Serial biomarker measurements in ambulatory patients with chronic heart failure: the importance of change over time

Importance of the 'area under the curve' from serial NT-proBNP measurements during treatment with sacubitril/valsartan

AIMS

Serial assessment of natriuretic peptides is widely utilized in heart failure clinics. Uncertainty exists regarding the value of multiple natriuretic peptide measurements and how they might be best interpreted.

METHODS AND RESULTS

Six hundred thirty-two patients with heart failure with reduced ejection fraction (<40%) and complete biomarker data were enrolled to receive sacubitril/valsartan. Patients underwent periodic study visits during 1-year follow-ups. Echocardiographic data and cardiac biomarkers, including N-terminal pro-B-type natriuretic peptide (NT-proBNP) were collected during study visits. Patients were categorized into three groups based on tertiles of baseline NT-proBNP levels. The area under the curve (AUC) of NT-proBNP measurements across study visits was calculated. Compared with patients with higher AUC (and thus higher concentrations over a longer period of time), those with lower AUC were younger, had a lower prevalence of chronic kidney disease, prior coronary artery bypass graft, atrial fibrillation, and higher body-mass index. A significant interaction existed between baseline NT-proBNP and subsequent AUC for predicting LVEF change across visits (P-value < 0.001): among those with lower baseline NT-proBNP, similar improvements in left ventricular (LV) volumes LV ejection fraction, and LV mass index were observed across subsequent AUC (P-value > 0.1). However, among those with higher baseline NT-proBNP, those with lower subsequent AUC had a greater improvement in cardiac remodelling indices (P-value < 0.05).

CONCLUSIONS

Serial NT-proBNP monitoring (integrating the totality of measurements as an AUC) during treatment with sacubitril/valsartan informs unique information regarding the future changes in cardiac remodelling indices, especially among those with higher NT-proBNP levels at baseline.

Long-Term Trajectories of Biomarkers, Functional, and Echocardiographic Parameters in Patients with Chronic Heart Failure from Dilated or Ischaemic Cardiomyopathy

INTRODUCTION

The long-term evolution of clinical, echocardiographic, and laboratory parameters of cardiac function in patients with chronic heart failure (HF) with either reduced (HFrEF) or mildly reduced (HFmrEF) left ventricular ejection fraction (LVEF) is incompletely characterised.

METHODS

We identified patients with chronic stable HF who presented at least twice to a university HF outpatient clinic between 1995 and 2021. Trajectories of NYHA functional class, LVEF, left ventricular internal end-diastolic diameter (LVIDD), NT-proBNP concentrations, and HF treatment over 10 years of follow-up were analysed using fractional polynomials. Analyses were repeated after stratifying patients according to aetiology (ischaemic vs. dilated) or HF category (HFrEF vs. HFmrEF).

RESULTS

A total of 2,132 patients were included, of whom 51% had ischaemic and 49% had dilated HF. Eighty six percent and 14% were classified as HFrEF and HFmrEF, respectively. Mean LVEF was 28 ± 10%, and median NT-proBNP and estimated glomerular filtration rate values were 1,170 (385-3,176) pmol/L and 81 (62-100) mL/min/1.73 m2, respectively. Median follow-up was 5.2 (2.6-9.2) years. Overall, NYHA functional class and LVIDD trajectories were U-shaped, whereas LVEF and NT-proBNP concentrations markedly improved during the first year and remained stable thereafter. However, the evolution of HF parameters significantly differed with respect to HF category and aetiology, with greater improvements seen in patients with HFrEF of non-ischaemic origin. Improvements in HF variables were associated with optimization of HF therapy, notably with initiation and up-titration of renin-angiotensin-system blockers.

CONCLUSION

This study provides insights into the natural history of HF in a large cohort of well-treated chronic HF outpatients with respect to subgroups of HF and different aetiologists.

Detection of soluble suppression of tumorigenicity 2 and N-terminal B-type natriuretic peptide in a rat model of aortic regurgitation: differential responses to omecamtiv mecarbil

OBJECTIVES

Both N-terminal fragment of B-type natriuretic peptide (NT-proBNP) and soluble isoform of ST2 (sST2) have been identified as biomarkers of heart failure. We evaluated the plasma levels of NT-proBNP and sST2 in a rat model of severe aortic valve regurgitation (AR) and correlated these findings with echocardiographic measurements. We also examined the impact of omecamtiv mecarbil (OM) on these parameters.

METHODS

The plasma levels of NT-proBNP and sST2 were measured in 18 rats both before and 2 months after surgical induction of AR, and at these same time points, in six rats assigned to a sham-procedure control group. Plasma biomarkers were then measured again after infusion of OM or placebo in rats with AR (n=8 and 10, respectively) and OM alone in the sham control rats (n=6). Echocardiographic measurements were collected before and 2 months after induction of AR.

RESULTS

Our results revealed increased levels of plasma NT-proBNP (219 ± 34 pg/mL vs. 429 ± 374 pg/mL; p<0.001) in rats with AR at day 7 after infusion of placebo, whereas plasma levels of sST2 were higher in this cohort after infusion of either OM or placebo. We identified a significant positive correlation between plasma sST2 with posterior wall thickness in diastole (r=0.34, p<0.05) and total body weight (r=0.45, p<0.01) in rats with surgically induced AR.

CONCLUSIONS

Because sST2 increased markedly, whereas NT-proBNP remained unchanged, when OM was administered, we hypothesize that sST2 has a distinct capability to detect deleterious effects of passive muscle tension, not reliably assessed by NT-proBNP, in the setting of AR.

Circulating heart failure biomarkers beyond natriuretic peptides: review from the Biomarker Study Group of the Heart Failure Association (HFA), European Society of Cardiology (ESC)

New biomarkers are being evaluated for their ability to advance the management of patients with heart failure. Despite a large pool of interesting candidate biomarkers, besides natriuretic peptides virtually none have succeeded in being applied into the clinical setting. In this review, we examine the most promising emerging candidates for clinical assessment and management of patients with heart failure. We discuss high-sensitivity cardiac troponins (Tn), procalcitonin, novel kidney markers, soluble suppression of tumorigenicity 2 (sST2), galectin-3, growth differentiation factor-15 (GDF-15), cluster of differentiation 146 (CD146), neprilysin, adrenomedullin (ADM), and also discuss proteomics and genetic-based risk scores. We focused on guidance and assistance with daily clinical care decision-making. For each biomarker, analytical considerations are discussed, as well as performance regarding diagnosis and prognosis. Furthermore, we discuss potential implementation in clinical algorithms and in ongoing clinical trials.

Longitudinal patterns of N-terminal pro B-type natriuretic peptide, troponin T, and C-reactive protein in relation to the dynamics of echocardiographic parameters in heart failure patients

Aims

To further elucidate the nature of the association between N-terminal pro-B type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-TnT), C-reactive protein (CRP), and clinical outcome, we examined the relationship between serial simultaneous measurements of echocardiographic parameters and these biomarkers in chronic heart failure (CHF) patients.

Methods and results

In 117 CHF patients with ejection fraction ≤50%, NT-proBNP, hs-TnT, and CRP were measured simultaneously with echocardiographic evaluation at 6-month intervals until the end of 30 months follow-up or until an adverse clinical event occurred. Linear mixed effects models were used for data-analysis. Median follow-up was 2.2 years (interquartile range 1.5–2.6). We performed up to six follow-up evaluations with 55% of patients having at least three evaluations performed. A model containing all three biomarkers revealed that doubling of NT-proBNP was associated with a decrease in left ventricular ejection fraction by 1.83 (95% confidence interval −2.63 to −1.03)%, P &lt; 0.0001; relative increase in mitral E/e′ ratio by 12 (6–18)%, P &lt; 0.0001; relative increase in mitral E/A ratio by 16 (9–23)%, P &lt; 0.0001; decrease in tricuspid annular plane systolic excursion by 0.66 (−1.27 to −0.05) mm, P = 0.03; rise in tricuspid regurgitation peak systolic gradient by 2.74 (1.43–4.05) mmHg, P = 0.001; and increase in left ventricular and atrial dimensions, P &lt; 0.05. Hs-TnT and CRP showed significant associations with some echocardiographic parameters after adjustment for clinical covariates, but after adjustment for the other biomarkers the associations were not significant.

Conclusion

Serum NT-proBNP independently reflects changes in echocardiographic parameters of systolic function, left ventricular filling pressures, estimated pulmonary pressure, and chamber dimensions. Our results support further studies on NT-proBNP as a surrogate marker for haemodynamic congestion and herewith support its potential value for therapy guidance.

Prognostic value of myocardial strain and late gadolinium enhancement on cardiovascular magnetic resonance imaging in patients with idiopathic dilated cardiomyopathy with moderate to severely reduced ejection fraction

BACKGROUND

It has been reported that left ventricular (LV) myocardial strain and late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging have prognostic value in patients with heart failure (HF). However, previous studies included patients with various systolic functions. This study aimed to investigate the prognostic value of LV myocardial strain and LGE on CMR imaging in patients with idiopathic dilated cardiomyopathy (DCM) with reduced ejection fraction (EF < 40%).

METHODS

From a prospectively followed cohort who underwent CMR between November 2008 and December 2015, subjects with LV EF < 40% and a diagnosis of idiopathic DCM were eligible for this study. The CMR images were analyzed for LV and right ventricular (RV) function, presence and extent of LGE, and LV myocardial strain. The primary outcome was a composite of all-cause death and heart transplantation. The secondary outcome was hospitalization for HF.

RESULTS

A total of 172 patients were included, in whom mean LV EF was 23.7 ± 7.9% (EF 30-40% n = 47; EF < 30% n = 125). During a median follow-up of 47 months, the primary outcome occurred in 43 patients (16 heart transplantations, 29 all-cause deaths), and there were 41 hospitalizations for HF. Univariate Cox proportional hazard regression analysis showed that mean arterial pressure, serum sodium concentration, log of plasma NT-proBNP level, and presence of LGE (HR 2.277, 95% CI: 1.221-4.246) were significantly associated with the primary outcome. However, LV strain had no significant association (HR 1.048, 95% CI: 0.945-1.163). Multivariable analysis showed that presence of LGE (HR 4.73, 95% CI: 1.11-20.12) and serum sodium (HR 0.823, 95% CI: 0.762-0.887) were independently associated with the primary outcome.

CONCLUSIONS

LGE in CMR imaging was a good predictor of adverse outcomes for patients with idiopathic DCM and reduced EF. Identification of LGE could thus improve risk stratification in high-risk patients. LV strain had no significant prognostic value in patients with moderate to severe systolic dysfunction.

Biomarkers to Assess Right Heart Pressures in Recipients of a Heart Transplant: A Proof-of-Concept Study

Background

This proof-of-concept study investigated the feasibility of using biomarkers to monitor right heart pressures (RHP) in heart transplanted (HTx) patients.

Methods

In 298 patients, we measured 7.6 years post-HTx mean pressures in the right atrium (mRAP) and pulmonary artery (mPAP) and capillaries (mPCWP) along with plasma high-sensitivity troponin T (hsTnT), a marker of cardiomyocyte injury, and the multidimensional urinary classifiers HF1 and HF2, mainly consisting of dysregulated collagen fragments.

Results

In multivariable models, mRAP and mPAP increased with hsTnT (per 1-SD, +0.91 and +1.26 mm Hg; P < 0.0001) and with HF2 (+0.42 and +0.62 mm Hg; P ≤ 0.035), but not with HF1. mPCWP increased with hsTnT (+1.16 mm Hg; P < 0.0001), but not with HF1 or HF2. The adjusted odds ratios for having elevated RHP (mRAP, mPAP or mPCWP ≥10, ≥24, ≥17 mm Hg, respectively) were 1.99 for hsTnT and 1.56 for HF2 (P ≤ 0.005). In detecting elevated RHPs, areas under the curve were similar for hsTnT and HF2 (0.63 vs 0.65; P = 0.66). Adding hsTnT continuous or per threshold or HF2 continuous to a basic model including all covariables did not increase diagnostic accuracy (P ≥ 0.11), whereas adding HF2 per optimized threshold increased both the integrated discrimination (+1.92%; P = 0.023) and net reclassification (+30.3%; P = 0.010) improvement.

Conclusions

Correlating RHPs with noninvasive biomarkers in HTx patients is feasible. However, further refinement and validation of such biomarkers is required before their clinical application can be considered.

Novel Biomarkers to Detect Target Organ Damage in Acute Hypertension

PURPOSE OF REVIEW

Early lowering of blood pressure is advised for patients with severe hypertension associated with signs of impending or progressive organ damage, whereas aggressive treatment is not recommended in patients with asymptomatic severe hypertension. As treatment goals for asymptomatic hypertension and true hypertensive emergency drastically differ, it is essential to identify patients with evidence of impending or progressive organ damage. Biomarkers may assist providers in identifying high-risk patients who would benefit from early blood pressure reduction.

RECENT FINDINGS

In this review, we discuss both currently available and investigational biomarkers that may help identify patients who might benefit from more aggressive therapy. We focus on serum and urinary biomarkers associated with acute cardiovascular, renal, and cerebrovascular damage. There is a dearth of literature regarding the use of biomarkers to assess acute hypertension-related target organ damage. We are primarily forced to draw conclusions on the use of biomarkers from studies of related conditions such as acute heart failure. Further research is needed on the clinical significance of abnormal levels of novel biomarkers of renal, cardiac, and cerebral dysfunction in the setting of severe hypertension, particularly in those patients without overt clinical signs of organ failure.

Prognostic performance of serial in-hospital measurements of copeptin and multiple novel biomarkers among patients with worsening heart failure: results from the MOLITOR study

Aims

In heart failure, various biomarkers are established for diagnosis and risk stratification; however, little is known about the relevance of serial measurements during an episode worsening heart failure (WHF). This study sought to investigate the trajectory of natriuretic peptides and multiple novel biomarkers during hospitalization for WHF and to determine the best time point to predict outcome.

Methods and results

MOLITOR (Impact of Therapy Optimisation on the Level of Biomarkers in Patients with Acute and Decompensated Chronic Heart Failure) was an eight‐centre prospective study of 164 patients hospitalized with a primary diagnosis of WHF. C‐terminal fragment of pre‐pro‐vasopressin (copeptin), N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP), mid‐regional pro‐atrial natriuretic peptide (MR‐proANP), mid‐regional pro‐adrenomedullin (MR‐proADM), and C‐terminal pro‐endothelin‐1 (CT‐proET1) were measured on admission, after 24, 48, and 72 h, and every 72 h thereafter, at discharge and follow‐up visits. Their performance to predict all‐cause mortality and rehospitalization at 90 days was compared. All biomarkers decreased during recompensation (P < 0.05) except MR‐proADM. Copeptin at admission was the best predictor of 90 day mortality or rehospitalization (χ² = 16.63, C‐index = 0.724, P < 0.001), followed by NT‐proBNP (χ² = 10.53, C‐index = 0.646, P = 0.001), MR‐proADM (χ² = 9.29, C‐index = 0.686, P = 0.002), MR‐proANP (χ² = 8.75, C‐index = 0.631, P = 0.003), and CT‐proET1 (χ² = 6.60, C‐index = 0.64, P = 0.010). Re‐measurement of copeptin at 72 h and of NT‐proBNP at 48 h increased prognostic value (χ² = 23.48, C‐index = 0.718, P = 0.00001; χ² = 14.23, C‐index = 0.650, P = 0.00081, respectively).

Conclusions

This largest sample of serial measurements of multiple biomarkers in WHF found copeptin at admission with re‐measurement at 72 h to be the best predictor of 90 day mortality and rehospitalization.

Cardiopulmonary and inflammatory biomarkers in heartworm disease

In heartworm disease, several biomarkers of cardiopulmonary injury and inflammatory activity have been studied during the recent years. D-dimer is a fibrin degradation product present after a clot is degraded, which has been reported to provide support for the diagnosis of pulmonary thromboembolism in heartworm disease. Furthermore, concentrations increment with increased disease severity and during the adulticide treatment. This increase in concentration has proved to be valuable. Cardiac biomarkers troponin I, myoglobin and NT-proBNP demonstrated presence of myocardial injury and heart failure, especially in chronic infections, which in some cases, slightly improve after the adulticide treatment. An acute phase response in dogs with Dirofilaria immitis, characterized by variations of acute phase proteins (APP), has been reported, indicating inflammatory processes that could contribute to disease progression. Among them, C-reactive protein (CRP) increases according to the severity of the disease; and a strong correlation between pulmonary hypertension and CRP has been observed. In cats, little work has been done to ascertain the utility of these biomarkers in feline heartworm; the only published study in D. immitis–seropositive cats reported significantly higher concentrations in positive APP serum amyloid A, haptoglobin and ceruloplasmin.

In search of an efficient strategy to monitor disease status of chronic heart failure outpatients: added value of blood biomarkers to clinical assessment

Introduction

Blood biomarkers have the potential to monitor the severity of chronic heart failure (CHF). Studies correlating repeated measurements of blood biomarkers with repeatedly assessed New York Heart Association (NYHA) class over a prolonged follow-up period, and concomitantly investigating their associations with clinical endpoints, have not yet been performed.

Methods

Between 2011–2013, 263 CHF patients were included. At inclusion and subsequently every 3 months, we measured N‑terminal pro-B-type natriuretic (NT-proBNP), high-sensitivity troponin T (Hs-TnT) and C‑reactive protein (CRP), and assessed NYHA class. The primary endpoint comprised heart failure hospitalisation, cardiovascular mortality, cardiac transplantation or left ventricular assist device implantation. Time-dependent Cox models were used.

Results

Mean age was 67 ± 13 years, 72% were men and 27% were in NYHA class III–IV. We obtained 886 repeated measures (median 3 [IQR 2–5] per patient). The primary endpoint was reached in 41 patients during a median follow-up of 1.0 [0.6–1.4] year. Repeatedly measured NT-proBNP and Hs-TnT were significantly associated with repeatedly assessed NYHA class, whereas CRP was not (NT-proBNP: β [95% CI]: 1.56 [1.17–2.06]ln(ng/l) increase per point increase in NYHA class, p = 0.002; HsTNT: β [95% CI]: 1.58 [1.21–2.07]). Serially measured NT-proBNP (HR [95% CI]:2.86 [1.73–4.73]), CRP (1.69 [1.21–2.34]) and NYHA class (2.33 [1.51–3.62]) were positively and independently associated with the primary endpoint, whereas Hs-TnT lost statistical significance after multivariable adjustment. A model containing serially measured NYHA class and NT-proBNP displayed a C-index of 0.84, while serially measured NYHA class and CRP showed a C-index of 0.82.

Conclusion

Temporal NT-proBNP, CRP and NYHA class patterns are independently associated with adverse clinical outcome. Serially measured NT-proBNP and NYHA class are best suited for monitoring CHF outpatients.

Electronic supplementary material

The online version of this article (10.1007/s12471-017-1040-x) contains supplementary material, which is available to authorized users.

Repeated Measurements of Cardiac Biomarkers in Atrial Fibrillation and Validation of the ABC Stroke Score Over Time

BACKGROUND

Cardiac biomarkers are independent risk markers in atrial fibrillation, and the novel biomarker-based ABC stroke score (age, biomarkers, and clinical history of prior stroke) was recently shown to improve the prediction of stroke risk in patients with atrial fibrillation. Our aim was to investigate the short-term variability of the cardiac biomarkers and evaluate whether the ABC stroke risk score provides a stable short-term risk estimate.

METHODS AND RESULTS

According to the study protocol, samples were obtained at entry and also at 2 months in 4796 patients with atrial fibrillation followed for a median of 1.8 years in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. Cardiac troponin I, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide were measured with high-sensitivity immunoassays. Associations with outcomes were evaluated by Cox regression. C indices and calibration plots were used to evaluate the ABC stroke score at 2 months. The average changes in biomarker levels during 2 months were small (median change cardiac troponin T +2.8%, troponin I +2.0%, and N-terminal pro-B-type natriuretic peptide +13.5%) and within-subject correlation was high (all ≥0.82). Repeated measurement of cardiac biomarkers provided some incremental prognostic value for mortality but not for stroke when combined with clinical risk factors and baseline levels of the biomarkers. Based on 8702 person-years of follow-up and 96 stroke/systemic embolic events, the ABC stroke score at 2 months achieved a similar C index of 0.70 (95% CI, 0.65-0.76) as compared with 0.70 (95% CI, 0.65-0.75) at baseline. The ABC stroke score remained well calibrated using predefined risk classes.

CONCLUSIONS

In patients with stable atrial fibrillation, the variability of the cardiac biomarkers and the biomarker-based ABC stroke score during 2 months are small. The prognostic information by the ABC stroke score remains consistent and well calibrated with similar good predictive performance if patients are retested after 2 months.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.

Exploring the relation between changes in NT-proBNP and renal function in patients with suspected heart failure using structural equation modelling

BACKGROUND

The relation between changes in NT-proBNP and renal function has commonly been studied using multiple regressions, which may ignore the complexity of relations between related variables.

METHODS AND RESULTS

Data were collected from patients referred with suspected heart failure (HF) to a community service. Structural equation modelling (SEM) was used to assess the association between changes in NT-proBNP at 1year, and other pre-specified variables including age, sex, BMI, eGFR, loop diuretics and ACE inhibitor. Of 1006 patients with a follow-up NT-proBNP at 1year, 882 (88%) had HF. The baseline median age was 72 (IQR: 63-78) years, 732 (73%) were men, 668 (66%) had left ventricular systolic dysfunction and 769 (76%) had NT-proBNP>400pg/ml. For all patients at 1year, 243 (24%) patients had at least a 50% reduction in NT-proBNP, and 199 (20%) had at least a 50% increase, only 40 (3%) had <3% change. Change in NT-proBNP was strongly associated with baseline NT-proBNP (the standardized coefficient (r)=0.73, p<0.001). The change in NT-proBNP was not associated with changes in eGFR, and was indirectly related with age, BMI, eGFR and loop diuretics (p<0.01 for all).

CONCLUSIONS

Baseline NT-proBNP was the main determinant of change in NT-proBNP at one year.

Serially measured circulating miR-22-3p is a biomarker for adverse clinical outcome in patients with chronic heart failure: The Bio-SHiFT study

BACKGROUND

Several studies have suggested circulating microRNAs (miRs) are associated with heart failure, but these studies were small, and limited to single miR measurements. We examined 7 miRs which were previously linked to heart failure, and tested whether their temporal expression level predicts prognosis in a prospective cohort of chronic heart failure (CHF) patients.

METHODS AND RESULTS

In 2011-2013, 263 CHF patients were included. At inclusion and subsequently every 3months, we measured 7miRs. The primary endpoint (PE) comprised heart failure hospitalization, cardiovascular mortality, cardiac transplantation and LVAD implantation. Associations between temporal miR patterns and the PE were investigated by joint modelling, which combines mixed models with Cox regression. Mean age was 67±13years, 72% were men and 27% NYHA classes III-IV. We obtained 873 blood samples (median 3 [IQR 2-5] per patient). The PE was reached in 41 patients (16%) during a median follow-up of 0.9 [0.6-1.4] years. The temporal pattern of miR-22-3p was independently associated with the PE (HR [95% CI] per doubling of level: 0.64 [0.47-0.77]). The instantaneous change in level (slope of the temporal miR pattern) of miR-22-3p was also independently associated with the PE (HR [95% CI] per doubling of slope: 0.33 [0.20-0.51]). These associations remained statistically significant after adjustment for temporal patterns of NT-proBNP, Troponin T and CRP.

CONCLUSIONS

The temporal pattern of circulating miR-22-3p contains important prognostic and independent information in CHF patients. This concept warrants further investigation in larger series with extended follow-up.

Application of Cardiac Troponin in Cardiovascular Diseases Other Than Acute Coronary Syndrome

BACKGROUND

Increased cardiac troponin concentrations in acute coronary syndrome (ACS) identify patients with ongoing cardiomyocyte necrosis who are at increased risk. However, with the use of more precise assays, cardiac troponin increases are commonly noted in other cardiovascular conditions as well. This has generated interest in the use of cardiac troponin for prognostic assessment and clinical management of these patients. In this review, we have summarized the data from studies investigating the implications of cardiac troponin concentrations in various acute and chronic conditions beyond ACS, i.e., heart failure, myocarditis, Takotsubo cardiomyopathy, aortic dissection, supraventricular arrhythmias, valve disease, pulmonary arterial hypertension, stroke, and in the perioperative setting.

CONTENT

Cardiac troponin concentrations are often detectable and frankly increased in non-ACS conditions, in particular when measured with high-sensitivity (hs) assays. With the exception of myocarditis and Takotsubo cardiomyopathy, cardiac troponin concentrations carry strong prognostic information, mainly with respect to mortality, or incipient and/or worsening heart failure. Studies investigating the prognostic benefit associated with cardiac troponin–guided treatments however, are almost lacking and the potential role of cardiac troponin in the management of non-ACS conditions is not defined.

SUMMARY

Increased cardiac troponin indicates increased risk for adverse outcome in patients with various cardiovascular conditions beyond ACS. Routine measurement of cardiac troponin concentrations can however, not be generally recommended unless there is a suspicion of ACS. Nonetheless, any finding of an increased cardiac troponin concentration in a patient without ACS should at least prompt the search for possible underlying conditions and these should be managed meticulously according to current guidelines to improve outcome.

Midterm Effect of Balloon Pulmonary Angioplasty on Hemodynamics and Subclinical Myocardial Damage in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

The acute favourable effect of balloon pulmonary angioplasty (BPA) has been proven in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, data on its effect 6 months after therapy (from now on referred to as mid-term) and influence on the right ventricle and myocardial damage are sparse. To evaluate factors that influence improvement in cardiac output (CO) and subclinical myocardial damage, we examined hemodynamics and serum high-sensitivity troponin T (hs-TnT) levels before, 1 week after, and 6 months after BPA.

METHODS

In a retrospective study, we reviewed 67 consecutive patients from November 2012 to January 2016 with CTEPH who had undergone BPA at Keio University Hospital.

RESULTS

Six months after BPA, the mean right atrium pressure, mean pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), B-type natriuretic peptide (BNP), and hs-TnT levels decreased; CO and 6-minute walking distance increased. Changes in CO and hs-TnT levels varied compared with other hemodynamic parameters and BNP levels. The CO-increase group (n = 42) had higher mean PAP and PVR, and lower CO at baseline than the CO-decrease/stable group (n = 25). The hs-TnT-decrease group (n = 36) had higher mean right atrium pressure, PAP, PVR, and BNP levels, and lower CO at baseline than the hs-TnT-increase/stable group (n = 31).

CONCLUSIONS

Six months after BPA, hemodynamics and exercise capacity improved and hs-TnT levels decreased. Improvements in CO and hs-TnT levels were more prominent in CTEPH patients with impaired baseline hemodynamics, suggesting that BPA has a favourable mid-term effect on hemodynamics and subclinical myocardial damage in patients with CTEPH, especially in those with impaired hemodynamics.

Cardiac troponin in patients hospitalized with acute decompensated heart failure: A systematic review and meta-analysis

BACKGROUND

Elevated cardiac troponin (cTn) is often observed in patients with acute decompensated heart failure (ADHF). We assessed the magnitude of association and quality of supporting evidence between cTn and clinically important outcomes in persons hospitalized for ADHF.

METHODS

We searched MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from inception through February 28, 2015. The outcomes analyzed included hospital length of stay (LOS), readmissions, and mortality. Random effects meta-analysis was used to combine outcomes across studies.

RESULTS

We included 26 clinical studies. A detectable or elevated cTn was associated with increased LOS (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 1.01-1.10), increased in-hospital mortality (OR: 2.57; 95% CI: 2.27-2.91), and a composite of mortality and major adverse events (OR: 1.33; 95% CI: 1.03-1.71) during hospitalization. ADHF patients with a detectable or elevated cTn were at increased risk for mortality and composite of mortality and readmission over the short term (mortality OR: 2.11; 95% CI: 1.43-3.12; composite OR: 2.81; 95% CI: 1.60-4.92), intermediate term (mortality OR: 2.21; 95% CI: 1.46-3.35; composite OR: 2.30; 95% CI: 1.78-2.99), and long term (mortality OR: 3.69; 95% CI: 2.64-5.18; composite OR: 3.49; 95% CI: 2.08-5.84). The overall confidence in estimates was moderate.

CONCLUSIONS

Among ADHF patients, a detectable or elevated cTn identifies subjects at increased risk for adverse clinical outcomes during acute hospitalization and those at higher risk for postdischarge mortality and composite of readmission and mortality. Journal of Hospital Medicine 2016;11:446-454. 2016 Society of Hospital Medicine.

The search for efficient diagnostic and prognostic biomarkers of heart failure

Several biomarkers have been tested for screening, diagnosis and prognosis purposes, as well as to guide treatment in heart failure, but only the assay of circulating B-type natriuretic peptides has widely recognized applications for clinical decision-making. Natriuretic peptides are sensitive in detecting the clinically overt or subclinical myocardial damage, but their plasma levels are increased following every generic insult to the cardiovascular system. Novel biomarkers are required to identify specific pathways of disease progression, such as diverse neurohormonal axes activation, inflammation and fibrogenesis, and to act as a tool for therapeutic tailoring. In this view, Gal-3 and ST-2 assays seem very promising, given their involvement in mechanisms of cardiac fibrosis and their prognostic value.

Biomarkers in heart failure: the importance of inconvenient details

The proliferation of cardiac-related biomarkers and advocacy for their use has often come without adequate discussion of limitations in the interpretation of values and their best use in heart failure (HF) patients to provide a balanced assessment of how cardiac biomarkers are advocated for use in HF and areas where we would argue there are no gaps in knowledge. We include suggestions to address these issues. We have focused on peer-reviewed publications over the period 2000 to present. Most studies have used samples at one or at most two points in time to define risk. Although biomarkers might add to the magnitude of risk, it is unclear how often they lead to changes in treatment. We suggest that defining the use of serial biomarker testing over time would be more helpful. To do this, it is necessary to take into account the biomarker's analytical and biological variability in addition to its ability to define and monitor therapy. These factors are often overlooked leading to conclusions that may be statistically significant but not clinically or analytically robust. An appreciation of the value and limitations of biomarker use is important to all clinicians who manage HF patients. If the proper studies are done so that biomarkers are used optimally, they will likely be helpful in defining when and how to intervene. If we continue as we have, we will continue to have ambiguity about the use of these valuable probes in the assessment and management of HF.

Effect of Diuretic or Calcium-Channel Blocker Plus Angiotensin-Receptor Blocker on Diastolic Function in Hypertensive Patients

BACKGROUND

Hypertension increases the risk of left ventricular (LV) diastolic dysfunction, and anti-hypertensive therapy may improve LV relaxation. The aim of this study was to investigate whether combining an angiotensin-receptor blocker (ARB) with either hydrochlorothiazide (HCTZ) or a calcium-channel blocker (CCB) improves LV relaxation in patients with hypertension and diastolic dysfunction.

METHODS AND RESULTS

Hypertensive patients who had not achieved their target blood pressure with at least 4 weeks of ARB therapy were randomly assigned to receive either a fixed-dose combination of losartan and HCTZ (losartan/HCTZ; n=110) or a combination of amlodipine and a typical ARB dosage (CCB/ARB; n=121) and followed for 24 weeks. The primary endpoint was change in early diastolic mitral annular velocity (e', cm/s). Systolic blood pressure decreased in both groups after switch to the combination therapies. E' velocity increased both in the losartan/HCTZ (0.52 cm/s) and in the CCB/ARB (0.59 cm/s) groups. The mean (95% CI) treatment difference was -0.02 (-0.37 to 0.34) cm/s, indicating that improvement in LV relaxation was similar between the groups. The ratio of early mitral inflow velocity to e' velocity and left atrial volume index were significantly decreased in the losartan/HCTZ group.

CONCLUSIONS

The combination of losartan and HCTZ is as effective as amlodipine plus ARB in improving LV relaxation in hypertensive patients.

Cardiac Troponins in Dogs and Cats

Cardiac troponins are sensitive and specific markers of myocardial injury. The troponin concentration can be thought of as a quantitative measure of the degree of injury sustained by the heart, however, it provides no information on the cause of injury or the mechanism of troponin release. Conventionally, the cardiac troponins have been used for diagnosis of acute myocardial infarction in humans and have become the gold standard biomarkers for this indication. They have become increasingly recognized as an objective measure of cardiomyocyte status in both cardiac and noncardiac disease, supplying additional information to that provided by echocardiography and ECG. Injury to cardiomyocytes can occur through a variety of mechanisms with subsequent release of troponins. Independent of the underlying disease or the mechanism of troponin release, the presence of myocardial injury is associated with an increased risk of death. As increasingly sensitive assays are introduced, the frequent occurrence of myocardial injury is becoming apparent, and our understanding of its causes and importance is constantly evolving. Presently troponins are valuable for detecting a subgroup of patients with higher risk of death. Future research is needed to clarify whether troponins can serve as monitoring tools guiding treatment, whether administering more aggressive treatment to patients with evidence of myocardial injury is beneficial, and whether normalizing of troponin concentrations in patients presenting with evidence of myocardial injury is associated with reduced risk of death.

Rationale and therapeutic opportunities for natriuretic peptide system augmentation in heart failure

The natriuretic peptide system (NPS) is intimately involved in cardiorenal homeostasis in health, and dysregulation of the NPS plays an important role in the pathophysiology of heart failure (HF). Indeed, the diuretic, vasorelaxation, beneficial remodeling, and potent neurohumoral inhibition of the NPS support the therapeutic development of chronic augmentation of the NPS in symptomatic HF. Further, chronic augmentation of the protective NPS and in early stages of HF may ultimately prevent the progression of HF and reduced subsequent morbidity and mortality. In the current manuscript, we review the rationale for as well as previous and current efforts aimed at chronic therapeutic augmentation of the NPS in HF.

Usefulness of High-Sensitive Troponin Elevation After Effort Stress to Unveil Vulnerable Myocardium in Patients With Heart Failure

Elevation of resting high-sensitivity troponin (hs-Tn) holds prognostic value in heart failure (HF), but its pathophysiological meaning is unclear. We aimed to investigate hs-Tn elevation after maximal exercise in patients with systolic HF and its neurohormonal and hemodynamic correlates: 30 patients diagnosed with systolic HF (left ventricular ejection fraction 32 ± 8%, mean ± SD), on guideline-directed medical therapy and not recognized inducible ischemia, underwent maximal cardiopulmonary stress test, with assay of plasma N-terminal proB-type natriuretic peptide (NT-proBNP), norepinephrine (NE), and hs-TnT (hs-TnT) at baseline, peak, and 1 and 4 hours after exercise. Cardiac output (CO) was measured during effort, with a rebreathing technique. The natural logarithm of the ratio between percentage (%) increase in CO and NT-proBNP (ln[CO%/NT-proBNP% increase]) was evaluated, as a noninvasive estimate of Frank-Starling adaptation to effort, with NT-proBNP variation considered as a surrogate of end-diastolic left ventricular pressure variation. Hs-TnT increased during exercise with a 4-hour peak (p = 0.001); 10 patients had hs-TnT increase >20%. Patients with Hs-TnT increase >20% were more symptomatic at rest (p = 0.039) and showed greater NE at peak exercise (p = 0.003) and less ln[CO%/NT-proBNP% increase] (p = 0.034). A lower ln[CO%/NT-proBNP% increase] correlated with greater NE at peak exercise (r = -0.430, p = 0.018). In conclusion, acute troponin elevation after maximal exercise was detected in 1/3 of this series. The association of troponin release with NE, CO, and NT-proBNP changes after effort suggests a pathophysiological link among transient hemodynamic overload, adrenergic activation, and myocardial cell damage, likely identifying a clinical subset at greater risk for HF progression.

Copeptin as a biomarker in heart failure

Increased neurohormonal activation is a key feature of heart failure (HF). Copeptin is a surrogate marker for proarginine vasopressin and the prognostic value of copeptin has been reported for multiple disease states of both nonvascular and cardiovascular etiology. Elevated plasma copeptin in HF has been associated with adverse outcomes such as increased mortality, risk of hospitalization and correlates with the severity of HF. Copeptin may add prognostic information to already established predictors such as clinical variables and natriuretic peptides in HF. In addition, copeptin has been found to be a superior marker when compared with BNP and NT-proBNP in HF patients discharged after hospitalization caused by HF or myocardial infarction (MI). The optimal use of copeptin in HF remains unresolved and future appropriately sized and randomized trials must determine the role of copeptin in HF as a marker of adverse outcomes, risk stratification or as a target in biomarker-guided therapy with arginine vasopressin-antagonists in individualized patient treatment and everyday clinical practice.

Changes in N-terminal pro-B-type natriuretic peptide levels and outcomes in heart failure with preserved ejection fraction: an analysis of the I-Preserve study

AIMS

In patients with heart failure (HF) and reduced ejection fraction, decreases or increases in NT-proBNP levels are associated with better and worse outcomes, respectively. The association in HF and preserved ejection fraction (HF-PEF) is unknown. We examined the association between change in level of NT-proBNP and prognosis in patients with HF-PEF.

METHODS AND RESULTS

We examined the association between change in NT-proBNP from baseline to 6 months and cardiovascular (CV) death or HF hospitalization in 2612 participants in the Irbesartan in Patients with Heart Failure and Preserved Systolic Function Study (I-Preserve). Change in NT-proBNP was modelled as a restricted cubic spline in a Cox model after adjusting for baseline NT-proBNP and known prognostic variables. Median change in NT-proBNP from baseline was -7 pg/mL (interquartile range -143 to +108). After adjustment, a 1000 pg/mL decrease in NT-proBNP from baseline was associated with a reduction in the risk of CV death or HF hospitalization [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.53-1.02]; a 1000 pg/mL increase was associated with an increase in risk (HR 2.01, 95% CI 1.50-2.69). Beyond a 1000 pg/mL rise or fall, there was little additional change in risk. Addition of change in NT-proBNP at 6 months to a model with only baseline NT-proBNP improved the C-statistic from 0.752 to 0.769 (P = 0.013).

CONCLUSION

In HF-PEF, a rise in NT-proBNP was associated with an increase in risk of CV death or HF hospitalization and a fall was associated with a trend towards a decrease in risk. NT-proBNP may be a useful marker to monitor prognosis in this condition.

Cardiac troponin I and T as prognostic markers in cats with hypertrophic cardiomyopathy

BACKGROUND

Myocardial injury detected by cardiac troponin I and T (cTnI and cTnT) in cardiac disease is associated with increased risk of death in humans and dogs.

HYPOTHESIS

Presence of myocardial injury predicts long-term death in cats with hypertrophic cardiomyopathy (HCM), and ongoing myocardial injury reflects change in left ventricular wall thickness over time.

ANIMALS

Thirty-six cats with primary HCM.

METHODS

Prospective cohort study. Cats with HCM were included consecutively and examined every 6 months. Echocardiography, ECG, blood pressure, and serum cTnI and cTnT were evaluated at each visit. Cox proportional hazards regression analysis was performed to evaluate prognostic potential of serum troponin concentrations at admission and subsequent examinations. Correlations were used to examine associations between troponin concentrations and cardiac hypertrophy.

RESULTS

Troponin concentrations at admission were median [range] 0.14 [0.004-1.02] ng/mL for cTnI, and 13 [13-79.5] ng/L for cTnT. Both were prognostic for death (P = .032 and .026) as were the last available concentrations of each (P = .016 and .003). The final cTnT concentration was a significant predictor of death even when adjusting for the admission concentration (P = .043). In a model containing both markers, only cTnT remained significant (P = .043). Left ventricular free wall thickness at end-diastole (LVFWd) at admission was correlated with cTnI at admission (r = 0.35, P = .035), however no significant correlations (r = 0.2-0.31, P = .074-.26) were found between changes in troponin concentrations and left ventricular thickness over time.

CONCLUSIONS AND CLINICAL IMPORTANCE

Myocardial injury is part of the pathophysiology leading to disease progression and death. Low sensitivities and specificities prevent outcome prediction in individual cats.

Troponins in heart failure

The signs and symptoms of heart failure are frequently unspecific and correlate poorly with objective indices of cardiac function. Objective assessment of cardiac function by echocardiography or other imaging modalities also correlate poorly with symptomatic status and functional capacity. Accordingly, there is a need for circulating biomarkers that can provide incremental diagnostic and prognostic information to the existing armamentarium of tests. The introduction of more sensitive assays that allow determination of very low circulating concentrations of the myofibrillar proteins cardiac troponin I and T has not only resulted in improved diagnostic accuracy in the setting of acute coronary syndromes. The high sensitivity assays have also shown that cardiac troponins are frequently found chronically circulating in a variety of acute and chronic, cardiac and non-cardiac disease conditions, including acute heart failure and chronic symptomatic and asymptomatic left ventricular dysfunction. Cardiac troponin I and T provide may provide clinically useful prognostic information both concerning the future risk of developing heart failure in asymptomatic subjects and the risk of fatal events and hospital admissions in those with already established heart failure This review summarizes current literature on the clinical performance and utility of cardiac troponin measurements as diagnostic and prognostic tools in patients with symptomatic heart failure, as well as in those with asymptomatic left ventricular dysfunction, and clinical phenotypes at high risk for developing heart failure, including stable coronary artery disease, left ventricular hypertrophy, and aortic stenosis.

[Essential cardiac biomarkers in myocardial infarction and heart failure]

With the discovery of novel biomarkers in cardiovascular diseases, over the past decades considerable improvements in diagnosis, risk stratification and patient care could be achieved; however, despite extensive research, only few biomarkers have met the requirements of significantly improving diagnostic or prognostic approaches. Among the most established markers are cardiac troponins and natriuretic peptides, which are recommended in current guidelines for myocardial infarction or heart failure and are routinely used in clinical practice. Cardiac troponins T and I are the preferred biomarkers of choice for definition of myocardial infarction and proved to be prognostically relevant not only in acute coronary syndrome but also in non-cardiac diseases. The natriuretic peptides B-type natriuretic peptide (BNP) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) aid in diagnosis, risk stratification and monitoring of heart failure. In recent years several new promising markers have been proposed which might add incremental clinical information, most notably copeptin and growth differentiation factor (GDF) 15; however, larger studies are still required before recommendations for routine clinical use can be made.

ICG-liver test versus new biomarkers as prognostic markers for prolonged length of stay in critically ill patients - a prospective study of accuracy for prediction of length of stay in the ICU

Background

Prognostic abilities of medical parameters, which are scoring systems, measurements and biomarkers, are important for stratifying critically ill patients. Indocyanine green plasma disappearance (ICG-PDR) is an established clinical tool for the assessment of liver perfusion and function. Copeptin, MR-proANP and pro-ADM are biomarkers whose prognostic value is still unclear. The goal of this prospective study was to evaluate ICG-PDR, copeptin, MR-proANP and pro-ADM to predict prolonged length of stay (pLOS) in the ICU.

Methods

This study was conducted as a prospective single center study including 110 consecutively admitted ICU patients. Primary endpoint was prolonged length of stay (pLOS) in the ICU, defined as more than three days of stay there.

Results

ROC analysis showed an AUC of 0.73 for ICG-PDR, 0.70 for SAPS II, 0.65 for MR-proANP, 0.64 for pro-ADM and 0.54 for copeptin for pLOS in the ICU.

Conclusions

The prediction of pLOS in the ICU might be better by means of ICG-PDR than with the new biomarkers copeptin, MR-proANP or pro-ADM. Nevertheless, there is more need for research to evaluate whether ICG-PDR is an overall prognostic marker for pLOS.

Trial registration

(ClinicalTrials.gov number, NCT01126554).

Biomarker predictors of cardiac hospitalization in chronic heart failure: a recurrent event analysis

BACKGROUND

Identification of heart failure (HF) patients at risk for hospitalization may improve care and reduce costs. We evaluated 9 biomarkers as predictors of cardiac hospitalization in chronic HF.

METHODS AND RESULTS

In a multicenter cohort of 1,512 chronic HF outpatients, we assessed the association between 9 biomarkers and cardiac hospitalization with the use of a recurrent events approach. Over a median follow-up of 4 years, 843 participants experienced ≥ 1 hospitalizations (total 2,178 hospitalizations). B-type natriuretic peptide (BNP) and troponin I (TnI) exhibited the strongest associations with risk of hospitalization (hazard ratio [HR] 3.8 [95% confidence interval (CI) 2.9-4.9] and HR 3.3 [95% CI 2.8-3.9]; 3rd vs 1st tertiles). Soluble Fms-like tyrosine kinase receptor 1 (sFlt-1) exhibited the next strongest association (HR 2.8 [95% CI 2.4-3.4]), followed by soluble Toll-like receptor 2 (HR 2.3 [95% CI 2.0-2.8]) and creatinine (HR 1.9 [95% CI 1.6-2.4]). Within ischemic/nonischemic subgroups, BNP and TnI remained most strongly associated. Except for creatinine, HRs for all biomarkers studied were smaller within the ischemic subgroup, suggesting greater importance of cardiorenal interactions in decompensation of ischemic HF.

CONCLUSION

Although BNP and TnI exhibited the strongest associations with hospitalization, etiology-dependent associations for the remaining biomarkers suggest etiology-specific mechanisms for HF exacerbation. sFlt-1 exhibited a strong association with cardiac hospitalization, highlighting its potential role as a biomarker of HF morbidity.

Cationic isotachophoresis separation of the biomarker cardiac troponin I from a high-abundance contaminant, serum albumin

Cationic ITP was used to separate and concentrate fluorescently tagged cardiac troponin I (cTnI) from two proteins with similar isoelectric properties in a PMMA straight-channel microfluidic chip. In an initial set of experiments, cTnI was effectively separated from R-Phycoerythrin using cationic ITP in a pH 8 buffer system. Then, a second set of experiments was conducted in which cTnI was separated from a serum contaminant, albumin. Each experiment took ∼10 min or less at low electric field strengths (34 V/cm) and demonstrated that cationic ITP could be used as an on-chip removal technique to isolate cTnI from albumin. In addition to the experimental work, a 1D numerical simulation of our cationic ITP experiments has been included to qualitatively validate experimental observations.

Prognostic implication of physical signs of congestion in acute heart failure patients and its association with steady-state biomarker levels

Background

Congestive physical findings such as pulmonary rales and third heart sound (S3) are hallmarks of acute heart failure (AHF). However, their role in outcome prediction remains unclear. We sought to investigate the association between congestive physical findings upon admission, steady-state biomarkers at the time of discharge, and long-term outcomes in AHF patients.

Methods

We analyzed the data of 133 consecutive AHF patients with an established diagnosis of ischemic or non-ischemic (dilated or hypertrophic) cardiomyopathy, admitted to a single-center university hospital between 2006 and 2010. The treating physician prospectively recorded major symptoms and congestive physical findings of AHF: paroxysmal nocturnal dyspnea, orthopnea, pulmonary rales, jugular venous distension (JVD), S3, and edema. The primary endpoint was defined as rehospitalization for HF.

Results

Majority (63.9%) of the patients had non-ischemic etiology and, at the time of admission, S3 was seen in 69.9% of the patients, JVD in 54.1%, and pulmonary rales in 43.6%. The mean follow-up period was 726 ± 31days. Patients with pulmonary rales (p < 0.001) and S3 (p  =  0.011) had worse readmission rates than those without these findings; the presence of these findings was also associated with elevated troponin T (TnT) levels at the time of discharge (odds ratio [OR] 2.8; p  =  0.02 and OR 2.6; p  =  0.05, respectively).

Conclusion

Pulmonary rales and S3 were associated with inferior readmission rates and elevated TnT levels on discharge. The worsening of the readmission rate owing to congestive physical findings may be a consequence of on-going myocardial injury.

Importance of persistent elevation of cardiac biomarkers in atrial fibrillation: a RE-LY substudy

OBJECTIVES

To evaluate the prognostic importance of transient or persistent elevations of cardiac troponin-I (cTnI) and N-terminal-B-type natriuretic peptide (NT-proBNP) in atrial fibrillation (AF).

METHODS

Plasma samples were obtained at randomisation and after 3 months in 2514 patients with AF in the RE-LY trial; median follow-up was 2.0 years. Patients were grouped based on levels at the two time points according to detectable cTnI levels (≥0.01 µg/L) or NT-proBNP levels above median (≥778 ng/L). These groups were related to occurrence of stroke or cardiovascular events evaluated with Cox models adjusting for established risk factors.

RESULTS

The proportion of patients with detectable cTnI levels at both time points was 48.5%, at one time point 28.5% and at neither time point 21.0%. Patients with detectable cTnI at both time points had substantially higher rates of stroke compared with those with transient elevations and those with no elevation at either time point (p<0.005, effect of cTnI). Persistent elevation of either or both cardiac biomarkers at baseline and 3 months was associated with a higher risk for cardiovascular events and mortality (p<0.0001). Prognostic prediction improved most with the use of repeated measurements of both cardiac biomarkers simultaneously (p<0.05) and achieved C-statistic 0.644 for stroke compared with 0.611 for CHADS2-score.

CONCLUSIONS

Persistent elevation of troponin and NT-proBNP indicates a worse prognosis than transient elevations or no elevations of either marker. Prognostication of stroke, death and thromboembolic events is improved by the use of repeated determinations of cardiac biomarkers.

TRIAL REGISTRATION NUMBER

http://www.clinicaltrials.gov, NCT00262600.

Can parathyroid hormone be used as a biomarker for heart failure?

Secondary hyperparathyroidism in heart failure is a consequence of renin-angiotensin-aldosterone activation, chronic hyperaldosteronism, and loop diuretic usage, resulting in calcium excretion. The result is an inflammatory state with adverse effects on myocardial remodeling and systemic complications. Recent literature has suggested that elevated parathyroid hormone predicts adverse outcomes in patients with heart failure independent of serum calcium and phosphate, vitamin D deficiency, and renal insufficiency. Parathyroid hormone has been correlated with elevated brain natriuretic peptide levels, an established biomarker of heart failure severity. There are several limitations to the utilization of parathyroid hormone as a biomarker for heart failure, and further prospective studies need to be conducted to assess the value of multiple parathyroid hormone measurements over time and elucidate the role of parathyroid hormone in diastolic dysfunction. Pending further validation, there is promise for parathyroid hormone as a complementary biomarker in heart failure.

Preload reserve is restored in patients with decompensated chronic heart failure who respond to treatment

The authors designed this prospective study to show the relationship between preload reserve and treatment effectiveness of chronic heart failure (CHF). Fifty patients, aged 77±24 years, with decompensated CHF (B-type brain natriuretic peptide [BNP] >1000 pg/mL) were included. Preload reserve was assessed by the changes in contraction indices during a passive leg raise (PLR). Contraction indices were assessed noninvasively using Bioreactance technology. After 4 days of optimized therapy, the same variables were reassessed and treatment-induced differences were calculated. Treatment effectiveness was assessed by the 4-day changes in BNP, body weight, and thoracic fluid content. The authors then compared treatment-induced changes in preload reserve with treatment effectiveness. Therapy was associated with an overall decrease in heart rate, blood pressure, and cardiac power index (CPi) and with an increase in all preload reserve indices. Treatment effectiveness correlated well with changes in preload reserve. The best correlation was found between treatment-induced changes in BNP and in PLR-induced changes of CPi (R=0.63, P<.001). The PLR-induced changes in CPi increased from 21±48 to 51±48 in BNP responders and decreased from 34±34 to 5±19 mW/m(2) in BNP nonresponders (P<.0001). Hence, effective treatment, as indexed by a decrease in BNP, restores the preload reserve in patients with decompensated CHF.