Prognostic value of growth differentiation factor-15 3 months after an acute chest pain admission

OBJECTIVE

Growth differentiation factor-15 (GDF-15) is a predictor of death and cardiovascular events when measured during index hospitalisation in patients with acute chest pain. This study investigated the prognostic utility of measuring GDF-15 3 months after an admission with suspected non-ST-elevation acute coronary syndrome (NSTE-ACS).

METHODS

GDF-15 was measured at baseline and 3 months after admission in 758 patients admitted with suspected NSTE-ACS. Patients were followed for a median of 1540 (IQR: 1087-1776) days after the 3-month visit. The primary endpoint was all-cause mortality, while the secondary composite endpoint included all-cause mortality, incident myocardial infarction and heart failure hospitalisation during follow-up.

RESULTS

In patients with GDF-15 ≥1200 pg/mL (n=248), 18% died and 25% met the composite endpoint. In patients with GDF-15 <1200 pg/mL (n=510), 1.7% died and 4% met the composite endpoint. The GDF-15 concentration (log2 transformed) at 3 months was significantly associated with all-cause mortality (adjusted HR: 2.2, 95% CI: 1.4 to 3.3, p<0.001) and the composite endpoint (adjusted HR: 1.9, 95% CI: 1.4 to 2.7, p<0.001), independently of traditional risk factors and baseline troponin T. A 10% change in GDF-15 concentration from baseline to the 3-month visit was associated with increased risk of all-cause mortality (HR: 1.06, 95% CI: 1.01 to 1.13, p=0.031), adjusting for baseline GDF-15 concentrations.

CONCLUSIONS

High GDF-15 concentrations 3 months after admission for suspected NSTE-ACS are associated with long-term mortality and cardiovascular events, independent of traditional risk factors and troponin T. A change in GDF-15 concentration can provide prognostic information.

Coronary calcium score in the initial evaluation of suspected coronary artery disease

OBJECTIVE

We 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).

METHODS

10 857 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.

RESULTS

Median 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 <45 years of age, although the NPV was high at 98.9%, the sensitivity of CAC=0 for obstructive CAD was only 82.3%.

CONCLUSIONS

In 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 (<45 years of age).

Long-term prognostic value of trimethylamine N-oxide in community-based adults and patients with coronary heart disease

Background

Trimethylamine N-oxide (TMAO) is an amine oxide generated by gut microbial metabolism. Emerging evidence suggests pro-atherosclerotic and pro-inflammatory properties of TMAO; however, the clinical utility of circulating TMAO in risk stratification is uncertain.

Purpose

We prospectively assessed relationships of plasma TMAO with long-term risk of all-cause, cardiovascular (CV) and non-CV mortality in community-dwelling adults and patients with coronary heart disease.

Methods

By Cox modelling, risk-associations were examined in the Hordaland Health Study (HUSK; 6393 community-based adults) and the Western Norway Coronary Angiography Cohort (WECAC; 4132 patients with suspected chronic coronary syndrome).

Results

Median follow-up time was 11.0 and 10.3 years in HUSK and WECAC, respectively. Following adjustments for established CV risk factors in HUSK, the HRs (95% CIs) comparing the 4th vs. 1st TMAO-quartile were 1.11 (0.88–1.40), 0.97 (0.65–1.46) and 1.17 (0.88–1.54) for all-cause, CV and non-CV mortality, respectively. Corresponding risk estimates in WECAC were 1.07 (0.86–1.32), 1.16 (0.83–1.62) and 1.02 (0.77–1.34). Similar results were observed in patients with angiographically significant coronary artery disease and patients with reduced left ventricular ejection fraction.

Conclusion

Plasma TMAO was not predictive of long-term all-cause, CV or non-CV mortality in patients with or without established coronary heart disease. This large-scale study does not support a role of TMAO for patient risk stratification in primary or secondary prevention.

Funding Acknowledgement

Type of funding sources: None.

Plasma hydroxyanthranilic acid as a predictor of stress induced myocardial ischemia in non-obstructive coronary artery disease

Background

The tryptophan catabolite hydroxyanthranilic acid (HAA) has potent immunomodulatory and vasoactive effects. HAA is also a precursor in the synthesis of nicotinamide adenine dinucleotide (NAD), a crucial cofactor in energy-metabolism. We have previously demonstrated that elevated plasma HAA predicted risk of myocardial infarction.

Purpose

To explore if plasma HAA is associated with stress induced myocardial ischemia in non-obstructive coronary artery disease (CAD).

Methods

In 132 patients with chest pain and non-obstructive CAD by coronary computed tomography angiography (CCTA), plasma HAA was analyzed by gas chromatography tandem mass spectrometry. All participants underwent myocardial contrast stress echocardiography. Myocardial ischemia was assessed as delayed contrast replenishment at peak dobutamine stress during real-time low mechanical index imaging and destruction replenishment. The extent of ischemia was defined as the number of segments with delayed contrast enhancement using a 17-segment left ventricular model. Associations of plasma HAA with myocardial ischemia was evaluated in a multivariate adjusted linear regression model.

Results

Mean (SD) age at inclusion was 63 (8) years and 56% were women. At CCTA, the median (25th, 75th percentile) coronary artery calcium (CAC) score was 42 (13–107) Agatston units, whereas the mean (SD) segment involvement score (SIS) was 2.6 (1.6). Myocardial ischemia was found in 52% of patients with on average 5 (3) ischemic segments per patient. Serum HAA did not correlate with the CAC score or SIS (p&gt;0.29). After multivariate adjustment including age, sex, body mass index, systolic blood pressure, diabetes, current smoking, and LDL cholesterol, the odds ratio and 95% confidence interval for myocardial ischemia was 1.55 (1.04–2.32), P=0.03, per SD increment of plasma HAA levels (log transformed). Plasma HAA was also associated with the extent of myocardial ischemia with a multivariate adjusted β of 0.26, P=0.004.

Conclusion

Plasma HAA is associated with the extent of myocardial ischemia in non-obstructive CAD. Potential roles of this metabolite in atherogenesis, vascular dysfunction and as a predictor of myocardial ischemia should be further elucidated.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Regional Health Authority

Even chained acylcarnitines predict long-term cardiovascular prognosis in patients with chest pain and non-obstructive coronary artery disease

Background

Acylcarnitines are essential for mitochondrial fatty acid oxidation. Earlier studies suggest that impaired energy metabolism may be implicated in the pathogenesis of microvascular angina. We explored metabolites from the carnitine pathway as predictors of cardiovascular disease (CVD) - and all-cause mortality among patients with non-obstructive coronary artery disease (NOCAD).

Methods

A total of 1046 patients with suspected stable coronary syndrome underwent coronary angiography during 2000–2004, with findings of NOCAD. Serum levels of 8 selected carnitine metabolites were analyzed through liquid chromatography tandem mass spectrometry. Associations with CVD- and all-cause mortality were assessed by multivariable Cox regression models.

Results

Median age at inclusion was 57 years. 51.5% were men. During median (25th- 75th percentiles), 14.1 (13.2–15.4) years of follow-up, 5.7% of the participants died from CVD and the incidence of all-cause mortality was 17.3%. Serum acetyl, octanoyl- and palmitoylcarnitine predicted CVD mortality with multivariable HR and 95% CI (per SD increment log transformed) of 1.36 (1.01–1.83), 1.49 (1.15–1.93) and 2.07 (1.49–2.85), p ≤ 0.04, respectively. Higher serum acetyl- and palmitoylcarnitines were also associated with increased risk of all-cause mortality (HR (95% CI): 1.27 (1.01–1.50), and 1.51 (1.26–1.81), p ≤ 0.007. Baseline levels of the precursors trimethyllysine and ƴ-butyrobetaine, carnitine or the odd chained propionylcarnitine and (iso)valerylcarnitine were not associated with adverse outcomes.

Conclusion

Elevated serum even-chained acylcarnitines predicted adverse long-term prognosis in NOCAD. The strongest risk estimates were observed for palmitoylcarnitine, which predicted both CVD- and all-cause mortality after extensive multivariable adjustments. Underlying pathomechanisms should be further elucidated.

Impact of epicardial adipose tissue accumulation on left ventricular mass and hypertrophy in non-obstructive coronary artery disease

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 (&lt;50% stenosis) by coronary computed tomography (CT) angiography. EAT volume was quantified using a semiautomatic analysis software on non-contrast cardiac CT images. Patients were grouped according to EAT volume, where high EAT volume was adjudicated when EAT volume was in the highest tertile (≥125 ml). Left ventricular mass was assessed by echocardiography, calculated by the Devereux formula and indexed for height in the allometric power of 2.7 (LVMi). LVH was defined as LVMi &gt;46.7 g/m2.7 in women and &gt;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&lt;0.05). Age, coronary calcium score and coronary artery segment involvement score did not differ between groups. Patients with high EAT volume had higher LVMi compared to those with low EAT volume (42.5 g/m2.7 vs. 36.1 g/m2.7, p=0.003), while there was no difference in EAT volume among patients with or without LVH. In univariable logistic regression analysis, high EAT volume was associated with higher LVMi (OR 1.05 [95% CI 1.01–1.10] per g/m2.7, p=0.015). After adjusting for hypertension and obesity in a multivariable model, higher LVMi remained significantly associated with high EAT volume (Model 1, Table 1), but the association was attenuated after adjusting for sex (Model 2, Table 1).

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

Associations of circulating polyunsaturated fatty acids with coronary artery calcium score in hospitalized patients with suspected coronary artery disease

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&lt;0.001. In contrast, total PUFA and LA were inversely associated with CAC score both providing standardized betas of −0.17, P=0.03 after multivariable adjustments. No significant associations were found between CAC score and DHA or GlycA (P≥0.22). Further, the addition of GlycA to the multivariable model did not materially affect the relationship between CAC score and total PUFA or LA, which remained statistically significant (P=0.04).

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

The associations of serum homoarginine to long-term prognosis in patients with chronic coronary syndrome and non-obstructive coronary artery disease

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 &gt;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&lt;0.001.

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

Circulating trimethyllysine predicts total and cardiovascular mortality in patients with and without coronary heart disease

Background

The carnitine precursor trimethyllysine (TML) is associated with the microbiota-derived metabolite trimethylamine N-oxide (TMAO) and predicts future cardiovascular events in patients with established coronary heart disease (CHD).

Purpose

To examine circulating TML as a predictor of total and cardiovascular mortality in two independent cohorts of subjects with or without CHD.

Methods

By Cox regression modelling, risk associations were examined in 6393 subjects in the community-based Hordaland Health Study (HUSK). A replication study was performed among 4117 patients undergoing coronary angiography for suspected stable angina pectoris in the Western Norway Coronary Angiography Cohort (WECAC).

Results

During a median follow-up of 10.9 years in the HUSK-cohort, 884 (13.8%) subjects died, of whom 287 from cardiovascular causes. After adjustments for traditional cardiovascular risk factors, the hazard ratio (HR) (95% CI) for total mortality comparing the 4th vs. 1st TML-quartile was 1.66 (1.31–2.10, p&lt;0.001). Particularly strong associations were observed with cardiovascular mortality (HR [95% CI] 2.04 [1.32–3.15, p=0.001]). Corresponding risk estimates in the WECAC-cohort (median follow-up of 10.3 years) were 1.35 (1.10–1.66, p=0.004) for total and 1.45 (1.06–1.98, p=0.02) for cardiovascular mortality. Additional adjustments for plasma TMAO did not materially influence the risk estimates in either cohort, and no effect modification by TMAO was observed.

Conclusions

Circulating TML is associated with increased risk of total and cardiovascular mortality in both subjects with and without CHD.

Funding Acknowledgement

Type of funding sources: None.

Development and validation of a ceramide- and phospholipid-based cardiovascular risk estimation score for coronary artery disease patients

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.

P2647Impact of hypertension on extent of non-obstructive coronary artery disease (The NORIC registry)

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<0.05). Coronary artery SIS and calcium score were higher in patients with hypertension compared to those without hypertension, (3.1±2.0 vs. 2.6±1.7, p<0.001 and 41 (116) vs. 32 (91) HU, p<0.05), respectively. There was no significant sex difference in the prevalence of hypertension. In univariable analysis, hypertension, age, calcium score and statin treatment were significantly associated with extensive non-obstructive CAD (Table). Hypertension remained a strong, independent predictor of extensive non-obstructive CAD after adjusting for other known covariables (Table).

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 <0.001 1.04 1.01–1.06 0.001 Calcium score 1.02 1.01–1.02 <0.001 1.01 1.01–1.02 <0.001 Statin treatment 1.34 1.03–1.75 0.029 1.20 0.83–1.70 0.341 Smoking 1.33 1.00–1.77 0.052 1.24 0.86–1.78 0.251 Diabetes mellitus 1.34 0.86–2.12 0.191 1.10 0.57–2.09 0.781 Obesity 1.03 0.76–1.41 0.839 1.19 0.79–1.80 0.425

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.

P1531The association between plasma choline and acute myocardial infarction is modified by potential markers of endogenous PPAR activation

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<0.0001; however no significant relationships were observed between plasma choline and later AMI among patients with either plasma MMA or DMG < median (P interaction <0.008) (Figure 1).

<MEDIAN (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) <0.0001 Smoking, n (%) 212 (37.9) 153 (27.9) <0.0001 Diabetes, n (%) 61 (10.9) 85 (15.5) 0.12 Previous acute myocardial infarction, n (%) 200 (35.7) 238 (43.4) <0.0001 Estimated glomerular filtration rate, mL/min/1.73m2 96 (87–104) 79 (63–92) <0.0001 Serum hs-troponin T, ng/L 4 (3–8) 9 (4–17) 0.0002 Serum triglycerides, mmol/L 1.35 (1.00–2.03) 1.60 (1.16–2.25) <0.0001 Serum apolipoprotein A1, mg/L 1.29 (1.12–1.51) 1.32 (1.17–1.53) 0.01 Statin therapy, n (%) 384 (68.6) 435 (79.4) 0.01

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

Plasma Amino Acids and Incident Type 2 Diabetes in Patients With Coronary Artery Disease

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.

Ceramide stearic to palmitic acid ratio predicts incident diabetes

AIMS/HYPOTHESIS

Ceramide lipids have a role in the development of insulin resistance, diabetes and risk of cardiovascular disease. Here we investigated four ceramides and their ratios to find the best predictors 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 HbA_1c (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.

Association of plasma neopterin with risk of an inpatient hospital diagnosis of atrial fibrillation: results from two prospective cohort studies

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.

Plasma 25-Hydroxyvitamin D and Mortality in Patients With Suspected Stable Angina Pectoris

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.

Relations between lipoprotein(a) concentrations, LPA genetic variants, and the risk of mortality in patients with established coronary heart disease: a molecular and genetic association study

BACKGROUND

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.

METHODS

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.

FINDINGS

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.

INTERPRETATION

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.

FUNDING

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.

Plasma ceramides predict cardiovascular death in patients with stable coronary artery disease and acute coronary syndromes beyond LDL-cholesterol

Aims

The aim was to study the prognostic value of plasma ceramides (Cer) as cardiovascular death (CV death) markers in three independent coronary artery disease (CAD) cohorts.

Methods and results

Corogene study is a prospective Finnish cohort including stable CAD patients (n = 160). Multiple lipid biomarkers and C-reactive protein were measured in addition to plasma Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0), and Cer(d18:1/24:1). Subsequently, the association between high-risk ceramides and CV mortality was investigated in the prospective Special Program University Medicine—Inflammation in Acute Coronary Syndromes (SPUM-ACS) cohort (n = 1637), conducted in four Swiss university hospitals. Finally, the results were validated in Bergen Coronary Angiography Cohort (BECAC), a prospective Norwegian cohort study of stable CAD patients. Ceramides, especially when used in ratios, were significantly associated with CV death in all studies, independent of other lipid markers and C-reactive protein. Adjusted odds ratios per standard deviation for the Cer(d18:1/16:0)/Cer(d18:1/24:0) ratio were 4.49 (95% CI, 2.24–8.98), 1.64 (1.29–2.08), and 1.77 (1.41–2.23) in the Corogene, SPUM-ACS, and BECAC studies, respectively. The Cer(d18:1/16:0)/Cer(d18:1/24:0) ratio improved the predictive value of the GRACE score (net reclassification improvement, NRI = 0.17 and ΔAUC = 0.09) in ACS and the predictive value of the Marschner score in stable CAD (NRI = 0.15 and ΔAUC = 0.02).

Conclusions

Distinct plasma ceramide ratios are significant predictors of CV death both in patients with stable CAD and ACS, over and above currently used lipid markers. This may improve the identification of high-risk patients in need of more aggressive therapeutic interventions.

Glycated hemoglobin and long-term prognosis in patients with suspected stable angina pectoris without diabetes mellitus: a prospective cohort study

OBJECTIVE

Associations of glycated hemoglobin A1c (HbA1c) levels to incident coronary and cardiovascular events among non-diabetic patients with coronary artery disease are unclear. We investigated relations of HbA1c to long-term prognosis in such patients.

METHODS

A prospective cohort of 2519 patients undergoing elective coronary angiography for suspected stable angina pectoris (SAP) was divided into pre-defined categories according to HbA1c (%) levels (<5.0, 5.0-5.6 (reference), 5.7-6.4), and followed for median 4.9 years. The primary end-point was major coronary events (including non-fatal and fatal acute myocardial infarctions, and sudden cardiac death). Secondary end-points were death from cardiovascular disease (CVD) and all-cause mortality. Hazard ratios (HRs) (95% confidence intervals [CIs]) were obtained by Cox regression.

RESULTS

Median age at inclusion was 62 years, 73% were males, median HbA1c was 5.6% and random plasma-glucose 5.4 mmol/L. After multivariate adjustment, HbA1c levels within the pre-diabetic range were not associated with risk of major coronary events, HR (95% CI): 1.13 (0.79-1.62); P=0.49, death from CVD or all-cause mortality HR (95% CI): 0.95 (0.55-1.66) and 1.04 (0.70-1.53), respectively; P≥0.85. Similarly, there was no significant association between HbA1c values within the lowest category and risk of study outcomes, (P≥0.18).

CONCLUSION

In non-diabetic patients with suspected SAP, there was no overall association between HbA1c levels and prognosis, questioning an independent role of glycemia in the pathogenesis of atherosclerotic complications in these patients.

Associations of Plasma Kynurenines With Risk of Acute Myocardial Infarction in Patients With Stable Angina Pectoris

Objective—

Enhanced tryptophan degradation, induced by the proinflammatory cytokine interferon-γ, has been related to cardiovascular disease progression and insulin resistance. We assessed downstream tryptophan metabolites of the kynurenine pathway as predictors of acute myocardial infarction in patients with suspected stable angina pectoris. Furthermore, we evaluated potential effect modifications according to diagnoses of pre-diabetes mellitus or diabetes mellitus.

Approach and Results—

Blood samples were obtained from 4122 patients (median age, 62 years; 72% men) who underwent elective coronary angiography. During median follow-up of 56 months, 8.3% had acute myocardial infarction. Comparing the highest quartile to the lowest, for the total cohort, multivariable adjusted hazard ratios (95% confidence intervals) were 1.68 (1.21–2.34), 1.81 (1.33–2.48), 1.68 (1.21–2.32), and 1.48 (1.10–1.99) for kynurenic acid, hydroxykynurenine, anthranilic acid, and hydroxyanthranilic acid, respectively. The kynurenines correlated with phenotypes of the metabolic syndrome, and risk associations were generally stronger in subgroups classified with pre-diabetes mellitus or diabetes mellitus at inclusion ( P int ≤0.05). Evaluated in the total population, hydroxykynurenine and anthranilic acid provided statistically significant net reclassification improvements (0.21 [0.08–0.35] and 0.21 [0.07–0.35], respectively).

Conclusions—

In patients with suspected stable angina pectoris, elevated levels of plasma kynurenines predicted increased risk of acute myocardial infarction, and risk estimates were generally stronger in subgroups with evidence of impaired glucose homeostasis. Future studies should aim to clarify roles of the kynurenine pathway in atherosclerosis and glucose metabolism.

Smoking and body fat mass in relation to bone mineral density and hip fracture: the Hordaland Health Study

Lower bone mineral density (BMD) in smokers may be attributable to lower body weight or fat mass, rather than to a direct effect of smoking. We analyzed the effects of smoking exposure, assessed by plasma cotinine, and body fat on BMD and the risk of subsequent hip fracture. In the community-based Hordaland Health Study (HUSK), 3003 participants 46-49 years and 2091 subjects 71-74 years were included. Cotinine was measured in plasma and information on health behaviors was obtained from self-administered questionnaires. BMD and total body soft tissue composition were measured by dual X-ray absorptiometry. Information on hip fracture was obtained from computerized records containing discharge diagnoses for hospitalizations between baseline examinations 1997-2000 through December 31st, 2009. In the whole cohort, moderate and heavy smokers had stronger positive associations between fat mass and BMD compared to never smokers (differences in regression coefficient (95% CI) per % change in fat mass = 1.38 (0.24, 2.52) and 1.29 (0.17, 2.4), respectively). In moderate and heavy smokers there was a nonlinear association between BMD and fat mass with a stronger positive association at low compared to high levels of fat mass (Davies segmented test, p<0.001). In elderly women and men, heavy smokers had an increased risk of hip fracture compared to never smokers (hazard ratio = 3.31, 95% CI: 2.05, 5.35; p<0.001). In heavy smokers there was a tendency of a lower risk of hip fracture with higher percentage of fat mass. The deleterious effect of smoking on bone health is stronger in lean smokers than in smokers with high fat mass.

Association of plasma B-6 vitamers with systemic markers of inflammation before and after pyridoxine treatment in patients with stable angina pectoris

BACKGROUND

A negative association between systemic markers of inflammation and plasma vitamin B-6 has been observed in population-based and patient cohorts; however, vitamin B-6 (pyridoxine) treatment has mostly failed to improve inflammatory indexes.

OBJECTIVE

We aimed to assess the effect of pyridoxine treatment on B-6 vitamer and inflammatory marker relations.

DESIGN

We measured pyridoxal 5'-phosphate (PLP), pyridoxal, 4-pyridoxic acid (PA), C-reactive protein (CRP), neopterin, and the kynurenine-to-tryptophan ratio (KTR) in plasma and the white blood cell count (WBC). A partial Spearman's correlation was used to assess associations of B-6 vitamers with inflammatory markers before and after daily treatment with 40 mg pyridoxine hydrochloride. Generalized additive models and segmented regression analysis were used for nonlinear relations.

RESULTS

A 9-60-fold increase in B-6 vitamer concentrations over baseline values was observed after 28 d of treatment with pyridoxine. PLP was negatively associated with all 4 inflammatory markers at baseline and, predominantly, with CRP and KTR at day 28. The catabolite PA was positively associated with neopterin and KTR before and after treatment. The dose-response relation between CRP and B-6 vitamers at day 28 was nonlinear, with an increased steepness of slope at CRP >7 mg/L. Finally, changes in B-6 vitamer concentrations were correlated with changes in inflammatory marker concentrations over a time span of 4 wk.

CONCLUSIONS

The associations between plasma vitamin B-6 and inflammatory markers were preserved or even increased after pyridoxine treatment. The results suggest that the acute phase and activated cellular immunity are associated with increased cellular uptake and catabolism of vitamin B-6, respectively.

Low plasma vitamin B-6 status affects metabolism through the kynurenine pathway in cardiovascular patients with systemic inflammation

It is unclear whether reduced plasma pyridoxal 5'-phosphate (PLP) during inflammation reflects an altered distribution or increased requirement of vitamin B-6 that may impair overall vitamin B-6 status in tissues. In plasma from 3035 patients undergoing coronary angiography for suspected coronary heart disease, we investigated if plasma concentrations of any metabolites in the kynurenine pathway, which depend on PLP as cofactor, may serve as metabolic marker(s) of vitamin B-6 status. We also examined the association of vitamin B-6 status with serum or plasma concentrations of several inflammatory markers. Among the kynurenines, only 3-hydroxykynurenine (HK) was inversely related to PLP and showed a positive relation to 4 investigated inflammatory markers. A segmented relationship was observed between PLP and HK, with a steep slope at PLP concentrations < 18.4 nmol/L, corresponding to the 5th percentile, and an almost zero slope at higher PLP concentrations. Low PLP and the steep PLP-HK slope were essentially confined to participants with 1 or more inflammatory markers in the upper tertile. Oral supplementation with pyridoxine hydrochloride (40 mg/d) for 1 mo increased plasma PLP 8-fold, reduced the geometric mean (95% CI) of HK from 29.5 to 20.2 nmol/L (P < 0.001), and abolished the steep segment of the PLP-HK curve. The steep inverse relationship of plasma PLP with HK at low plasma PLP and the lowering of HK by pyridoxine suggest plasma HK as a metabolic marker of vitamin B-6 status. Thus, low plasma PLP during inflammation may reflect impaired cellular vitamin B-6 status, as indicated by the concurrent increase in plasma HK.

Combined analyses and extended follow-up of two randomized controlled homocysteine-lowering B-vitamin trials

OBJECTIVES

In the Norwegian Vitamin Trial and the Western Norway B Vitamin Intervention Trial, patients were randomly assigned to homocysteine-lowering B-vitamins or no such treatment. We investigated their effects on cardiovascular outcomes in the trial populations combined, during the trials and during an extended follow-up, and performed exploratory analyses to determine the usefulness of homocysteine as a predictor of cardiovascular outcomes.

DESIGN

Pooling of data from two randomized controlled trials (1998-2005) with extended post-trial observational follow-up until 1 January 2008.

SETTING

Thirty-six hospitals in Norway.

SUBJECTS

6837 patients with ischaemic heart disease.

INTERVENTIONS

One capsule per day containing folic acid (0.8 mg) plus vitamin B12 (0.4 mg) and vitamin B6 (40 mg), or folic acid plus vitamin B12, or vitamin B6 alone or placebo.

MAIN OUTCOME MEASURES

Major adverse cardiovascular events (MACEs; cardiovascular death, acute myocardial infarction or stroke) during the trials and cardiovascular mortality during the extended follow-up.

RESULTS

Folic acid plus vitamin B12 treatment lowered homocysteine levels by 25% but did not influence MACE incidence (hazard ratio, 1.07; 95% CI, 0.95-1.21) during 39 months of follow-up, or cardiovascular mortality (hazard ratio, 1.12; 95% CI, 0.95-1.31) during 78 months of follow-up, when compared to no such treatment. Baseline homocysteine level was not independently associated with study outcomes. However, homocysteine concentration measured after 1-2 months of folic acid plus vitamin B12 treatment was a strong predictor of MACEs.

CONCLUSION

We found no short- or long-term benefit of folic acid plus vitamin B12 on cardiovascular outcomes in patients with ischaemic heart disease. Our data suggest that cardiovascular risk prediction by plasma total homocysteine concentration may be confined to the homocysteine fraction that does not respond to B-vitamins.

Fcgamma receptor IIIA polymorphism as a risk-factor for coronary artery disease

BACKGROUND

Inflammation is important in the pathogenesis of atherosclerosis. Polymorphisms of Fc receptors for IgG (FcgammaR) are associated with modifying effects of several infectious and autoimmune diseases. We have assessed the relationship between polymorphisms in three different FcgammaR genes and coronary artery disease (CAD).

METHODS AND RESULTS

We genotyped for the FcgammaRIIA-R/H131, the FcgammaRIIIB-Na1/Na2, and the FcgammaRIIIA-F/V158 polymorphisms in 882 patients undergoing diagnostic coronary angiography. Significant CAD was defined as >/=50% lumen diameter stenosis in at least one coronary artery. In the analysis, no association was found between the FcgammaRIIA and FcgammaRIIIB genotypes and CAD, whereas the FcgammaRIIIA genotype was strongly related. Compared to those being heterozygous, or homozygous for the F allele, patients homozygous for the V allele had significantly reduced risk: OR, 0.53; (CI, 0.32-0.90). Additional adjustment for classical risk factors and sedimentation rate did not affect the results. The V/V genotype was also inversely related to the extent of CAD defined as no CAD, single, double or triple vessel disease (P trend=0.002).

CONCLUSIONS

Our data provide evidence for an association between FcgammaRIIIA allelic variants and coronary atherosclerosis. Genetic variation in this IgG-receptor may influence the clearance of antibodies by monocyte-derived macrophages involved in the pathogenesis of CAD.

Non-tropical sprue. Malignant diseases and mortality rate

The complications of non-tropical sprue were registered in 100 patients seen during an 18-year period. The patients had a significantly higher mortality than the age- and sex-matched general population. They had an increased incidence of malignancies, predominantly malignant lymphomas and carcinomas of the gastrointestinal tract. The disease must be considered a premalignant condition.