Cytokine activation and disease progression in patients with stable moderate chronic heart failure

BACKGROUND: Activation of the cytokine and the complement system is associated with disease progression in severe congestive heart failure (CHF). Magnitude and prognostic relevance of cytokine and complement activation remain uncertain in patients with moderate CHF. OBJECTIVES: Measurement of cytokine and complement activation in patients with moderate CHF and testing whether C-reactive protein (CRP) can serve as a surrogate marker of their activation, adding independent prognostic information when co-measured with B-type natriuretic peptide (BNP). METHODS: The 118 study participants were separated into three groups based on pre-determined CRP and BNP levels: Group I (n = 27; CRP > 5 mg/liter, BNP > or = 200 pg/ml); Group II (n = 46; CRP < or = 5 mg/liter, BNP > or = 200 pg/ml); and Group III (n = 45; CRP < or = 5 mg/liter, BNP < 200 pg/ml). RESULTS: Mortality was high in Group I (30%; log-rank p < 0.001) but low in Groups II and III (2% and 4%, respectively; log rank, p = 0.7). No differences were observed for left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD) between Groups I and II (31 +/- 16 vs 32 +/- 14% and 66 +/- 16 vs 65 +/- 11 mm, respectively), whereas in Group III LVEF was higher (42 +/- 17%, p = 0.002) with smaller LVEDD (57 +/- 13 mm, p = 0.012). Cytokine sCD14 and tumor necrosis factor (TNF)-alpha levels were not different between the three groups. However, interleukin-6 levels (9.75 +/- 8.17 pg/ml, p = 0.001) and the terminal complement complex C5b-9 (109.9 +/- 68 ng/ml; p = 0.04) were elevated in Group I, both correlating with CRP (interleukin-6: r = 0.5, p < 0.001; C5b-9: r = 0.41, p = 0.001). CONCLUSIONS: CRP may be used as a surrogate parameter for interleukin-6 and complement activation in moderate CHF. CRP in combination with BNP identifies a high-risk group with a tendency for poor outcome not discriminated by cardiac function.

C-reactive protein predicts mortality in patients referred for coronary angiography and symptoms of heart failure with preserved ejection fraction

AIMS Heart failure with preserved ejection fraction (HFpEF) has a different pathophysiological background compared to heart failure with reduced ejection fraction (HFrEF). Tailored risk prediction in this separate heart failure group with a high mortality rate is of major importance. Inflammation may play an important role in the pathogenesis of HFpEF because of its significant contribution to myocardial fibrosis. We therefore aimed to assess the predictive value of C-reactive protein (CRP) in patients with HFpEF. METHODS AND RESULTS Plasma levels of CRP were determined in 459 patients with HFpEF in the LUdwigshafen Risk and Cardiovascular Health (LURIC) study using a high-sensitivity assay. During a median follow-up of 9.7 years 40% of these patients died. CRP predicted all-cause mortality with an adjusted hazard ratio (HR) of 1.20 [95% confidence interval (CI) 1.02-1.40, P = 0.018] and cardiovascular mortality with a HR of 1.32 (95% CI 1.08-1.62, P = 0.005) per increase of one standard deviation. CRP was a significantly stronger mortality predictor in HFpEF patients than in a control group of 522 HFrEF patients (for interaction, P = 0.015). Furthermore, CRP added prognostic value to N-terminal pro B-type natriuretic peptide (Nt-proBNP): the lowest 5-year mortality rate of 6.8% was observed for patients in the lowest tertile of Nt-proBNP as well as CRP. The mortality risk peaked in the group combining the highest values of Nt-proBNP and CRP with a 5-year rate of 36.5%. CONCLUSION It was found that CRP was an independent and strong predictor of mortality in HFpEF. This observation may reflect immunological processes with an adverse impact on the course of HFpEF.

Cardiac biomarkers and clinical scores for risk stratification in elderly patients with non-high-risk pulmonary embolism.

OBJECTIVE To determine the prognostic accuracy of cardiac biomarkers alone and in combination with clinical scores in elderly patients with non-high-risk pulmonary embolism (PE). DESIGN Ancillary analysis of a Swiss multicentre prospective cohort study. SUBJECTS A total of 230 patients aged ≥65 years with non-high-risk PE. MAIN OUTCOME MEASURES The study end-point was a composite of PE-related complications, defined as PE-related death, recurrent venous thromboembolism or major bleeding during a follow-up of 30 days. The prognostic accuracy of the Pulmonary Embolism Severity Index (PESI), the Geneva Prognostic Score (GPS), the precursor of brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) was determined using sensitivity, specificity, predictive values, receiver operating characteristic (ROC) curve analysis, logistic regression and reclassification statistics. RESULTS The overall complication rate during follow-up was 8.7%. hs-cTnT achieved the highest prognostic accuracy [area under the ROC curve: 0.75, 95% confidence interval (CI): 0.63-0.86, P < 0.001). At the predefined cut-off values, the negative predictive values of the biomarkers were above 95%. For levels above the cut-off, the risk of complications increased fivefold for hs-cTnT [odds ratio (OR): 5.22, 95% CI: 1.49-18.25] and 14-fold for NT-proBNP (OR: 14.21, 95% CI: 1.73-116.93) after adjustment for both clinical scores and renal function. Reclassification statistics indicated that adding hs-cTnT to the GPS or the PESI significantly improved the prognostic accuracy of both clinical scores. CONCLUSION In elderly patients with nonmassive PE, NT-proBNP or hs-cTnT could be an adequate alternative to clinical scores for identifying low-risk individuals suitable for outpatient management.

Prognostic significance of multidetector CT in normotensive patients with pulmonary embolism: results of the protect study.

BACKGROUND In patients with acute pulmonary embolism (PE), rapid and accurate risk assessment is paramount in selecting the appropriate treatment strategy. The prognostic value of right ventricular dysfunction (RVD) assessed by multidetector CT (MDCT) in normotensive patients with PE has lacked adequate validation. METHODS The study defined MDCT-assessed RVD as a ratio of the RV to the left ventricle short axis diameter greater than 0.9. Outcomes assessed through 30 days after the diagnosis of PE included all-cause mortality and 'complicated course', which consisted of death from any cause, haemodynamic collapse or recurrent PE. RESULTS MDCT detected RVD in 533 (63%) of the 848 enrolled patients. Those with RVD on MDCT more frequently had echocardiographic RVD (31%) than those without RVD on MDCT (9.2%) (p<0.001). Patients with RVD on MDCT had significantly higher brain natriuretic peptide (269±447 vs 180±457 pg/ml, p<0.001) and troponin (0.10±0.43 vs 0.03±0.24 ng/ml, p=0.001) levels in comparison with those without RVD on MDCT. During follow-up, death occurred in 25 patients with and in 13 patients without RVD on MDCT (4.7% vs 4.3%; p=0.93). Those with and those without RVD on MDCT had a similar frequency of complicated course (3.9% vs 2.3%; p=0.30). CONCLUSIONS The PROgnosTic valuE of CT study showed a relationship between RVD assessed by MDCT and other markers of cardiac dysfunction around the time of PE diagnosis, but did not demonstrate an association between MDCT-RVD and prognosis.

Defensin Levels in Spider Hemolymph

Spiders, like all arthropods, exclusively rely on an innate immune system localized in the hemocytes to protect against pathogen invasion. In the hemocytes of the wandering spider Cupiennius salei (C. salei), defensin expression was found to be constitutive. Defensins belong to the group of antimicrobial peptides, which appear in most taxonomic groups, and play an essential role in innate immunity. It has further been reported that during the primary immune answer of C. salei, the peptide content of hemocytes changes markedly, which may indicate the release of defensins from the hemocytes. However, no data on the peptide levels in C. salei hemolymph has so far been published. Formerly, the involvement in the primary immune answer was considered the only function of defensins. However, recent findings strongly suggest that the importance of defensins goes far beyond. There is evidence for defensins contributing to the adaptive immune response, to angiogenesis, and furthermore to tissue repair, i.e. to a variety of essential processes in living organisms. To date, only very little is known about the identity of C. salei defensins and their detailed mode of action. The goal of the work presented herein is the identification of hitherto unknown C. salei defensins in hemocytes and the hemolymph. Moreover, the levels of defensin expression under differential conditions are compared by the means of liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Fibroblast Growth Factor 23 Is an Independent and Specific Predictor of Mortality in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND Strategies to improve risk prediction are of major importance in patients with heart failure (HF). Fibroblast growth factor 23 (FGF-23) is an endocrine regulator of phosphate and vitamin D homeostasis associated with an increased cardiovascular risk. We aimed to assess the prognostic effect of FGF-23 on mortality in HF patients with a particular focus on differences between patients with HF with preserved ejection fraction and patients with HF with reduced ejection fraction (HFrEF). METHODS AND RESULTS FGF-23 levels were measured in 980 patients with HF enrolled in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study including 511 patients with HFrEF and 469 patients with HF with preserved ejection fraction and a median follow-up time of 8.6 years. FGF-23 was additionally measured in a second cohort comprising 320 patients with advanced HFrEF. FGF-23 was independently associated with mortality with an adjusted hazard ratio per 1-SD increase of 1.30 (95% confidence interval, 1.14-1.48; P<0.001) in patients with HFrEF, whereas no such association was found in patients with HF with preserved ejection fraction (for interaction, P=0.043). External validation confirmed the significant association with mortality with an adjusted hazard ratio per 1 SD of 1.23 (95% confidence interval, 1.02-1.60; P=0.027). FGF-23 demonstrated an increased discriminatory power for mortality in addition to N-terminal pro-B-type natriuretic peptide (C-statistic: 0.59 versus 0.63) and an improvement in net reclassification index (39.6%; P<0.001). CONCLUSIONS FGF-23 is independently associated with an increased risk of mortality in patients with HFrEF but not in those with HF with preserved ejection fraction, suggesting a different pathophysiologic role for both entities.

Cohort study of plasma natriuretic peptides for identifying left ventricular systolic dysfunction in primary care

Objectives: To determine whether blood natriuretic peptide concentrations are helpful in identifying or excluding left ventricular systolic dysfunction in stable survivors of acute myocardial infarction.

Sildenafil Potentiates a cGMP-Dependent Pathway to Promote Melanoma Growth.

Sildenafil, an inhibitor of the cGMP-degrading phosphodiesterase 5 that is used to treat erectile dysfunction, has been linked to an increased risk of melanoma. Here, we have examined the potential connection between cGMP-dependent signaling cascades and melanoma growth. Using a combination of biochemical assays and real-time monitoring of melanoma cells, we report a cGMP-dependent growth-promoting pathway in murine and human melanoma cells. We document that C-type natriuretic peptide (CNP), a ligand of the membrane-bound guanylate cyclase B, enhances the activity of cGMP-dependent protein kinase I (cGKI) in melanoma cells by increasing the intracellular levels of cGMP. Activation of this cGMP pathway promotes melanoma cell growth and migration in a p44/42 MAPK-dependent manner. Sildenafil treatment further increases intracellular cGMP concentrations, potentiating activation of this pathway. Collectively, our data identify this cGMP-cGKI pathway as the link between sildenafil usage and increased melanoma risk.

NT-proBNP in patients with out-of-hospital cardiac arrest: Results from the FINNRESUSCI Study

AIM To assess whether the established cardiovascular biomarker N-terminal pro-B-type natriuretic peptide (NT-proBNP) provides prognostic information in patients with out-of-hospital cardiac arrest due to ventricular tachycardia or fibrillation (OHCA-VT/VF). METHODS We measured NT-proBNP levels in 155 patients with OHCA-VT/VF enrolled into a prospective multicenter observational study in 21 ICUs in Finland. Blood samples were drawn <6h of OHCA-VT/VF and later after 24h, 48h, and 96h. The end-points were mortality and neurological outcome classified according to Cerebral Performance Category (CPC) after one year. NT-proBNP levels were compared to high-sensitivity troponin T (hs-TnT) levels and established risk scores. RESULTS NT-proBNP levels were higher in non-survivors compared to survivors on study inclusion (median 1003 [quartile (Q) 1-3 502-2457] vs. 527 [179-1284]ng/L, p=0.001) and after 24h (1913 [1012-4573] vs. 1080 [519-2210]ng/L, p<0.001). NT-proBNP levels increased from baseline to 96h after ICU admission (p<0.001). NT-proBNP levels were significantly correlated to hs-TnT levels after 24h (rho=0.27, p=0.001), but not to hs-TnT levels on study inclusion (rho=0.05, p=0.67). NT-proBNP levels at all time points were associated with clinical outcome, but only NT-proBNP levels after 24h predicted mortality and poor neurological outcome, defined as CPC 3-5, in models that adjusted for SAPS II and SOFA scores. hs-TnT levels did not add prognostic information to NT-proBNP measurements alone. CONCLUSION NT-proBNP levels at 24h improved risk assessment for poor outcome after one year on top of established risk indices, while hs-TnT measurements did not further add to risk prediction.

Air pollution exposure and novel biomarkers of inflammation and cardiac stress in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air)

Thesis (Master's)--University of Washington, 2016-06

Screening for heart disease in diabetic subjects

Background The prevalence of left ventricular hypertrophy (LVH), coronary artery disease, and subclinical cardiomyopathy in diabetic patients without known cardiac disease is unclear. We sought the frequency of these findings to determine whether plasma brain natriuretic peptide (BNP) could be used as an alternative screening tool to identify subclinical LV dysfunction. Methods Asymptomatic patients with diabetes mellitus without known cardiac disease (n = 10 1) underwent clinical evaluation, measurement of BNP, exercise stress testing, and detailed echocardiographic assessment. After exclusion of overt dysfunction or ischemia, subclinical myocardial function was sought on the basis of myocardial systolic (Sm) and diastolic velocity (Em). Association was. sought between subclinical dysfunction and clinical, biochemical, exercise, and echocardiographic variables. Results Of 101 patients, 22 had LVH and 16 had ischemia evidenced by exercise-induced wall motion abnormalities. Only 4 patients had abnormal BNP levels; BNP was significantly increased in patients with LVH. After exclusion of LVH and coronary artery disease, subclinical cardiomyopathy was identified in 24 of 66 patients: Subclinical disease could not be predicted by BNP. Conclusions Even after exclusion of asymptomatic ischemia and hypertrophy, subclinical systolic and diastolic dysfunction occurs in a significant number of patients with type 2 diabetes. However, screening approaches, including BNP, do not appear to be sufficiently sensitive to identify subclinical dysfunction, which requires sophisticated echocardiographic analysis.

D-amino acid residue in a defensin-like peptide from platypus venom: effect on structure and chromatographic properties

The recent discovery that the natriuretic peptide OvCNPb (Ornithorhynchus venom C-type natriuretic peptide B) from platypus (Ornithorynchus anatinus) venom contains a D-amino acid residue suggested that other D-amino-acid-containing peptides might be present in the venom. In the present study, we show that DLP-2 (defensin-like peptide-2), a 42-amino-acid residue polypeptide in the platypus venom, also contains a D-amino acid residue, D-methionine, at position 2, while DLP-4, which has an identical amino acid sequence, has all amino acids in the L-form. These findings were supported further by the detection of isomerase activity in the platypus gland venom extract that converts DLP-4 into DLP-2. In the light of this new information, the tertiary structure of DLP-2 was recalculated using a new structural template with D-Met(2). The structure of DLP-4 was also determined in order to evaluate the effect of a D-amino acid at position 2 on the structure and possibly to explain the large retention time difference observed for the two molecules in reverse-phase HPLC. The solution structures of the DLP-2 and DLP-4 are very similar to each other and to the earlier reported structure of DLP-2, which assumed that all amino acids were in the L-form. Our results suggest that the incorporation of the D-amino acid at position 2 has minimal effect on the overall fold in solution.

Identification and analysis of venom gland-specific genes from the coastal taipan (Oxyuranus scutellatus) and related species

Australian terrestrial elapid snakes contain amongst the most potently toxic venoms known. However, despite the well-documented clinical effects of snake bite, little research has focussed on individual venom components at the molecular level. To further characterise the components of Australian elapid venoms, a complementary (cDNA) microarray was produced from the venom gland of the coastal taipan (Oxyuranus scutellatus) and subsequently screened for venom gland-specific transcripts. A number of putative toxin genes were identified, including neurotoxins, phospholipases, a pseudechetoxin-like gene, a venom natriuretic peptide and a nerve growth factor together with other genes involved in cellular maintenance. Venom gland-specific components also included a calglandulin-like protein implicated in the secretion of toxins from the gland into the venom. These toxin transcripts were subsequently identified in seven other related snake species, producing a detailed comparative analysis at the cDNA and protein levels. This study represents the most detailed description to date of the cloning and characterisation of different genes associated with envenomation from Australian snakes.

Novel natriuretic peptides from the venom of the inland taipan (Oxyuranus microlepidotus): isolation, chemical and biological characterisation

Three natriuretic-like peptides (TNP-a, TNP-b, and TNP-c) were isolated from the venom of Oxyuranus microlepidotus (inland taipan) and were also present in the venoms of Oxyuranus scutellatus canni (New Guinea taipan) and Oxyuranus scutellatus scutellatus (coastal taipan). They were isolated by HPLC, characterised by mass spectrometry and Edman analysis, and consist of 35-39 amino acid residues. These molecules differ from ANP/BNP through replacement of invariant residues within the 17-membered ring structure and by inclusion of proline residues in the C-terminal tail. TNP-c was equipotent to ANP in specific GC-A assays or aortic ring assays whereas TNP-a and TNP-b were either inactive (GC-A over-expressing cells and endothelium-denuded aortic rings) or weakly active (endothelium-in tact aortic rings). TNP-a and TNP-b were also unable to competitively inhibit the binding of TNP-c in endothelium-denuded aortae (GC-A) or endothelium-in tact aortae (NPR-C). Thus, these naturally occurring isoforms provide a new platform for further investigation of structure-function relationships of natriuretic peptides. (C) 2004 Elsevier Inc. All rights reserved.

Guidelines for the prevention, detection and management of people with chronic heart failure in Australia 2006

* Chronic heart failure (CHF) is found in 1.5%–2.0% of Australians. Considered rare in people aged less than 45 years, its prevalence increases to over 10% in people aged ≥ 65 years. * CHF is one of the most common reasons for hospital admission and general practitioner consultation in the elderly (≥ 70 years). * Common causes of CHF are ischaemic heart disease (present in > 50% of new cases), hypertension (about two-thirds of cases) and idiopathic dilated cardiomyopathy (around 5%–10% of cases). * Diagnosis is based on clinical features, chest x-ray and objective measurement of ventricular function (eg, echocardiography). Plasma levels of B-type natriuretic peptide (BNP) may have a role in diagnosis, primarily as a test for exclusion. Diagnosis may be strengthened by a beneficial clinical response to treatment(s) directed towards amelioration of symptoms. * Management involves prevention, early detection, amelioration of disease progression, relief of symptoms, minimisation of exacerbations, and prolongation of survival.