperative Health Research in the Augsburg Area, Augsburg, Bavaria, Germany [KORA] F3 [n=581]) and identified replicated loci (DDAH1, MED23, Arg1, and AGXT2) associated with the interindividual variability in ADMA, l-arginine, and SDMA. Experimental in silico and in vitro studies confirmed functional significance of the identified AGXT2 variants. Clinical outcome analysis in 384 patients of the Leeds stroke study demonstrated an association between increased plasma levels of SDMA, AGXT2 variants, and various cardiometabolic risk factors. AGXT2 variants were not associated with poststroke survival in the Leeds study or were they associated with incident stroke in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium.

CONCLUSIONS

These genome-wide association study support the importance of DDAH1 and MED23/Arg1 in regulating ADMA and l-arginine metabolism, respectively, and identify a novel regulatory renal pathway for SDMA by AGXT2. AGXT2 variants might explain part of the pathogenic link between SDMA, renal function, and outcome. An association between AGXT2 variants and stroke is unclear and warrants further investigation.

Depression in atrial fibrillation in the general population

Background

Initial evidence suggests that depressive symptoms are more frequent in patients with atrial fibrillation. Data from the general population are limited.

Methods and Results

In 10,000 individuals (mean age 56±11 years, 49.4% women) of the population-based Gutenberg Health Study we assessed depression by the Patient Health Questionnaire (PHQ-9) and a history of depression in relation to manifest atrial fibrillation (n = 309 cases). The median (25th/75th percentile) PHQ-9 score of depressive symptoms was 4 (2/6) in atrial fibrillation individuals versus 3 (2/6) individuals without atrial fibrillation, . Multivariable regression analyses of the severity of depressive symptoms in relation to atrial fibrillation in cardiovascular risk factor adjusted models revealed a relation of PHQ-9 values and atrial fibrillation (odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01–1.08; P = 0.023). The association was stronger for the somatic symptom dimension of depression (OR 1.08, 95% CI 1.02–1.15; P = 0.0085) than for cognitive symptoms (OR 1.05, 95% CI 0.98–1.11; P = 0.15). Results did not change markedly after additional adjustment for heart failure, partnership status or the inflammatory biomarker C-reactive protein. Both, self-reported physical health status, very good/good versus fair/bad, (OR 0.54, 95% CI 0.41–0.70; P<0.001) and mental health status (OR 0.61 (0.46–0.82); P = 0.0012) were associated with atrial fibrillation in multivariable-adjusted models.

Conclusions

In a population-based sample we observed a higher burden of depressive symptoms driven by somatic symptom dimensions in individuals with atrial fibrillation. Depression was associated with a worse perception of physical or mental health status. Whether screening and treatment of depressive symptoms modulates disease progression and outcome needs to be shown.

Type D personality as a cardiovascular risk marker in the general population: results from the Gutenberg health study

BACKGROUND

Type D personality is considered as an independent risk factor for morbidity and mortality in cardiovascular patients and a vulnerability factor for distress in the general population. Because representative community studies are rare, we sought to determine the prevalence of type D personality and its relationship with demographic characteristics, different features of mental disorders, cardiovascular risk factors, health behavior, endothelial function and cardiovascular biomarkers in the general population.

METHODS

The prevalence of type D personality and its correlates were analyzed cross-sectionally in a population-based sample of 5,000 Mid-Europeans aged 35-74 years from the Gutenberg Health Study.

RESULTS

The prevalence of type D personality was 22.2% without remarkable differences in sex distribution. Type D subjects were characterized by lower socioeconomic status, lack of a partnership, increased depression, anxiety, depersonalization and health care utilization. Despite its strong association with mental disorders, type D personality emerged as psychometrically distinct. Although type D personality was independently associated with coronary heart disease (OR = 1.54, p = 0.044), no associations with traditional cardiovascular risk factors were found independently from depression or anxiety.

CONCLUSIONS

Although type D personality is strongly associated with depression, anxiety, impaired mental and somatic health status, and increased health care utilization, the type D construct seems to comprise dysfunctional personality patterns not covered by depression and anxiety scales. Beyond these associations, the pathways of the cardiotoxic impact of type D personality remain to be elucidated. There is a need for prospective population studies on potential links between type D personality and cardiac disease.

Prevalence of distress, comorbid conditions and well being in the general population

BACKGROUND

The purposes of this paper are to determine the prevalence of distress in the community, to identify its determinants and to assess its relationship to somatic conditions and subjective well being.

METHODS

Distress and associated factors were investigated in a random sample of 5000 participants (35-74 years) of a community-based, prospective, observational cohort study in western Mid-Germany ("Gutenberg Heart Study") between 04/2007 and 10/2008. The sample was stratified 1:1 for gender and residence and in equal strata for decades of age. Data were assessed by self-report instruments, interviews and medical examination.

RESULTS

We found a prevalence rate for depression of 7.2% (6.5-8.0%), social anxiety 7.0% (6.3-7.7%), panic 4.6% (4.0-5.2%), generalized anxiety 3.4% (2.9-3.9%), and Type D personality 22.1% (21.0-23.2%). Mental conditions declined by age. Depression was related to diabetes (OR=1.99, 95% CI=1.26-3.15), dyslipidemia (OR=1.35, 95% CI=1.02-1.79), coronary heart disease (CHD; OR=1.88, 95% CI=1.04-3.39), and the history of stroke (OR=2.43, 95% CI=1.02-5.76). Panic was related to the history of myocardial infarction (OR=2.46, 95% CI=1.15-5.25), and generalized anxiety to obesity (OR=1.65, 95% CI=1.11-2.44). Mental distress was unrelated to hypertension, atrial fibrillation and cancer. In ordinal logistic regression subjective physical and mental well being were associated with anxiety, depression and Type D personality.

CONCLUSIONS

While mental conditions are highly prevalent, especially depression is associated with several somatic conditions. Mental and physical well being are strongly related to mental conditions. Future work should take into account comorbid conditions when identifying the impact of depression on CHD.