Sex-specific associations of established and emerging cardiac biomarkers with all-cause mortality in older adults: the ActiFE study

Diagnosing Myocardial Injury in an Acute Chest Pain Cohort; Long-Term Prognostic Implications of Cardiac Troponin T and I

BACKGROUND

There are limited data regarding the utility of follow-up cardiac troponin (cTn) measurements after admission for acute chest pain and how long-term stability of myocardial injury and prognostic value differ when using cardiac troponin T (cTnT) or I (cTnI).

METHODS

We measured high-sensitivity (hs)-cTnT (Roche Diagnostics) and hs-cTnI (Siemens Healthineers) during hospitalization for acute chest pain and after 3 months. Acute myocardial injury was defined as concentrations > sex-specific upper reference limit (URL) during hospitalization and ≤URL at 3-months. Chronic myocardial injury (CMI) was defined as concentrations > URL at both time points. Patients were followed from the 3-month sampling point for a median of 1586 (IQR 1161-1786) days for a primary composite endpoint of all-cause mortality, myocardial infarction (MI), revascularization, and heart failure, and a secondary endpoint of all-cause mortality.

RESULTS

Among 754 patients, 33.8% (hs-cTnT) and 19.2% (hs-cTnI) had myocardial injury during hospitalization. The rate of CMI was 5 times higher by hs-cTnT (20%) assay than hs-cTnI (4%), while acute myocardial injury was equally common; 14% (hs-cTnT) and 15% (hs-cTnI), respectively (6% and 5% when excluding index non-ST-elevation MI (NSTEMI). For hs-cTnT, peak index concentration, 3-month concentration and classification of CMI predicted the primary endpoint; hazard ratios (HRs) 1.38 (95% CI 1.20-1.58), 2.34 (1.70-3.20), and 2.31 (1.30-4.12), respectively. For hs-cTnI, peak index concentration predicted the primary endpoint; HR 1.14 (1.03-1.25). This association was nonsignificant after excluding index NSTEMI.

CONCLUSIONS

Acute myocardial injury is equally frequent, whereas CMI is more prevalent using hs-cTnT assay than hs-cTnI. Measuring hs-cTnT 3 months after an acute chest pain episode could assist in further long-term risk assessment. ClinicalTrials.gov Registration Number: NCT02620202.

Prevalence of Elevated NT-proBNP and its Prognostic Value by Blood Pressure Treatment and Control

BACKGROUND

The prognostic utility of NT-proBNP in the setting of hypertension has not been well-characterized in the general US adult population.

METHODS

We measured NT-proBNP in stored blood samples collected from participants 1 year or older who participated in the 1999-2004 National Health and Nutrition Examination Survey. In adults 20 years or older without a history of cardiovascular disease, we assessed the prevalence of elevated NT-pro-BNP by blood pressure (BP) treatment and control categories. We examined the extent to which NT-proBNP identifies participants at higher risk for mortality across BP treatment and control categories.

RESULTS

Among US adults without CVD, the prevalence of elevated NT-proBNP (≥125 pg/ml) was 27.2% among those with untreated hypertension, 24.9% among those with treated controlled hypertension, and 43.3% among those with treated uncontrolled hypertension. Over a median follow-up of 17.3 years and after adjusting for demographic and clinical risk factors, US adults with treated controlled hypertension and elevated NT-proBNP had increased risk of all-cause mortality (HR 2.29, 95% CI 1.79, 2.95) and cardiovascular mortality (HR 3.83, 95% CI 2.34, 6.29), compared to adults without hypertension and with low levels of NT-proBNP (<125 pg/ml). Across all levels of SBP and irrespective of antihypertensive medication use, elevated NT-proBNP was associated with an increased risk of mortality, compared to low levels of NT-proBNP.

CONCLUSIONS

Among a general population of adults free of CVD, NT-proBNP can provide additional prognostic information within and across categories of BP. Measurement of NT-proBNP may have potential for clinical use to optimize hypertension treatment.

Sex Differences in Cardiac Troponin Trajectories Over the Life Course

BACKGROUND

Cardiac troponin concentrations are lower in women than men. We examined whether age- and risk factor-related changes in cardiac troponin over the life course differ by sex and if the trajectory of cardiac troponin was informative in respect of cardiovascular outcomes in women and men in the general population.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on 3 occasions over a 15-year period. Using linear mixed-effects models, the sex-specific trajectories of cardiac troponin were evaluated, and the relationship with conventional cardiovascular risk factors determined. Using multistate joint models, the association between sex-specific trajectories of cardiac troponin and a composite outcome of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death was evaluated.

RESULTS

In 2142 women and 5151 men (mean, 58±7 and 57±7 years of age, respectively), there were 177 (8.3%) and 520 (10.1%) outcome events, respectively, during a median follow-up of 20.9 (25th to 75th percentile, 15.8-21.3) years. Cardiac troponin concentrations were persistently lower in women than in men (median baseline concentration: 2.4 [25th to 75th percentile, 1.7-3.6] ng/L versus 3.7 [25th to 75th percentile, 2.6-5.8] ng/L, respectively, P<0.001), with women exhibiting a relatively larger increase with advancing age as compared with men (Pinteraction<0.001). Apart from age, a significant and divergent interaction with sex was found for the association between cardiac troponin and body mass index (BMI) (Pinteraction=0.008) and diabetes (Pinteraction=0.003). During follow-up, cardiac troponin concentrations were associated to the outcome in both women and men (adjusted hazard ratio per 2-fold difference [95% CI, 1.34 (1.17-1.52) and 1.30 (1.21-1.40), respectively], Pinteraction=0.752). The slope of cardiac troponin was significantly associated with the outcome in women, but not in men (adjusted hazard ratio [95% CI, 2.70 (1.01-7.33) and 1.31 (0.62-2.75), respectively], Pinteraction=0.250).

CONCLUSIONS

Trajectories of cardiac troponin differ between women and men in the general population, with differing associations to conventional risk factors and cardiovascular outcomes. Our findings highlight the importance of a sex-specific approach when serial cardiac troponin testing is applied for cardiovascular risk prediction.

Differences between high-sensitivity cardiac troponin T and I in stable populations: underlying causes and clinical implications

OBJECTIVES

Measurement of high-sensitivity (hs) cardiac troponin (cTn) T and I is widely studied for cardiac assessment of stable populations. Recent data suggest clinical and prognostic discrepancies between both hs-cTn. We aimed at reviewing published studies with respect to underlying causes and clinical implications.

CONTENT

We summarized current evidence on release and clearance mechanisms of cTnT and I, and on preanalytical and assay-related issues potentially portending to differences in measured concentrations. We also performed a systematic review of outcome studies comparing both hs-cTn in the general population, patients with congestive heart failure, stable coronary artery disease and atrial fibrillation.

SUMMARY AND OUTLOOK

For the interpretation of concentrations of hs-cTnT, stronger association with renal dysfunction compared to hs-cTnI should be considered. Hs-cTnT also appears to be a stronger indicator of general cardiovascular morbidity and all-cause mortality. Hs-cTnI concentrations tend to be more sensitive to coronary artery disease and ischemic outcomes. These findings apparently reflect variations in the mechanisms of cardiac affections resulting in cTn release. Whether these differences are of clinically relevance remains to be elucidated. However, having the option of choosing between either hs-cTn might represent an option for framing individualized cardiac assessment in the future.

The influence of age and sex on the prognostic importance of traditional cardiovascular risk factors, selected circulating biomarkers and other markers of subclinical cardiovascular damage

PURPOSE OF REVIEW

There is an increasing need for improved risk stratification to better individualize cardiovascular preventive measures. Although age and sex are strong and easily obtained cardiovascular risk factors (CVRFs), their influence on the prognostic importance of other CVRF, circulating biomarkers and other markers of subclinical cardiovascular damage has not previously been systematically and critically appraised. Therefore, we have revisited the European MORGAM and the Danish MONI10 cohorts.

RECENT FINDINGS

Theoretically, the relative risk of many CVRF is expected to be lower in older healthy individuals due to a combination of selection bias by disease, higher absolute risk primarily due to older age, and the fact that the CVRF and markers may primarily influence or reflect early parts of the cardiovascular disease process. This influence of age may vary between sexes, as the cardiovascular disease process is delayed and possibly different in women compared with men.

SUMMARY

Adjusted for the remaining Systematic COronary Risk Evaluation (SCORE) CVRF, higher SBP, serum cholesterol, soluble urokinase-type plasminogen activator receptor, left ventricular mass index and atherosclerotic plaques were more closely associated with outcomes in individuals younger than 52 years with some sex-specific differences, whereas higher N-terminal pro-brain natriuretic peptide and urine albumin/creatine ratio were more closely associated with outcomes in subjects aged 61 or 71 years.

Prognostic Value of High-Sensitivity Cardiac Troponin in Women

High-sensitivity cardiac troponin assays have become the gold standard for diagnosing acute and chronic myocardial injury. The detection of troponin levels beyond the 99th percentile is included in the fourth universal definition of myocardial infarction, specifically recommending the use of sex-specific thresholds. Measurable concentrations below the proposed diagnostic thresholds have been shown to inform prognosis in different categories of inpatients and outpatients. However, clinical investigations from the last twenty years have yielded conflicting results regarding the incremental value of using different cut-offs for men and women. While advocates of a sex-specific approach claim it may help reduce gender bias in cardiovascular medicine, particularly in acute coronary syndromes, other groups question the alleged incremental diagnostic and prognostic value of sex-specific thresholds, ultimately asserting that less is more. In the present review, we aimed to synthesize our current understanding of sex-based differences in cardiac troponin levels and to reappraise the available evidence with regard to (i) the prognostic significance of sex-specific diagnostic thresholds of high-sensitivity cardiac troponin assays compared to common cut-offs in both men and women undergoing cardiovascular disease risk assessment, and (ii) the clinical utility of high-sensitivity cardiac troponin assays for cardiovascular disease prevention in women.

N-terminal pro brain natriuretic peptide reference values in community-dwelling older adults

AIMS

Available upper reference levels (URLs) in older adults for N-terminal pro brain natriuretic peptide (NT-proBNP), an established biomarker for heart failure, are mainly based on small samples. We aimed to identify NT-proBNP URL in a population-based reference sample of individuals aged ≥65 years.

METHODS AND RESULTS

We analysed established NT-proBNP predictors using quantile regression among 2459 participants of two-independent population-based cohorts located in Germany, the Activity and Function in the Elderly Study (ActiFE, n = 1450) and the Study of Health in Pomerania (SHIP-TREND-0, n = 1009). Based on predictors a reference population of 441 subjects (ActiFE, n = 227; SHIP-TREND-0, n = 214) without history of diabetes, cardiovascular, or pulmonary diseases and with systolic blood pressure (BP) <140 mmHg, diastolic BP ≥60 and ≤90 mmHg, haemoglobin in men ≥14 and ≤18 g/dL and in women ≥12 and ≤16 g/dL, GFR ≥60 mL/min/1.73 m² , CRP <5 mg/L, BMI ≥18 and ≤33 kg/m² , and hs-cTnI <40 ng/L were built with NT-proBNP median levels and 97.5% quantiles reported stratified by sex and age. In a secondary analysis the URL among 97 SHIP-TREND-0 participants with a left ventricular ejection fraction (LVEF) ≥50 and no diastolic dysfunction were estimated. The median age in the identified reference sample was 70 years, with 41.9% and 40.2% male participants in ActiFE and SHIP-TREND-0, respectively. We observed an age-dependent increment of NT-proBNP levels with higher values in women compared to men. Notably, NT-proBNP levels were >125 ng/L in 165 participants (37.4%), with NT-proBNP URL (97.5% quantiles) equal to 663, 824, 592, and 697 ng/L in men, and 343, 463, 2641, 1276 ng/L in women for ages 65-69, 70-74, 75-79, and 80+ years, respectively. In the secondary analysis with a LVEF ≥50 and no diastolic dysfunction (35 men and 62 women) NT-proBNP levels >125 ng/L were still observed in 38 (39.2%) participants.

CONCLUSIONS

This reference sample of apparently healthy asymptomatic older adults showed an age-related increment of NT-proBNP levels with URL markedly higher than the European Society of Cardiology recommended cut-off of 125 ng/L for the diagnosis of heart failure in ambulatory settings. Identifying URL in those ≥80 years remains complex. Our results attempt to provide a frame for the further investigation of age-specific NT-proBNP cut-offs in older adults. Considering the demographic changes, further evaluation of NT-proBNP URL in larger samples of older adults followed by the validation of age-specific cut-off values for the identification of heart failure in those 65 years or older are urgently needed.

Sex Differences in Cardiac Troponin I and T and the Prediction of Cardiovascular Events in the General Population

BACKGROUND

Cardiac troponin concentrations differ in women and men, but how this influences risk prediction and whether a sex-specific approach is required is unclear. We evaluated whether sex influences the predictive ability of cardiac troponin I and T for cardiovascular events in the general population.

METHODS

High-sensitivity cardiac troponin (hs-cTn) I and T were measured in the Generation Scotland Scottish Family Health Study of randomly selected volunteers drawn from the general population between 2006 and 2011. Cox-regression models evaluated associations between hs-cTnI and hs-cTnT and the primary outcome of cardiovascular death, myocardial infarction, or stroke.

RESULTS

In 19 501 (58% women, mean age 47 years) participants, the primary outcome occurred in 2.7% (306/11 375) of women and 5.1% (411/8126) of men during the median follow-up period of 7.9 (IQR, 7.1-9.2) years. Cardiac troponin I and T concentrations were lower in women than men (P < 0.001 for both), and both were more strongly associated with cardiovascular events in women than men. For example, at a hs-cTnI concentration of 10 ng/L, the hazard ratio relative to the limit of blank was 9.7 (95% CI 7.6-12.4) and 5.6 (95% CI 4.7-6.6) for women and men, respectively. The hazard ratio for hs-cTnT at a concentration of 10 ng/L relative to the limit of blank was 3.7 (95% CI 3.1-4.3) and 2.2 (95% CI 2.0-2.5) for women and men, respectively.

CONCLUSIONS

Cardiac troponin concentrations differ in women and men and are stronger predictors of cardiovascular events in women. Sex-specific approaches are required to provide equivalent risk prediction.

Sex-specific cut-off values for soluble suppression of tumorigenicity 2 (ST2) biomarker increase its cardiovascular prognostic value in the community

BACKGROUND

Suppression of tumorigenicity 2 (ST2) has important cardiovascular prognostic value in community patients; however, previous analyses have utilized non-sex specific cut-off values. We assessed whether sex-specific ST2 cut-off values would improve the prognostic utility of ST2 in the asymptomatic community.

METHODS

A total of 2042 participants underwent clinical assessment and echocardiographic evaluation. Baseline measurements of high sensitivity troponin, natriuretic peptides and ST2 were obtained in 1681 individuals. ST2, cardiac biomarkers and associated co-morbidities were evaluated by sex-specific ST2 quartile analysis. ST2 concentrations were also analysed as dichotomous variables defined as being above the sex-specific cut-off for each the outcomes of heart failure (HF), major adverse cardiac event (MACE) and mortality.

RESULTS

Median ST2 concentration was 29.4 ng/mL in male subjects and 24.1 ng/mL in female subjects. Higher ST2 concentrations were associated with incident HF (p<0.001; preserved ejection fraction (EF) p<0.001, reduced EF p=0.23), MACE (p=0.003) and mortality (p<0.001) across sex-specific quartiles. Event-based, hazard ratio (HR) analysis revealed sex-specific ST2 cut-offs were significantly more predictive of incident HF, MACE and mortality compared to non-sex-specific analysis even following adjustment for cardiac co-morbidities and traditional biomarkers.

CONCLUSIONS

These data suggest that sex-specific cut-offs, greater than non-sex specific cut-offs, significantly impact the prognostic value of the biomarker ST2 in the asymptomatic community cohort.Clinical SignificanceSuppression of tumorigenicity 2 (ST2) is a biomarker which has known associations with heart failure (HF), major adverse cardiac events (MACEs) and mortality in the general population.Recent data support the concept of sex-specific cut off values and individualized approaches based on sex to predict cardiovascular disease. Given the difference in pathobiology between the sexes, the fact that such approaches improve risk stratification is understandable. Thus, when sex-specific treatments are developed, this may similarly lead to improved outcomes.The use of sex-specific ST2 cut-off values significantly improved the prognostic value in predicting HF, MACE, and mortality in an asymptomatic community. This prognostication was particularly strong for HF with preserved ejection fraction and remained clinically significant following adjustment for cardiac co-morbidities and other traditional cardiac biomarkers (NTproBNP and hscTnI).

Effects of Sex and Physical Activity Level on Serum Biomarker-Based Physiological Dysregulation: The Impact to Predict Frailty and Mortality in the Quebec NuAge Cohort

BACKGROUND

Age-related changes in biological processes such as physiological dysregulation (the progressive loss of homeostatic capacity) vary considerably among older adults and may influence health profiles in late life. These differences could be related, at least in part, to the impact of intrinsic and extrinsic factors such as sex and physical activity level (PAL).

OBJECTIVES

The objectives of this study were (1) to assess the magnitude and rate of changes in physiologi-cal dysregulation in men and women according to PAL and (2) to determine whether/how sex and PAL mediate the apparent influence of physiological dysregulation on health outcomes (frailty and mortality).

METHODS

We used data on 1,754 community-dwelling older adults (age = 74.4 ± 4.2 years; women = 52.4%) of the Quebec NuAge cohort study. Physiological dysregulation was calculated based on Mahalanobis distance of 31 biomarkers regrouped into 5 systems: oxygen transport, liver/kidney function, leukopoiesis, micronutrients, and lipids.

RESULTS

As expected, mean physiological dysregulation significantly increased with age while PAL decreased. For the same age and PAL, men showed higher levels of physiological dysregulation globally in 3 systems: oxygen transport, liver/kidney function, and leukopoiesis. Men also showed faster global physiological dysregulation in the liver/kidney and leukopoiesis systems. Overall, high PAL was associated with lower level and slower rate of change of physiological dysregulation. Finally, while mortality and frailty risk significantly increased with physiological dysregulation, there was no evidence for differences in these effects between sexes and PAL.

CONCLUSION

Our results showed that both sex and PAL have a significant effect on physiological dysregulation levels and rates of change. Also, although a higher PAL was associated with lower level and slower rate of change of physiological dysregulation, there was no evidence that PAL attenuates the effect of physiological dysregulation on subsequent declines in health at the end of life. Substantial work remains to understand how modifiable behaviors impact the relationship between physiological dysregulation, frailty, and mortality in men and women.

High sensitivity troponin, analytical advantages, clinical benefits and clinical challenges - An update

The measurement of cardiac troponin (cTn) by a high sensitivity method now represents the standard method for cTn measurement in the laboratory. High sensitivity method are not measuring a novel form of troponin but have undergone methodological improvement in assay sensitivity to allow both very low level detection and repeat measurements at low levels with very low degrees of analytical imprecision. The methods identify additional patients with myocardial injury who would benefit from evidence-based interventions. Rapid predictive algorithms utilising measurement on admission as well as short sampling periods (1-2 h) allow much more rapid categorisation of patients to appropriate clinical pathways. The shift in the diagnosis from traditional "cardiac enzymes" to troponin based on the 99th percentile has accounted for the majority of the detection of myocardial injury in patients without acute coronary syndromes. These patients have a worse prognosis irrespective of the underlying cause of their hospital admission. The appropriate management strategy in this group, beyond managing the underlying problem, remains to be defined. Measurement of cTn in otherwise asymptomatic individuals may have a role for patient selection for preventive treatment or for patients monitoring. Clinical trials in this area are awaited.

Repeated Measurements of Cardiac Troponin T and N-Terminal Pro-B-Type Natriuretic Peptide to Assess Long-Term Mortality Risk in Subjects with Osteoarthritis

Osteoarthritis (OA) is associated with higher cardiovascular mortality risk. High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are well-characterized prognostic cardiac markers. We aimed to describe the changes in biomarkers measured one year apart in a cohort of 347 subjects with OA who underwent hip or knee replacement surgery in 1995/1996 and to analyze the prognostic value of repeated measurements for long-term mortality. During a median follow-up of 19 years, 209 (60.2%) subjects died. Substantial changes in cardiac biomarkers, especially for NT-proBNP, and an independent prognostic value of NT-proBNP for long-term mortality were found for both baseline measurement concentration (hazard ratio (HR) 1.32, 95% confidence interval (CI) (1.13–1.55)) and follow-up measurement concentration (HR 1.39, 95% CI 1.18–1.64) (all HR per standard deviation increase after natural log-transformation). Baseline concentrations were correlated with follow-up concentrations of NT-proBNP and no longer showed prognostic value when included simultaneously in a single model (HR 1.08, 95% CI 0.86–1.37), whereas the estimate for the one-year measurement remained robust (HR 1.31, 95% CI 1.04–1.66). Therefore, no significant additional benefit of repeated NT-proBNP measurements was found in this cohort, facilitating the use of a single NT-proBNP measurement as a stable prognostic marker.

Relationship between cardiac biomarker concentrations and long-term mortality in subjects with osteoarthritis

Osteoarthritis (OA) is associated with adverse cardio-metabolic features. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponins T and I (hs-cTnT and hs-cTnI) are well-characterized cardiac markers and provide prognostic information. The objective was to assess the association of cardiac biomarker concentrations with long-term mortality in subjects with OA. In a cohort of 679 OA subjects, undergoing hip or knee replacement during 1995/1996, cardiac biomarkers were measured and subjects were followed over 20 years. During a median follow-up of 18.4 years, 332 (48.9%) subjects died. Median of hs-cTnT, hs-cTnI, and NT-proBNP at baseline was 3.2 ng/L, 3.9 ng/L, and 96.8 ng/L. The top quartile of NT-proBNP was associated with increased risk of mortality (Hazard Ratio (HR) 1.79, 95% confidence interval (CI) 1.17–2.73) after adjustment for covariates including troponins (hs-cTnT HR 1.30 (95% CI 0.90–1.89), hs-cTnI HR 1.32 (95% CI 0.87–2.00) for top category). When biomarker associations were evaluated as continuous variables, only NT-proBNP (HR per log-unit increment 1.34, 95% CI 1.16–1.54) and hs-cTnI (HR 1.38, 95% CI 1.11–1.72) showed robust results. Elevated cardiac biomarker concentrations predicted an increased risk of long-term mortality and strongest for NT-proBNP and hs-cTnI. These results might help to identify subjects at risk and target preventive efforts early.

High-Sensitivity Cardiac Troponin-T and N-Terminal Prohormone of B-Type Natriuretic Peptide in Relation to Cardiovascular Outcomes in Type 1 Diabetes

OBJECTIVE

High-sensitivity cardiac troponin-T (hs-cTnT) and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), biomarkers of cardiovascular disease (CVD) and heart failure, respectively, have not been widely studied in type 1 diabetes (T1D). We evaluated whether their assessment in T1D enhances the prediction of CVD and major adverse cardiovascular events (MACE).

RESEARCH DESIGN AND METHODS

hs-cTnT and NT-proBNP were analyzed on the Roche Cobas E601 using the first available stored specimen (n = 581; mean age 29 years and diabetes duration 21 years). CVD was defined as CVD death, myocardial infarction, coronary revascularization, angina, ischemia, or stroke, and MACE as CVD death, myocardial infarction, or stroke.

RESULTS

Median hs-cTnT (5.0 ng/L; interquartile range <3.0, 10.0) was higher among men (P < 0.0001), whereas median NT-proBNP (22.0 ng/L; 7.0, 61.0) did not differ by sex. In Cox models, log hs-cTnT (hazard ratio [HR] 1.38, P = 0.0006) and log NT-proBNP (HR 1.24, P = 0.0001) independently predicted CVD during 21 years of follow-up. However, their addition to models, singly or together, did not significantly improve CVD prediction. Furthermore, a marginally significant sex interaction was observed (P = 0.06), indicating that the hs-cTnT prediction was limited to men. hs-cTnT and NT-proBNP also predicted MACE, although only NT-proBNP remained significant (HR 1.27, P = 0.0009) when the biomarkers were included in a model simultaneously. Nonetheless, their addition to multivariable models did not enhance MACE prediction.

CONCLUSIONS

Sex differences were observed in the concentration and predictive ability of hs-cTnT and NT-proBNP in T1D. Overall, their addition to traditional risk factor models increased the area under the curve for neither CVD nor MACE.

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.

Association of lung function with overall mortality is independent of inflammatory, cardiac, and functional biomarkers in older adults: the ActiFE-study

Reduced lung function is associated with overall and cardiovascular mortality. Chronic low grade systemic inflammation is linked to impaired lung function and cardiovascular outcomes. We assessed the association of lung function with overall 8-year mortality in 867 individuals of the Activity and Function in the Elderly study using confounder-adjusted Cox proportional hazards models (including gait speed and daily walking time as measures of physical function) without and with adjustment for inflammatory and cardiac markers. Forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) but not FVC was related to mortality after adjustment for physical function and other confounders. Additional adjustment for inflammatory and cardiac markers did not change the hazard ratios (HR) markedly, e.g. for a FEV₁/FVC below 0.7 from 1.55 [95% confidence-interval (CI) 1.14-2.11] to 1.49 (95% CI 1.09-2.03). These independent associations were also observed in the apparently lung healthy subpopulation with even higher HRs up to 2.76 (95% CI 1.52-4.93). A measure of airflow limitation but not vital capacity was associated with overall mortality in this community-dwelling older population and in the subgroup classified as lung healthy. These associations were independent of adjustment for inflammatory and cardiac markers and support the role of airflow limitation as independent predictor of mortality in older adults.

Comparison between High-Sensitivity Cardiac Troponin T and Cardiac Troponin I in a Large General Population Cohort

BACKGROUND

Few data compare cardiac troponin T (cTnT) and cardiac troponin I (cTnI) in a general population. We sought to evaluate the distribution and association between cTnT, cTnI, and cardiovascular risk factors in a large general population cohort.

METHODS

High-sensitivity cTnT and cTnI were measured in serum from 19501 individuals in the Generation Scotland Scottish Family Health Study. Associations with cardiovascular risk factors were compared using age- and sex-adjusted regression. Observed age- and sex-stratified 99th centiles were compared with 99th centiles for cTnT (men, 15.5 ng/L; women, 9.0 ng/L) and cTnI (men, 34.2 ng/L; women, 15.6 ng/L) used in clinical practice.

RESULTS

cTnT and cTnI concentrations were detectable in 53.3% and 74.8% of participants, respectively, and were modestly correlated in unadjusted analyses (R ² = 21.3%) and only weakly correlated after adjusting for age and sex (R ² = 9.5%). Cardiovascular risk factors were associated with both troponins, but in age- and sex-adjusted analyses, cTnI was more strongly associated with age, male sex, body mass index, and systolic blood pressure (P < 0.0001 for all vs cTnT). cTnT was more strongly associated with diabetes (P < 0.0001 vs cTnI). The observed 99th centiles were broadly consistent with recommended 99th centiles in younger men and women. After the age of 60 years, observed 99th centiles increased substantially for cTnT, and beyond 70 years of age, the 99th centiles approximately doubled for both troponins.

CONCLUSIONS

In the general population, cTnT and cTnI concentrations are weakly correlated and are differentially associated with cardiovascular risk factors. The 99th centiles currently in use are broadly appropriate for men and women up to but not beyond the age of 60 years.

Sex-Related Aspects of Biomarkers in Cardiac Disease

Biomarkers play an important role in the clinical management of cardiac care. In particular, cardiac troponins (cTn) and natriuretic peptides are the cornerstones for the diagnosis of acute myocardial infarction (AMI) and for the diagnosis of heart failure (HF), respectively. Current guidelines do not make a distinction between women and men. However, the commonly used "one size fits all" algorithms are topic of debate to improve assessment of prognosis, particularly in women. Due to the high-sensitivity assays (hs-cTn), lower cTn levels (and 99th percentile upper reference limits) were observed in women as compared with men. Sex-specific diagnostic thresholds may improve the diagnosis of AMI in women, though clinical relevance remains controversial and more trials are needed. Also other diagnostic aspects are under investigation, like combined biomarkers approach and rapid measurement strategies. For the natriuretic peptides, previous studies observed higher concentrations in women than in men, especially in premenopausal women who might benefit from the cardioprotective actions. Contrary to hs-cTn, natriuretic peptides are particularly incorporated in the ruling-out algorithms for the diagnosis of HF and not ruling-in. Clinical relevance of sex differences here seems marginal, as clinical research has shown that negative predictive values for ruling-out HF were hardly effected when applying a universal diagnostic threshold that is independent from sex or other risk factors. Apart from the diagnostic issues of AMI in women, we believe that in the future most sex-specific benefits of cardiac biomarkers can be obtained in patient follow-up (guiding therapy) and prognostic applications, fitting modern ideas on preventive and personalized medicine.

Cardiac troponins: 25 years on the stage and still improving their clinical value

Twenty-five years ago, non-isotopic immunoassays for measuring the cardiac specific isoforms of troponin I (cTnI) and T (cTnT) were developed. Both biomarkers radically changed the diagnosis, prognosis, and therapy indication of acute coronary syndromes (ACS) and, particularly, of myocardial infarction (MI). However, cardiac troponins (cTn) rapidly demonstrated their usefulness in other cardiac and non-cardiac conditions, a part of the ischemic coronary diseases. Consequently, the number of patients to be tested for cTn and the number of tests requested to clinical laboratories sharply increased. Though the manufacturers continuously improved the analytical characteristics of the first cTn assays and produced different cTn assay "generations", the universal definition of myocardial infarction required less-than-available analytical imprecision at the cTn concentration used to assess MI (i.e. the 99th reference percentile). To address the clinical requirements, manufacturers developed the high-sensitivity cTn (hs-cTn) assays that allow to measure the 99th reference percentile with adequate precision, to detect cTn in many healthy subjects and, hence, to calculate the hs-cTn biological variation and especially to observe in very short time intervals serial differences in hs-cTn attributable to cardiac ischemia. Since the number of patients attending the emergency departments (ED) for a suspected ACS or MI is increasing, the improved properties of hs-cTn assays, allowing faster and safer patient assessment, will help to alleviate the sometimes overcrowded EDs. However, there are many biological, analytical, and clinical factors that can influence the true hs-cTn values of a patient. Clinicians and laboratory professionals should know about them for the best interpretation of the otherwise largely useful hs-cTn measurements. In conclusion, 25 years after their introduction for clinical use, "cTn are still on the stage and improving their clinical value".

Impact of Sex on Cardiac Troponin Concentrations—A Critical Appraisal

BACKGROUND

The use of sex-specific cutoffs for cardiac troponin (cTn) is currently debated. Although endorsed by scientific working groups, concerns have been raised that sex-specific cutoffs may have only a small clinical effect at the cost of increased complexity in decision-making.

METHODS

We reviewed studies investigating the interrelations between high-sensitivity (hs) cTn results and sex, diagnoses, and outcome. Investigated populations included community-dwelling subjects and patients with stable angina, congestive heart failure, or acute chest pain including those with acute coronary syndromes.

RESULTS

Men usually have higher hs-cTn concentrations compared with women, regardless of the assessed population or the applied assay. The distribution and prognostic implications of hs-cTn concentrations indicate that women have a broader cardiovascular risk panorama compared with men, particularly at lower hs-cTn concentrations. At higher concentrations, particularly above the 99th percentile, this variation is often attenuated. Sex-specific hs-cTn 99th percentiles have so far shown clinical net benefit in only 1 study assessing patients with chest pain. However, several methodological aspects need to be considered when interpreting study results, e.g., issues related to the determination of the 99th percentiles, the selection bias, and the lack of prospective and sufficiently powered analyses.

CONCLUSIONS

Available studies do not show a consistent clinical superiority of sex-specific hs-cTn 99th percentiles. This may reflect methodological aspects. However, from a pathobiological perspective, the use of sex-specific hs-cTn 99th percentiles makes sense for the ruling in of myocardial infarction. We propose a new approach to hs-cTn 99th cutoffs taking into account the analytical properties of the used assays.

Improving Prediction of Postoperative Myocardial Infarction With High-Sensitivity Cardiac Troponin T and NT-proBNP

BACKGROUND

This study sought to determine whether preoperatively measured high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) improve cardiac risk prediction in patients undergoing major noncardiac surgery compared with the standard risk indices.

METHODS

In this ancillary study to the Vitamins in Nitrous Oxide trial, patients were included who had preoperative hs-cTnT and NT-proBNP measured (n = 572). Study outcome was the incidence of postoperative myocardial infarction (MI) within the first 3 postoperative days. hs-cTnT was considered elevated if >14 ng/L and NT-proBNP if >300 ng/L. Additional cutoff values were investigated on the basis of receiver operating characteristic statistics. Biomarker risk prediction was compared with Lee's Revised Cardiac Risk Index (RCRI) with the use of standard methods and net reclassification index.

RESULTS

The addition of hs-cTnT (>14 ng/L) and NT-proBNP (>300 ng/L) to RCRI significantly improved the prediction of postoperative MI (event rate 30/572 [5.2%], Area under the receiver operating characteristic curve increased from 0.590 to 0.716 with a 0.66 net reclassification index [95% confidence interval 0.32-0.99], P < .001). The use of 108 ng/L as a cutoff for NT-proBNP improved sensitivity compared with 300 ng/L (0.87 vs 0.53). Sensitivity, specificity, positive, and negative predictive value for hs-cTnT were 0.70, 0.60, 0.09, and 0.97 and for NT-proBNP were 0.53, 0.68, 0.08, and 0.96.

CONCLUSIONS

The addition of cardiac biomarkers hs-cTnT and NT-proBNP to RCRI improves the prediction of adverse cardiac events in the immediate postoperative period after major noncardiac surgery. The high negative predictive value of preoperative hs-cTnT and NT-proBNP suggest usefulness as a "rule-out" test to confirm low risk of postoperative MI.

Cardiac Biomarkers and the Diagnosis of Myocardial Infarction in Women

PURPOSE OF REVIEW

Women with suspected acute coronary syndrome are less likely to undergo investigation or receive treatment than men, and women consistently have poorer outcomes. This review summarises how the latest development in cardiac biomarkers could improve both diagnosis and outcomes in women.

RECENT FINDINGS

Novel high-sensitivity cardiac troponin assays have identified differences in the reference range and therefore diagnostic threshold for myocardial infarction in men and women. These differences are present across multiple populations with different ethnic backgrounds and for a range of assays. The use of a uniform threshold for cardiac troponin does not provide equivalent prediction in men and women, with lower thresholds needed for women to provide comparable risk stratification. Sex differences in cardiac troponin concentrations are not widely recognised in clinical practice and may be contributing to the under-diagnosis of myocardial infarction in women and discrepancies in patient care and outcomes.

N-terminal pro-brain natriuretic peptide and cardiovascular or all-cause mortality in the general population: A meta-analysis

The prognostic role of N-terminal pro-brain natriuretic peptide (NT-proBNP) in the general population remains controversial. We conducted this meta-analysis to investigate the association between baseline NT-proBNP concentrations and cardiovascular or all-cause mortality in the general population. PubMed and Embase databases were systematically searched from their inception to August 2016. Prospective observational studies that investigated the association between baseline NT-proBNP concentrations and cardiovascular or all-cause mortality in the general population were eligible. A summary of the hazard ratio (HR) and 95% confidence interval (CI) of mortality were calculated by the highest versus the lowest category of NT-proBNP concentrations. Eleven studies with a total of 25,715 individuals were included. Compared individuals in the highest with those in the lowest category of NT-proBNP, the pooled HR was 2.44 (95% CI 2.11-2.83) for all-cause mortality, 3.77 (95% CI 2.85-5.00) for cardiovascular mortality, and 2.35 (95% CI 1.45-3.82) for coronary heart disease mortality, respectively. Subgroup analyses indicated that the effects of NT-proBNP on the risk of cardiovascular mortality (RR 2.27) and all-cause mortality (RR 3.00) appeared to be slightly lower among men. Elevated NT-proBNP concentrations appeared to be independently associated with increased risk of cardiovascular and all-cause mortality in the general population.

Invasive Hemodynamic Assessment of Cardiac Output State after MitraClip Therapy in Nonanaesthetized Patients with Functional Mitral Regurgitation

Background. Surgical correction of mitral regurgitation (MR) can lead to postoperative low cardiac output state. We aimed to assess the acute hemodynamic changes after percutaneous MitraClip therapy (a unique model without influence of factors linked to surgical procedure) in patients with functional MR without the influence of general anaesthesia. Methods. We studied invasive hemodynamic parameters in 23 patients before procedure (conscious, nonsedated patients), during procedure (intubated patients), and the first day after MitraClip implantation (conscious, extubated patients). Results. Mitral valve clipping significantly increased cardiac index (CI) (from 2.0 ± 0.5 to 3.3 ± 0.6 L/min/m²; p < 0.01). Conversely, there was significant reduction in the mean pulmonary capillary wedge pressure (PCWP) (from 18.6 ± 5.7 to 10.5 ± 3.8 mmHg; p < 0.01), mean pulmonary artery pressure (from 29.8 ± 10.9 to 25.2 ± 10.3 mmHg; p = 0.03), and pulmonary vascular resistance index (from 531 ± 359 to 365 ± 193 dyn·s·cm^-5/m²; p = 0.03). Conclusions. The functional MR therapy with percutaneous MitraClip device results in significant increase in CI (+66%) and concomitant decrease in PCWP (-42%). None of our patients developed low cardiac output state. Our results support the idea that significant part of low cardiac output state after cardiac surgery is due to surgery related factors rather than due to increase in afterload after MR elimination.

Prognostic value of basal high-sensitive cardiac troponin levels on mortality in the general population: A meta-analysis

Interest in the use of cardiac troponin T (cTnT) and cardiac troponin I (cTnI) has expanded from diagnosis of acute myocardial infarction to risk assessment for morbidity and mortality. Although cTnT and cTnI were shown to have equivalent diagnostic performance in the setting of suspected acute myocardial infarction, potential prognostic differences are largely unexplored.The aim of this study is to quantify and compare the relationship between cTnT and cTnI, and cardiovascular and all-cause mortality in the general population.Medline, Embase, and the Cochrane Library (from inception through October 2016) were searched for prospective observational cohort studies reporting on the prognostic value of basal high-sensitive cTnT and/or cTnI levels on cardiovascular and all-cause mortality in the general population. Data on study characteristics, participants' characteristics, outcome parameters, and quality [according to the Effective Public Health Practice Project (EPHPP) "Quality Assessment Tool For Quantitative Studies] were retrieved. Hazard ratios per standard deviation increase in basal cardiac troponin level (HR per 1-SD; retrieved from the included articles or estimated) were pooled using a random-effects model.On a total of 2585 reviewed citations, 11 studies, with data on 65,019 participants, were included in the meta-analysis. Random effects pooling showed significant associations between basal cardiac troponin levels and HR for cardiovascular and all-cause mortality [HR per 1-SD 1.29 (95% confidence interval, 95% CI, 1.20-1.38) and HR per 1-SD 1.18 (95% CI, 1.11-1.26), respectively]. Stratified analyses showed higher HRs for cTnT than cTnI [cardiovascular mortality: cTnT HR per 1-SD 1.37 (95% CI, 1.23-1.52); and cTnI HR per 1-SD 1.21 (95% CI, 1.16-1.26); all-cause mortality: cTnT HR per 1-SD 1.31 (955 CI, 1.13-1.53); and cTnI HR per 1-SD 1.14 (95% CI, 1.06-1.22)]. These differences were significant (P < 0.01) in meta-regression analyses for cardiovascular mortality but did not reach statistical significance for all-cause mortality.Elevated, basal cTnT, and cTnI show robust associations with an increased risk of cardiovascular and all-cause mortality during follow-up in the general population.Systematic review registration number PROSPERO CRD42014006964.

Do we need to consider age and gender for accurate diagnosis of myocardial infarction?

According to the universal definition, a diagnosis of acute myocardial infarction (AMI) can be made in the presence of a kinetic change of cardiac troponin (cTn) with at least one value above the 99th percentile of a healthy population together with clinical signs of myocardial ischemia. Thus, differences in 99th percentile cut-off values may have important diagnostic and therapeutic consequences for the correct AMI diagnosis. Following the introduction of high-sensitivity (hs) cTn assays with the ability to detect cTn in virtually every healthy individual, almost all available hs Tn assays suggest to use solitary 99th percentile cut-offs. However, several findings have questioned the use of a solitary cut-off for AMI diagnosis, as apparent age- and gender-dependent differences were found concerning the 99th percentile cut-off value. Moreover, there is an increasing number of studies which suggest a relevant diagnostic and prognostic benefit, when age- or gender-specific cut-offs values are used in comparison to general cut-offs. In contrast, other studies observed only a small impact on diagnostic reclassification and risk stratification. Given these ambiguous findings, there is currently no clear evidence for the use of age- and/or gender-dependent 99th percentiles. This review gives an overview of the rationale for gender- and age-dependent differences in cTn biomarker findings and discusses the implementation of these findings into clinical practice.

Prognostic Value of Cardiac Troponin T and Sex in Patients Undergoing Elective Percutaneous Coronary Intervention

BACKGROUND

In patients with stable coronary artery disease undergoing elective percutaneous coronary intervention, the prognostic value of high-sensitivity cardiac troponin T (hs-cTnT) and the influence of sex remain poorly defined.

METHODS AND RESULTS

Consecutive patients with stable coronary artery disease who underwent elective percutaneous coronary intervention were included. Primary endpoint was all-cause mortality. Unadjusted hazard ratio (HR) in overall and sex-specific population and multivariable adjusted HR were calculated by using Cox proportional hazard models. In a total of 5626 patients, elevated hs-cTnT levels, more than the sex-specific 99th percentile upper reference limit of normal (URL), were observed in 2221 patients (39%) at baseline. During follow-up (median, 14.5 months; 25th-75th percentiles, 6.4-27.2 months), 265 patients died. Mortality was higher in patients with the sex-specific 99th percentile URL compared to those with normal hs-cTnT (17.3% vs 3.4%; HR=6.10; 95% CI, 4.58-8.14; P<0.001). hs-cTnT was an independent predictor of mortality in multivariable adjusted models. The C-statistic was significantly increased by adding hs-cTnT to the basic prediction model for mortality (0.793-0.815; P<0.001). There was a significant interaction between hs-cTnT and sex on mortality. Differences in all-cause mortality between patients with more than the sex-specific 99th percentile URL and those with normal hs-cTnT were numerically larger in male than female patients (male, HR=6.45; 95% CI, 4.68-8.87, P<0.001; female, HR=4.29, 95% CI, 2.36-9.03; P<0.001).

CONCLUSIONS

In patients with stable coronary artery disease undergoing elective percutaneous coronary intervention, preprocedural hs-cTnT was a strong predictor of mortality in both men and women.

Prognostic Importance of Sex-Specific Cardiac Troponin T 99(th) Percentiles in Suspected Acute Coronary Syndrome

OBJECTIVE

Cardiac troponin levels differ between the sexes, with higher values commonly seen in men. The use of sex-specific troponin thresholds is, thus, subject of an ongoing debate. We assessed whether sex-specific cardiac troponin T (cTnT) 99(th) percentiles would improve risk prediction in patients admitted to Swedish coronary care units due to suspected acute coronary syndrome.

METHODS

In this retrospective register-based study (48,250 patients), we investigated the prediction of all-cause mortality and the composite of cardiovascular death or nonfatal myocardial infarction within 1 year using the single 99(th) cTnT percentile (>14 ng/L) or sex-specific cTnT 99(th) percentiles (>16/9 ng/L).

RESULTS

A total of 1078 men (3.0%) with cTnT 15-16 ng/L and 1854 women (8.4%) with cTnT 10-14 ng/L would have been reclassified regarding their cTnT status by the means of sex-specific 99(th) percentiles. The prevalence of cardiovascular risk factors and crude event rates increased across higher cTnT strata in both men and women. Multivariable-adjusted Cox models, however, did not demonstrate better risk prediction by sex-specific 99(th) percentiles. Assessing cTnT as a continuous variable demonstrated an increase in multivariable-adjusted risk starting at levels around 10-12 ng/L in both men and women.

CONCLUSIONS

We found no evidence supporting the use of sex-specific cTnT 99(th) percentiles in men and women admitted because of suspected acute coronary syndrome. This likely depends on sex-specific differences in disease mechanisms associated with small cTnT elevations. From a pragmatic perspective, a single cTnT cutoff slightly below 14 ng/L seems to be preferable as a threshold for medical decision-making.

Associations Between the Serum Metabolome and All-Cause Mortality Among African Americans in the Atherosclerosis Risk in Communities (ARIC) Study

Early and accurate identification of people at high risk of premature death may assist in the targeting of preventive therapies in order to improve overall health. To identify novel biomarkers for all-cause mortality, we performed untargeted metabolomics in the Atherosclerosis Risk in Communities (ARIC) Study. We included 1,887 eligible ARIC African Americans, and 671 deaths occurred during a median follow-up period of 22.5 years (1987-2011). Chromatography and mass spectroscopy identified and quantitated 204 serum metabolites, and Cox proportional hazards models were used to analyze the longitudinal associations with all-cause and cardiovascular mortality. Nine metabolites, including cotinine, mannose, glycocholate, pregnendiol disulfate, α-hydroxyisovalerate, N-acetylalanine, andro-steroid monosulfate 2, uridine, and γ-glutamyl-leucine, showed independent associations with all-cause mortality, with an average risk change of 18% per standard-deviation increase in metabolite level (P < 1.23 × 10(-4)). A metabolite risk score, created on the basis of the weighted levels of the identified metabolites, improved the predictive ability of all-cause mortality over traditional risk factors (bias-corrected Harrell's C statistic 0.752 vs. 0.730). Mannose and glycocholate were associated with cardiovascular mortality (P < 1.23 × 10(-4)), but predictive ability was not improved beyond the traditional risk factors. This metabolomic analysis revealed potential novel biomarkers for all-cause mortality beyond the traditional risk factors.

Transcatheter Mitral Valve Repair in Surgical High-Risk Patients: Gender-Specific Acute and Long-Term Outcomes

BACKGROUND

Analyses emphasizing gender-related differences in acute and long-term outcomes following MitraClip therapy for significant mitral regurgitation (MR) are rare.

METHODS

592 consecutive patients (75 ± 8.7 years, 362 men, 230 women) underwent clinical and echocardiographic follow-up for a median of 2.13 (0.99-4.02) years.

RESULTS

Significantly higher prevalence of cardiovascular comorbidities, renal failure, and adverse echocardiographic parameters in men resulted in longer device time (p = 0.007) and higher numbers of implanted clips (p = 0.0075), with equal procedural success (p = 1.0). Rehospitalization for heart failure did not differ (p[logrank] = 0.288) while survival was higher in women (p[logrank] = 0.0317). Logarithmic increase of NT-proBNP was a common independent predictor of death. Hypercholesterolemia and peripheral artery disease were predictors of death only in men while ischemic and dilative cardiomyopathy (CM) and age were predictors in women. Independent predictors of rehospitalization for heart failure were severely reduced ejection fraction and success in men while both ischemic and dilative CM, logistic EuroSCORE, and MR severity were predictive in women.

CONCLUSIONS

Higher numbers of implanted clips and longer device time are likely related to more comorbidities in men. Procedural success and acute and mid-term clinical outcomes were equal. Superior survival for women in long-term analysis is presumably attributable to a comparatively better preprocedural health.

Cardiovascular biomarkers and sex: the case for women

Measurement of biomarkers is a critical component of cardiovascular care. Women and men differ in their cardiac physiology and manifestations of cardiovascular disease. Although most cardiovascular biomarkers are used by clinicians without taking sex into account, sex-specific differences in biomarkers clearly exist. Baseline concentrations of many biomarkers (including cardiac troponin, natriuretic peptides, galectin-3, and soluble ST2) differ in men versus women, but these sex-specific differences do not generally translate into a need for differential sex-based cut-off points. Furthermore, most biomarkers are similarly diagnostic and prognostic, regardless of sex. Two potential exceptions are cardiac troponins measured by high-sensitivity assay, and proneurotensin. Troponin levels are lower in women than in men and, with the use of high-sensitivity assays, sex-specific cut-off points might improve the diagnosis of myocardial infarction. Proneurotensin is a novel biomarker that was found to be predictive of incident cardiovascular disease in women, but not men, and was also predictive of incident breast cancer. If confirmed, proneurotensin might be a unique biomarker of disease risk in women. With any biomarker, an understanding of sex-specific differences might improve its use and might also lead to an enhanced understanding of the physiological differences between the hearts of men and women.

A prospective assessment of cardiac biomarkers for hemodynamic stress and necrosis and the risk of falls among older people: the ActiFE study

Falls are related to a complex interaction of risk factors. We examined if cardiac biomarkers for hemodynamic stress (N-terminal pro Brain Natriuretic Peptide-NT-proBNP), and for necrosis [high sensitive (hs) cardiac troponins T (cTnT) and I (cTnI)] are associated with falls in older people. Biomarkers were measured at baseline in a cohort of 1506 community-dwelling adults ≥65 years. Falls were assessed prospectively in a falls calendar (median 370 days). Cox-proportional hazards models evaluated the association of each biomarker with the incidence of the first fall accounting for established confounders. We observed 430 incident falls among 1327 participants and an effect modification by sex for all biomarkers. In multivariable analyses among men a one unit increment of log-transformed hs-cTnI was associated with a hazard ratio (HR) of 1.26 (95 % CI 1.04, 1.53). Men with hs-cTnT ≥ 14 ng/L had a HR of 1.74 (95 % CI 1.15, 2.61) compared to those with undetectable hs-cTnT levels. In women cTn were not associated with falls. We did not detect an association between NT-proBNP and the risk of fall. Our results suggest that cardiac troponins may not only identify subjects at risk for cardiovascular diseases, but also help to understand the underlying complex pathophysiology of falls.

Cardiac troponin I levels in an elderly population from the community--The implications of sex

OBJECTIVES

The importance of sex on cardiac troponin levels is increasingly recognized. We investigated whether the entities associated with troponin leakage and the prognostic consequences thereof would differ between elderly men and women from the community.

DESIGN AND METHODS

Cardiac troponin I (cTnI) levels were measured using a high-sensitivity assay (Abbott Laboratories) in 70-year old men (n = 502) and women (n = 502) from the PIVUS study. All study participants were followed up for 10 years regarding all-cause mortality and incident cardiovascular (CV) disease.

RESULTS

Median cTnI levels were 4.1 and 3.0 ng/L in men and women, respectively (p<0.001). By multiple linear regression, the relative contribution of lower left-ventricular ejection fraction and ischemic ECG changes to cTnI levels was greater in men compared to women. For other clinical and echocardiographic variables, similar associations were found. cTnI independently predicted all-cause mortality in men (n = 93 [18.5%]; hazard ratio [HR] 1.38 [1.12-1.70]) and women (n = 62 [12.4%]; HR 1.59 [1.11-2.28]) but not incident CV disease in subjects being CV healthy at baseline (n = 163/857). The interaction terms of sex on the associations of cTnI with both outcomes were non-significant. Sex-specific cut-offs did not improve prognostication. Variations in the pattern of entities associated with cTnI leakage had no impact on event rates.

CONCLUSIONS

We found some differences in the entities associated with higher cTnI levels in elderly community-dwelling men and women. However, this did not translate into differences in the associations of cTnI with adverse outcome.