Cystatin C and NT-proBNP, a powerful combination of biomarkers for predicting cardiovascular mortality in elderly patients with heart failure: results from a 10-year study in primary care

New aspects in cardiorenal syndrome and HFpEF

Cardiorenal syndrome (CRS) is a complex disease in which the heart and kidneys are simultaneously affected, and subsequently, the malfunction of one organ promotes the deterioration of the other. Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. The pathophysiology of CRS is not well known and several mechanisms have been proposed. An elevation of central venous pressure seems to be one of the key points to consider, among others such as an increase in intraabdominal pressure. Several diagnostic tools have been identified to establish the diagnosis of CRS in patients with HFpEF. Currently, the availability of biomarkers of renal and cardiac injury, the use of pulmonary ultrasound, the monitoring of the size of the inferior vena cava and the study of the renal venous pattern offer a new dimension in accurately diagnosing and quantifying organ damage in CRS. Beyond the symptomatic treatment of congestion, until recently specific therapeutic tools for patients with CRS and HFpEF were not available. Interestingly, the development of new drugs such as the angiotensin/neprilysin inhibitors and sodium-glucose cotransporter-2 (SGLT-2) inhibitors offer new therapeutic strategies with potential benefits in reduction of cardiorenal adverse outcomes in this population. Randomized clinical trials that focus on patients with HFpEF are currently ongoing to delineate optimal new treatments that may be able to modify their prognosis. In addition, multidisciplinary teamwork (nephrologist, cardiologist and nurse) is expected to decrease the number of visits and the rate of hospitalizations, with a subsequent patient benefit.

Early Detection of Renal Impairment Among Patients with Type 2 Diabetes Mellitus Through Evaluation of Serum Cystatin C in Comparison with Serum Creatinine Levels: A Cross-Sectional Study

BACKGROUND

The proportion of patients with end-stage renal disease caused by diabetes has progressively increased during the last few decades. Serum creatinine level is the most commonly used biochemical parameter to estimate GFR in routine practice. However, 50% of GFR can be lost before significant elevation of serum creatinine. Cystatin C is found to be a new promising marker for early detection of renal diseases.

OBJECTIVE OF THE STUDY

The aim of this study was to determine the value of serum cystatin C and serum creatinine levels for early detection of renal disease in patients with type 2 diabetes mellitus.

METHODOLOGY

A hospital-based comparative cross-sectional study was conducted with a sample size of 120. For early detection of renal disease in patients with type 2 diabetes mellitus, serum creatinine and cystatin C levels were measured and compared.

RESULT AND DISCUSSION

Serum creatinine and cystatin C levels were significantly increased in patients with type 2 diabetes mellitus compared to healthy controls. The mean±SD value of serum creatinine was found to be 0.87±0.44 mg/dL in patients and 0.63±0.27 mg/dL in control. Serum cystatin C level was also found to be significantly (P=0.0001) higher in patients (0.92±0.38 mg/L) compared to controls (0.52±0.20 mg/L). The mean±SD of eGFR in three equations (Creatinine Equation, Cystatin C Equation, and Creatinine-Cystatin C Equation) were 105.7±27.5 mL/min/m², 90.4±28.2 mL/min/m², and 100±29.5 mL/min/m², respectively.

CONCLUSION

Cystatin C-based GFR estimation equations detect renal impairment in patients with type 2 diabetes mellitus earlier than creatinine-based GFR estimation equations.

Association Between Increased Levels of Cystatin C and the Development of Cardiovascular Events or Mortality: A Systematic Review and Meta-Analysis

BACKGROUND

Cystatin C seems promising for evaluating the risk of cardiovascular events and mortality.

OBJECTIVE

To evaluate the association between high levels of cystatin C and the development of cardiovascular events or mortality.

METHODS

The articles were selected in the Medline/PubMed, Web of Science, and Scielo databases. The eligibility criteria were prospective cohort observational trials that assessed the association of high serum levels of cystatin C with the development of cardiovascular events or mortality in individuals with normal renal function. Only studies that evaluated the mortality outcome compared the fourth with the first quartile of cystatin C and performed multivariate Cox's proportional hazard regression analysis were included in the meta-analysis. A p value < 0,05 was considered significant.

RESULTS

Among the 647 articles found, 12 were included in the systematic review and two in the meta-analysis. The risk of development of adverse outcomes was assessed by eight studies using the hazard ratio. Among them, six studies found an increased risk of cardiovascular events or mortality. The multivariate regression analysis was performed by six studies, and the risk of developing adverse outcomes remained significant after the analysis in four of these studies. The result of the meta-analysis [HR = 2.28 (1.70-3.05), p < 0.001] indicated that there is a significant association between high levels of cystatin C and the risk of mortality in individuals with normal renal function.

CONCLUSION

There is a significant association between high levels of cystatin C and the development of cardiovascular events or mortality in individuals with normal renal function.

Incremental value of cystatin C over conventional renal metrics for predicting clinical response and outcomes in cardiac resynchronization therapy: The BIOCRT study

BACKGROUND

Despite the benefit of CRT in select patients with heart failure (HF), there remains significant need for predicting those at risk for adverse outcomes for this effective but costly therapy. CysC, an emerging marker of renal function, is predictive of worsening symptoms and mortality in patients with HF. This study assessed the utility of baseline and serial measures of cystatin C (CysC), compared to conventional creatinine-based measures of renal function (estimated glomerular filtration rate, eGFR), in predicting clinical outcomes following cardiac resynchronization therapy (CRT).

METHODS

In 133 patients, we measured peripheral venous (PV) and coronary sinus (CS) CysC concentrations and peripheral creatinine levels at the time of CRT implant. Study endpoints included clinical response to CRT at 6 months and major adverse cardiac events (MACE) at 2 years.

RESULTS

While all 3 renal metrics were predictive of MACE (all adjusted p ≤ 0.02), only CysC was associated with CRT non-response at 6 months (adjusted odds ratio 3.6, p = 0.02). CysC improved prediction of CRT non-response (p ≤ 0.003) in net reclassification index analysis compared to models utilizing standard renal metrics. Serial CysC > 1mg/L was associated with 6-month CRT non-response and reduced 6-minute walk distance as well as 2-year MACE (all p ≤ 0.04).

CONCLUSION

In patients undergoing CRT, CysC demonstrated incremental benefit in the prediction of CRT non-response when compared to standard metrics of renal function. Baseline and serial measures of elevated CysC were predictive of CRT non-response and functional status at 6 months as well as long-term clinical outcomes.

Effect of atorvastatin on serum oxidative stress and N-terminal brain natriuretic peptide expression in rats

OBJECTIVE

To investigate the effect of atorvastatin on serum oxidative stress and N-terminal brain natriuretic peptide expression in rats.

METHODS

A total of 40 healthy male SD rats were randomly divided into the sham group (Group A, n=10, saline 5 mL/d), ischemia-reperfusion group (Group B, n=10, saline 5 mL/d), atorvastatin group (Group C, n=10, atorvastatin 20 mg/kg · d), atorvastatin + N-amino-arginine group (Group D, n=10, atorvastatin 20 mg/kg · d + N-amino arginine 15 mg/kg). Myocardial ischemia-reperfusion rat model was established after 3 days of gavage. N-amino arginine 15 mg/kg was given by tail vein injection 15 min before ischemia. After reperfusion, enzymology indicators such us creatine kinase (CK) and lactate dehydrogenase and the oxidative stress parameters such as nitric oxide (NO), malondialdehyde (MDA) and total superoxide dismutase (TSOD), and n-terminal pro-brain natriuretic peptide (NT-proBNP) expression was detected by immunohistochemistry.

RESULTS

LDH and CK levels of group A were significantly lower than the other three groups, and group B was the highest. There was significant difference between group B and group C (P<0.05), and no significant difference between group B and group D (P>0.05). MDA levels in group B were significantly higher than the other three groups. The lowest was group A, followed by group C, the difference among groups was significantly (P<0.05). TSOD and NO levels in group B was the lowest, the level in group A was the highest, followed by group C, the difference among groups was significant (P<0.05). NT-proBNP level in group B was significantly higher than the other three groups, the lowest was group A, followed by group C, the difference among groups was significant (P<0.05).

CONCLUSIONS

Atorvastatin has a protective effect on the myocardial injury in the myocardial ischemia and reperfusion rats. It can increase NO synthesis and decrease MDA content, increase serum TSOD activity and the oxidative stress effect, meanwhile protect myocardial cells and reduce myocardial injury.

Evaluation of chronic kidney disease in chronic heart failure: From biomarkers to arterial renal resistances

Chronic kidney disease and its worsening are recurring conditions in chronic heart failure (CHF) which are independently associated with poor patient outcome. The heart and kidney share many pathophysiological mechanisms which can determine dysfunction in each organ. Cardiorenal syndrome is the condition in which these two organs negatively affect each other, therefore an accurate evaluation of renal function in the clinical setting of CHF is essential. This review aims to revise the parameters currently used to evaluate renal dysfunction in CHF with particular reference to the usefulness and the limitations of biomarkers in evaluating glomerular dysfunction and tubular damage. Moreover, it is reported the possible utility of renal arterial resistance index (a parameter associated with abnormalities in renal vascular bed) for a better assesment of kidney disfunction.

[Usefulness of cystatin C as a prognostic marker in venous thromboembolism]

BACKGROUND AND OBJECTIVE

Cystatin C (cysC) is a prognostic marker in patients with hypertension, coronary heart disease and heart failure. The aim of this study was to determine the prognostic value of cysC levels obtained at the time of diagnosis in patients with venous thromboembolism (VTE).

MATERIAL AND METHOD

Retrospective study of a cohort of 226 consecutive patients with VTE, followed for 6 months. Serum samples were obtained for the determination of cysC, creatinine, and the N-terminal fraction of the brain natriuretic peptide (NT-proBNP) at the time of diagnosis.

RESULTS

The highest discriminating power value of dying at 6 months for cysC was 1,175mg/dl (sensitivity 76%, specificity 65%, positive predictive value 26%, negative predictive value 94%). Above the cut-off, 17/48 patients died, versus 9/152 that had lower levels (odds ratio: 5.98, 95% confidence interval [95% CI]: 2.50-14.29, P<.001). The adjusted hazard ratio in a multivariate model was 3.76 (95% CI 1.46-9.66). The accuracy of this parameter was similar to that for creatinine (1.24mg/dl) but lower than the NT-proBNP (435pg/ml). Patients who exceeded the limit values of cysC and NT-proBNP together had no greater risk of death than those above NT-proBNP only (odds ratio: 9.43, 95% CI 3.90-22.81, P<.001). There was no value, which was significantly associated with bleeding episodes or recurrent thromboembolism.

CONCLUSION

CysC concentration at the time of diagnosis in VTE patients has prognostic value, which is similar to that of serum creatinine and lower than that of NT-proBNP.

Clinical implications of different biomarkers in elderly patients with heart failure

AIMS

The aim of this article was to determine the importance of neuroendocrine and inflammatory biomarkers in elderly patients (>70 years) with heart failure (HF).

METHODS

In this retrospective and observational study, TNF-α, IL-6, IL-18, Fas (Apo1), BNP, C-reactive protein and cystatin C values were calculated, as well as the relationship between them and the clinical evolution of patients.

RESULTS

A total of 124 patients (mean age ± standard deviation: 83±5 years) were included. After a mean follow-up of 2.4 years, 40.3% of patients were hospitalized for HF and 15.3% of patients died. Those patients who were hospitalized for HF compared with those that did not were hospitalized for HF showed higher values of IL-6 (9.8±13.1 vs 4.65±5.8 pg/ml; p=0.003) and those who died compared with those who are alive higher values of IL-18 (437.1±137.4 vs 299.7±167.2 pg/ml; p=0.01), C-reactive protein (12.6±19.4 vs 6.1±9.4 mg/l; p=0.03), BNP (704.2±428.6 vs 418.5±410.6 pg/ml; p=0.008) and cystatin C (1.76±0.6 vs 1.45±0.5 mg/l; p=0.04). In the multivariate analysis, only IL-18 (hazard ratio: 1.4; 95% CI: 1.05-1.8; p=0.027) remained as an independent predictor for mortality.

CONCLUSION

In elderly patients with HF, the determination of biomarkers may be helpful to establish those patients at higher risk.

Cysteine cathepsins and their potential in clinical therapy and biomarker discovery

Since their discovery, cysteine cathepsins were generally considered to be involved mainly in the nonspecific bulk protein degradation that takes place within the lysosomes. However, it has become clear that their proteolytical activity can also influence various specific pathological processes such as cancer, arthritis, and atherosclerosis. Furthermore, their localization was found not to be limited strictly to the lysosomes. In the light of those findings, it is not surprising that cysteine cathepsins are currently considered as highly relevant clinical targets. Moreover, recent development of proteomic-based methods for identification of novel physiological substrates of proteases provides a major opportunity also in the field of cysteine cathepsins. In this review, we will therefore present cysteine cathepsin roles in disease progression and discuss their potential relevance as prognostic and diagnostic biomarkers.

Renal impairment, worsening renal function, and outcome in patients with heart failure: an updated meta-analysis

AIMS

Chronic kidney disease (CKD) and worsening renal function (WRF) have been associated with poor outcome in heart failure (HF).

METHODS AND RESULTS

Articles were identified by literature search of MEDLINE (from inception to 1 July 2012) and Cochrane. We included studies on HF patients and mortality risk with CKD and/or WRF. In a secondary analysis, we selected studies investigating predictors of WRF. We retrieved 57 studies (1,076,104 patients) that investigated CKD and 28 studies (49,890 patients) that investigated WRF. The prevalence of CKD was 32% and associated with all-cause mortality: odds ratio (OR) 2.34, 95% confidence interval (CI) 2.20-2.50, P < 0.001). Worsening renal function was present in 23% and associated with unfavourable outcome (OR 1.81, 95% CI 1.55-2.12, P < 0.001). In multivariate analysis, moderate renal impairment: hazard ratio (HR) 1.59, 95% CI 1.49-1.69, P < 0.001, severe renal impairment, HR 2.17, 95% CI 1.95-2.40, P < 0.001, and WRF, HR 1.95, 95% CI 1.45-2.62, P < 0.001 were all independent predictors of mortality. Across studies, baseline CKD, history of hypertension and diabetes, age, and diuretic use were significant predictors for the occurrence of WRF.

CONCLUSION

Across all subgroups of patients with HF, CKD, and WRF are prevalent and associated with a strongly increased mortality risk, especially CKD. Specific conditions may predict the occurrence of WRF and thereby poor prognosis.

Diagnostic value of the combined measurement of serum hcy, serum cys C, and urinary microalbumin in type 2 diabetes mellitus with early complicating diabetic nephropathy

Diabetic nephropathy (DN) is a major cause of end-stage kidney disease, and therefore early diagnosis and intervention may help reverse renal damage. One hundred and sixty-eight patients with T2DM and 56 healthy volunteers (control group) were enrolled at Shandong University Qilu Hospital between April 2010 and October 2012. All subjects underwent blood sampling for sera homocysteine (Hcy) and cystatin C (Cys C) assays and a urine microalbumin test. The patients were divided into three groups according to the urine microalbumin excretion rate (UMAER): the simple DM group (SDM group, n = 51), the early-stage DN group (EDN group, n = 60), and the clinical DN and renal failure group (CDN group, n = 57). Correlation analysis was performed to examine the association between sera Hcy and Cys C levels with UMAER. Our findings showed that sera Hcy level, Cys C level, and UMAER increased significantly in the SDM group (P < 0.05, P < 0.01), the EDN group (P < 0.01), and the CDN group (P < 0.01) as compared with the control group. These three biochemical markers also increased significantly with DN progression (P < 0.01). Correlation analysis showed that sera Hcy and Cys C levels were positively correlated with UMAER (r = 0.702, P < 0.01; r = 0.873, P < 0.01). In conclusion, our results showed that sera Hcy and Cys C levels increased consistently with the development and progression of DN as indicated by UMAER. Sera Hcy and Cys C are sensitive biomarkers for the detection of early-stage DN and monitoring its progression.

Cystatin C: a step forward in assessing kidney function and cardiovascular risk

The cardiorenal syndrome is a clinical manifestation of the bidirectional interaction between the heart and kidneys. Evaluating renal function is an essential part of the assessment of every cardiac patient. It has become clear that serum creatinine is not an accurate enough marker of glomerular filtration rate (GFR) and should not be used to evaluate kidney dysfunction. Creatinine-based estimates of GFR are preferred, but require renal function to be stable and are not suitable when changes in kidney function occur. Cystatin C (CysC) has been the target of much interest in the search for an alternative measure of GFR. As an endogenous biomarker, CysC possesses many of the properties required of a good marker of renal function. Compared with that of creatinine, plasma concentrations of CysC are less influenced by factors other than GFR. Consequently, CysC correlates with true GFR more accurately than creatinine. Equations for estimating GFR from CysC values have also been developed, which makes values easier to interpret and facilitates the clinical use of this new marker. The use of CysC in acute kidney injury has also shown promising results. CysC has been studied as a risk marker for prognosis in cardiovascular disease. This effect is attributed to the strong impact of renal dysfunction on progressive cardiovascular disease and impaired survival. Higher levels of CysC have consistently been predictive of incident or recurrent cardiovascular events and adverse outcomes. CysC is a predictor of the development of heart failure and increased levels of CysC have an independent association with higher mortality in both chronic and acute heart failure. In conclusion, CysC appears to be an interesting marker of renal function and is useful for risk stratification in heart failure.

Serum cystatin C and prediabetes in non-obese US adults

Diabetes mellitus is the leading cause of end stage renal disease. Cystatin C, a marker of early renal impairment has been shown to be associated with diabetes. However, it is not clear if cystatin C is associated with prediabetes, an early stage in the hyperglycemic continuum where prevention efforts have been shown to be effective in delaying or preventing the onset of diabetes. We examined 2,033 participants from the National Health and Nutrition Examination Survey 1999-2002, aged ≥ 20 years (female 47.2 %) who were free of diabetes mellitus, chronic kidney disease and with body mass index <30 kg/m(2). Prediabetes (n = 541) was defined as a 2-h glucose concentration of 140-199 mg/dL, or a fasting glucose concentration of 110-125 mg/dL, or an A1C value of 5.7-6.4 %. Cystatin C levels were categorized into gender-specific quartiles for analysis. Elevated levels of serum cystatin C were associated with prediabetes after adjusting for potential confounders including serum total cholesterol, systolic blood pressure, body mass index and C-reactive protein. Compared to those with cystatin C in the lowest quartile, the multivariable odds ratio (95 % confidence interval) of prediabetes among those in the highest quartile was 2.08 (1.09-3.97), p for trend = 0.02. Although, this association was stronger among women and non-Hispanic whites, there was no significant interaction by sex (p = 0.1) or by race-ethnicity (p = 0.6). Our findings suggest that elevated levels of serum cystatin C are associated with prediabetes in a nationally representative sample of non-obese US adults.

Prognostic value of serum cystatin C and N-terminal pro b-type natriuretic peptide in patients with acute heart failure

BACKGROUND

Cystatin C (CysC) is a good prognostic marker in heart failure. However, there is not much information of CysC combined with other biomarkers in acute heart failure (AHF).

AIM

To assess prognostic value of CysC and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients hospitalized for AHF with no apparent deterioration of renal function.

DESIGN

Prospective, multicenter, observational study.

METHODS

CysC and NTpro-BNP were measured in patients consecutively admitted with a diagnosis of AHF. Patients with, NTpro-BNP concentration above 900 pg/mL and serum creatinine below 1.3mg/dL, were included for statistical analysis. End-point of the study was all-cause mortality during a 12-month follow-up.

RESULTS

526 patients with AHF and NTpro-BNP concentration above 900 pg/mL were included in the study. From this group, 367 patients (69.8%) had serum creatinine below 1.3mg/dL. Receiver operating characteristic (ROC) curves were used to determine the best cut-off value for CysC. Patients with a concentration of CsyC above 1.25mg/dL had a 37.8% mortality rate, vs. 13.6% for those below cut-off (p<0.001). After Cox proportional hazard model, age, CysC, low total cholesterol and HF with preserved ejection fraction remained significantly associated with all-cause mortality during one-year follow-up.

CONCLUSIONS

In AHF and normal or slightly impaired renal function, performance of CysC may be superior to NT-proBNP. Hence, CysC may be the preferred biomarker in the assessment of patients with AHF and slightly impaired renal function.

Cysteinyl cathepsins: multifunctional enzymes in cardiovascular disease

Until recently, the role of lysosomal cysteine protease cathepsins in intracellular protein degradation was believed to be mainly restricted to scavenging. However, recent studies have revealed nontraditional roles for cysteine protease cathepsins in the extracellular space during the development and progression of cardiovascular disease. Although the precise mechanisms are unknown, data from animal studies suggest that members of the cathepsin family, like other extracellular proteases, contribute to extracellular matrix protein remodeling and interstitial matrix degradation, as well as to cell signaling and cell apoptosis in heart disease. Inflammatory cytokines and hormones regulate the expression and secretion of cathepsins in cultured cardiovascular cells and macrophages. Serum levels of cathepsins L, S, and K and their endogenous inhibitor cystatin C may be useful predictive biomarkers in patients with coronary artery disease and cardiac disease. Furthermore, in vivo pharmacological intervention with a synthetic cathepsin inhibitor and cardiovascular drugs (including statins and angiotensin II type 1 receptor antagonists) has the potential for pharmacologic targeting of cathepsins in cardiovascular disease. This review focuses on cathepsin biology (structure, synthesis, processing, activation, secretion, activity regulation, and function) and the involvement of cysteinyl cathepsins in the pathogenesis of several heart and vessel diseases, especially with respect to their potential application as diagnostic and prognostic markers and drug targets to prevent inappropriate proteolysis in cardiovascular disease.

Increased comorbidities in heart failure patients ≥ 85 years but declined from >90 years: data from the Swedish Heart Failure Registry

OBJECTIVES

Epidemiological studies of elderly heart failure (HF) patients (≥ 85 years) are limited with inconsistent findings. Our objective is to confirm and extend epidemiological study in elderly (≥ 85 years) patients using the Swedish Heart Failure Registry database.

METHODS

This retrospective study included 8,347 HF patients aged ≤ 65 years and 15,889 HF patients aged ≥ 85 years. Elderly population was further divided into two subgroups: 11,412 patients were 85-90 years and 4,477 patients were >90 years.

RESULTS

The ≥ 85 year group was characterized by more women, higher systolic blood pressure (SBP), lower body-mass index (BMI), more than twice as many HF with normal left ventricular ejection fraction (HFNEF), higher incidence of cardiovascular and non-cardiovascular comorbidities and less use of proven therapeutics compared with the ≤ 65 year group. Compared with the 85-90 year subgroup, the > 90 year subgroup had a decline in cardiovascular and non-cardiovascular comorbidities except renal insufficiency and anaemia which continued to increase with ageing (p<0.01). Tendency was the same regardless of gender but slightly different between systolic HF (SHF) and HFNEF. In the group with HFNEF, there were more women, higher SBP, lower N-terminal pro-B-type natriuretic peptide levels, less ischaemic heart disease, more hypertension and left bundle branch block regardless of age. Atrial fibrillation was more frequent in patients with HFNEF than with SHF in the elderly group (p<0.01). Patients with HFNEF in the > 90 year subgroup had increasing incidence of ischaemic heart disease compared to 85-90 year group (p<0.01).

CONCLUSIONS

HF patients ≥ 85 years had increased cardiovascular and non-cardiovascular comorbidities but with a decline from >90 years.

Novel biomarkers in chronic heart failure

Understanding of chronic heart failure (HF) has progressed from a syndrome of disordered hemodynamics caused by alterations in the structure of the heart to one that involves intertwined molecular pathways in disarray. Accordingly, the assessment and treatment of patients with chronic HF has shifted from a focus on hemodynamics to modification of maladaptive molecular processes. Accumulating evidence shows that molecular biomarkers of disease could provide a unique window into the pathophysiology of chronic HF, potentially improving our ability to predict adverse outcomes, provide novel drug targets, and even help gauge therapeutic efficacy. The more 'traditional' biomarkers such as cardiac troponin, natriuretic peptides, and C-reactive protein have been studied in large cohorts of patients with chronic HF and have relatively established clinical applications. In this Review, we summarize the properties, clinical data, and potential applications of some emerging biomarkers that could uniquely indicate the level of biomechanical stretch, inflammation, ventricular remodeling, myocardial injury, and renal dysfunction that occurs in chronic HF. We will also discuss the potential role for these biomarkers within a multimarker-based strategy that could, in the future, lead to better care for these patients.

Cystatin C in a composite risk score for mortality in patients with infective endocarditis: a cohort study

OBJECTIVE

To develop a multimarker prognostic score for infective endocarditis (IE).

DESIGN

Retrospective case-control.

SETTING

Secondary care. Single centre.

PARTICIPANTS

125 patients with definite IE.

PRIMARY OUTCOME MEASURES

90-day and 5-year mortality.

RESULTS

Mean age was 62.7±17 years. The 90-day and 5-year mortality was 10.4% and 33.6%, respectively. CysC levels at admission and over 20% increases in CysC levels during 2 weeks of treatment were prognostic for 90-day and 5-year mortality independent of creatinine estimated glomerular filtration rate. In multivariate analyses, CysC (OR 5.42, 95% CI 1.90 to 15.5, p=0.002) and age (OR 1.06, 95% CI 1.02 to 1.10, p=0.002) remained prognostic for 5-year mortality. NT-proBNP, TnT, C reactive protein and interleukin 6 were also linked to prognosis. A composite risk scoring system using levels of CysC, NT-proBNP, age and presence of mitral valve insufficiency was able to separate a high-risk and a low-risk group.

CONCLUSIONS

CysC levels at admission and increase in CysC after 2 weeks of treatment were independent prognostic markers for both 90-day and 5-year mortality in patients with IE. A multimarker composite risk scoring system including CysC identified a high-risk group.

N-terminal pro B-type natriuretic peptide identifies patients with chest pain at high long-term cardiovascular risk

BACKGROUND

Little is known about the long-term prognostic value of N-terminal pro B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) in low-risk patients with chest pain.

METHODS

Between June 1997 and January 2000, a standard rule-out protocol was performed in patients presenting to the emergency department within 6 hours of onset of chest pain with a normal or nondiagnostic electrocardiogram (ECG) on admission at the Academic Medical Center Amsterdam, VU University Medical Center Amsterdam and Medical Center Alkmaar, The Netherlands. Patients with acute coronary syndrome were identified by troponin T, recurrent angina, and serial ECGs. CRP and NT-proBNP on admission were measured using standardized methods.

RESULTS

A total of 524 patients were included (145 with acute coronary syndrome and 379 with rule-out acute coronary syndrome). Long-term follow-up was successfully carried out in 96% of the study population. Death occurred in 78 patients (15%), 43 (11%) in the rule-out acute coronary syndrome group and 35 (24%) in the acute coronary syndrome group (P<.001). In the rule-out acute coronary syndrome group, 21 patients (42%) died of a cardiovascular cause compared with 24 patients (69%) in the acute coronary syndrome group (P<.001). In multivariate Cox regression analysis, age more than 65 years, previous myocardial infarction, known chronic heart failure, a nondiagnostic ECG on admission, and elevated NT-proBNP levels (>87 pg/mL, as derived from the receiver operating characteristic curve) were independent predictors of long-term cardiovascular mortality in the rule-out acute coronary syndrome group. In the acute coronary syndrome group, these predictors were age more than 65 years, documented coronary artery disease, and elevated NT-proBNP levels. Elevated levels of CRP were an independent predictor for cardiovascular mortality in patients with rule-out acute coronary syndrome at 3-year follow-up only. In patients with rule-out acute coronary syndrome with normal CRP and NT-proBNP levels, the cardiovascular mortality incidence rate was 4.7 per 1000 person-years, compared with a death rate of 20 in patients with both biomarkers elevated, which was comparable to the 17.9 per 1000 person-years incidence rate in patients with acute coronary syndrome.

CONCLUSION

A positive biomarker panel discriminates patients with rule-out acute coronary syndrome chest pain with a normal or nondiagnostic ECG who have a high risk for long-term cardiovascular mortality.

Differential prognostic utility of NTproBNP and Cystatin C in patients with acute exacerbation of chronic pulmonary disease

Objectives

To determine whether serum Cystatin C (CysC) and NTproBNP have prognostic value among patients with long-standing chronic lung disease.

Design

Prospective, observational, non-interventional study.

Setting

CysC and NTproBNP are prognostic markers in several cardiac conditions. In addition, CysC acts as an antiprotease following Cathepsin activation, which has been involved in the pathogenesis of chronic obstructive pulmonary disease.

Participants

Patients with a basal functional status of II-IV (NYHA), admitted for an acute exacerbation of chronic pulmonary diseases and no previous history of symptoms related to pulmonary hypertension or heart failure.

Main outcome measures

NTproBNP and CysC were determined at admission in 107 patients with acute exacerbation of chronic lung disease. During 12-month follow-up, mortality, new hospital admissions and prescription of diuretics were recorded.

Results

During follow-up there were eight patient deaths (7.5%). Mean NTproBNP among the deceased was 1510.20 pg/mL (95% CI 498.44–4628.55) vs 502.70 pg/mL (95% CI 395.44–645.48) among survivors (p = 0.01). Twenty-seven patients (25%) were prescribed loop diuretics. Mean concentration of CysC was 1.45 mg/dL (95% CI 1.21–1.69 mg/dL) vs 1.17 mg/dL (95% IC 1.09–1.25 mg/dL) in those not prescribed (p = 0.004). NTproBNP concentration was 837.14 pg/mL (95% CI 555.57–1274.10 pg/mL) in patients prescribed diuretics vs 473.42 pg/mL (95% CI 357.80–632.70 pg/mL) in those not prescribed (p = 0.03). Kaplan-Meier analysis revealed a significant difference between death and diuretic prescription during follow-up when cut-off value for NTproBNP was 550 pg/mL (p = 0.03 and p = 0.02, respectively). For 1.16mg/dL of CsysC, a significant difference was only observed in diuretic prescription (p = 0.007).

Conclusions

In patients with chronic respiratory diseases NTproBNP has predictive value in terms of mortality whereas CysC does not. However, it is still possible that both can contribute to the early identification of patients at risk of developing clinical ventricular dysfunction.

Impact of elevated cystatin C level on cardiovascular disease risk in predominantly high cardiovascular risk populations: a meta-analysis

BACKGROUND

Chronic kidney disease is a growing public health problem that carries substantial risk for cardiovascular disease (CVD). Single studies have differentially examined the role of cystatin C, a novel renal index, with varying cut-point use. We undertook a meta-analysis of prospective studies to properly assess the link between cystatin C (dichotomized and continuous) versus CVD.

METHODS AND RESULTS

Systematic literature search for studies reporting a multivariate-adjusted estimate, represented as relative risk (RR) with 95% confidence interval (CI), of the association between cystatin C and subsequent risk of (1) any CVD event and (2) specific CVD events. Data were collated from 14 studies, with 13 high cardiovascular risk population cohorts and 1 general population cohort, involving 22 509 subjects with 2321 CVD events, 741 coronary heart disease events, and 828 stroke events. Highest cystatin C category versus lowest was associated with greater risk of CVD (RR, 2.62; 95% CI, 2.05 to 3.37, P<0.001), coronary heart disease (RR, 1.72; 95% CI, 1.27 to 2.34; P<0.001), and stroke (RR, 1.83; 95% CI, 1.12 to 3.00; P=0.02) after adjustment for established cardiovascular risk factors. Each standard deviation rise in cystatin C concentration boosted CVD risk (RR, 1.34; 95% CI, 1.18 to 1.51; P<0.001). Highest cystatin C category was also independently linked to greater risk of all-cause mortality and heart failure.

CONCLUSIONS

The meta-analysis, mostly derived from high cardiovascular populations, showed that cystatin C is strongly and independently associated with subsequent CVD risk. Further investigation is warranted to clarify whether measurement of cystatin C can usefully enhance CVD stratification beyond established predictors already in clinical use.

Improved pharmacological therapy of chronic heart failure in primary care: a randomized Study of NT-proBNP Guided Management of Heart Failure--SIGNAL-HF (Swedish Intervention study--Guidelines and NT-proBNP AnaLysis in Heart Failure)

AIMS

Treatment of chronic heart failure (CHF) guided by natriuretic peptides has been studied in clinical trials with conflicting results. The aim of this study was to investigate if N-terminal pro-B-type natriuretic peptide (NT-proBNP)-guided therapy in symptomatic heart failure patients in primary care would improve clinical outcomes over and above treatment according to guidelines.

METHODS AND RESULTS

SIGNAL-HF was a 9 month, randomized, single-blind, parallel group study in patients with CHF in NYHA class II-IV, ejection fraction (EF)<50% and elevated NT-proBNP levels (males>800, females>1000 ng/L). All investigators underwent a pre-study educational programme about current CHF guidelines. A control group managed by non-trained investigators was considered not possible for ethical and practical reasons. Patients were randomized to structured treatment of CHF according to guidelines with or without NT-proBNP monitoring. The choice and dose of therapy for CHF was at the investigator's discretion. The primary outcome variable was the composite endpoint of days alive, days out of hospital, and symptom score from the Kansas City Cardiomyopathy Questionnaire. In all, 252 patients were randomized. The allocation groups were well balanced with regards to age, NT-proBNP, and EF. Treatment doses of beta-blockers and blockers of the renin-angiotensin-aldosterone system were markedly increased towards target doses and to a similar degree in both groups. There were no differences between the groups concerning either the primary endpoint (P=0.28) or its components [cardiovascular (CV) death, P=0.93; CV hospitalization, P=0.88; or symptom score, P=0.28].

CONCLUSION

NT-proBNP-guided CHF treatment did not result in important improvements in clinical outcomes in patients with CHF in primary care above and beyond what could be achieved by education and structured CHF treatment according to guidelines.

Comparison of the long-term prognostic value of cystatin C to other indicators of renal function, markers of inflammation and systolic dysfunction among patients with acute coronary syndrome

OBJECTIVE

Emerging evidence indicates the prognostic importance of cystatin C (Cys-C) in patients with coronary artery disease. However, whether Cys-C concentrations are associated with adverse clinical events among patients with acute coronary syndromes (ACS) have not been studied extensively. We compared the long-term prognostic efficacy of Cys-C with other markers of renal dysfunction, inflammation and systolic dysfunction in patients with ACS.

METHODS AND RESULTS

Serum levels of Cys-C, high sensitive C-reactive protein (hs-CRP), brain natriuretic peptide (BNP) and creatinine were measured in 160 patients with ACS (112 males, 48 females, mean age 60+/-10 years) on admission. Primary end point of the study was major adverse cardiac events (MACE) defined as the combination of cardiac death, non-fatal myocardial infarction and recurrent rest angina that required hospitalization within 12 months of follow-up. During the follow-up period, 42 (26%) patients met the MACE criteria. The occurrence of MACE was significantly higher among patients with higher Cys-C levels. In multivariate analysis, Cys-C was the most important parameter associated with the occurrence of MACE (OR=9.62, 95% CI=2.3-40.5, p<0.001). ROC curve analysis showed that the predictive cut-off value of Cys-C for MACE was 1051ng/ml. In the Cox regression analysis adjusted for multiple risk factors, Cys-C was found as the most powerful predictor for MACE (RR=9.43, 95% CI=4.0-21.8, p<0.001).

CONCLUSION

The results of the present study indicate that admission levels of Cys-C may be a good prognostic indicator of recurrent cardiovascular events in patients with ACS. Further studies are needed to confirm these results.