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ObjectiveWe evaluated coronary artery calcium (CAC) scoring as an initial diagnostic tool in outpatients and in patients presenting at the emergency department due to suspected coronary artery disease (CAD).Methods10 857 patients underwent CAC scoring and coronary CT angiography (CCTA) at Haukeland University Hospital in Norway during 2013–2020. Based on CCTA, obstructive CAD was defined as at least one coronary stenosis ≥50%. High-risk CAD included obstructive stenoses of the left main stem, the proximal left ascending artery or affecting all three major vascular territories with at least one proximal segment involved.ResultsMedian age was 58 years and 49.5% were women. The overall prevalence of CAC=0 was 45.0%. Among those with CAC=0, 1.8% had obstructive CAD and 0.6% had high-risk CAD on CCTA. Overall, the sensitivity, specificity, positive predictive value and negative predictive value (NPV) of CAC=0 for obstructive CAD were 95.3%, 53.4%, 30.0% and 98.2%, respectively. However, among patients ConclusionsIn symptomatic patients, CAC=0 correctly ruled out obstructive CAD and high-risk CAD in 98.2% and 99.4% of cases. This large registry-based cross-sectional study supports the incorporation of CAC testing in the early triage of patients with chest pain and as a gatekeeper to further cardiac testing. However, a full CCTA may be needed for safely ruling out obstructive CAD in the youngest patients (

Background: Higher systemic concentrations of cardiac troponins and biomarkers of inflammation and endothelial dysfunction as well as obesity are associated with increased risk of cardiovascular disease (CVD) and may share pathophysiological pathways. We sought to explore the association between serum high sensitive cardiac troponin T (hs-cTnT) and future acute myocardial infarction (AMI) according to body mass index (BMI) among patients with suspected chronic coronary syndrome (CCS), as well as interactions with C-reactive protein (CRP) and asymmetric dimethylarginine (ADMA). Methods: A total of 3879 patients with baseline hs-cTnT ≤ 30 ng/L who underwent elective coronary angiography due to chronic coronary syndrome (CCS) were followed to subsequent AMI or end of 2009. Risk associations between hs-cTnT and incident AMI were explored with Cox regression according to BMI categories 30kg/m2 and quartiles of serum CRP and plasma ADMA. Results: Median (25 th −75 th percentile) age was 62 (54–69) years and 2773 (77.5%) were men. During median 7.5 (25 th −75 th percentile) (6.9–9.2) years of follow-up, 460 (11.9%) patients experienced an AMI. The risk relationship between hs-cTnT and incident AMI was stronger among patients in the higher vs lower BMI categories, HR 1.087 (1.055–1.119), P for interaction 0.043. A similar interaction was not found in categories of CRP or ADMA. Conclusion: The risk relationship of hs-cTnT with incident AMI was stronger in patients with higher BMI. Our results motivate further studies into potential pathophysiological mechanisms connecting hs-cTnT with increased cardiovascular risk.

Introduction Increased left ventricular mass index (LVMi) and left ventricular hypertrophy (LVH) by echocardiography are common in obesity and important cardiovascular risk predictors associated with myocardial ischemia in non-obstructive coronary artery disease (CAD). Accumulation of epicardial adipose tissue (EAT) suggest a possible direct impact on LVMi and LVH. Purpose To explore the association between EAT volume, LVMi and LVH in patients with chest pain and non-obstructive CAD. Methods We included 129 patients with chest pain and non-obstructive CAD (46.7 g/m2.7 in women and >49.2 g/m2.7 in men. Coronary artery plaque burden was assessed as calcium score and segment involvement score on coronary CT angiography. Results High EAT volume was more common in men with higher BMI, waist circumference, serum triglycerides and higher prevalence of hypertension and obesity (all p Conclusion High EAT volume was associated with increased LVMi in patients with non-obstructive CAD, independent of hypertension and obesity, while there was no association with LVH. This suggest that direct infiltration of adipose tissue in the myocardium may contribute to the development of increased LVMi. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Western Norwegian Regional Health Authorities Table 1

Background Inadequate intake of polyunsaturated fatty acids (PUFAs) is recognized as a modifiable risk factor for atherosclerotic cardiovascular disease (CVD) (1,2). The n-6 PUFA linoleic acid (LA) constitutes the predominant portion of total dietary PUFAs (3). However, whereas cardiometabolic effects of PUFAs belonging to the n-3 series have been studied for decades, less attention has been payed to potential health effects from n-6 PUFAs (4). Further, there has been concern regarding possible proinflammatory properties of several n-6 PUFA related metabolites. Purpose We explored correlations of serum total PUFAs, LA and the n-3 PUFA docosahexaenoic acid (DHA) with the inflammation marker GlycA. Further, we evaluated associations of total PUFAs, LA and DHA with the extension of atherosclerosis, as determined by the Agatston coronary artery calcium (CAC) score (5). Methods The study includes 250 patients who were hospitalized due to acute chest pain and referred to coronary CT angiography (CCTA) during in hospital stay. Exclusion criteria included diagnosis of acute myocardial infarction and/or revascularization within 24 hours after admittance. Serum levels of total PUFAs, LA, DHA and GlycA were analyzed by NMR technology in samples that had been frozen and stored at −80°C. After logarithmic transformation, relations of total PUFA, LA, and DHA with GlycA were evaluated by Pearson correlation analyses. The associations with CAC score were visualized in generalized additive regression plots and further evaluated in linear regression models including age, gender, body mass index, diabetes, hypertension and smoking status as independent covariables. Results Mean (SD) age was 57.6 (12.0) years, and 91 (36.4%) of the patients were women. Median (25th-75th percentiles) serum levels (in mmol/L) were for total PUFA 6.36 (5.76–7.06), LA 5.00 (4.51–5.55), DHA 0.36 (0.31–0.43) and GlycA 1.04 (0.94–1.13). Interestingly, GlycA was strongly, positively correlated with total PUFA (r=0.54). LA (r=0.53) and DHA (r=0.27), all P Conclusion In patients undergoing CCTA due to acute chest pain, serum levels of total PUFA and LA were strongly positively correlated with the pro-inflammatory marker GlycA. Still, total PUFA and LA were both inversely associated with the CAC score and the associations remained statistically significant after adjustments for CVD risk factors and GlycA levels. Future studies should further address the diverse effects of n-6 PUFAs on inflammatory pathways, atherogenesis and coronary calcification. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Regional Health Authority

Background Although generally at lower risk than those with obstructive CAD, patients with non-obstructive CAD (NOCAD) are heterogeneous concerning long-term prognosis. Notably, reversible ischemia due to vascular dysfunction is a frequent finding in NOCAD patients (1). The endogenous, non-proteinogenic amino acid homoarginine (hArg) increases the availability of nitric oxide (NO) and thereby the NO-dependent vasodilatation (2). Several studies have reported a strong inverse relation between serum hArg levels and cardiovascular disease (CVD) risk among patients with obstructive CAD. However, the prognostic implications of serum hArg levels in NOCAD patients have not been explored previously. Purpose We evaluated serum hArg as a predictor of long-term risk of CVD mortality among patients with NOCAD. Methods 1046 patients with chronic coronary syndrome (CCS) underwent elective coronary angiography during 2000–2004, with the findings of NOCAD. Serum hArg was measured by liquid chromatography-tandem mass spectrometry in samples that had been frozen and stored at −80°C. The association of serum hArg to CVD mortality risk was visualized in a generalized additive regression plot and further explored using Cox regression. The models included age, sex, body mass index, hypertension, diabetes, smoking status, serum LDL cholesterol and estimated glomerular filtration rate as independent covariables. We evaluated model discrimination and risk classification by calculating C-statistics and net reclassification improvement (NRI >0), respectively. Results Median (25th-75th percentiles) age at inclusion was 57 (51–65) years, 48.5% were women and median (25th-75th percentiles) level of serum hArg was 1.87 (1.47–2.38) μmol/L. During median (25th- 75th percentiles) 14.1 (13.2–15.4) years of follow-up 5.7% of the patients died from CVD. The multivariable adjusted hazard ratio (95% confidence interval) per SD increment of (log transformed) hArg was 0.53 (0.40–0.70) in relation to CVD mortality. The multivariable model without biomarker provided a C- statistics for CVD mortality of 0.79 which increased to 0.82 by the addition of serum-hArg to the model (Δ area =0.03, P=0.01). Further, serum hArg provided a high NRI (95% CI) of 0.53 (0.40–0.70), P Conclusion We demonstrated a strong inverse relationship between serum hArg and long-term risk of CVD mortality among patients with NOCAD. Our study adds to previous literature linking low hArg with vascular dysfunction and adverse CVD prognosis. The potential clinical usefulness of serum hArg measurements for the identification of a high-risk phenotype in NOCAD warrants further evaluation. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): The Western Norway Regional Health Authority

Aims Trimethyllysine (TML) is involved in carnitine synthesis, serves as a precursor of trimethylamine N-oxide (TMAO) and is associated with cardiovascular events in patients with established coronary heart disease (CHD). We prospectively examined circulating TML as a predictor of all-cause and cardiovascular mortality in community-dwelling adults and patients with CHD. Methods and results By Cox regression modelling, risk associations were examined in 6393 subjects in the community-based Hordaland Health Study (HUSK). A replication study was conducted among 4117 patients with suspected stable angina pectoris in the Western Norway Coronary Angiography Cohort (WECAC). During a mean follow-up of 10.5 years in the HUSK-cohort, 884 (13.8%) subjects died, of whom 287 from cardiovascular causes. After multivariable adjustments for traditional cardiovascular risk factors, the hazard ratio (HR) [95% confidence interval (95% CI)] for all-cause mortality comparing the 4th vs. 1st TML-quartile was 1.66 (1.31–2.10, P Conclusions Elevated TML-levels were associated with increased risk of all-cause and cardiovascular mortality both in subjects with and without established CHD.

OBJECTIVE Altered plasma amino acid levels have been implicated as markers of risk for incident type 2 diabetes; however, amino acids are also related to established diabetes risk factors. Therefore, potential for confounding and the impact from competing risks require evaluation. RESEARCH DESIGN AND METHODS We prospectively followed 2,519 individuals with coronary artery disease but without diabetes. Mixed Gaussian modeling identified potential for confounding. Confounding, defined as a change in effect estimate (≥10%), was investigated by comparing amino acid–incident diabetes risk in a Cox model containing age and sex with that in models adjusted for potential confounders (BMI, estimated glomerular filtration rate, HDL cholesterol, triacylglycerol, C-reactive protein), which were further adjusted for plasma glucose, competing risks, and multiple comparisons (false discovery rate = 0.05, Benjamini-Hochberg method). Finally, component-wise likelihood-based boosting analysis including amino acids and confounders was performed and adjusted for competing risks in order to identify an optimal submodel for predicting incident diabetes. RESULTS The mean age of the source population was 61.9 years; 72% were men. During a median follow-up of 10.3 years, 267 incident cases of diabetes were identified. In age- and sex-adjusted models, several amino acids, including the branched-chain amino acids, significantly predicted incident diabetes. Adjustment for confounders, however, attenuated associations. Further adjustment for glucose and multiple comparisons rendered only arginine significant (hazard ratio/1 SD 1.21 [95% CI 1.07–1.37]). The optimal submodel included arginine and asparagine. CONCLUSIONS Adjustment for relevant clinical factors attenuated the amino acid–incident diabetes risk. Although these findings do not preclude the potential pathogenic role of other amino acids, they suggest that plasma arginine is independently associated with incident diabetes. Both arginine and asparagine were identified in an optimal model for predicting new-onset type 2 diabetes.

Background Reduced serum levels of high density lipoprotein cholesterol (HDL-C) is a hallmark of the metabolic syndrome. Epidemiologic studies have reported an inverse correlation between HDL- C and cardiovascular disease (CVD) risk. However, recent works suggest that the association is strongest in healthy individuals. Changes in particle number and functional properties of HDL may more closely reflect CVD prognosis in patients with pre-existent disease. The majority of such patients receive statin treatment, which affects both HDL-C levels, and particle composition. Hence, serum apoA1 and the HDL-C:apoA1 ratio have been proposed as more sensitive indicators of cardio-metabolic prognosis. Purpose We studied the associations of serum HDL-C, apoA1 and the HDL-C: apoA1 ratio to long term risk of CVD mortality and incident type 2 diabetes (T2D) patients with suspected stable angina pectoris (SAP). Methods A total of 41064 patients underwent elective coronary angiography in 2000–2004 and were followed-up for CVD mortality throughout 2016. In a subgroup of 2519 participants without verified or possible diabetes at baseline, the associations to incident type 2 diabetes (T2D) were evaluated throughout 2014. Information on clinical endpoints was obtained through national health registries. Risk estimates are reported per 1 SD increment of (log transformed) biomarkers and were calculated by cox or logistic regression. We explored risk classification by calculating the continuous net reclassification improvement (NRI). Results At inclusion, median (25th-75th percentiles) age was 62 (55–70) years, 28% were women 76% had obstructive coronary artery disease and 80% received statins. During median (25th-75th percentiles) 13.9 (12.0–15.3) years of follow-up, 14.1% of the participants died from CVD. After multivariate adjustment (age, gender, body mass index, HbA1c, triglycerides, statin treatment, fasting status) HDL and apoA1, but not the HDL: apoA1 ratio, significantly predicted CVD mortality. The hazard ratio (HR) and 95% confidence interval (CI) was: 0.86 (0.78–0.94), 0.88 (0.80–0.98) and 0.96 (0.86–1.03) for HDL-C, apoA1 and the HDL-C:apoA1 ratio, respectively. HDL-C was the only of the evaluated biomarkers providing a significant NRI (95% CI) of 0.14 (0.04–0.19). In the subset evaluated for incdent T2D, HDL-C provided multivariate adjusted odds ratios (OR; 95% CI) and NRI (95% CI) of 0.69 (0.58–0.82) and 0.34 (0.21–0.47) for new onset TSD. The corresponding OR (95% CI) and NRI (95% CI) for apoA1 were: 0.85 (0.73–0.99) and 0.20 (0.06–0.33), respectively. The HDL:apo A1 ratio provided an OR (95% CI) of 0.66 (0.55–0.80) and NRI (95% CI) of 0.24 (0.11–0.37) for T2D. No significant effect modifications according to statin treatment were found (P≥0.22). Conclusion Among patients with suspected SAP, of which the majority received statins, HDL-C was non-inferior to apoA1 and the HDL:apoA1 ratio in predicting long term risk of CVD mortality and T2D. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Department of Heart Disease, Haukeland University Hospital; Department of Clinical Science, University of Bergen

Higher concentrations of cardiac troponin T are associated with coronary artery disease (CAD) and adverse cardiovascular prognosis. The relation with incident atrial fibrillation (AF) is less explored. We studied this association among 3,568 patients evaluated with coronary angiography for stable angina pectoris without previous history of AF. The prospective association between high-sensitivity cardiac troponin T (hs-cTnT) categories (≤3 ng/L; n = 1,694, 4-9; n = 1,085, 10 to 19; n = 614 and 20 to 30; n = 175) and incident AF and interactions with the extent of CAD were studied by Kaplan-Meier plots and Cox regression. Risk prediction improvements were assessed by receiver operating characteristic area under the curve (ROC-AUC) analyses. During median (25 to 75 percentile) 7.3 (6.3 to 8.6) years of follow-up 412 (11.5%) were diagnosed with AF. In a Cox model adjusted for age, gender, body mass index, hypertension, diabetes mellitus, smoking, estimated glomerular filtration rate, and left ventricular ejection fraction, hazard ratios (HRs) (95% confidence intervals [CIs]) were 1.53 (1.16 to 2.03), 2.03 (1.49 to 2.78), and 2.15 (1.40 to 3.31) when comparing the second, third, and fourth to the first hs-cTnT group, respectively (P for trend

Aims Distinct ceramide lipids have been shown to predict the risk for cardiovascular disease (CVD) events, especially cardiovascular death. As phospholipids have also been linked with CVD risk, we investigated whether the combination of ceramides with phosphatidylcholines (PCs) would be synergistic in the prediction of CVD events in patients with atherosclerotic coronary heart disease in three independent cohort studies. Methods and results Ceramides and PCs were analysed using liquid chromatography–mass spectrometry (LC-MS) in three studies: WECAC (The Western Norway Coronary Angiography Cohort) (N = 3789), LIPID (Long-Term Intervention with Pravastatin in Ischaemic Disease) trial (N = 5991), and KAROLA (Langzeiterfolge der KARdiOLogischen Anschlussheilbehandlung) (N = 1023). A simple risk score, based on the ceramides and PCs showing the best prognostic features, was developed in the WECAC study and validated in the two other cohorts. This score was highly significant in predicting CVD mortality [multiadjusted hazard ratios (HRs; 95% confidence interval) per standard deviation were 1.44 (1.28–1.63) in WECAC, 1.47 (1.34–1.61) in the LIPID trial, and 1.69 (1.31–2.17) in KAROLA]. In addition, a combination of the risk score with high-sensitivity troponin T increased the HRs to 1.63 (1.44–1.85) and 2.04 (1.57–2.64) in WECAC and KAROLA cohorts, respectively. The C-statistics in WECAC for the risk score combined with sex and age was 0.76 for CVD death. The ceramide-phospholipid risk score showed comparable and synergistic predictive performance with previously published CVD risk models for secondary prevention. Conclusion A simple ceramide- and phospholipid-based risk score can efficiently predict residual CVD event risk in patients with coronary artery disease.

ObjectivesOxidised cholesterol metabolites are linked to increased production of the active vitamin A (Vit-A) form and monocyte/macrophage activation, which may be reflected by neopterin, a marker of both interferon-γ–mediated immune activation and coronary artery disease risk. We examined the influence of serum lipid parameters and Vit-A on the risk association between neopterin and incident acute myocardial infarction (AMI).MethodsWe included 4130 patients with suspected stable angina pectoris (SAP), of whom 80% received lipid-lowering treatment with statins. Risk associations between plasma neopterin and AMI are given as HRs per SD increase in log-transformed neopterin.ResultsDuring a median follow-up of 7.5 years, 530 (12.8%) patients experienced an AMI. In age-adjusted and sex-adjusted analysis, plasma neopterin was positively associated with incident AMI (HR (95% CI) per SD: 1.26 (1.17 to 1.35)). However, the estimates were most pronounced in patients with serum low-density lipoprotein cholesterol (LDL-C) or apolipoprotein (apo) B100 below-median (HR (95% CI) per SD: 1.35 (1.24 to 1.48) and 1.42 (1.27 to 1.58), respectively; both pinteraction ≤0.03). We also observed a particularly strong risk association in those with above-median Vit-A (HR (95% CI) per SD: 1.32 (1.21 to 1.44); pinteraction=0.03). The estimates were slightly modified after multivariable adjustment.ConclusionsIn patients with suspected SAP, the majority of whom receiving statin therapy, high plasma neopterin was associated with increased risk of AMI particularly among those with low LDL-C and apoB100 or high Vit-A levels. The particularly strong relationship of plasma neopterin with residual cardiovascular risk in patients with low lipid levels should be further investigated.

In patients with stable angina, the association between high-sensitivity cardiac troponin T (hs-cTnT) and incident acute myocardial infarction (AMI), as well as pathophysiologic mechanisms accounting for an adverse prognosis, remain to be determined. We explored the association between hs-cTnT and future AMI among 3,882 patients evaluated for suspected stable angina pectoris and investigated to which extent hs-cTnT attenuated the relations between traditional coronary heart disease (CHD) risk factors and AMI. Associations between increasing hs-cTnT categories (≤3, 4 to 9, 10 to 19, and 20 to 30 ng/L) and risk of AMI were studied by Cox regression. We investigated whether the associations between traditional CHD risk factors and future AMI were influenced by adjusting for hs-cTnT. Median age was 62 years. During median (25th to 75th percentile) 8 (6.4 to 8.7) years of follow-up, 460 (11.8%) experienced an AMI. There was a strong association between hs-cTnT categories and risk of AMI. The relation was somewhat attenuated, but still present, when adjusting for potential confounders, traditional CHD risk factors, previous peripheral vascular disease, and percutaneous coronary intervention or coronary bypass surgery. Moreover, hs-cTnT slightly attenuated the risk relations between traditional CHD risk factors and incident AMI, but each risk factor remained significantly associated with AMI. In conclusion, among patients with suspected stable angina, hs-cTnT was positively related to incident AMI.

Background Plasma trimethylamine-N-oxide (TMAO) is associated with cardiovascular disease; however specific relationships with cardiac arrhythmias are unknown. We evaluated the association between plasma TMAO and incident atrial fibrillation (AF). Methods Risk associations were explored among 3797 patients with suspected stable angina in the Western Norway Coronary Angiography Cohort (WECAC) and verified in 3143 elderly participants in the community-based Hordaland Health Study (HUSK). Information on endpoints was obtained from nationwide registries. Results Median follow-up was 7.3 and 10.8 years in the WECAC and HUSK cohorts, respectively, and 412 (10.9%) and 484 (15.4%) subjects were registered with incident AF. The age and gender adjusted HRs were 1.16, 95% CI 1.05–1.28 and 1.10, 95% CI 1.004–1.19 per 1 SD increase in log-transformed plasma TMAO. Adjusting for hypertension, BMI, smoking, diabetes, or intake of total choline, a TMAO precursor, did not materially influence the risk associations. Among patients in WECAC, further extensive adjustment for other AF risk factors yielded similar results. Adding TMAO to traditional AF risk factors (age, gender, hypertension, BMI, smoking and diabetes) yielded a continuous net reclassification improvement of 0.108, 95% CI 0.015–0.202 and 0.139, 95% CI 0.042–0.235. Conclusions Plasma TMAO was associated with and improved reclassification of incident AF in two independent Norwegian cohorts with long-term follow-up. The relationship was independent of traditional AF risk factors, as well as of dietary choline intake. Our findings motivate further studies to explore endogenous metabolic factors influencing the relationship between TMAO and cardiovascular disease.

Background Link between inflammation and atrial fibrillation (AF) has been increasingly recognized. Neopterin, a biomarker of cellular immune activation, may be associated with incident AF. Objective To investigate the association between plasma neopterin levels and risk of an inpatient hospital diagnosis of AF, and to evaluate a joint association of neopterin and a nonspecific inflammatory marker C-reactive protein (CRP) in two prospective cohorts. Methods We performed a prospective analysis from a community-based cohort (the Hordaland Health Study (HUSK), n = 6891), and validated the findings in a cohort of patients with suspected stable angina pectoris (the Western Norway Coronary Angiography Cohort (WECAC), n = 2022). Results In both cohorts, higher plasma levels of neopterin were associated with an increased risk of incident AF after adjustment for age, sex, body mass index, current smoking, diabetes, hypertension and renal function. The multivariable-adjusted hazard ratio (HR) (95% CI) per one SD increment of log-transformed neopterin was 1.20 (1.10-1.32) in HUSK and 1.26 (1.09-1.44) in WECAC. Additional adjustment for CRP did not materially affect the risk association for neopterin. The highest risk of AF was found among individuals with both neopterin and CRP levels above the median (HR: 1.54; 95% CI: 1.16-2.05 in HUSK and HR: 1.67; 95% CI: 1.11-2.52 in WECAC). Conclusions Our findings indicate an association of plasma neopterin with risk of an inpatient hospital diagnosis of AF, which remains after adjustment for traditional risk factors as well as for CRP. This study highlights a role of cellular immune activation, in addition to inflammation, in AF pathogenesis.

Context Carnitine and its metabolites are centrally involved in fatty acid metabolism. Although elevated circulating concentrations have been observed in obesity and insulin resistance, prospective studies examining whether these metabolites are associated with incident type 2 diabetes mellitus (T2D) are sparse. Objective We performed a comprehensive evaluation of metabolites along the carnitine pathway relative to incident T2D. Design A total of 2519 patients (73.1% men) with coronary artery disease, but without T2D, were followed for median 7.7 years until the end of 2009, during which 173 (6.9%) new cases of T2D were identified. Serum levels of free carnitine, its precursors trimethyllysine (TML) and γ-butyrobetaine, and the esters acetyl-, propionyl-, (iso)valeryl-, octanoyl-, and palmitoylcarnitine were measured by liquid chromatography/tandem mass spectrometry. Risk associations were explored by logistic regression and reported per (log-transformed) standard deviation increment. Results Median age at inclusion was 62 years and median body mass index (BMI) 26.0 kg/m2. In models adjusted for age, sex, fasting status, BMI, estimated glomerular filtration rate, glycated hemoglobin A1c, triglyceride and high-density lipoprotein cholesterol levels, and study center, serum levels of TML and palmitoylcarnitine associated positively [odds ratio (95% confidence interval), 1.22 (1.04 to 1.43) and 1.24 (1.04 to 1.49), respectively], whereas γ-butyrobetaine associated negatively [odds ratio (95% confidence interval) 0.81 (0.66 to 0.98)] with T2D risk. Conclusion Serum levels of TML, γ-butyrobetaine, and the long-chained palmitoylcarnitine predict long-term risk of T2D independently of traditional risk factors, possibly reflecting dysfunctional fatty acid metabolism in patients susceptible to T2D development.

Background and aims Apolipoproteins B (apoB) and A1 (apoA1) are major protein constituents of low-density and high-density lipoproteins, respectively, and serum concentrations of these apolipoproteins are associated with risk of atherosclerosis. Vitamin A (VA) has been implicated in lipoprotein metabolism. We evaluated the associations of serum apoB, apoA1 and their ratio (apoBAR) with risk of incident acute myocardial infarction (AMI) and the possible modification by serum VA. Methods Risk associations were assessed by Cox regression, and presented as hazard ratios (HRs) per standard deviation (SD) increment in log-transformed values of the lipid parameters, among 4117 patients with suspected stable angina pectoris, located in Western Norway. Interactions with VA were evaluated by including interaction terms in the models. The multivariate model included age, sex, smoking, hypertension, number of stenotic coronary arteries, left ventricular ejection fraction, C-reactive protein, estimated glomerular filtration rate and statin treatment at discharge. Results Median (25th, 75th percentile) age of the 4117 patients (72% male) was 62 (55, 70) years. ApoB and apoA1 were higher among patients in the upper versus lower tertiles of VA. During a median of 4.6 (3.6, 5.7) years of follow-up, 8.2% of patients experienced an AMI. Overall, we observed no significant associations between lipid parameters and AMI after multivariate adjustment. However, apoB and apoBAR were associated with AMI among patients in the upper tertile of VA (HR per SD 1.35, (95% CI: 1.11–1.65), and 1.42 (1.16–1.74), respectively, p for interactions ≤0.003). Conclusions The associations of apoB and apoBAR with incident AMI were confined to patients with elevated VA.

Aims/hypothesis The tryptophan metabolite kynurenine has potent immune modulatory and vasoactive properties. Experimental data implicate kynurenine in obesity-related morbidities. Epidemiological studies are, however, sparse. We evaluated associations of the plasma and urine kynurenine:tryptophan ratio (KTR) to incident type 2 diabetes. Methods We followed 2519 individuals with coronary artery disease (CAD; 73.1% men) without diabetes at baseline for a median of 7.6 years, during which 173 (6.9%) new incidences of type 2 diabetes were identified. Multivariate Cox regression analyses were applied to investigate the prospective relationships of plasma and urine KTR with new onset type 2 diabetes. Results At inclusion, mean (SD) age was 61.3 (10.4) years, BMI was 25.9 (3.71) kg/m2 and median (interquartile range) HbA1c was 5.6% (5.0%–6.0%) (38 [31–42] mmol/mol). Plasma KTR was not significantly related to type 2 diabetes risk. By contrast, urine KTR showed a strong positive association. Comparing quartile 4 with quartile 1, the HRs (95% CIs) were 2.59 (1.56, 4.30) and 2.35 (1.39, 3.96) in the age- and sex-adjusted and multivariate models, respectively. Conclusions/interpretation Urine KTR is a strong predictor of incident type 2 diabetes in individuals with CAD. Potential clinical implications and possible pathogenic roles of renal kynurenine excretion in type 2 diabetes development should be further elucidated. Electronic supplementary material The online version of this article (doi:10.1007/s00125-017-4329-9) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

Background— Serine and glycine interconversion and methylenetetrahydrofolate dehydrogenase 1 (MTHFD1)–mediated 1-carbon transfer are the major sources of methyl groups for 1-carbon metabolism. Recently, plasma glycine and a common polymorphism in MTHFD1 have been associated with risk of acute myocardial infarction (AMI). It is, therefore, of interest to explore if these 2 pathways interact in relation to AMI. Methods and Results— A total of 2571 participants in the WENBIT (Western Norway B Vitamin Intervention Trial) undergoing coronary angiography for stable angina pectoris were studied. Associations of plasma serine and glycine concentrations with risk of AMI across 2 common and functional MTHFD1 polymorphisms ( rs2236225 and rs1076991 ) were explored in Cox regression models. During a median follow-up of 4.7 years, 212 patients (8.2%) experienced an AMI. In age- and sex-adjusted analyses, plasma glycine ( P P =0.52), showed an overall association with AMI. However, interactions of MTHFD1 rs2236225 polymorphism with both plasma serine and glycine were observed ( P interaction =0.03 for both). Low plasma serine and glycine were associated with an increased risk of AMI among patients carrying the rs2236225 minor A allele. Similarly, low plasma glycine showed stronger risk relationship with AMI in the rs1076991 CC genotype carriers but weaker associations in patients carrying the minor T allele ( P interaction =0.02). Conclusions— Our results showed that 2 common and functional polymorphisms in the MTHFD1 gene modulate the risk associations of plasma serine and glycine with AMI. These findings emphasize the possible role of the MTHFD1 in regulating serine and glycine metabolism in relation to atherosclerotic complications. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique Identifier: NCT00354081.

Background Choline is related to lipid handling and higher plasma concentrations have been associated with an adverse cardiovascular risk profile. However, previous studies have suggested that the relationship between plasma free choline and later cardiovascular events may differ according to patient phenotypes. Purpose To explore the risk association between plasma choline and later acute myocardial infarction (AMI) according to plasma methylmalonic acid (MMA) or dimethylglycine (DMG). The latter two metabolites are suggested markers of endogenous activation of perixosome proliferator-activated receptors (PPARs), which are nuclear receptor proteins involved in lipid metabolism. Methods Risk relationships were explored by Cox regression among 2232 patients evaluated for suspected stable angina pectoris in the overall population and according to median plasma MMA and DMG. Results Baseline plasma choline was related to several cardiovascular risk factors (Table 1). After median follow-up of 7.3 years, 338 patients were reported with at least one incident AMI. In the overall population, the age and gender adjusted HR (95% CI) for each increment of 1 SD log-transformed plasma choline and AMI was 1.21 (1.08–1.35), P=0.001, and the association persisted in multivariate analyses. In patients with plasma MMA or DMG≥median, the HRs (95% CIs) were 1.33 (1.16–1.54) and 1.38 (1.20–1.58), respectively, both P Table 1. Baseline characteristics according to plasma choline quartiles Quartile 1 Quartile 4 P for trend Age, years 58 (52–66) 66 (58–73) Figure 1 Conclusion Among patients with stable angina, plasma choline was related to increased long-term AMI risk among patients with higher plasma MMA or DMG only. This finding potentially reflects increased risk conferred by choline during concomitant endogenous PPAR activation. Acknowledgement/Funding None

Background In non-obstructive coronary artery disease (CAD), increasing extent of disease is associated with a worse prognosis. Statin therapy has been suggested to improve the prognosis. Whether hypertension, a modifiable CV risk factor, affects the extent of non-obstructive CAD in patients with stable angina is less explored. Purpose To assess the association between hypertension and extent of non-obstructive coronary artery disease. Methods We identified 1117 patients (mean age 62±10 years, 48% women) from the Norwegian Registry for Invasive Coronary angiography (NORIC). All subjects had stable angina and non-obstructive CAD defined as 1–49% stenosis in any coronary artery segment by coronary computed tomography angiography (CCTA). The extent of non-obstructive CAD was assessed as coronary artery segment involvement score (SIS) on CCTA. Extensive non-obstructive CAD was defined as SIS≥4. Results Hypertension was present in 44% and patients with hypertension were older with a higher prevalence of diabetes, obesity, smoking and statin therapy (all p Table 1. Covariables of extensive non-obstructive CAD in univariable and multivariable logistic regression analysis Univariable analysis Multivariable analysis OR 95% CI p-value OR 95% CI p-value Hypertension 1.57 1.21–2.04 0.001 1.47 1.03–2.10 0.035 Age 1.06 1.05–1.08 Conclusions Hypertension is associated with extensive non-obstructive CAD in patients with stable angina, suggesting that early and aggressive antihypertensive treatment may impact disease progression.

BACKGROUND Metabolites of the kynurenine pathway (mKP) relate to important aspects of heart failure pathophysiology, such as inflammation, energy-homeostasis, apoptosis, and oxidative stress. We aimed to investigate whether mKP predict mortality in patients with heart failure. METHODS The study included 202 patients with heart failure (73.8% with coronary artery disease (CAD)), propensity score matched to 384 controls without heart disease, and 807 controls with CAD (71%). All underwent coronary angiography and ventriculography at baseline. Plasma mKP, pyridoxal 5'phosphate (PLP) and CRP were measured at baseline. Case-control differences were assessed by logistic regression and survival by Cox regression, adjusted for age, gender, smoking, diabetes, ejection fraction, PLP, eGFR and CRP. Effect measures are reported per standard deviation increments. RESULTS Higher plasma levels of kynurenine, 3- hydroxykynurenine (HK), quinolinic acid (QA), the kynurenine-tryptophan-ratio (KTR) and the ratio of HK to xanthurenic acid (HK/XA) were detected in heart failure compared to both control groups. The mortality rate per 1000 person-years was 55.5 in patients with heart failure, 14.6 in controls without heart disease and 22.2 in CAD controls. QA [HR 1.80, p = 0.013], HK [HR 1.77, p = 0.005], HK/XA [HR 1.67, p < 0.001] and KTR [HR 1.55, p = 0.009] were associated with increased mortality in patients with heart failure, while XA [HR 0.68-0.80, p = 0.013-0.037] were associated with lower mortality in all groups. HK and HK/XA had weak associations with increased mortality in CAD-controls. CONCLUSION Elevated plasma levels of mKP and metabolite ratios are associated with increased mortality, independent of CAD, in patients with heart failure.

Purpose We hypothesized that biomarkers and dietary factors related to cardiovascular disease risk were associated with serum retinol and evaluated these potential associations in patients with suspected coronary artery disease (CAD). Methods We used cross-sectional data from 4116 patients hospitalised for suspected CAD. Dietary data were obtained from a subgroup of 1962 patients using a food frequency questionnaire. Potential biomarkers and dietary factors were explored using linear regression modelling adjusted for age and sex. Regression coefficients and corresponding confidence intervals (CI) are given as % change in serum retinol per unit change in the predictors. Analyses were performed in the total population and in strata of serum retinol tertiles. Results In age- and sex-adjusted models, serum creatinine (standardized β: 0.38, 95% CI [0.35, 0.42]), plasma total cysteine (0.26, [0.23, 0.29]), serum uric acid (0.30, [0.26, 0.33]) and plasma neopterin (0.22, [0.18, 0.25]) were positively associated, whereas plasma serine (− 0.15, [− 0.18, − 0.12]) and serum C-reactive protein (− 0.15, [− 0.18, − 0.12]) were inversely associated with serum retinol. When we included the significant biomarkers in a multivariate model, the model explained 33% of the variability (R2 = 0.33) in serum retinol. The results were similar in the lower and upper tertiles of serum retinol. Weak or no associations were observed for dietary factors. Conclusions In patients with suspected CAD, concentrations of creatinine, cysteine and uric acid were positively associated with serum retinol. Future studies should assess whether retinol concentrations are influenced by metabolic alterations in patients at risk of cardiovascular disease.

BACKGROUND Low vitamin B-6 status has been related to increased risk of coronary artery disease (CAD), which is a condition that is associated with inflammation. The most common status marker, plasma pyridoxal 5'-phosphate (PLP), decreases during inflammation; therefore, causal relations are uncertain. OBJECTIVE We evaluated the vitamin B-6 biomarkers PLP, pyridoxal, and pyridoxic acid (PA) and the pyridoxic acid:(pyridoxal + PLP) ratio (PAr), a proposed marker of vitamin B-6 catabolism during activated cellular immunity, as predictors of mortality. DESIGN Associations with risks of long-term all-cause mortality and cardiovascular mortality were evaluated with the use of Cox regression in patients who were undergoing elective coronary angiography for suspected stable angina pectoris (SAP) (n = 4131) and an independent cohort of patients who were hospitalized for acute myocardial infarction (AMI) (n = 3665). RESULTS Plasma PLP (AMI patients only) and PA predicted all-cause mortality in models that were adjusted for established risk predictors, but associations were attenuated or nonsignificant after additional adjustment for inflammatory markers. PAr was correlated with biomarkers of inflammation (Pearson's r ≥ 0.37) and predicted all-cause mortality and cardiovascular mortality after adjustment for established risk predictors. In SAP patients, PAr had greater predictive strength than did current smoking, diabetes, hypertension, apolipoproteins, or C-reactive protein. PAr provided multiadjusted HRs per SD of 1.45 (95% CI: 1.30, 1.63) and 1.31 (95% CI: 1.21, 1.41) in SAP and AMI patients, respectively. In both cohorts, PAr was a particularly strong predictor of all-cause mortality for patients with no previous CAD history (P-interaction ≤ 0.04). CONCLUSION PAr may capture unique aspects of inflammatory activation and thus provide new insights into disease mechanisms that may aid in identifying patients at increased risk of future fatal events.

Background: Methylenetetrahydrofolate dehydrogenase (MTHFD1) catalyzes three sequential reactions that metabolize derivatives of tetrahydrofolate (THF) in folate-dependent one-carbon metabolism. Impaired MTHFD1 flux has been linked to disturbed lipid metabolism and oxidative stress. However, limited information is available on its relation to the development of atherothrombotic cardiovascular disease. Methods and results: We explored the association between a MTHFD1 polymorphism (rs1076991 C > T ) and acute myocardial infarction (AMI), and potential effect modifications by folic acid/B12 and/or vitamin B6 treatment in suspected stable angina pectoris patients (n Z 2381) participating in the randomized Western Norway B Vitamin Intervention Trial (WENBIT). During the median follow-up of 4.9 years 204 participants (8.6%) suffered an AMI. After adjusting for established CVD risk factors, the MTHFD1 polymorphism was significantly associated with AMI (HR: 1.49; 95% CI, 1.23e1.81). A similar association was observed among patients allocated to treatment with vitamin B6 alone (HR: 1.53; 95% CI, 1.01e2.31), and an even stronger relationship was seen in patients treated with both vitamin B6 and folic acid/B12 (HR: 2.35; 95% CI, 1.55 e3.57). However, no risk association between the MTHFD1 polymorphism and AMI was seen in patients treated with placebo (HR: 1.29; 95% CI, 0.86e1.93) or folic acid/B12 (1.17; 95% CI, 0.83e1.65). Conclusion: A common and functional MTHFD1 polymorphism is associated with increased risk of AMI, although the risk seems to be dependent on specific B vitamin treatment. Further studies are warranted to elucidate the possible mechanisms, also in order to explore potential effect modifications by nutritional factors. publishedVersion

Background Although choline metabolism has been associated with atherosclerotic heart disease, less research attention has been paid to the associations of choline and its oxidative metabolite betaine with cardiac arrhythmias. Methods and Results We evaluated associations of plasma concentrations and dietary intakes of choline and betaine with long‐term atrial fibrillation ( AF ) risk in a community‐based cohort, HUSK ([the Hordaland Health Study] n=6949), and validated the findings in 2 patient cohorts: the Western Norway Coronary Angiography Cohort (n=4164) and the NORVIT (Norwegian B‐Vitamin) Trial (n=3733). Information on AF was obtained from the CVDNOR (Cardiovascular Disease in Norway) project. In HUSK , WECAC (Western Norway Coronary Angiography Cohort), and NORVIT , 552, 411, and 663 AF cases were identified during a median follow‐up time of 10.9, 7.3, and, 8.7 years, respectively. Plasma concentrations of choline and betaine were significantly positively associated with later AF risk after multivariable adjustments in HUSK . Such associations were independently replicated in the 2 external prospective patient cohorts. The pooled hazard ratio was 1.13 (95% confidence interval 1.08‐1.19, P P SD increment for log‐transformed choline and betaine, respectively. Moreover, dietary intake of choline was marginally associated with AF risk (pooled hazard ratio 1.29, 95% confidence interval 1.01‐1.66, fifth versus first quintile), whereas no significant association was observed between dietary betaine and AF risk. Conclusions Our findings indicate that plasma concentrations as well as dietary intake of choline, but not betaine, are associated with subsequent risk of AF , suggesting a potential role of choline metabolism in the pathogenesis of AF . Clinical Trial Registration URL: https://www.clinicaltrials.gov.Unique identifier: NCT 00671346.

Systemic fibrinogen and neopterin are related to inflammation. We investigated the prognostic utility and possible interactions of these biomarkers in stable coronary artery disease (SCAD) patients undergoing coronary angiography. We included 3,545 patients with suspected stable angina with a median follow-up of 7.3 and 10.2 years for incident acute myocardial infarction (AMI) and all-cause mortality, respectively. Prospective associations were explored by Cox regression. Potential effect modifications were investigated according to strata of fibrinogen, neopterin or high-sensitivity troponin T (hsTnT) below and above the median, as well as gender and smoking habits. During follow-up, 543 patients experienced an AMI and 769 patients died. In a multivariable model, the hazard ratios (HRs; 95% confidence interval [CI]) per 1 SD increase for fibrinogen in relation to these endpoints were 1.30 (1.20, 1.42; p

Background Plasma total homocysteine (tHcy) has been implicated in the development of cardiovascular disease, but the mechanisms remain unclear. Vitamin A (Vit-A) is involved in homocysteine metabolism and we therefore explored the potential interaction between plasma tHcy and serum Vit-A in relation to incident acute myocardial infarction. Methods Cox proportional hazards models were used to assess the prospective relationships between tHcy and acute myocardial infarction in 2205 patients from Western Norway undergoing elective coronary angiography for suspected stable angina pectoris. Results are reported as hazard ratio per standard deviation increase in log-transformed tHcy. An interaction term for tHcy × Vit-A was added to multivariate models including age, sex, smoking, apolipoprotein B fasting, statin and aspirin prescription and estimated glomerular filtration rate. Results Geometric mean (geometric standard deviation) age of the participants (64.3% men) was 62.3 (1.24) years. Plasma tHcy was higher among participants in the upper versus lower Vit-A tertile. During 7 (2.4) years of follow-up, 15.1% suffered an AMI. A significant association of plasma tHcy with AMI in the total study population was observed. When we stratified the population according to Vit-A tertiles, plasma tHcy was associated with acute myocardial infarction only in the upper Vit-A tertile (hazard ratio per SD: 1.25, 95% confidence interval: 1.04–1.53, pinteraction = 0.03). Conclusions The risk relationship between plasma tHcy and acute myocardial infarction was modified by serum concentrations of Vit-A in patients with suspected stable angina pectoris. This finding may clarify the relationship between tHcy and cardiovascular disease.

Context and Objective Vitamin D status may affect cardiovascular disease (CVD) development and survival. We studied the relationship between concentrations of the circulating biomarker 25-hydroxyvitamin D (25OHD) and all-cause and cardiovascular mortality risk. Design, Setting, Participants, and Main Outcome Measures 25OHD, the sum of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2, was analyzed in plasma samples from 4114 white patients suspected of having stable angina pectoris and was adjusted for seasonal variation. Hazard ratios (HRs) for all-cause and cardiovascular mortality were estimated by using multivariable Cox models with 25OHD as the main exposure variable, with adjustment for study site, age, sex, smoking, body mass index, estimated glomerular filtration rate, and systolic blood pressure. Results A total of 895 (21.8%) deaths, including 407 (9.9%) from CVD causes, occurred during a mean ± standard deviation follow-up of 11.9 ± 3.0 years. Compared with the first 25OHD quartile, HRs in the second, third, and fourth quartiles were 0.64 [95% confidence interval (CI), 0.54 to 0.77], 0.56 (95% CI, 0.46 to 0.67), and 0.56 (95% CI, 0.46 to 0.67) for all-cause mortality and 0.70 (95% CI, 0.53 to 0.91), 0.60 (95% CI, 0.45 to 0.79), and 0.57 (95% CI, 0.43 to 0.75) for cardiovascular mortality, respectively. Threshold analysis demonstrated increased all-cause and CVD mortality in patients with 25OHD concentrations below ∼42.5 nmol/L. Moreover, analysis suggested increased all-cause mortality at concentrations >100 nmol/L. Conclusion Plasma 25OHD concentrations were inversely associated with cardiovascular mortality and nonlinearly (U-shaped) associated with all-cause mortality.

Aims/hypothesis: A validated mass-spectrometric method was applied to measure Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1) from serum or plasma samples. These ceramides were analysed in a population-based risk factor study (FINRISK 2002, n = 8045), in a cohort of participants undergoing elective coronary angiography for suspected stable angina pectoris (Western Norway Coronary Angiography Cohort [WECAC], n = 3344) and in an intervention trial investigating improved methods of lifestyle modification for individuals at high risk of the metabolic syndrome (Prevent Metabolic Syndrome [PrevMetSyn], n = 371). Diabetes risk score models were developed to estimate the 10 year risk of incident diabetes. Methods: A validated mass-spectrometric method was applied to measure Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1) from serum or plasma samples. These ceramides were analysed in a population-based risk factor study (FINRISK 2002, n = 8045), in a cohort of participants undergoing elective coronary angiography for suspected stable angina pectoris (Western Norway Coronary Angiography Cohort [WECAC], n = 3344) and in an intervention trial investigating improved methods of lifestyle modification for individuals at high risk of the metabolic syndrome (Prevent Metabolic Syndrome [PrevMetSyn], n = 371). Diabetes risk score models were developed to estimate the 10 year risk of incident diabetes. Results: Analysis in FINRISK 2002 showed that the Cer(d18:1/18:0)/Cer(d18:1/16:0) ceramide ratio was predictive of incident diabetes (HR per SD 2.23, 95% CI 2.05, 2.42), and remained significant after adjustment for several risk factors, including BMI, fasting glucose and HbA1c (HR 1.34, 95% CI 1.14, 1.57). The finding was validated in the WECAC study (unadjusted HR 1.81, 95% CI 1.53, 2.14; adjusted HR 1.39, 95% CI 1.16, 1.66). In the intervention trial, the ceramide ratio and diabetes risk scores significantly decreased in individuals who had 5% or more weight loss. Conclusions/interpretation: The Cer(d18:1/18:0)/Cer(d18:1/16:0) ratio is an independent predictive biomarker for incident diabetes, and may be modulated by lifestyle intervention.

Enhanced tryptophan degradation via the kynurenine pathway has been related to several pathological conditions. However, little is known about the effect of diet on individual metabolites of this pathway. We investigated cross-sectional associations between reported intake of fish and omega-3 (n-3) long-chain PUFA (LC-PUFA) and plasma metabolites related to the kynurenine pathway. Participants were 2324 individuals with coronary artery disease from the Western Norway B Vitamin Intervention Trial. Fish and n-3 LC-PUFA intakes were assessed using a food frequency questionnaire. Plasma concentrations of tryptophan, kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, xanthurenic acid, 3-hydroxyanthranilic acid, neopterin, and kynurenine-to-tryptophan ratio (KTR) were analyzed. Associations were investigated using partial Spearman’s rank correlations and multiple linear regressions. Median age at inclusion was 62 years (80 % males), and 84 % had stable angina pectoris. Intake of fatty fish and n-3 LC-PUFA was inversely associated with plasma 3-hydroxykynurenine. Consumption of total fish, lean fish, and n-3 LC-PUFA was inversely associated with plasma neopterin. Intake of total fish, fatty fish, and n-3 LC-PUFA was inversely associated with KTR. All these correlations were weak (ρ between −0.12 and −0.06, P

Background: The kynurenine pathway, the main metabolic route of tryptophan degradation, has been related to inflammatory responses. Some of its metabolites, referred to as kynurenines, have been associated with prevalence of coronary heart disease (CHD) in cross-sectional studies. This prospective study aims to investigate whether increased concentrations of kynurenines are associated with risk of acute coronary events, defined as unstable angina pectoris, acute myocardial infarction, and/or sudden death in community-dwelling elderly.Methods: The baseline examinations included 2819 individuals aged 71-74 years recruited into the Hordaland Health Study. Participants with known CHD at baseline were excluded from analyses. Baseline plasma concentrations of tryptophan, kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, xanthurenic acid, and 3-hydroxyanthranilic acid were measured by LC-MS/MS. During a median follow-up period of 10.8 years, with linkage to acute coronary event endpoints through the CVDNOR project, hazard ratios (HRs) for acute coronary events (n = 376) were estimated using Cox proportional hazard analyses.Results: After adjustment for established cardiovascular risk factors, HRs (95% CI) comparing the 4th vs 1st quartile were 1.86 (1.19-2.92) for kynurenine and 1.72 (1.19-2.49) for 3-hydroxykynurenine. Tryptophan, kynurenic acid, anthranilic acid, xanthurenic acid and 3-hydroxyanthranilic acid were not associated with acute coronary events.Conclusions: Kynurenine and 3-hydroxykynurenine were associated with increased risk of acute coronary events in community-dwelling elderly without a known history of CHD. These results suggest the involvement of the kynurenine pathway in the early development of CHD, and their potential usefulness to estimate CHD risk. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

Background Data from recent meta-analyses question an association between dietary intake of saturated fatty acids (SFAs) and risk of cardiovascular disease (CVD). Moreover, the prognostic effect of dietary SFA in patients with established CVD treated with modern conventional medication has not been extensively studied. Objective We investigated the associations between self-reported dietary SFA intake and risk of subsequent coronary events and mortality in patients with coronary artery disease (CAD). Methods This study included patients who participated in the Western Norway B-Vitamin Intervention Trial and completed a 169-item semiquantitative food-frequency questionnaire after coronary angiography. Quartiles of estimated daily intakes of SFA were related to risk of a primary composite endpoint of coronary events (unstable angina pectoris, nonfatal acute myocardial infarction, and coronary death) and separate secondary endpoints (total acute myocardial infarction, fatal coronary events, and all-cause death) with use of Cox-regression analyses. Results This study included 2412 patients (81% men, mean age: 61.7 y). After a median follow-up of 4.8 y, a total of 292 (12%) patients experienced at least one major coronary event during follow-up. High intake of SFAs was associated with a number of risk factors at baseline. However, there were no significant associations between SFA intake and risk of coronary events [age- and sex-adjusted HR (95% CI) was 0.85 (0.61, 1.18) for the upper vs. lower SFA quartile] or any secondary endpoint. Estimates were not appreciably changed after multivariate adjustments. Conclusions There was no association between dietary intake of SFAs and incident coronary events or mortality in patients with established CAD.

Cystathionine is a thio-ether and a metabolite formed from homocysteine during transsulfuration. Elevated plasma cystathionine levels are reported in patients with cardiovascular disease; however prospective relationships with acute myocardial infarction (AMI) are unknown. We investigated associations between plasma cystathionine and AMI among patients with suspected and/or verified coronary heart disease (CHD).Subjects from two independent cohort studies, the Western Norway Coronary Angiography Cohort (WECAC) (3033 patients with stable angina pectoris; 263 events within 4.8 years of median follow-up) and the Norwegian Vitamin Trial (NORVIT) (3670 patients with AMI; 683 events within 3.2 years of median follow-up) were included.In both cohorts, plasma cystathionine was associated with several traditional CHD risk factors (P 0.001). Comparing the cystathionine quartile 4 to 1, age and gender adjusted hazard ratios (95% confidence intervals) for AMI were 2.08 (1.43-3.03) and 1.41 (1.12-1.76) in WECAC and NORVIT, respectively. Additional adjustment for traditional risk factors slightly attenuated the risk estimates, which were generally stronger in both cohorts among non-smokers, patients with higher age, and lower BMI or PLP status (P-interaction ≤ 0.04). Risk associations also tended to be stronger in patients not treated with B-vitamins. Additionally, in a subset of 80 WECAC patients, plasma cystathionine associated strongly negatively with glutathione, an important antioxidant and positively with lanthionine, a marker of HPlasma cystathionine is associated with increased risk of AMI among patients with either suspected or verified coronary heart disease, and is possibly related to altered redox homeostasis.

Background Excess levels of serum acylcarnitines, which are intermediate products in metabolism, have been observed in metabolic diseases such as type 2 diabetes mellitus. However, it is not known whether acylcarnitines may prospectively predict risk of cardiovascular death or acute myocardial infarction in patients with stable angina pectoris. Methods and Results This study included 4164 patients (median age, 62 years; 72% men). Baseline serum acetyl‐, octanoyl‐, palmitoyl‐, propionyl‐, and (iso)valerylcarnitine were measured using liquid chromatography/tandem mass spectrometry. Hazard ratios ( HR s) and 95% CI s for quartile 4 versus quartile 1 are reported. The multivariable model included age, sex, body mass index, fasting status, current smoking, diabetes mellitus, apolipoprotein A1, apolipoprotein B, creatinine, left ventricular ejection fraction, extent of coronary artery disease, study center, and intervention with folic acid or vitamin B6. During median 10.2 years of follow‐up, 10.0% of the patients died of cardiovascular disease and 12.8% suffered a fatal or nonfatal acute myocardial infarction. Higher levels of the even‐chained acetyl‐, octanoyl‐, and palmitoyl‐carnitines were significantly associated with elevated risk of cardiovascular death, also after multivariable adjustments ( HR [95% CI ]: 1.52 [1.12, 2.06]; P =0.007; 1.73 [1.23, 2.44]; P =0.002; and 1.61 [1.18, 2.21]; P =0.003, respectively), whereas their associations with acute myocardial infarction were less consistent. Conclusions Among patients with suspected stable angina pectoris, elevated serum even‐chained acylcarnitines were associated with increased risk of cardiovascular death and, to a lesser degree with acute myocardial infarction, independent of traditional risk factors. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 00354081.

Background: \ud \ud Lipoprotein(a) concentrations in plasma are associated with cardiovascular risk in the general population. Whether lipoprotein(a) concentrations or LPA genetic variants predict long-term mortality in patients with established coronary heart disease remains less clear.\ud \ud Methods: \ud \ud We obtained data from 3313 patients with established coronary heart disease in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. We tested associations of tertiles of lipoprotein(a) concentration in plasma and two LPA single-nucleotide polymorphisms ([SNPs] rs10455872 and rs3798220) with all-cause mortality and cardiovascular mortality by Cox regression analysis and with severity of disease by generalised linear modelling, with and without adjustment for age, sex, diabetes diagnosis, systolic blood pressure, BMI, smoking status, estimated glomerular filtration rate, LDL-cholesterol concentration, and use of lipid-lowering therapy. Results for plasma lipoprotein(a) concentrations were validated in five independent studies involving 10 195 patients with established coronary heart disease. Results for genetic associations were replicated through large-scale collaborative analysis in the GENIUS-CHD consortium, comprising 106 353 patients with established coronary heart disease and 19 332 deaths in 22 studies or cohorts.\ud \ud Findings: \ud \ud The median follow-up was 9·9 years. Increased severity of coronary heart disease was associated with lipoprotein(a) concentrations in plasma in the highest tertile (adjusted hazard radio [HR] 1·44, 95% CI 1·14–1·83) and the presence of either LPA SNP (1·88, 1·40–2·53). No associations were found in LURIC with all-cause mortality (highest tertile of lipoprotein(a) concentration in plasma 0·95, 0·81–1·11 and either LPA SNP 1·10, 0·92–1·31) or cardiovascular mortality (0·99, 0·81–1·2 and 1·13, 0·90–1·40, respectively) or in the validation studies.\ud \ud Interpretation: \ud \ud In patients with prevalent coronary heart disease, lipoprotein(a) concentrations and genetic variants showed no associations with mortality. We conclude that these variables are not useful risk factors to measure to predict progression to death after coronary heart disease is established.\ud \ud Funding: \ud \ud Seventh Framework Programme for Research and Technical Development (AtheroRemo and RiskyCAD), INTERREG IV Oberrhein Programme, Deutsche Nierenstiftung, Else-Kroener Fresenius Foundation, Deutsche Stiftung für Herzforschung, Deutsche Forschungsgemeinschaft, Saarland University, German Federal Ministry of Education and Research, Willy Robert Pitzer Foundation, and Waldburg-Zeil Clinics Isny.

Background Plasma total homocysteine ( tH cy) is related to plasma neopterin, an indicator of interferon‐γ‐mediated immune activation, and both biomarkers positively predict cardiovascular risk. We examined whether the association between tH cy and subsequent risk of acute myocardial infarction ( AMI ) was modified by systemic concentrations of neopterin and C‐reactive protein among patients with coronary heart disease. Methods and Results By Cox modeling, we explored the association between tH cy and risk of AMI in 4164 patients with suspected stable angina pectoris. Subgroup analyses were performed according to median levels of neopterin and C‐reactive protein. A replication study was performed among 3749 patients with AMI at baseline. Median follow‐up was 7.3 and 8.3 years among patients with stable angina pectoris and AMI , respectively. tH cy and neopterin correlated in both cohorts ( r s =0.34 and r s =0.30 among stable angina pectoris and AMI patients, respectively, both P tH cy predicted AMI in both cohorts, independent of B‐vitamin treatment. However, significant risk associations were confined to patients with plasma neopterin above the median (hazard ratios [95% confidence interval] per 1‐ SD increment of log‐transformed tH cy 1.38 [1.26–1.50] and 1.18 [1.10–1.26] among stable angina pectoris and AMI patients, respectively) ( P int tH cy and neopterin improved model discrimination and reclassification. tH cy and C‐reactive protein were weakly related, and no effect modification was found by C‐reactive protein. Conclusions Among patients with coronary heart disease, tH cy predicted risk of AMI only in subjects with concomitantly elevated plasma neopterin. Our results motivate further research on the relationship between homocysteine metabolism, cellular immune activation, and atherothrombosis.

Plasma choline has been associated with cardiovascular disease and nonalcoholic steatohepatitis.We sought to study relations of plasma choline and its metabolite betaine to long-term risk of acute myocardial infarction (AMI) and all-cause mortality according to smoking status, in patients undergoing coronary angiography for stable angina pectoris.Samples were obtained before angiography from 2568 patients who were subsequently randomized in the Western Norway B-Vitamin Intervention Trial (WENBIT). Hazard ratios (HR) were calculated using multivariate Cox-regression and p-values were reported for trends over quartiles.Plasma concentrations of choline, but not betaine, were lower in smokers, and choline was positively associated with C-reactive protein and troponin T in nonsmokers, but not in smokers (p for interaction0.03). During a follow up of 4.8 ± 1.4 (mean ± SD) years, 8.3% suffered from AMI and 6.1% died. In the total population, choline was not associated with AMI or all-cause mortality. However, comparing the highest vs. the lowest quartiles, plasma choline was associated with increased risk of AMI in nonsmokers (HR 2.63, 95% CI 1.56 to 5.51; p for trend = 0.013) and no risk in smokers (p for interaction 0.001). Plasma choline significantly improved discrimination and reclassification when added to established cardiovascular risk factors. Plasma betaine was not associated with either endpoint.In patients with stable angina pectoris, elevated plasma choline is associated with elevated troponin levels and increased risk of AMI in nonsmokers. These results motivate further research into the relation between choline metabolism, smoking, and atherothrombosis.

Immune system activation is involved in atherosclerosis. Neopterin production and tryptophan catabolism through the kynurenine pathway, measured by the kynurenine-tryptophan ratio (KTR), are induced by interferon gamma, thus both are considered markers of cell mediated immune activation. This study prospectively investigated their predictive value on acute coronary events among Norwegian community-dwelling older adults without previous coronary heart disease.1112 men and 1631 women, 71-74 years old were examined during 1997-99 as part of the Hordaland Health Study. They were followed until an acute coronary event (defined as unstable angina, non-fatal or fatal acute myocardial infarction or sudden death) or December 31, 2006. Kaplan-Meier hazard curves were constructed for quartiles of plasma neopterin and KTR. Cox proportional hazards models adjusted for sex, body mass index, smoking, hypertension, renal function and cholesterol were used to examine the relation between neopterin and KTR quartiles and the study endpoint.Median (interquartile range) values were 8.6 (7.2-10.4) nmol/L for neopterin and 25.8 (25.3-31.1) nmol/μmol for KTR. During the follow up, 265 participants had at least one acute coronary event. Increased baseline levels of plasma neopterin and KTR were associated with continuous increased risk of developing the study endpoint (P-values for trend0.001 and 0.019, respectively). Adjusted hazard ratios comparing the fourth quartile to the first were 1.65 (95% CI; 1.11-2.47; P=0.013) for neopterin and 1.57 (95% CI 1.03-2.39; P=0.036) for KTR.Plasma neopterin and KTR levels predict acute coronary events in older adults without previous coronary heart disease.