Cardiac Troponin T vs Other Biochemical Markers in Patients With Congestive Heart Failure

Action and therapeutic targets of myosin light chain kinase, an important cardiovascular signaling mechanism

The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is complex and not fully understood, and the physiological function of the heart is inextricably linked to well-regulated cardiac muscle movement. Myosin light chain kinase (MLCK) is essential for myocardial contraction and diastole, cardiac electrophysiological homeostasis, vasoconstriction of vascular nerves and blood pressure regulation. In this sense, MLCK appears to be an attractive therapeutic target for cardiac diseases. MLCK participates in myocardial cell movement and migration through diverse pathways, including regulation of calcium homeostasis, activation of myosin light chain phosphorylation, and stimulation of vascular smooth muscle cell contraction or relaxation. Recently, phosphorylation of myosin light chains has been shown to be closely associated with the activation of myocardial exercise signaling, and MLCK mediates systolic and diastolic functions of the heart through the interaction of myosin thick filaments and actin thin filaments. It works by upholding the integrity of the cytoskeleton, modifying the conformation of the myosin head, and modulating innervation. MLCK governs vasoconstriction and diastolic function and is associated with the activation of adrenergic and sympathetic nervous systems, extracellular transport, endothelial permeability, and the regulation of nitric oxide and angiotensin II. Additionally, MLCK plays a crucial role in the process of cardiac aging. Multiple natural products/phytochemicals and chemical compounds, such as quercetin, cyclosporin, and ML-7 hydrochloride, have been shown to regulate cardiomyocyte MLCK. The MLCK-modifying capacity of these compounds should be considered in designing novel therapeutic agents. This review summarizes the mechanism of action of MLCK in the cardiovascular system and the therapeutic potential of reported chemical compounds in cardiac diseases by modifying MLCK processes.

Natriuretic Peptides as Biomarkers for Congestive States: The Cardiorenal Divergence

Congestion represents the primary reason for hospitalization of patients with heart failure and is associated with adverse outcomes. Fluid overload has been shown to be inadequately addressed in a significant subset of these patients in part due to lack of robust, reliable, and readily available biomarkers for objective assessment and monitoring of therapy. Natriuretic peptides have long been used in this setting, often in conjunction with other assessment tools such as imaging studies. Patients presenting with concomitant cardiac and renal dysfunction represent a unique population with regard to congestion in that the interactions between the heart and the kidney can affect the utility and performance of biomarkers of fluid overload. Herein, we provide an overview of the currently available evidence on the utility of natriuretic peptides in these patients and discuss the clinical conundrum associated with their use in the setting of renal dysfunction. We highlight the potential divergence in the role of natriuretic peptides for assessment of volume status in a subset of patients with renal dysfunction who receive renal replacement therapy and call for future research to elucidate the utility of the biomarkers in this setting.

Preoperative cardiac troponin level is associated with all-cause mortality of liver transplantation recipients

This study was aimed to evaluate the association between preoperative high-sensitivity cardiac troponin I (hs-cTnI) level and mortality in patients undergoing liver transplantation (LT). From January 2011 to May 2016, preoperative hs-cTnI level was measured in consecutive 487 patients scheduled for LT. Patients with elevated preoperative hs-cTnI were compared with those who had normal level. The primary outcome was all-cause death in follow-up period of 30 days to 1 year after operation. Of the 487 patients, 58 (11.9%) had elevated preoperative hs-cTnI and 429 (88.1%) had normal preoperative hs-cTnI. In multivariate analysis, the rate of 1-year mortality and 30-day mortality were higher in elevated preoperative hs-cTnI group (hazard ratio [HR], 3.69; confidence interval [CI] 95%, 1.83–7.42; p < 0.001, HR, 6.61; CI, 1.91–22.82; p = 0.003, respectively). After adjustment with inverse probability weighting (IPW), the incidence of 1-year mortality and 30-day mortality were higher in elevated group (HR, 4.66; CI, 3.56–6.1; p < 0.001, HR, 10.31; CI, 6.39–16.66; p < 0.001, respectively). In conclusion, this study showed that in patients who underwent LT, elevation of preoperative hs-cTnI level was associated with 1-year mortality and 30-day mortality.

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.

Copeptin in Heart Failure

Heart failure (HF) is one of the most common causes of hospitalization and mortality in the modern Western world and an increasing proportion of the population will be affected by HF in the future. Although HF management has improved quality of life and prognosis, mortality remains very high despite therapeutic options. Medical management consists of a neurohormonal blockade of an overly activated neurohormonal axis. No single marker has been able to predict or monitor HF with respect to disease progression, hospitalization, or mortality. New methods for diagnosis, monitoring therapy, and prognosis are warranted. Copeptin, a precursor of pre-provasopressin, is a new biomarker in HF with promising potential. Copeptin has been found to be elevated in both acute and chronic HF and is associated with prognosis. Copeptin, in combination with other biomarkers, could be a useful marker in the monitoring of disease severity and as a predictor of prognosis and survival in HF.

Chasing myocardial outcomes: perioperative myocardial infarction and cardiac troponin

Perioperative myocardial infarction represents the most common cardiovascular complication following non-cardiac surgery, but frequently presents without the usual clinical signs and symptoms consistent with acute coronary syndrome. Given the silent nature of this event, a clinician's reliance on risk stratification tools and cardiac specific biomarkers to assist in the identification of at-risk individuals is heightened in the perioperative setting. Although cardiac troponin elevations following non-cardiac surgery have been consistently linked to increased mortality, uncertainty remains over how to clinically intervene to prevent harm. This decision is further complicated by the increasing sensitivity of the newest generation of cardiac biomarker immunoassays. In this narrative review, the growing body of evidence surrounding cardiac troponin elevations in the perioperative setting, how the evidence has been integrated into recent clinical practice guidelines, and its implications for the detection of perioperative myocardial infarction are discussed.

Cardiac biomarkers in heart failure

BACKGROUND

Heart failure is a syndrome characterized by the inability of the heart to meet the body's circulatory demands. Heart failure is a growing health issue worldwide and the prevalence of heart failure is expected to rise as populations age. Therapies and interventions for a variety of cardiac conditions continue to advance and biomarkers will play an increasing role in patient management.

METHODS

This is a review of the clinical research in blood based biomarkers for diagnosis, prognosis and therapeutic guidance of heart failure. The focus of this review is biomarkers that are currently available for clinical measurement, and their current and potential for applications for managing heart failure patients.

RESULTS

The various biologic pathways and physiologic processes of heart failure biomarkers represent a host of different including inflammation, remodeling, strain, neurohormonal activation, metabolism and cardiac myocyte injury. The clinical characteristics and applications of each heart failure biomarker are discussed.

CONCLUSION

As populations age and effective treatments and interventions for coronary artery disease improve, heart failure will increase in incidence and prevalence. Blood biomarkers will play an increasing role in the early diagnosis, therapeutic monitoring and management of heart failure patients in the future.

Do optimal prognostic thresholds in continuous physiological variables really exist? Analysis of origin of apparent thresholds, with systematic review for peak oxygen consumption, ejection fraction and BNP

Background

Clinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies.

Objectives

We studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO₂), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF).

Data Sources and Eligibility Criteria

Studies testing pVO₂, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed.

Methods

First, we examined studies testing pVO₂, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk.

Results

33 studies (8946 patients) tested a pVO₂ threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10–18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO₂ (r = 0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p = 0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r = 0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r = 0.86 (p<0.0001).

Second, survival simulations always discovered a “most significant” threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r = 0.99, p<0.001).

Limitations

This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds.

Key Findings

First, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO₂, EF or BNP. Second, apparently-optimal thresholds always appear, even with no step in prognosis.

Conclusions

Emphatic therapeutic guidance based on thresholds from observational studies may be ill-founded. We should not assume that optimal thresholds, or any thresholds, exist.

Clinical utility of biomarkers in chronic kidney disease and chronic heart failure

Biomarkers have an increasingly important clinical role in managing patients with heart failure as well as those with kidney disease, both common conditions with generally poor prognostic outcomes and huge impacts on healthcare economics. For patients with chronic heart failure, biomarkers have become centre place in streamlining diagnostic pathways as well as identifying those with worse prognosis. There is much interest in the role for biomarkers in identifying patients at risk of acute kidney injury, although a number of these currently remain as research tools or are in the early stages of evaluation in clinical practice. Patients with cardiorenal syndrome represent a particular challenge to the clinician, and recent studies have suggested a valuable clinical role for certain biomarkers in this setting, either on their own or in combination. This paper will focus on biomarkers with a current clinical role in patients with cardiorenal disease (natriuretic peptides and neutrophil gelatinase-associated lipocalin), although brief reference will be made to other biomarkers with potential future application.

Cardiorenal biomarkers in acute heart failure

Managing patients with heart failure (HF) is a challenging task within itself, but the presence of associated worsening renal function can greatly increase mortality and morbidity. Early diagnosis and treatment is the key to prevent re-hospitalizations and reduce healthcare costs. Biomarkers have long been established as highly sensitive and specific tools in diagnosing and prognosticating patients with HF. Reflecting distinct pathophysiological events and ongoing cellular insult, biomarkers have been proven superior to conventional laboratory tests. Availability of better assays and rapid analysis has allowed the use of biomarkers as point-of-care tests in the emergency department and at the patient's bed-side. Acute HF patients often go on to develop worsening renal function, termed as acute cardiorenal syndrome. The growing breadth of studies has shown the implications of combining multiple biomarkers to better chart outcomes and produce desirable results in such patients.

Cardiac troponin and heart failure in the era of high-sensitivity assays

The Joint European Society of Cardiology-American College of Cardiology Foundation-American Heart Association-World Heart Federation Task Force for the Redefinition of Myocardial Infarction recommends cardiac troponin (cTn)-T as a first-line biomarker, and suggests the use of the 99th percentile of a reference population with acceptable precision (i.e. a coefficient of variance≤10%) as a cut-off for the diagnosis of acute myocardial infarction. Recently developed troponin assays fulfill this analytical precision. While conventional cTnT assays have often been used as a positive or negative categorical variable, stepwise rises in high sensitivity (Hs)-cTnT in patients presenting with chronic heart failure (HF) have been associated with a progressive increase in the incidence of cardiovascular events. Similar observations have been made in the general population. Hs-cTnT at baseline and during follow-up is a powerful predictor of cardiac events in patients with HF and in the general population. Whether it is the ideal biomarker remains to be confirmed, however. We review the potential contributions of TnT assays in the assessment of risk of HF, in HF, and in myocardial diseases that cause HF.

Recurrent low-level troponin I elevation is a worse prognostic indicator than occasional injury pattern in patients hospitalized with heart failure

BACKGROUND

Elevated troponin at baseline is associated with higher mortality in heart failure (HF) patients, but the prognostic role of recurrently elevated troponin is not well described.

METHODS AND RESULTS

We performed chart reviews of 196 HF patients without acute coronary syndrome, with at least three Troponin I (TnI) measurements on different admissions. For the analyses, three sets of TnI values closest to baseline, one year and two years were selected for each patient. Based on the three sets of TnI, the lowest value of TnI (minimum), the highest value of TnI (maximum), median value of TnI and delta TnI (3rd TnI-baseline TnI) were derived for each patient. The study population of 196 patients had 632 person-year follow-up, consisted predominantly of elderly (68 ± 10 years) male patients (99%) with mean ejection fraction of 26 ± 13%. Using multivariate Cox proportional hazards model only minimum TnI, but not the maximum, median or delta of TnI values, was significantly associated with mortality (HR: 13.7, 95% CI: 3.7 to 50.8, p<0.001). As a categorical variable, minimum TnI value of >0.04ng/ml was also independently associated with mortality (p=0.01, HR=1.6, 95% CI: 1.1 to 2.3).

CONCLUSIONS

In HF patients without acute coronary syndrome, the persistence of TnI elevation, even at low levels, is associated with a worse survival than sporadic TnI elevations of higher magnitude or any single elevation in TnI; and a recurrent elevation of TnI >0.04ng/ml portends a poor prognosis.

Prospective evaluation of the association between cardiac troponin T and markers of disturbed erythropoiesis in patients with heart failure

BACKGROUND

Elevated cardiac troponin T is a well-documented marker of cardiomyocyte damage and poor prognosis in patients with heart failure. We prospectively evaluated the relationship between this marker and hematopoietic disturbances in heart failure.

METHODS

Data were analyzed from 254 patients in the UNITE-HF Biomarker Registry, a prospective, observational, multicenter study of the clinical and biomarker correlates of anemia in heart failure. Logistic regression modeling assessed relationships between detectable troponin T and indices of hematologic function including anemia and red cell distribution width.

RESULTS

Anemia (hemoglobin≤12 g/dL) was present in 65 of the 254 study patients, and detectable troponin T was found in 39. Anemia was a significant independent predictor of detectable troponin T in models that considered a number of clinical characteristics including renal function, functional class, heart rate, and systolic blood pressure (odds ratio 2.57, 95% CI 1.09-6.09, P=.032). Likewise, detectable troponin T was directly and independently related to red cell distribution width in similar multivariable analyses (odds ratio 1.36 per unit increase, 95% CI 1.08-1.71, P=.008).

CONCLUSIONS

Anemia and increasing red cell distribution width were independently associated with elevated troponin T, a marker of cardiomyocyte injury or death in patients with heart failure.

Prognostic utility of cardiac troponin in heart failure: a novel role for an established biomarker

Many individual variables are predictive of an increased risk of mortality and morbidity in heart failure. These include a range of data from patient demographics, clinical findings, comorbidities and invasive and noninvasive parameters. Some of these markers, for example the B-type natriuretic peptides, have been identified as independently predictive in large, robust, multivariable analyses. However, many markers have had less vigorous scrutiny and were identified in small cohorts after only univariate or limited multivariable analyses. Recently, cardiac troponins have emerged as potential biomarkers for patients with heart failure. In this article, we consider the utility of cardiac troponins in heart failure and propose what role they may play in improving the risk stratification of this disease.

Elevated troponin T on discharge predicts poor outcome of decompensated heart failure

Persistent elevation of cardiac troponin T (cTnT) predicts an adverse clinical outcome in patients with chronic heart failure (HF), but the underlying mechanisms remain to be determined. We investigated the association between predischarge cTnT elevation and coexistent pathophysiology in patients with decompensated HF. Plasma cTnT levels were determined before discharge in 170 patients with decompensated HF. We divided the patients into a group that was positive for cTnT [cTnT(+) group, n = 40] and a group that was negative for cTnT [cTnT(-) group, n = 130]. Multivariate analysis showed that use of beta-blocker therapy (odds ratio [OR] = 0.236, P = 0.003), an elevated high-sensitivity C-reactive protein (hsCRP) level (OR = 3.731, P = 0.006), a high brain natriuretic peptide (BNP) level (OR = 3.570, P = 0.007), diabetes (OR = 3.090, P = 0.018), and anemia (OR = 2.330, P = 0.047) were independently associated with cTnT positivity. During a mean follow-up period of 441 days after discharge, total mortality (P < 0.001), cardiac death (P < 0.001), and exacerbation of HF requiring hospitalization (P = 0.007) were all more common in the cTnT(+) group than in the cTnT(-) group. Cox proportional hazards analysis showed that cTnT positivity was an independent predictor of total mortality (hazard ratio = 5.008, P = 0.004) in an age- and gender-matched model. Elevation of cTnT during convalescence was associated with lack of beta-blocker therapy, a high hsCRP level at discharge, a high BNP level at discharge, diabetes, and anemia, and a worse clinical outcome in patients with decompensated HF.

Spectroscopic diagnosis of myocardial infarction and heart failure by Fourier transform infrared spectroscopy in serum samples

Cardiovascular disease is the leading cause of death in Western civilization. In this pilot study we evaluated a new method for the diagnosis of myocardial infarction and heart failure by determining the typical fingerprint in the infrared (IR) spectrum of 1 microL of a dried patient serum sample by Fourier transform IR spectroscopy. For classification, cluster analysis and artificial neural networks (ANN) were applied. In this study 567 subjects were enrolled, comprising 225 controls (Co) and 342 patients with myocardial infarction (MI) (n = 157) and heart failure (HF) (n = 185). By applying artificial neural network algorithms, the following sensitivities and specificities of the same spectra were determined: MI versus Co (98%, 97%), HF versus Co (98%, 100%), MI versus HF (100%, 100%), and MI plus HF versus Co (100%, 100%). Based on our data, mid-IR spectroscopy appears to be a promising new method to diagnose heart diseases from serum samples. Artificial neural network algorithms proved to be superior to cluster analysis for correct prediction.

Biomarkers of extracellular matrix turnover

The extracellular cardiac matrix (ECCM) plays an important role in the support of myocytes and fibroblasts. ECCM turnover is influenced by ischemia, stretch, inflammation, and neurohormonal mediators. Myocardial fibrosis is the consequence of several pathologic processes mediated by mechanical, neurohormonal, and cytokine factors. It is a major determinant of diastolic dysfunction and pumping capacity and may result in tissue heterogeneity, dys-synchrony, and arrhythmias. The measurement of various serum peptides arising from the metabolism of collagen types 1 and 3, of degradation fragments, and of specific metalloproteinases may provide noninvasive assessment of fibrosis. ECCM biomarkers are clinically useful tools, particularly given the potential for cardioprotective and cardioreparative pharmacologic strategies.

In patients with heart failure and non-ischemic heart disease, cardiac troponin T is a reliable predictor of long-term echocardiographic changes and adverse cardiac events

BACKGROUND

The relationships between (1) serum concentration of cardiac troponin T (cTnT) and clinical hemodynamic profiles, (2) cTnT versus B-type natriuretic peptide (BNP) and long-term echocardiographic changes, and (3) cTnT versus BNP and echocardiographic changes, and rates of adverse cardiac events, have not been well elucidated.

METHODS

Retrospective analysis of 100 consecutive patients with heart failure, left ventricular ejection fraction < 50%, and non-ischemic heart disease was performed.

RESULTS

Baseline cTnT was > or = 0.01 ng/ml in 30 patients. By multiple variable logistic regression analysis, diabetes mellitus [DM; odds ratio (OR) 7.5; p=0.014], serum creatinine (OR 25.9; p=0.0157), and pulmonary capillary wedge pressure (PCWP; OR 1.12; p=0.0214) were independent predictors of baseline elevation of cTnT. At a follow-up of 40.6+/-20.6 months, echocardiograms and cTnT and BNP measurements were available in 93 patients, of whom 23 experienced an adverse cardiac event. By multiple variable analyses, elevated cTnT at follow-up was negatively correlated with echocardiographic improvements in cardiac function (OR 0.10; p=0.019), and was a significant predictor of adverse cardiac events after adjustment for covariables, including follow-up BNP and echocardiographic changes (hazard ratio 5.6; p=0.0046).

CONCLUSIONS

DM, serum creatinine, and PCWP were correlated with elevated baseline serum cTnT concentrations. cTnT concentration during follow-up might be a surrogate marker of heart failure.

GSK-3beta, a therapeutic target for cardiomyocyte protection

Glycogen synthase kinase-3beta (GSK-3beta) is a multifunctional Ser/Thr kinase that plays important roles in necrosis and apoptosis of cardiomyocytes. A major mechanism of cell necrosis is the opening of the mitochondrial permeability transition pore (mPTP), which consists of multiple protein subunits, including adenine nucleotide translocase (ANT). The threshold for mPTP opening is elevated by phosphorylation of GSK-3beta at Ser9, which reduces activity of this kinase. How inactivation of GSK-3beta suppresses mPTP opening has not been fully understood, but evidence to date suggests that preservation of hexokinase-II in the mPTP complex, inhibition of cyclophilin-D-ANT binding, inhibition of p53 and inhibition of ANT into the mitochondria are contributory. GSK-3beta phosphorylation is a step to which multiple protective signaling pathways converge, and thus GSK-3beta phosphorylation is crucial in cardioprotection of a variety of interventions against ischemia/reperfusion injury. Apoptosis of cardiomyocytes by pressure overload or ischemia/reperfusion is also suppressed by inactivation of GSK-3beta, in which reduced phosphorylation of p53, heat shock factor-1 and myeloid cell leukemia sequence-1 and inhibition of Bax translocation might be involved. Considering predominant roles of GSK-3beta in cardiomyocyte death, manipulation of this protein kinase is a promising strategy for myocardial protection in coronary artery disease and heart failure.

C-reactive protein and fibrinogen of bedridden older patients in a six-month vitamin D supplementation trial

OBJECTIVE

To elucidate the association between vitamin D status, C-reactive protein (CRP) and fibrinogen.

DESIGN

Secondary analysis of a randomised double-blind placebo controlled trial.

SETTING

Four longterm care hospitals (1215 beds) in Helsinki, Finland.

PARTICIPANTS

218 long-term inpatients aged over 65 years.

INTERVENTION

Eligible patients (n = 218) were randomized to receive 0 IU/d, 400 IU/d, or 1200 IU/d cholecalciferol for six months.

METHODS

Plasma 25-hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), high sensitive CRP, fibrinogen, amino-terminal propeptide of type I procollagen (PINP), and carboxy-terminal telopeptide of type I collagen (ICTP) were measured.

RESULTS

The patients were aged (84.5 +/- 7.5 years), vitamin D deficient (25-OHD = 23 +/- 10 nmol/l), chronically bedridden and in stable general condition. The mean baseline CRP and fibrinogen were 10.86 mg/l (0.12 mg/l - 125.00 mg/l) and 4,7 g/l (2.3 g/l - 8.6 g/l), respectively. CRP correlated with ICTP (r = 0.217, p = 0.001), but not with vitamin D status. Supplementation significantly increased 25-OHD concentrations, but the changes in CRP and fibrinogen were insignificant and inconsistent. The post-trial CRP concentrations (0.23 mg/l -138.00 mg/l) correlated with ICTP (r = 0.156, p < 0.001), but no association was found with vitamin D status. The baseline and post-trial fibrinogen correlated with CRP, only.

CONCLUSIONS

CRP concentrations are associated with bone turnover, but not with vitamin D status, and vitamin D supplementation has no major effect on CRP or fibrinogen concentrations in bedridden older patients.

Short-term amiodarone treatment attenuates the production of monocyte cytokines and chemokines by C-reactive protein and improves cardiac function in patients with idiopathic dilated cardiomyopathy and ventricular tachycardia

BACKGROUND

Increased expression of cytokines and chemokines has been observed in chronic heart failure (CHF). Amiodarone reduces circulating cytokine levels, so it may attenuate the production of monocyte cytokines and chemokines by C-reactive protein (CRP) and thus improve the left ventricular ejection fraction (LVEF) in dilated cardiomyopathy (DCM) patients with ventricular tachycardia (VT).

METHODS AND RESULTS

Peripheral blood mononuclear cells (PBMCs) were stimulated by 25 microg/ml CRP in 23 patients with DCM, who were divided into 2 groups based on whether or not amiodarone was included in their treatment (Amiodarone group n=8; No amiodarone group n=15). Tumor necrosis factor (TNF)-alpha and monocyte chemoattractant protein (MCP)-1 on monocytes at baseline and after 4 weeks of treatment was measured by ELISA and expressed as mean+/-SD (pg.ml(-1)x10(-6) PBMCs). The LVEF and the CRP-induced monocyte cytokine and chemokine production were unchanged in the No amiodarone group after 4 weeks; however, LVEF in the Amiodarone group was increased (32.7+/-6.9 to 39.2+/-6.9%; P=0.005), and TNF-alpha and MCP-1 production in the Amiodarone group were decreased (P=0.012, respectively).

CONCLUSIONS

Amiodarone attenuates the production of monocyte cytokines and chemokines by CRP, and improves LVEF in CHF patients with VT.

Phosphorylation of myosin regulatory light chain by myosin light chain kinase, and muscle contraction

Not only muscle contraction, but also most cell movements depend on myosin - actin interaction using ATP. Many components of the contraction machinery are involved in the efficient coupling of energy source and force development. Among these, I have focused on myosin light chain kinase (MLCK) in this review. MLCK phosphorylates myosin regulatory light chain and controls all 3 types of muscle contraction: skeletal muscle, smooth muscle, and cardiac muscle. However, each muscle has specific MLCK and the role of MLCK in each muscle is different. This difference explains the specific role of each muscle in vivo and contributes to the activity of various force development in different ways in each tissue. Therefore, I also review the differences in the connection between each MLCK and muscle contraction in the 3 muscle types.

The clinical and hemodynamic factors that influence the concentrations of biomarkers of myocyte injury measured by high sensitive assay PATHFAST

BACKGROUND

Subclinical myocyte injury plays an important role in the progression of congestive heart failure. However, the clinical and hemodynamic factors that influence the concentrations of biomarkers of myocyte injury have not been clarified.

METHODS

Blood was sampled during diagnostic cardiac catheterization from 108 consecutive patients without acute coronary syndrome and acute cardiac decompensation. The serum concentrations of B-type natriuretic peptide (BNP), cardiac troponin I (cTnI), creatine kinase (CK)-MB, and myoglobin were measured simultaneously by high sensitive PATHFAST assay. Single and multiple variable regression analyses were carried out in search of correlations between clinical and hemodynamic variables and concentrations of biomarkers.

RESULTS

By multiple variable analysis, hemoglobin concentration, pulmonary capillary wedge pressure (PCWP), left ventricular (LV) ejection fraction, and estimated glomerular filtration rate (GFR) were independently correlated with a BNP concentration ≥ median 72.1 pg/ml. The only factors independently correlated with a concentration of cTnI ≥ median 0.01 ng/ml were PCWP and estimated GFR. Cardiac index emerged as a single, powerful, independent correlate of CK-MB concentration ≥ median 0.66 ng/ml, and estimated GFR emerged as a single independent correlate of myoglobin concentration ≥ median 40.1 ng/ml.

CONCLUSIONS

Clinical and hemodynamic factors influence the concentrations of BNP, cTnI, CK-MB, and myoglobin. These factors should be considered when interpreting the concentrations of these biochemical markers.

Decreased renal function as an independent predictor of re-hospitalization for congestive heart failure

BACKGROUND

Patients with congestive heart failure (CHF) are often re-hospitalized, worsening both their quality of life and prognosis. Although renal dysfunction reportedly increases the risk of CHF, the association between renal dysfunction and re-hospitalization for CHF remains unclear.

METHODS AND RESULTS

Patients with CHF and decreased renal function were reviewed. The estimated glomerular filtration rate (GFR) was calculated with the Modification of Diet in Renal Disease equation. Patients with decreased renal function (estimated GFR on admission <45 ml .min(-1) . 1.73 m(-2)) were re-hospitalized more frequently than were patients with preserved renal function (estimated GFR on admission >or=45). Patients with decreased renal function were older and had higher rates of anemia, worsening renal function during hospitalization, and previous hospitalization for CHF. Independent predictors of re-hospitalization for CHF identified with multivariate analysis were age, previous hospitalization for CHF, decreased renal function, and non-use of an angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker.

CONCLUSIONS

Renal dysfunction is an independent predictor of re-hospitalization for CHF, so careful follow-up is needed, even after discharge.

Bench-to-bedside review: the value of cardiac biomarkers in the intensive care patient

The use of cardiac biomarkers in the intensive care setting is gaining increasing popularity. There are several reasons for this increase: there is now the facility for point-of-care biomarker measurement providing a rapid diagnosis; biomarkers can be used as prognostic tools; biomarkers can be used to guide therapy; and, compared with other methods such as echocardiography, the assays are easier and much more affordable. Two important characteristics of the ideal biomarker are disease specificity and a linear relationship between the serum concentration and disease severity. These characteristics are not present, however, in the majority of biomarkers for cardiac dysfunction currently available. Those clinically useful cardiac biomarkers, which naturally received the most attention, such as troponins and B-type natriuretic peptide, are not as specific as was originally thought. In the intensive care setting, it is important for the user to understand the degree of specificity of these biomarkers and that the interpretation of the results should always be guided by other clinical information. The present review summarizes the available biomarkers for different cardiac conditions. Potential biomarkers under evaluation are also briefly discussed.

Persistently Increased Serum Concentrations of Cardiac Troponin in Patients With Acutely Decompensated Heart Failure are Predictive of Adverse Outcomes

BACKGROUND

Persistently increased serum concentrations of cardiac troponin (cTn) are a prognostic marker in patients suffering from chronic congestive heart failure (CHF), but the significance in acute cardiac decompensation is unclear.

METHODS AND RESULTS

Serial blood samples were collected from 52 patients presenting with acute cardiac decompensation in the absence of an acute coronary event. Serial serum concentrations of cTnI, creatine kinase (CK)-MB, and brain natriuretic peptide (BNP) were measured by rapid assay. BNP and CK-MB steadily decreased from 902+/-529 pg/ml and 2.3+/-1.6 ng/ml at baseline to 453+/-427 pg/ml and 1.2+/-1.6 ng/ml on day 7, respectively, (p<0.0001 for both comparisons). In contrast, cTnI did not decrease significantly and, in 17 patients (35%), increased from 0.063+/-0.047 ng/ml at baseline to 0.167+/-0.181 ng/ml on day 1 (p<0.05). By single variable regression analysis, systolic blood pressure (SBP), use of inotropes or inodilators, vasodilators, and an initially elevated cTnI were predictors of elevated cTnI on day 1. By multiple variable analysis, an elevated SBP (as a mitigating factor) (odds ratios (OR) 0.12; 95% confidence intervals (CI): 0.02-0.76; p=0.0248), and high baseline cTnI (OR 13.85; 95%CI: 1.97-97.54; p=0.0083) were significant predictors of an elevated cTnI on day 1. Patients with elevated cTnI on day 1 had higher rates of worsening CHF and death from CHF than patients without such an increase (p<0.05).

CONCLUSIONS

Persistently increased serum concentrations of cTn in patients with acutely decompensated heart failure are predictive of adverse outcomes.