Meinhard Haltmayer

A Variant Associated with Nicotine Dependence, Lung Cancer and Peripheral Arterial Disease

Smoking is a leading cause of preventable death, causing about 5 million premature deaths worldwide each year. Evidence for genetic influence on smoking behaviour and nicotine dependence (ND) has prompted a search for susceptibility genes. Furthermore, assessing the impact of sequence variants on smoking-related diseases is important to public health. Smoking is the major risk factor for lung cancer (LC) and is one of the main risk factors for peripheral arterial disease (PAD). Here we identify a common variant in the nicotinic acetylcholine receptor gene cluster on chromosome 15q24 with an effect on smoking quantity, ND and the risk of two smoking-related diseases in populations of European descent. The variant has an effect on the number of cigarettes smoked per day in our sample of smokers. The same variant was associated with ND in a previous genome-wide association study that used low-quantity smokers as controls, and with a similar approach we observe a highly significant association with ND. A comparison of cases of LC and PAD with population controls each showed that the variant confers risk of LC and PAD. The findings provide a case study of a gene–environment interaction, highlighting the role of nicotine addiction in the pathology of other serious diseases.

Diagnostic accuracy of B type natriuretic peptide and amino terminal proBNP in the emergency diagnosis of heart failure.

Objective: To compare head to head the diagnostic accuracy of B type natriuretic peptide (BNP) and the amino terminal fragment of its precursor hormone (NT-proBNP) for congestive heart failure (CHF) in an emergency setting. Methods: 251 consecutive patients presenting to the emergency department with dyspnoea as a chief complaint were prospectively studied. Patients with acute coronary syndromes were excluded. The diagnosis of CHF was based on the Framingham score for CHF plus echocardiographic evidence of systolic or diastolic dysfunction. Blood concentrations of BNP and NT-proBNP were measured by two commercially available assays (Abbott and Roche methods). The diagnostic accuracies of BNP and NT-proBNP were assessed by receiver operating characteristic curve analysis. Results: Areas under the curve for BNP and NT-proBNP in patients with dyspnoea caused by CHF (n  =  137) and in patients with dyspnoea attributable to other reasons (n  =  114) did not differ significantly (area under the curve 0.916 v 0.903, p  =  0.277, statistical power 94%). Cut off concentrations with the highest diagnostic accuracy were 295 ng/l for BNP (sensitivity 80%, specificity 86%, diagnostic accuracy 83%) and 825 ng/l for NT-proBNP (sensitivity 87%, specificity 81%, diagnostic accuracy 84%). Evaluation of discordant false classifications at these cut off concentrations showed no advantage for either BNP nor NT-proBNP in the biochemical diagnosis of CHF (17 misclassifications by BNP and 14 by NT-proBNP, p  =  0.720). In the population studied, age, sex, and renal function had no impact on the diagnostic utility of both tests when compared by logistic regression models. Conclusions: BNP and NT-proBNP may be equally useful as an aid in the diagnosis of CHF in short of breath patients presenting to the emergency department.

Analytical and clinical evaluation of a novel high-sensitivity assay for measurement of soluble ST2 in human plasma — The Presage™ ST2 assay

BACKGROUND The protein ST2 is a member of the interleukin-1 receptor family. Blood concentrations of the soluble isoform of ST2 (sST2) are increased in inflammatory diseases and in heart disease and are considered a prognostic marker in both. The aim of this study was the analytical and clinical evaluation of the novel Presage ST2 assay for the determination of sST2 in human plasma. METHODS We evaluated precision and linearity of the assay, analyte stability, and biological variability, determined reference values, performed a method comparison with an established ELISA, and quantified sST2 concentrations in various diseases. RESULTS Within-run and total coefficients of variation were <2.5% and <4.0%. The method was linear across the whole measurement range of the assay. The analyte was stable for 48 h at room temperature, for 7 days at 4 degrees C, and for at least 2 months at -20 degrees C and -80 degrees C. The reference change value for healthy individuals was 30%. Age-independent reference values were 3-28 U/mL in males, and 2-16 U/mL in females. The method comparison revealed a high proportional bias. sST2 plasma concentrations were increased modestly in heart failure and moderately in pneumonia and chronic obstructive pulmonary disease. Patients with sepsis exhibited highly elevated sST2 values. In patients with chronic renal disease, however, there was no difference compared to healthy individuals. CONCLUSION The Presage ST2 assay meets the needs of quality specifications of laboratory medicine. The results of the clinical assay evaluation are novel with respect to sST2 in various diseases and should initiate further studies.

Increased Plasma Concentrations of Soluble ST2 are Predictive for 1-Year Mortality in Patients with Acute Destabilized Heart Failure

BACKGROUND The soluble isoform of the interleukin-1 receptor family member ST2 (sST2) has been implicated in heart failure. The aim of the present study was to evaluate the capability of sST2 as a prognostic marker in patients with acute destabilized heart failure. METHODS sST2 plasma concentrations were obtained in 137 patients with acute destabilized heart failure attending the emergency department of a tertiary care hospital. The endpoint was defined as all-cause mortality, and the study participants were followed up for 365 days. RESULTS Of the 137 patients enrolled, 41 died and 96 survived during follow-up. At baseline the median sST2 plasma concentration was significantly higher in the patients who died than in those who survived (870 vs 342 ng/L, P <0.001). Kaplan-Meier curve analyses demonstrated that the risk ratios for mortality were 2.45 (95% CI, 0.88-6.31; P = 0.086) and 6.63 (95% CI, 2.55-10.89; P <0.001) in the second tercile (sST2, 300-700 ng/L; 11 deaths vs 34 survivors) and third tercile (sST2, >700 ng/L; 25 deaths vs 21 survivors) of sST2 plasma concentrations compared with the first tercile (sST2, < or =300 ng/L; 5 deaths vs 41 survivors). In multivariable Cox proportional-hazards regression analyses, an sST2 plasma concentration in the upper tercile was a strong and independent predictor of all-cause mortality. CONCLUSIONS Increased sST2 concentrations determined in plasma samples drawn from patients with acute destabilized heart failure at their initial presentation indicate increased risk of future mortality. Increased sST2 plasma concentrations are independently and strongly associated with one-year all-cause mortality in these patients.

Long-term stability of endogenous B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) in frozen plasma samples.

Abstract The aim of the present study was to assess the long-term stability of endogenous B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) in plasma samples stored at –20°C without addition of protease inhibitors (e.g., aprotinin). Stability of BNP and NT-proBNP was tested in 60 EDTA plasma samples with BNP values between 30 and 420 pg/ml. Initial BNP and NT-proBNP plasma concentrations were determined within four hours after blood collection using the AxSYM BNP and the Elecsys NT-proBNP assays. Subsequently, all samples were stored at –20°C and were thawed for the second BNP and NT-proBNP determination on the two instruments after one day, 30 days, 60 days, 90 days and 120 days, respectively. Mean recovery (i.e., residual immunoreactivity) of BNP and NT-proBNP expressed in percent of the initial value for the given time interval of storage was calculated. Mean recovery of BNP was less than 70% after one day of storage at –20°C and decreased to less than 50% after two to four months of storage (e.g., recovery of endogenous BNP after three months of storage at –20°C ranging from 0% to 71%). In contrast, mean recovery of NT-proBNP was generally greater than 90%, irrespective of the duration of storage at –20°C (e.g., recovery of endogenous NT-proBNP after three months of storage at –20°C ranging from 91% to 112%). In conclusion, the determination of endogenous BNP with the AxSYM assay using frozen plasma samples may not be valid under the conditions tested. In contrast, NT-proBNP as measured by the Elecsys assay may be stored at –20°C for at least four months without a relevant loss of the immunoreactive analyte.

Comparison of the Biomedica NT-proBNP Enzyme Immunoassay and the Roche NT-proBNP Chemiluminescence Immunoassay: Implications for the Prediction of Symptomatic and Asymptomatic Structural Heart Disease

The amino-terminal fragment of the B-type natriuretic peptide prohormone (NT-proBNP) is a marker for functional cardiac impairment and is increased in heart disease with or without symptoms of heart failure (HF) (1). There are indications that currently used assays for NT-proBNP may differ in their cross-reactivity with circulating NT-proBNP split products and may also be affected by breakdown products of NT-proBNP produced after blood collection (2). A newer generation assay, a commercially available competitive enzyme immunoassay (EIA) for NT-proBNP (Biomedica Gruppe) (3) that does not require sample pretreatment, has been used in various methodologic and clinical studies (4)(5)(6), but noncompetitive immunoassays may offer advantages of better speed, sensitivity, precision, and possibly specificity over competitive immunoassays (7). Recently, a noncompetitive immunoassay for NT-proBNP has been developed (8). A fully automated version of this assay (Roche Diagnostics) has now been cleared by the US Food and Drug Administration. Our aim was to compare the Biomedica and Roche NT-proBNP assays, addressing whether the predictive values of both assays are similar with respect to structural heart disease with or without symptoms of HF. The present study, carried out at the Division of Internal Medicine, St. John of God Hospital (Linz, Austria), was approved by the local ethics committee in accordance to the Helsinki Declaration. We prospectively recruited 157 consecutive patients admitted for extensive cardiac evaluation (including performance of bicycle ergometry) and 23 consecutive patients with symptomatic HF admitted for inpatient treatment; all participants gave written informed consent. Study participants were classified according to the American College of Cardiology/American Heart Association guidelines for the evaluation and management of chronic HF in the adults (9) to one of the four following categories: ( a ) healthy individuals (n = 42); ( b ) patients at high risk for developing HF but without structural disorders of the …

Evaluation of novel biomarkers for the diagnosis of acute destabilised heart failure in patients with shortness of breath

Objective: The evaluation of novel biomarkers for the diagnosis of acute destabilised heart failure (HF). Design: Prospectively conducted study on diagnostic accuracy. Setting: Emergency department of a tertiary care hospital. Patients: 251 consecutive patients presenting to the emergency department with dyspnoea as the chief complaint. Main outcome measures: Index tests were plasma concentrations of 10 biomarkers (BNP, MR-proANP, MR-proADM, copeptin, CT-proET-1, ST2, adiponectin, chromogranin A, proguanylin and prouroguanylin). The reference standard was the diagnosis of acute destabilised HF, which was based on the Framingham score for HF plus echocardiographic evidence of systolic or diastolic dysfunction. Results: Median plasma concentrations of all 10 biomarkers were higher in patients with dyspnoea attributable to acute destabilised HF (n = 137) than in patients with dyspnoea attributable to other reasons (n = 114). Applying receiver operating characteristic curve (ROC) analyses, areas under the curve (AUCs) for BNP (0.92) and MR-proANP (0.88) were significantly higher than the AUCs of the other eight biomarkers (MR-proADM, 0.75; adiponectin, 0.73; CT-proET-1, 0.72; proguanylin, 0.68; ST2, 0.67; prouroguanylin, 0.62; copeptin, 0.62; and chromogranin A, 0.56). In multivariate logistic regression analysis only increased BNP and MR-proANP concentrations remained independent markers for the diagnosis of HF. Both markers alone or in combination added similar diagnostic information besides all clinical information available in the emergency department. Conclusions: The data showed that BNP and MR-proANP were the only independent diagnostic markers of HF. Both markers provided similar diagnostic information and were clinically useful as an aid in the diagnosis of acute destabilised HF in an emergency setting.

Prognostic value of established and novel biomarkers in patients with shortness of breath attending an emergency department.

OBJECTIVES Acute dyspnea is a common cause for emergency department visits. The aim of this study was to evaluate the prognostic value of established and novel biomarkers in patients with acute dyspnea. DESIGN AND METHODS We measured 10 biomarkers [B-type natriuretic peptide (BNP), midregional pro-A-type natriuretic peptide (MR-proANP), midregional-proadrenomedullin (MR-proADM), copeptin, C-terminal endothelin-1 precursor fragment (CT-proET-1), soluble ST2 (sST2), chromogranin A (CgA), adiponectin, proguanylin, and prouroguanylin] in 251 consecutive patients with acute dyspnea presenting to the emergency department of a tertiary care hospital. Outcome measure was all-cause mortality at 1 year. RESULTS At baseline decedents (n=62) had significantly higher median plasma concentrations of all 10 biomarkers than survivors (n=189). Applying univariate Cox proportional-hazard regression analyses, all biomarkers were significant outcome predictors displaying risk ratios (RR) from 1.4 to 2.4 (per 1 SD increase in log transformed values). In multivariate Cox proportional-hazard regression analysis, however, only MR-proANP (RR 1.6; 95% CI, 1.1-2.2; p=0.008), sST2 (RR 1.7; 95% CI, 1.3-2.3; p<0.001), and CgA (RR 1.5; 95% CI, 1.2-1.9, p<0.001) were independently associated with 1-year mortality. We provide a possible explanation for the complementary prognostic value of those three biomarkers in our cohort, where coincidence of heart failure and inflammatory pulmonary disease was common and also related to worse outcome. CONCLUSIONS Our evaluation of biomarkers in patients with acute dyspnea suggests that MR-proANP, sST2, and CgA are strong, independent and complementary outcome predictors. MR-proANP is considered a specific marker of cardiac stretch, sST2 might reflect both inflammation and cardiac stretch, and CgA obviously indicates neuroendocrine activation in various diseases.

Pro-A-type natriuretic peptide and pro- adrenomedullin predict progression of chronic kidney disease: the MMKD Study

A-type natriuretic peptide (ANP) and adrenomedullin (ADM) are potent hypotensive, diuretic, and natriuretic peptides involved in maintaining cardiovascular and renal homeostasis. We conducted a prospective 7-year study of 177 nondiabetic patients with primary chronic kidney disease to see if ANP and ADM plasma concentrations predict the progression of their disease, using novel sandwich immunoassays covering the midregional epitopes of the stable prohormones (MRproANP and MR-proADM). Progression of chronic kidney disease was defined as doubling of baseline serum creatinine and/or terminal renal failure, which occurred in 65 patients. Analysis of the receiver operating characteristic curve for the prediction of renal endpoints showed similar areas under the curve for the glomerular filtration rate (GFR) (0.838), MR-proANP (0.810), and MRproADM (0.876), respectively, as did the Kaplan-Meier curve analyses of the patients stratified according to the median of the respective markers. In separate multiple Cox-proportional hazard regression analyses, increased plasma concentrations of both peptides were each strongly predictive of the progression of chronic kidney disease after adjustments for age, gender, GFR, proteinuria and amino-terminal pro-B-type natriuretic peptide. Our study suggests that MR-proANP and MR-proADM are useful new markers of progression of primary nondiabetic chronic kidney disease.

Biochemical diagnosis of impaired left ventricular ejection fraction--comparison of the diagnostic accuracy of brain natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP).

Abstract The aim of the present investigation was to evaluate the diagnostic accuracy of brain natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) for the detection of mild/moderate and severe impairment of left ventricular ejection fraction (LVEF). In 180 subjects BNP and NT-proBNP were measured by two novel fully automated chemiluminescent assays (Bayer and Roche methods). LVEF as determined by echocardiography was categorized as normal (>60%), mildly/moderately reduced (35–60%) and severely diminished (<35%). Discriminating between patients with LVEF<35% (n=32) and subjects with LVEF ≥35% (n=148), receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.912 for BNP and of 0.896 for NT-proBNP (difference 0.016, p=0.554). In contrast, BNP displayed an AUC of 0.843and NT-proBNP an AUC of 0.927 (difference of 0.084, p=0.034) when comparing patients with LVEF 35–60% (n=37) and individuals with LVEF >60% (n=111). Evaluation of discordant false classifications at cut-off levels with the highest diagnostic accuracy showed advantages for BNP in the biochemical diagnosis of LVEF<35% (4 misclassifications by BNP and 25 by NT-proBNP, p<0.001) and for NT-proBNP in the detection of LVEF 35–60% (25 misclassifications by BNP and 7 by NT-proBNP, p=0.002). In conclusion, the present study indicates a different diagnostic accuracy of BNP and NT-pro-BNP for the detection of mildly/moderately reduced LVEF and severely diminished LVEF. Advantages of BNP may be advocated for the biochemical diagnosis of more severely impaired LVEF, while NT-proBNP might be a more discerning marker of early systolic left ventricular dysfunction.