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.

In this work, the role of cardiac biomarkers measured from blood to predict cardiovascular events and death is tested in individuals of the general population and particularly in those with known diabetes. The work is based on a cooperation of different population studies across Europe and includes more than 90 000 individuals, with more than 6000 having diabetes. We could demonstrate that the determination of three cardiac biomarkers helps to identify individuals at highest risk for cardiovascular events (e.g. myocardial infarction or stroke) and death, despite accounting for known cardiovascular risk factors in these individuals. Therefore, these biomarkers should be considered for routine risk assessment for cardiovascular diseases and could improve the early identification of high-risk individuals, consequently leading to an earlier initiation of preventive therapies.

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.

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.

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.

Non-invasive 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 Plog 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 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.

Comparison of microstructural alterations in the proximal aorta between aortic stenosis and regurgitation.

OBJECTIVE: We aimed to analyze the association among flow patterns, gene expression, and histologic alterations of the proximal aorta in patients with aortic valve disease. METHODS: A total of 131 patients referred for aortic valve replacement were grouped by valve dysfunction (aortic stenosis vs aortic regurgitation) and valve morphology (bicuspid vs tricuspid). On the basis of magnetic resonance imaging, aortic tissue from outer and inner curvature was collected for gene expression and histologic analysis. To identify differences in aortic remodeling, age- and sex-adjusted data for inflammation (CCL2, VCAM1, inflammation and atherosclerosis) and medial degeneration (COL1A1, ELN, fibrosis, elastin fragmentation, and cystic medial necrosis) were compared. RESULTS: First, we compared all patients with aortic regurgitation (n = 64) and patients with aortic stenosis (n = 67). In patients with aortic regurgitation, COL1A1 expression and all histologic markers were significantly increased. With respect to aortic diameter, all subsequent analyses were refined by considering only individuals with aortic diameter 40 mm or greater. Second, patients with bicuspid aortic valve were compared, resulting in a similar aortic diameter. Although patients with aortic regurgitation were younger, no differences were found in gene expression or histologic level. Third, valve morphology was compared in patients with aortic regurgitation. Although aortic diameter was similar, patients with regurgitant bicuspid aortic valve were younger than patients with regurgitant tricuspid aortic valve. Inflammatory markers were similar, whereas markers for medial degeneration were increased in patients with regurgitant tricuspid aortic valve. CONCLUSIONS: Our results indicate that the proximal aorta in patients with aortic regurgitation showed an increased inflammation and medial degeneration compared with patients with aortic stenosis. Refining both groups by valve morphology, in patients with bicuspid aortic valve, no difference except age was detected between aortic regurgitation and aortic stenosis. In patients with aortic regurgitation, tricuspid aortic valve revealed increased markers for medial degeneration but no differences regarding inflammatory markers.

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.

Temporal relations between atrial fibrillation and ischaemic stroke and their prognostic impact on mortality.

AIMS: Limited evidence is available on the temporal relationship between atrial fibrillation (AF) and ischaemic stroke and their impact on mortality in the community. We sought to understand the temporal relationship of AF and ischaemic stroke and to determine the sequence of disease onset in relation to mortality. METHODS AND RESULTS: Across five prospective community cohorts of the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) project we assessed baseline cardiovascular risk factors in 100 132 individuals, median age 46.1 (25th-75th percentile 35.8-57.5) years, 48.4% men. We followed them for incident ischaemic stroke and AF and determined the relation of subsequent disease diagnosis with overall mortality. Over a median follow-up of 16.1 years, N = 4555 individuals were diagnosed solely with AF, N = 2269 had an ischaemic stroke but no AF diagnosed, and N = 898 developed both, ischaemic stroke and AF. Temporal relationships showed a clustering of diagnosis of both diseases within the years around the diagnosis of the other disease. In multivariable-adjusted Cox regression analyses with time-dependent covariates subsequent diagnosis of AF after ischaemic stroke was associated with increased mortality [hazard ratio (HR) 4.05, 95% confidence interval (CI) 2.17-7.54; P < 0.001] which was also apparent when ischaemic stroke followed after the diagnosis of AF (HR 3.08, 95% CI 1.90-5.00; P < 0.001). CONCLUSION: The temporal relations of ischaemic stroke and AF appear to be bidirectional. Ischaemic stroke may precede detection of AF by years. The subsequent diagnosis of both diseases significantly increases mortality risk. Future research needs to investigate the common underlying systemic disease processes.

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.

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.

Sex-Specific Epidemiology of Heart Failure Risk and Mortality in Europe: Results From the BiomarCaRE Consortium.

OBJECTIVES: This study investigates differences between women and men in heart failure (HF) risk and mortality. BACKGROUND: Sex differences in HF epidemiology are insufficiently understood. METHODS: In 78,657 individuals (median 49.5 years of age; age range 24.1 to 98.7 years; 51.7% women) from community-based European studies (FINRISK, DanMONICA, Moli-sani, Northern Sweden) of the BiomarCaRE (Biomarker for Cardiovascular Risk Assessment in Europe) consortium, the association between incident HF and mortality, the relationship of cardiovascular risk factors, prevalent cardiovascular diseases, biomarkers (C-reactive protein [CRP]; N-terminal pro-B-type natriuretic peptide [NT-proBNP]) with incident HF, and their attributable risks were tested in women vs. men. RESULTS: Over a median follow-up of 12.7 years, fewer HF cases were observed in women (n = 2,399 [5.9%]) than in men (n = 2,771 [7.3%]). HF incidence increased markedly after 60 years of age, initially with a more rapid increase in men, whereas incidence in women exceeded that of men after 85 years of age. HF onset substantially increased mortality risk in both sexes. Multivariable-adjusted Cox models showed the following sex differences for the association with incident HF: systolic blood pressure hazard ratio (HR) according to SD in women of 1.09 (95% confidence interval [CI]: 1.05 to 1.14) versus HR of 1.19 (95% CI: 1.14 to 1.24) in men; heart rate HR of 0.98 (95% CI: 0.93 to 1.03) in women versus HR of 1.09 (95% CI: 1.04 to 1.13) in men; CRP HR of 1.10 (95% CI: 1.00 to 1.20) in women versus HR of 1.32 (95% CI: 1.24 to 1.41) in men; and NT-proBNP HR of 1.54 (95% CI: 1.37 to 1.74) in women versus HR of 1.89 (95% CI: 1.75 to 2.05) in men. Population-attributable risk of all risk factors combined was 59.0% in women and 62.9% in men. CONCLUSIONS: Women had a lower risk for HF than men. Sex differences were seen for systolic blood pressure, heart rate, CRP, and NT-proBNP, with a lower HF risk in women.

Noninvasive peripheral vascular function and atrial fibrillation in the general population.

BACKGROUND: Arterial stiffness is a strong predictor of atrial fibrillation in the community. Whether noninvasively measured conduit artery function and peripheral vascular reactivity are related to atrial fibrillation remains unknown. METHODS AND RESULTS: In 15 010 individuals of the population-based Gutenberg Health Study, mean age 55 ±â€Š11 years, 50.5% men, we determined noninvasive vascular function by flow-mediated dilation (FMD) and peripheral arterial tonometry (PAT) in relation to manifest atrial fibrillation (N = 466). Patients with atrial fibrillation exhibited a higher mean brachial artery diameter [4.81 mm (4.17, 5.33) in atrial fibrillation vs. 4.31 mm (3.67, 4.93)] and baseline pulse amplitude in arbitrary units [6.35 (5.76, 6.78) in atrial fibrillation vs. 6.09 (5.36, 6.71)] as well as a reduced FMD in arbitrary units [1.29 (1.26, 1.33) in atrial fibrillation vs. (1.31 (1.26, 1.37)] and PAT ratio [0.42 (0.19, 0.77) in atrial fibrillation vs. 0.67 (0.33, 0.94)] compared with individuals without atrial fibrillation (all PWilcoxon rank-sum test). In age-adjusted and sex-adjusted logistic regression analyses, only baseline brachial artery diameter [odds ratio (OR) per standard deviation 1.19; 95% confidence interval (CI), 1.04-1.37; P = 0.012] and PAT ratio (OR 0.83; 0.74-0.94; P = 0.0029) were associated with atrial fibrillation. In risk factor and heart rate-adjusted models, there was no statistically significant correlation of atrial fibrillation and brachial artery diameter, FMD and PAT ratio while baseline pulse amplitude was reduced in individuals with atrial fibrillation (OR 0.81; 95% CI 0.71-0.93; P = 0.0034). CONCLUSION: In our large contemporary cohort, peripheral vascular function was compromised in individuals with atrial fibrillation. However, observed associations were mediated by age and classical risk factors. Noninvasive vascular function measures did not improve discriminatory ability for atrial fibrillation.

Precursor proadrenomedullin influences cardiomyocyte survival and local inflammation related to myocardial infarction.

Increased adrenomedullin (ADM) levels are associated with various cardiac diseases such as myocardial infarction (MI). ADM is cleaved off from the full-length precursor protein proadrenomedullin (ProADM) during its posttranslational processing. To date, no biological effect of ProADM is reported, while ADM infusion leads to antiapoptotic effects and improved cardiac function. Using an MI mouse model, we found an induction of ProADM gene as well as protein expression during the early phase of MI. This was accompanied by apoptosis and increasing inflammation, which substantially influence the post-MI remodeling processes. Simulating ischemia in vitro, we demonstrate that ProADM expression was increased in cardiomyocytes and cardiac fibroblasts. Subsequently, we treated ischemic cardiomyocytes with either ProADM or ADM and found that both proteins increased survival. This effect was diminishable by blocking the ADM1 receptor. To investigate whether ProADM and ADM play a role in the regulation of cardiac inflammation, we analyzed chemokine expression after treatment of cells with both proteins. While ProADM induced an expression of proinflammatory cytokines, thus promoting inflammation, ADM reduced chemokine expression. On leukocytes, both proteins repressed chemokine expression, revealing antiinflammatory effects. However, ProADM but not ADM dampened concurrent activation of leukocytes. Our data show that the full-length precursor ProADM is biologically active by reducing apoptosis to a similar extent as ADM. We further assume that ProADM induces local inflammation in affected cardiac tissue but attenuates exaggerated inflammation, whereas ADM has low impact. Our data suggest that both proteins are beneficial during MI by influencing apoptosis and inflammation.

Cross-Sectional Associations between Homoarginine, Intermediate Phenotypes, and Atrial Fibrillation in the Community-The Gutenberg Health Study.

Homoarginine has come into the focus of interest as a biomarker for cardiovascular disease. Atrial fibrillation (AF) causes a substantial increase in morbidity and mortality. Whether circulating homoarginine is associated with occurrence or persistence of AF and may serve as a new predictive biomarker remains unknown. We measured plasma levels of homoarginine in the population-based Gutenberg health study (3761 patients included, of them 51.7% males), mean age 55.6 ± 10.9 years-old. Associations between homoarginine and intermediate electrocardiographic and echocardiographic phenotypes and manifest AF were examined. Patients with AF (124 patients, of them 73.4% males) had a mean age 64.8 ± 8.6 years-old compared to a mean age of 55.3 ± 10.9 in the population without AF (p-value < 0.001) and showed a less beneficial risk factor profile. The median homoarginine levels in individuals with and without AF were 1.9 µmol/L (interquartile range (IQR) 1.5⁻2.5) and 2.0 µmol/L (IQR 1.5⁻2.5), respectively, p = 0.56. In multivariable-adjusted regression analyses homoarginine was not statistically significantly related to electrocardiographic variables. Among echocardiographic variables beta per standard deviation increase was -0.12 (95% confidence interval (CI) -0.23⁻(-0.02); p = 0.024) for left atrial area and -0.01 (95% CI -0.02⁻(-0.003); p = 0.013) for E/A ratio. The odds ratio between homoarginine and AF was 0.91 (95% CI 0.70⁻1.16; p = 0.45). In our large, population-based cross-sectional study, we did not find statistically significant correlations between lower homoarginine levels and occurrence or persistence of AF or most standard electrocardiographic phenotypes, but some moderate inverse associations with echocardiographic left atrial size and E/A. Homoarginine may not represent a strong biomarker to identify individuals at increased risk for AF. Further investigations will be needed to elucidate the role of homoarginine and cardiac function.