Prognostic Value of Cardiovascular Biomarkers in the Population

Importance

Identification of individuals at high risk for atherosclerotic cardiovascular disease within the population is important to inform primary prevention strategies.

Objective

To evaluate the prognostic value of routinely available cardiovascular biomarkers when added to established risk factors.

Design, Setting, and Participants

Individual-level analysis including data on cardiovascular biomarkers from 28 general population-based cohorts from 12 countries and 4 continents with assessments by participant age. The median follow-up was 11.8 years.

Exposure

Measurement of high-sensitivity cardiac troponin I, high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, B-type natriuretic peptide, or high-sensitivity C-reactive protein.

Main Outcomes and Measures

The primary outcome was incident atherosclerotic cardiovascular disease, which included all fatal and nonfatal events. The secondary outcomes were all-cause mortality, heart failure, ischemic stroke, and myocardial infarction. Subdistribution hazard ratios (HRs) for the association of biomarkers and outcomes were calculated after adjustment for established risk factors. The additional predictive value of the biomarkers was assessed using the C statistic and reclassification analyses.

Results

The analyses included 164 054 individuals (median age, 53.1 years [IQR, 42.7-62.9 years] and 52.4% were women). There were 17 211 incident atherosclerotic cardiovascular disease events. All biomarkers were significantly associated with incident atherosclerotic cardiovascular disease (subdistribution HR per 1-SD change, 1.13 [95% CI, 1.11-1.16] for high-sensitivity cardiac troponin I; 1.18 [95% CI, 1.12-1.23] for high-sensitivity cardiac troponin T; 1.21 [95% CI, 1.18-1.24] for N-terminal pro-B-type natriuretic peptide; 1.14 [95% CI, 1.08-1.22] for B-type natriuretic peptide; and 1.14 [95% CI, 1.12-1.16] for high-sensitivity C-reactive protein) and all secondary outcomes. The addition of each single biomarker to a model that included established risk factors improved the C statistic. For 10-year incident atherosclerotic cardiovascular disease in younger people (aged <65 years), the combination of high-sensitivity cardiac troponin I, N-terminal pro-B-type natriuretic peptide, and high-sensitivity C-reactive protein resulted in a C statistic improvement from 0.812 (95% CI, 0.8021-0.8208) to 0.8194 (95% CI, 0.8089-0.8277). The combination of these biomarkers also improved reclassification compared with the conventional model. Improvements in risk prediction were most pronounced for the secondary outcomes of heart failure and all-cause mortality. The incremental value of biomarkers was greater in people aged 65 years or older vs younger people.

Conclusions and Relevance

Cardiovascular biomarkers were strongly associated with fatal and nonfatal cardiovascular events and mortality. The addition of biomarkers to established risk factors led to only a small improvement in risk prediction metrics for atherosclerotic cardiovascular disease, but was more favorable for heart failure and mortality.

Reference intervals of circulating secretoneurin concentrations determined in a large cohort of community dwellers: the HUNT study

OBJECTIVES

Secretoneurin (SN) is a novel cardiac biomarker that associates with the risk of mortality and dysfunctional cardiomyocyte Ca2+ handling in heart failure patients. Reference intervals for SN are unknown.

METHODS

SN was measured with a CE-marked ELISA in healthy community dwellers from the fourth wave of the Trøndelag Health Study (HUNT4) conducted in 2017-2019. The common, sex and age specific 90th, 95th, 97.5th and 99th percentiles were calculated using the non-parametric method and outlier exclusion according to the Reed test. The applicability of sex and age specific reference intervals were investigated using Harris and Boyd test. We also estimated the percentiles in a subset with normal findings on echocardiographic screening.

RESULTS

The total cohort included 887 persons (56.4 % women). After echocardiographic screening 122 persons were excluded, leaving a total of 765 persons (57.8 % women). The 97.5th percentile (95 % CI in brackets) of SN was 59.7 (57.5-62.1) pmol/L in the total population and 58.6 (57.1-62.1) pmol/L after echocardiography screening. In general, slightly higher percentiles were found in women and elderly participants, but less than 4 % in these subgroups had concentrations deviating from the common 97.5th percentile. Low BMI or eGFR was also associated with higher concentrations of SN.

CONCLUSIONS

Upper reference limits for SN were similar amongst healthy adult community dwellers regardless of prescreening including cardiac echocardiography or not. Women and elderly showed higher concentrations of SN, but the differences were not sufficiently large to justify age and sex stratified upper reference limits.

Trajectories of cardiac troponin in the decades before cardiovascular death: a longitudinal cohort study

BACKGROUND

High-sensitivity cardiac troponin testing is a promising tool for cardiovascular risk prediction, but whether serial testing can dynamically predict risk is uncertain. We evaluated the trajectory of cardiac troponin I in the years prior to a cardiovascular event in the general population, and determine whether serial measurements could track risk within individuals.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on three occasions over a 15-year period. Time trajectories of troponin were constructed in those who died from cardiovascular disease compared to those who survived or died from other causes during follow up and these were externally validated in the HUNT Study. A joint model that adjusts for cardiovascular risk factors was used to estimate risk of cardiovascular death using serial troponin measurements.

RESULTS

In 7,293 individuals (mean 58 ± 7 years, 29.4% women) cardiovascular and non-cardiovascular death occurred in 281 (3.9%) and 914 (12.5%) individuals (median follow-up 21.4 years), respectively. Troponin concentrations increased in those dying from cardiovascular disease with a steeper trajectory compared to those surviving or dying from other causes in Whitehall and HUNT (Pinteraction < 0.05 for both). The joint model demonstrated an independent association between temporal evolution of troponin and risk of cardiovascular death (HR per doubling, 1.45, 95% CI,1.33-1.75).

CONCLUSIONS

Cardiac troponin I concentrations increased in those dying from cardiovascular disease compared to those surviving or dying from other causes over the preceding decades. Serial cardiac troponin testing in the general population has potential to track future cardiovascular risk.

The prevalence of cardiac complications and their impact on outcomes in patients with non-traumatic subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a serious condition, and a myocardial injury or dysfunction could contribute to the outcome. We assessed the prevalence and prognostic impact of cardiac involvement in a cohort with SAH. This is a prospective observational multicenter study. We included 192 patients treated for non-traumatic subarachnoid hemorrhage. We performed ECG recordings, echocardiographic examinations, and blood sampling within 24 h of admission and on days 3 and 7 and at 90 days. The primary endpoint was the evidence of cardiac involvement at 90 days, and the secondary endpoint was to examine the prevalence of a myocardial injury or dysfunction. The median age was 54.5 (interquartile range [IQR] 48.0-64.0) years, 44.3% were male and the median World Federation of Neurological Surgeons (WFNS) score was 2 (IQR 1-4). At day 90, 22/125 patients (17.6%) had left ventricular ejection fractions ≤ 50%, and 2/121 patients (1.7%) had evidence of a diastolic dysfunction as defined by mitral peak E-wave velocity by peak e' velocity (E/e') > 14. There was no prognostic impact from echocardiographic evidence of cardiac complications on neurological outcomes. The overall prevalence of cardiac dysfunction was modest. We found no demographic or SAH-related factors associated with 90 days cardiac dysfunction.

Prediction of incident atrial fibrillation with GDF-15 and echocardiographic left atrial volumes: data from the Akershus cardiac examination 1950 study

Background

Left atrial structural remodeling is associated with the risk of incident atrial fibrillation, but there is uncertainty as to what echocardiographic left atrial indices that best predict incident atrial fibrillation. GDF-15 is a marker of oxidative stress and inflammation that is closely associated with the risk of stroke, bleeding and mortality in patients with atrial fibrillation. There is, however, limited data regarding its relation with left atrial remodeling and incident atrial fibrillation in the general population.

Purpose

To investigate the association between GDF-15 and left atrial volumes, and their prognostic properties for incident atrial fibrillation in a general population cohort.

Methods

The Akershus Cardiac Examination 1950 Study is a population-based cohort of individuals born in 1950. Comprehensive baseline examinations were performed for 3706 study participants in 2012–2015. Left atrial maximum and minimum volumes were measured, indexed to body surface area yielding LAVimax and LAVimin. Left atrial emptying fraction (LAEF) was calculated as ((LAVimax - LAVimin)/LAVimax)x100%. Individuals with known atrial fibrillation at baseline (n=166) were excluded, leaving 3540 included in this analysis. National health registries provided clinical outcome data regarding atrial fibrillation and death from any cause. Incident atrial fibrillation cases were validated by health records. Atrial flutter was included in the outcome definition. The CHARGE-AF risk score for atrial fibrillation was quantified. Prediction of incident atrial fibrillation was assessed by Cox proportional hazards regression models and visualised by Kaplan-Meier plots.

Results

Mean age at baseline was 63.9±0.7 years and 1763 (49.8%) were female. GDF-15 correlated weakly with LAVimax (r=−0.07, p&lt;0.001) and LAVimin (r=−0.05 p=0.007), but not with LAEF (r=−0.01, p=0.61). During a median follow-up of 6.4 years, incident atrial fibrillation occurred in 135 (3.8%) individuals. Subjects who developed atrial fibrillation had larger LAVimax (30.1±8.3 vs. 26.2±6.9 mL/m2; p&lt;0.001), larger LAVimin (17.1±7.1 vs. 14.1±4.7 mL/m2; p&lt;0.001), and lower LAEF (44.3±10.7 vs. 46.3±9.0%; p=0.019). Concentrations of GDF-15 were not significantly different in those who experienced atrial fibrillation (median 850 [670–1107] vs. 790 [630–1020] ng/L; p=0.06). Left atrial volumes and LAEF, but not GDF-15, were associated with incident atrial fibrillation (Table 1 and Figure 1).

Conclusions

In this population-based cohort study, LAVimax, LAVimin, and LAEF predicted incident atrial fibrillation independently of the CHARGE-AF risk score. GDF-15 was not significantly associated with left atrial structural remodeling or with increased risk of incident atrial fibrillation.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Vestre Viken HF, Hospital TrustAkershus University Hospital

Associations between cardiovascular risk factors, biomarkers, and left ventricular mechanical dispersion: insights from the ACE 1950 Study

Aims

Mechanical dispersion measures left ventricular contraction heterogeneity and is associated with the risk of sudden cardiac death. However, the associations between mechanical dispersion and cardiovascular risk factors in early mid-life, and established biomarkers of sub-clinical myocardial injury and dysfunction are not known. We aimed to examine this in the general population.

Methods and results

During 2012–15, we included 2527 Norwegian individuals from the general population born in 1950, with measurements of mechanical dispersion by 2D speckle tracking echocardiography and concentrations of high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) available. Mechanical dispersion was calculated as the standard deviation of the contraction duration of 17 strain segments. We assessed the associations between mechanical dispersion, concentrations of hs-cTnT and NT-proBNP, and cardiovascular risk factors collected at a national health screening survey two decades earlier. At echocardiography baseline, median age was 64 (interquartile range 63.5–64.5) years, 49.8% were women, 59.1% had hypertension, and 5.9% reported established coronary artery disease. Median mechanical dispersion was 38.0 (29.5–47.0) ms, median hs-cTnT concentration 6 (4–8) ng/L, and the median NT-proBNP concentration 54 (34–93) ng/L. Mechanical dispersion was associated with both hs-cTnT and NT-proBNP concentrations in multivariable models adjusted for clinical and echocardiographic variables. High body mass index, serum triglyceride concentrations, and low resting heart rate at Age 40 were independently associated with increased mechanical dispersion two decades later.

Conclusion

Established risk factors at Age 40 are associated with mechanical dispersion two decades later, and mechanical dispersion is cross-sectionally associated with biomarkers of subclinical myocardial injury and dysfunction.

Genome-wide association study of cardiac troponin I in the general population

Circulating cardiac troponin proteins are associated with structural heart disease and predict incident cardiovascular disease in the general population. However, the genetic contribution to cardiac troponin I (cTnI) concentrations and its causal effect on cardiovascular phenotypes are unclear. We combine data from two large population-based studies, the Trøndelag Health Study and the Generation Scotland Scottish Family Health Study, and perform a genome-wide association study of high-sensitivity cTnI concentrations with 48 115 individuals. We further use two-sample Mendelian randomization to investigate the causal effects of circulating cTnI on acute myocardial infarction (AMI) and heart failure (HF). We identified 12 genetic loci (8 novel) associated with cTnI concentrations. Associated protein-altering variants highlighted putative functional genes: CAND2, HABP2, ANO5, APOH, FHOD3, TNFAIP2, KLKB1 and LMAN1. Phenome-wide association tests in 1688 phecodes and 83 continuous traits in UK Biobank showed associations between a genetic risk score for cTnI and cardiac arrhythmias, metabolic and anthropometric measures. Using two-sample Mendelian randomization, we confirmed the non-causal role of cTnI in AMI (5948 cases, 355 246 controls). We found indications for a causal role of cTnI in HF (47 309 cases and 930 014 controls), but this was not supported by secondary analyses using left ventricular mass as outcome (18 257 individuals). Our findings clarify the biology underlying the heritable contribution to circulating cTnI and support cTnI as a non-causal biomarker for AMI in the general population. Using genetically informed methods for causal inference helps inform the role and value of measuring cTnI in the general population.

Insomnia symptoms and subclinical myocardial injury: Data from the Nord-Trøndelag Health (HUNT) study

Insomnia symptoms are associated with increased risk of heart failure (HF) and cardiovascular (CV) mortality. We hypothesised that insomnia symptoms are cross-sectionally associated with increased cardiac troponin I (cTnI), a biomarker of subclinical myocardial injury, and that phenotyping by insomnia symptoms and cTnI enhances longitudinal risk stratification in the general population. In a population-based study, cTnI was measured in 8,398 participants (median age 49 years, 55% women), who had answered questionnaires regarding insomnia symptoms. Association between cTnI and insomnia symptoms was assessed by linear regression analysis for each response category of a sleep questionnaire. Insomnia symptoms were defined as having difficulty falling asleep almost every night, difficulty maintaining sleep almost every night, and/or non-restorative sleep once a week or more. The primary outcome measure was a composite endpoint of CV mortality or first admission for HF. In all, 844 participants reported insomnia symptoms, 585 (69%) were women. Those with insomnia symptoms had marginally, but significantly higher median cTnI than those without insomnia symptoms, (median [interquartile range] 3.4 [2.4-5.2] ng/L versus 3.2 [2.2-4.9] ng/L; p = .014), but there was no association between any insomnia symptom and cTnI in unadjusted linear regression models (β 0.06, 95% confidence interval [CI] -0.01 to 0.12). In adjusted analyses, participants with insomnia symptoms and increased cTnI were at increased risk of the composite endpoint (hazard ratio 1.71, 95% CI 1.04-2.79) compared to participants with insomnia symptoms and low cTnI. In the general population, insomnia symptoms are not associated with biochemical evidence of subclinical myocardial injury.

Left ventricular mechanical dispersion in a general population: Data from the Akershus Cardiac Examination 1950 study

AIMS

Increased left ventricular mechanical dispersion by 2D speckle tracking echocardiography predicts ventricular arrhythmias in ischaemic heart disease and heart failure. However, little is known about mechanical dispersion in the general population. We aimed to study mechanical dispersion in the general population and in diseases associated with increased risk of cardiovascular disease.

METHODS AND RESULTS

The present cross-sectional study consists of 2529 subjects born in 1950 included in the Akershus Cardiac Examination (ACE) 1950 study. Global longitudinal strain (GLS) was assessed from 17 strain segments, and mechanical dispersion calculated as the standard deviation of contraction duration of all segments. The cohort was divided according to the median value of mechanical dispersion, and multivariable linear regression models were performed with mechanical dispersion as the dependent variable. The prevalence of coronary artery disease (CAD), hypertension, obesity, and diabetes (P < 0.01 for all) was significantly higher in subjects with supra-median mechanical dispersion. In a multivariable clinical model, CAD (B = 7.05), hypertension (B = 4.15; both P < 0.001), diabetes (B = 3.39), and obesity (B = 1.89; both P < 0.05) were independently associated with increasing mechanical dispersion. When echocardiographic indices were added to the multivariable model, CAD (B = 4.38; P < 0.01) and hypertension (B = 2.86; P < 0.001) remained significant in addition to peak early diastolic tissue velocity e' (B = -2.00), GLS (B = 1.68), and ejection fraction (B = 0.22; P < 0.001 for all).

CONCLUSION

In a general middle-aged population, prevalent CAD and hypertension were associated with increasing mechanical dispersion, possibly indicating elevated risk of fatal arrhythmias and sudden cardiac death. Albeit weaker, systolic and diastolic dysfunction, were also associated with increasing mechanical dispersion.

Diagnostic Thresholds for Pre-Diabetes Mellitus and Diabetes Mellitus and Subclinical Cardiac Disease in the General Population: Data From the ACE 1950 Study

Background Diabetes mellitus (DM) is associated with left ventricular remodeling and incident heart failure, but the association between glycated hemoglobin A1c (HbA1c) and subclinical cardiac disease is not established. We aimed to determine the associations between HbA1c and (1) echocardiographic measures of left ventricular structure and function, and (2) cardiovascular biomarkers: cardiac troponin T, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and CRP (C-reactive protein). Methods and Results Participants (n=3688) born in 1950 from the population-based ACE (Akershus Cardiac Examination) 1950 Study were classified as DM (HbA1c≥6.5% or self-reported DM), pre-DM (HbA1c 5.7%-6.5%), and no-DM (HbA1c<5.7%). DM, pre-DM, and no-DM were classified in 380 (10%), 1630 (44%), and 1678 (46%) participants, respectively. Mean age was 63.9±0.7 years, mean body mass index was 27.2±4.4 kg/m², and 49% were women. Higher HbA1c was associated with worse left ventricular systolic (ejection fraction and global longitudinal strain) and diastolic (E/e'-ratio) function, myocardial injury (cardiac troponin T), inflammation (CRP), and impaired neurohormonal homeostasis (NT-proBNP) (P<0.001 in unadjusted and P<0.01 in adjusted analysis for all). The associations between HbA1c and cardiovascular biomarkers were independent of the echocardiographic variables, and vice versa. Associations were nonlinear (P<0.05 for nonlinearity) and appeared stronger in the pre-DM range of HbA1c than the no-DM and DM range. Conclusions HbA1c was associated with indexes of subclinical cardiovascular disease, and this was more pronounced in pre-DM. Our results suggest that cardiovascular preventive measures should be considered also in subjects with hyperglycemia and HbA1c below the established DM cutoff. Registration clinicaltrials.gov. Identifier: NCT01555411.

Carotid Atherosclerosis and Cognitive Function in a General Population Aged 63-65 Years: Data from the Akershus Cardiac Examination (ACE) 1950 Study

BACKGROUND

Studies on the relationship between carotid atherosclerosis and cognitive function in subjects from the general population are few and results have been inconsistent.

OBJECTIVE

We aimed to investigate the association between carotid atherosclerotic burden and cognitive function in a cross-sectional analysis of a population-based cohort aged 63-65 years.

METHODS

All habitants born in 1950 from Akershus County, Norway were invited to participate. A linear regression model was used to assess the association between carotid atherosclerosis and cognitive function. We used carotid plaque score as a measure of carotid atherosclerotic burden and the Montreal Cognitive Assessment (MoCA) for global cognitive function.

RESULTS

We analyzed 3,413 individuals aged 63-65 with mean MoCA score 25.3±2.9 and 87% visible carotid plaques. We found a negative correlation between carotid plaque score and MoCA score (r = -0.14, p < 0.001), but this association was lost in multivariable analysis. In contrast, diameter or area of the thickest plaque was independently associated with MoCA score. Lower educational level, male sex, current smoking, and diabetes were also associated with lower MoCA score in multivariable analysis.

CONCLUSION

Carotid atherosclerotic burden was, unlike other measures of advanced carotid atherosclerosis, not independently associated with global cognitive function.

Gastric bypass surgery is associated with reduced subclinical myocardial injury and greater activation of the cardiac natriuretic peptide system than lifestyle intervention

AIMS

Morbid obesity is a risk factor for cardiovascular disease. The relative effects of Roux-en-Y gastric bypass surgery (GBS) and intensive lifestyle intervention (ILI) on subclinical myocardial injury, the activity of the cardiac natriuretic system, and systemic inflammation remain unclear.

METHODS

In a 59-week non-randomized clinical trial that included 131 patients with morbid obesity, we compared the effects ofGBS and ILI on concentrations of cardiac troponin T (cTnT) and I (cTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP).

RESULTS

In the GBS and ILI group, median body mass index (BMI) was reduced by 14.4 kg/m² versus 3.9 kg/m², respectively (p value < 0.001). Cardiac troponins decreased after GBS, p = 0.014 (cTnT) and p = 0.065 (cTnI) and increased significantly in those treated with ILI (p values ≤ 0.021) (between-group differences for deltas: p ≤ 0.003). NT-proBNP increased in both groups, but significantly more in the GBS than in the ILI group (between-group differences for deltas: p = 0.008). CRP decreased significantly within the GBS and the ILI group, with this change significantly greater in the GBS group (between-group differences for deltas p < 0.001). The dominating mediator of the biomarker changes was weight loss. Prior coronary artery disease and diabetes were predictive of the magnitude of the changes in cTnI and NT-proBNP, respectively.

CONCLUSION

Compared to ILI, GBS was associated with reduced subclinical myocardial injury and systemic inflammation, and enhancement of the cardiac natriuretic peptide system. The biomarker changes were predominantly mediated by weight loss.

Cardiac troponin is associated with cardiac outcomes in men and women with atrial fibrillation, insights from the ARISTOTLE trial

BACKGROUND

Cardiac troponin T (cTnT) and I (cTnI) concentrations provide strong prognostic information in anticoagulated patients with atrial fibrillation (AF). Whether the associations between cardiac troponin concentrations and mortality and morbidity differ by sex is not known.

OBJECTIVES

To assess whether men and women have different concentrations and prognostic value of cTnT and cTnI measurements in anticoagulated patients with AF.

METHODS

cTnT and cTnI concentrations were measured with high-sensitivity (hs) assays in EDTA plasma samples obtained from the multicentre ARISTOTLE trial, which randomized patients with AF and at least one risk factor for stroke or systemic embolic event to warfarin or apixaban. Patients were stratified according to sex and the associations between hs-troponin concentrations, and all-cause death, cardiac death, myocardial infarction, stroke or systemic embolic event and major bleeding were assessed in multivariable regression models.

RESULTS

We found higher cardiac troponin concentrations in men (n = 9649) compared to women (n = 5331), both for hs-cTnT (median 11.8 [Q1-3 8.1-18.0] vs. 9.6 [6.7-14.3] ng L^-1 , P < 0.001) and hs-cTnI (5.8 [3.4-10.8] vs. 4.9 [3.1-8.8] ng L^-1 , P < 0.001). Adjusting for baseline demographics, comorbidities and medications, men still had significantly higher hs-troponin concentrations than women. C-reactive protein and N-terminal pro-B-type natriuretic peptide concentrations were higher in female patients. Both hs-cTnT and hs-cTnI concentrations were associated with all clinical outcomes similarly in men and women (p-value for interaction >0.05 for all end-points).

CONCLUSION

Men have higher hs-troponin concentrations than women in AF. Regardless of sex, hs-troponin concentrations remain similarly associated with adverse clinical outcomes in anticoagulated patients with AF.

P1270 Systolic blood pressure at age 40 is associated with left atrial volumes at age 64

Funding Acknowledgements

Vestre Viken Hospital Trust

Background

Left atrial (LA) enlargement is associated with elevated blood pressure (BP) and with cardiovascular morbidity and mortality. In the assessment of LA size, echocardiographic guidelines recommend the use of LA end-systolic volume (LAVmax). LA end-diastolic volume (LAVmin) and LA emptying fraction (LAEF) may add valuable information in risk assessment. The knowledge of early adulthood BP and its association to LA volumes and LAEF later in life is limited.

Purpose

To explore the association between systolic BP at age 40 and LA volumes and LAEF at age 64.

Methods

We linked data from subjects who had participated in both a nationwide cardiovascular screening survey (1990-1991) at the age of 40, and the Akershus Cardiac Examination (ACE) 1950 Study (2012-2015) at the age of 64 (n = 2,597). In the ACE 1950 Study, LAVmax and LAVmin were measured with echocardiography according to the summation of discs method. LAEF was calculated as (LAVmax-LAVmin/LAVmax)x100%. The association between systolic BP at age 40 and LA volumes and LAEF at age 64 was assessed in univariate and multivariate linear regression analyses.

Results

Systolic BP at age 40 was associated with LAVmax and LAVmin but not with LAEF at age 64. In our multivariate model, a 10 mm Hg higher systolic BP at age 40 was associated with a 0.9 ml greater LA end-systolic volume and a 0.5 ml greater LA end-diastolic volume at age 64.

Conclusion

Early adulthood systolic BP is associated with LA volumes 24 years later in life.

Table. Association of systolic blood pressure at age 40 to left atrial (LA) volumes and LAEF at age 64 Univariate Multivariate* Dependent variable B (95% CI) p-value B (95% CI) p-value LAVmax (ml) 2.4 (2.0, 2.9) &lt;0.001 0.9 (0.4, 1.4) 0.001 LAVmin (ml) 1.5 (1.1, 1.8) &lt;0.001 0.5 (0.1, 0.9) 0.015 LAEF (%) -0.01 (-0.3, 0.3) 0.938 0.2 (-0.2, 0.5) 0.294 *Adjusted for gender, body mass index, smoking, resting heart rate and antihypertensive treatment, all assessed at age 40. B (95% CI), regression coefficient for systolic blood pressure (per 10 mm Hg) with 95% confidence interval; LAVmax, LA end-systolic volume; LAVmin LA end-diastolic volume; LAEF, LA emptying fraction

103 Normal values and gender differences of left atrial volumes

Funding Acknowledgements

Vestre Viken Hospital Trust

Background

Left atrial (LA) enlargement is associated with cardiovascular morbidity and mortality. Echocardiographic guidelines recommend body surface area (BSA) indexed LA end-systolic volume (LAVimax) in the assessment of LA size with an upper normal limit of 34 ml/m² for both genders and all age groups. LA end-diastolic volume (LAVimin) and LA emptying fraction (LAEF) may add valuable information in risk assessment, but there are limited data on normal values.

Purpose

To add knowledge and explore gender differences of LA volumetric measures.

Methods

In The Akershus Cardiac Examination 1950 Study, all inhabitants of Akershus County, Norway, born in 1950 were invited. In 3,489 individuals LAVmax and LAVmin were measured with echocardiography according to the summation of discs method and indexed to BSA. LAEF was calculated. A healthy group was defined by excluding those with heart failure, atrial fibrillation, coronary artery disease, stroke, hypertension, diabetes, chronic obstructive pulmonary disease, body mass index &gt; 30kg/m², eGFR &lt; 60 ml/min/1.73 m², left ventricular ejection fraction &lt; 50%, E/e’&gt;14 and E/A &gt; 2.0. Data are presented as mean ± standard deviation (SD) and a normal range of mean ± 2SD. T-tests were used for comparisons.

Results

In 840 healthy individuals, aged 63.8 ± 0.6 years, mean LAVimax was 25.6 ± 6.3 ml/m² and the normal range was 13.0-38.2 ml/m². Men had significantly larger volumes than women.

Conclusion

We present LA volumes and LAEF in a large cohort from the general population at age 64. The upper normal limit of LAVimax in 840 healthy individuals was 38 ml/m². Men had larger LA volumes than women, contrary to most previous studies. Thus, 13% of the healthy men in our cohort would be defined with an enlarged atrium with the current cut-off value at 34 ml/m².

Table. Left atrial (LA) volumes and LAEF Total (mean ± SD) Total (2SD range) Male (mean ± SD) Female (mean ± SD) P-value (male vs. female) All participants (n = 3489) LAVimax (ml/m&sup2;) 26.8 ± 7.6 11.6-42.0 27.9 ± 8.1 25.6 ± 6.8 &lt;0.001 LAVimin (ml/m&sup2;) 14.7 ± 5.8 3.1-26.3 15.5 ± 6.5 13.9 ± 4.9 &lt;0.001 LAEF (%) 45.6 ± 9.7 26.2-65.0 45.3 ± 10.2 45.9 ± 9.2 0.07 Healthy group (n = 840) LAVimax (ml/m&sup2;) 25.6 ± 6.3 13.0-38.2 26.6 ± 6.7 24.9 ± 5.8 &lt;0.001 LAVimin (ml/m&sup2;) 13.7 ± 4.3 5.1-22.3 14.1 ± 4.6 13.3 ± 3.9 0.008 LAEF (%) 46.8 ± 8.8 29.2-64.4 47.0 ± 9.1 46.5 ± 8.4 0.37 LAVimax, LA end-systolic volume, body surface area (BSA)-indexed; LAVimin, LA end-diastolic volume, BSA-indexed; LAEF, LA emptying fraction; SD, standard deviation

P3528Circulating microRNA-210 concentrations are increased in patients with acute heart failure and provide prognostic information

Background

MicroRNA (miR)-210 is induced by cellular hypoxia and circulating miR-210 concentrations are associated with clinical outcome in patients with myocardial infarction and aortic stenosis. Whether circulating miR-210 concentrations provide diagnostic and prognostic information in unselected patients with dyspnea is not known.

Purpose

To assess the diagnostic and prognostic value of circulating miR-210 concentrations in patients hospitalised due to acute dyspnea.

Methods

We extracted microRNA from plasma samples obtained on admission from 314 patients hospitalised for acute dyspnea and 10 healthy control subjects. miR-210 concentrations were measured by quantitative polymerase chain reaction and we used miR-425 for normalisation. The merit of circulating miR-210 concentrations to diagnose and provide prognostic information in patients with acute heart failure (HF) was compared to the merit of N-terminal pro-B-type natriuretic peptide (NT-proBNP).

Results

In total, 143 patients (46%) were adjudicated as hospitalised due to acute heart failure (HF) and 84 patients (27%) due to acute exacerbation of chronic obstructive lung disease (AECOPD). All patients and control subjects had miR-210 concentrations within the range of detection (Cq 26–32) and analytical variation was low. miR-210 concentrations correlated with age, NT-proBNP and cardiac troponin T concentrations in the total cohort. Circulating miR-210 concentrations were increased in patients with HF (4.7±3.3 fold increase, p<0.0001) and AECOPD (3.4±1.7 fold increase, p<0.0001) compared to control subjects. Circulating miR-210 concentrations were not different between patient groups and receiver operating characteristics area under the curve (AUC) for miR-210 to diagnose acute HF was 0.50 (95% CI 0.43–0.57) compared to AUC 0.85 (0.81–0.89) for NT-proBNP. During a median 817 days of follow-up, 66 patients (46%) with acute HF died and 35 patients (42%) with AECOPD died. Circulating miR-210 concentrations separated acute HF patients with a poor and favourable outcome (Figure 1; p by the log rank test =0.017). Circulating miR-210 concentrations were also associated with mortality during follow-up in Cox regression model: hazard ratio (HR) for lnRQ of miR-210 was 2.11 (95% CI 1.27–2.50), p=0.004. The association between circulating miR-210 concentrations and outcome was attenuated and no longer significant after adjusting for NT-proBNP concentrations. Circulating miR-210 concentrations did not predict outcome in patients with AECOPD: HR 1.38 (0.65–2.93); p=0.4.

Figure 1

Conclusions

Circulating miR-210 concentrations are increased in patients with acute HF, and provide prognostic information during follow-up. Still, circulating miR-210 concentrations did not diagnose acute HF among unselected patients with dyspnea and the association with outcome was attenuated by NT-proBNP.

Acknowledgement/Funding

Nasjonalforeningen for Folkehelsen

P1544Circulating secretoneurin concentrations provide incremental prognostic information to established risk indices in patients with moderate to severe aortic stenosis

Background

Secretoneurin (SN) concentrations provide important prognostic information in patients with myocardial dysfunction. Whether preoperative SN concentrations improve risk assessment in patients with moderate to severe aortic stenosis (AS) is unknown.

Methods

We included 57 patients with moderate to severe AS referred for presurgical evaluation and recorded all-cause mortality during follow-up. All patients were examined with comprehensive echocardiography, electrocardiogram (ECG), and high-sensitivity cardiac troponin T (hs-TnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements.

Results

Median (quartile 1–3) SN concentration in the AS patients was 141 (121–163) pmol/L. Lower estimated creatinine clearance and use of diuretics, but not standard ECG or echocardiographic indices and cardiac biomarkers, were associated with increasing SN concentrations. In total, 15 patients (26%) died during 3.5 years median follow-up. SN concentrations were higher in non-survivors than survivors: 156 (133–209) vs. 140 (116–155) pmol/L, p=0.007. The optimal cut-off concentration for SN in discriminating long-term mortality was 147 pmol/L (sensitivity 67% [95% CI 38–88%], specificity 74% [58–86%]) and patients with SN concentrations above the optimal cut-off had worse prognosis than patients below the cut-off (Figure; p=0.005 with the log-rank test). Higher SN concentrations were associated with increased risk of mortality after adjustment for clinical risk factors, echocardiographic and ECG variables, hs-TnT and NT-proBNP concentrations, and whether patients were subjected to aortic valvular surgery (n=34): hazard ratio per lnSN 15.13 (95% CI 1.05–219.00); p=0.046. Receiver operating characteristics area under the curve for SN to predict mortality was 0.74 (95% CI 0.60–0.88) compared to 0.73 (0.59–0.87) for hs-TnT and 0.67 (0.51–0.82) for NT-proBNP.

Conclusions

SN concentrations seem to reflect additional pathophysiology to established risk indices and improve risk assessment in patients with moderate to severe AS.

P3433Growth differentiation factor 15 predicts subclinical left ventricular dysfunction: Data from the Akershus Cardiac Examination 1950 Study

Background

Growth differentiation factor 15 (GDF-15) is upregulated in response to both acute and chronic cardiac injury, and concentrations of GDF-15 are increased in acute myocardial infarction and acute heart failure. Associations between GDF-15, left ventricular structure and preclinical stages of left ventricular dysfunction in the general population remain unclear.

Methods

We measured GDF-15 in 1237 women and 1158 men participating in the prospective observational Akershus Cardiac Examination (ACE) 1950 Study, which included community dwellers aged 63–65 residing in Akershus county, Norway. All study participants were free from known coronary heart disease and underwent extensive cardiovascular phenotyping at baseline, including detailed echocardiography. Regression models were constructed on global longitudinal strain (GLS), left ventricular mass index (LVMI), and left ventricular ejection fraction (LVEF), and adjusted for demographics, established cardiovascular risk factors, hs-cTnT and NT-proBNP.

Results

Concentrations of GDF-15 were measurable in 98.1% of study participants, and were positively associated with male sex, age, BMI, current smoking, diabetes mellitus, as well as concentrations C-reactive protein, hs-cTnT and NT-proBNP. Higher education, alcohol consumption, eGFR and concentrations of total cholesterol were all associated with lower concentrations of GDF-15. Concentrations of lnGDF-15 were significantly associated with GLS (B −0.44 [95% CI −0.70 to −0.18]; Figure) and LVEF (B 0.72 [95% CI 0.14–1.29]), but not LVMI (Table).

Table 1. Associations between GDF-15 and indices of left ventricular structure and function. Model 1 Model 2 Model 3 B (95% CI)   GLS (n=2395) 0.17 (−0.07 to 0.42) −0.04 (−0.28 to 0.20) −0.44 (−0.70 to −0.18)   LVEF (n=2383) 0.01 (−0.52 to 0.54) 0.21 (−0.31 to 0.73) 0.72 (0.14 to 1.29)   LVMI (n=2371) 2.00 (0.32 to 3.68) −0.37 (−1.98 to 1.24) −0.42 (−2.16 to 1.33) OR (95% CI)   GLS (n=2395) 1.35 (0.98 to 1.87) 1.28 (0.92 to 1.78) 0.81 (0.56 to 1.17)   LVEF (n=2383) 1.04 (0.75 to 1.44) 0.88 (0.62 to 1.24) 0.73 (0.50 to 1.07)   LVMI (n=2371) 1.27 (0.91 to 1.76) 1.12 (0.79 to 1.57) 1.11 (0.75 to 1.64) Linear regression models constructed on continuous levels of GLS, LVMI and LVEF. Logistic regression models constructed on the upper sex specific deciles of GLS and LVMI, and on the lower sex specific decile of LVEF. GDF-15, hs-cTnT and NT-proBNP were all transformed by the natural logarithm. Model 1, unadjusted. Model 2, adjusted for sex, age and study site. Model 3, adjusted for sex, age, study site, BMI, eGFR, total and HDL cholesterol, CRP, higher education, hypertension, diabetes mellitus, statin use, current smoking, alcohol consumption, hs-cTnT and NT-proBNP.

Figure 1

Conclusion

Concentrations of GDF-15 are inversely associated with GLS, a highly sensitive index of subclinical myocardial dysfunction. In healthy subjects free from known cardiovascular disease, GDF-15 appears protective and promotes beneficial cardiac function.

Circulating secretoneurin concentrations in patients with moderate to severe aortic stenosis

BACKGROUND

Secretoneurin (SN) concentrations provide important prognostic information in patients with myocardial dysfunction. Whether preoperative SN concentrations improve risk assessment in patients with moderate to severe aortic stenosis (AS) is unknown.

METHODS

We included 57 patients with moderate to severe AS referred for presurgical evaluation. All patients were examined with comprehensive echocardiography, electrocardiogram (ECG), and biochemical measurements and compared to 10 age- and sex-matched healthy subjects.

RESULTS

Median (quartile 1-3) SN concentrations were 141 (121-163) pmol/L in AS patients and 132 (106-148) pmol/L in control subjects (p = .17). Lower estimated creatinine clearance and use of diuretics, but not standard ECG or echocardiographic indices and cardiac biomarkers, were associated with increasing SN concentrations. Fifteen patients (26%) died during 3.5 years median follow-up. SN concentrations were higher in non-survivors than survivors: 156 (133-209) vs. 140 (116-155) pmol/L, p = .007. Higher SN concentrations were associated with increased risk of mortality also after adjustment for established risk indices, biomarkers, and status regarding valvular surgery: hazard ratio per _lnSN 15.13 (95% CI 1.05-219.00); p = .046. Receiver operating characteristics area under the curve for SN to predict mortality was 0.74 (95% CI 0.60-0.88) compared to 0.73 (0.59-0.87) for high-sensitivity cardiac troponin T and 0.67 (0.51-0.82) for N-terminal pro-B-type natriuretic peptide. The previously identified cut-off of SN >204 pmol/L in cardiac surgical patients predicted mortality also in this cohort.

CONCLUSIONS

SN concentrations improve risk assessment in patients with moderate to severe AS by providing additional prognostic information to established risk indices such as echocardiography, ECG, and established cardiac biomarkers.

Temporal Changes in Cardiac Troponin I Are Associated with Risk of Cardiovascular Events in the General Population: The Nord-Trøndelag Health Study

BACKGROUND

Cardiac troponins are associated with cardiovascular risk in the general population, but whether temporal changes in cardiac troponin I provide independent prognostic information remains uncertain. Using a large community-based cohort with follow-up close to the present day, we aimed to investigate the associations between temporal changes in cardiac troponin and cardiovascular events.

METHODS

We measured cardiac troponin I with a high-sensitivity assay (hs-cTnI) in 4805 participants attending both the second (HUNT 2, 1995-97) and third wave (HUNT 3, 2006-2008) of the prospective observational Nord-Trøndelag Health (HUNT) Study. We constructed statistical models with both relative and absolute changes of hs-cTnI from HUNT 2 to HUNT 3. A composite end point of cardiovascular death or first admission for myocardial infarction or heart failure was generated.

RESULTS

Participants with relative decrease in hs-cTnI were more frequently younger and female and had lower blood pressure and body mass index. Participants with relative increase in hs-cTnI more frequently were older and male, with higher systolic blood pressure. The adjusted hazard ratio (HR) for relative increase in hs-cTnI was 1.68 (95% CI, 1.16-2.42) and the adjusted HR for relative decrease was 1.19 (95% CI, 0.84-1.68). Absolute increases in hs-cTnI exhibited similar prognostic properties as relative increases in hs-cTnI. The most recent measurement of hs-cTnI outperformed the change variables in discrimination and reclassification models.

CONCLUSIONS

Both relative and absolute increases in hs-cTnI are independently associated with cardiovascular risk. For refinement of risk prediction models, the most recent measurement of hs-cTnI should be preferred in clinical practice.

Relative Prognostic Value of Cardiac Troponin I and C-Reactive Protein in the General Population (from the Nord-Trøndelag Health [HUNT] Study)

C-reactive protein and cardiac troponin I measured with high-sensitivity assays (high-sensitivity C-reactive protein [hs-CRP] and high-sensitivity troponin I [hs-TnI]) have been associated with risk of fatal and nonfatal cardiovascular events in the general population. The relative prognostic merits of hs-CRP and hs-TnI, and whether these markers of inflammation and subclinical myocardial injury provide incremental information to established cardiovascular risk prediction models, remain unclear. hs-CRP and hs-TnI were measured in 9,005 participants from the prospective observational Nord-Trøndelag Health (HUNT) study. All study subjects were free from known cardiovascular disease at baseline. During a median follow-up period of 13.9 years, 733 participants reached the composite end point of hospitalization for acute myocardial infarction or heart failure, or cardiovascular death. In adjusted models, increased hs-TnI concentrations (>10 ng/L for women and >12 ng/L for men) were associated with the incidence of the composite end point (hazard ratio 3.61, 95% confidence interval [CI] 2.89 to 4.51]), whereas the risk associated with increased hs-CRP concentrations (>3 mg/L for both genders) appeared to be weaker (HR 1.71, 95% CI 1.40 to 2.10). The addition of hs-TnI to established cardiovascular risk prediction models led to a net reclassification improvement of 0.35 (95% CI 0.27 to 0.42), superior to that of hs-CRP (0.21, 95% CI 0.13 to 0.28). The prognostic accuracy of hs-TnI, assessed by C-statistics, was significantly greater than that of hs-CRP (0.753, 95% CI 0.735 to 0.772, vs 0.644, 95% CI 0.625 to 0.663). In conclusion, in subjects from the general population without a history of cardiovascular disease, hs-TnI provides prognostic information superior to that provided by hs-CRP and may therefore be a preferred marker for targeted prevention.

Effect of weight loss on subclinical myocardial injury: A clinical trial comparing gastric bypass surgery and intensive lifestyle intervention

AIMS

To investigate the effect of weight loss induced by bariatric surgery and intensive lifestyle intervention on levels of circulating high-sensitivity cardiac troponin I.

METHODS AND RESULTS

We measured high-sensitivity cardiac troponin I concentrations pre- and 12 months post-intervention in 136 subjects with morbid obesity participating in a controlled clinical trial comparing the effect of intensive lifestyle intervention vs. Roux-en-Y gastric bypass. At baseline median (interquartile range) high-sensitivity cardiac troponin I levels were 2.40 (1.28-3.95) ng/L in the bariatric surgery group and 2.35 (1.38-4.40) ng/L in the intensive lifestyle intervention group (p = 0.736). The high-sensitivity cardiac troponin I concentration in a normal-weight control group was 0.90 (0.60-2.13) ng/L. During 12 months of follow-up, high-sensitivity cardiac troponin I decreased significantly more in the bariatric surgery group than in the intensive lifestyle intervention group (0.80 (0-1.80) vs. 0.15 (-0.50 to 1.00) ng/L; p = 0.002). In a multivariate logistic regression model, surgery emerged as a predictor of reduction in high-sensitivity cardiac troponin I levels (odds ratio 2.32; 95% confidence intervals 1.03-5.22; p = 0.041) independent of age, gender and other possible confounding baseline variables. In subsequent multivariate analyses, reductions in body weight and triglycerides emerged as possible mediators of reduction in circulating levels of high-sensitivity cardiac troponin I.

CONCLUSION

In patients with morbid obesity, bariatric surgery was associated with a significantly greater reduction in high-sensitivity cardiac troponin I, an index of subclinical myocardial injury, than intensive lifestyle intervention. The reduction appeared to be mediated by reductions in body weight and serum triglycerides. This suggests that weight loss following bariatric surgery may reduce cardiometabolic stress and subsequent risk of heart failure.