Thenral Socrates

Use of Myeloperoxidase for Risk Stratification in Acute Heart Failure

BACKGROUND Myeloperoxidase (MPO) is a biomarker of inflammation and oxidative stress produced by neutrophils, monocytes, and endothelial cells. Concentrations of MPO predict mortality in patients with chronic heart failure. This study sought to investigate the diagnostic accuracy and prognostic value of MPO in patients with acute heart failure (AHF). METHODS We prospectively enrolled 667 patients presenting to the emergency department with dyspnea and observed them for 1 year. MPO and B-type natriuretic peptide (BNP) were measured at presentation. Two independent cardiologists adjudicated final discharge diagnoses. RESULTS MPO concentrations were similar in patients with AHF (n = 377, median 139 pmol/L) and patients with noncardiac causes of dyspnea (n = 290, median 150 pmol/L, P = 0.26). The diagnostic accuracy of MPO for AHF was limited [area under the ROC curve (AUC) 0.53] and inferior to that of BNP (AUC 0.95, P < 0.001). In patients with AHF, MPO concentrations above the lowest tertile (MPO >99 pmol/L) were associated with significantly increased 1-year mortality (hazard ratio 1.58, P = 0.02). The combination of MPO (< or = 99 vs >99 pmol/L) and BNP (median of < or = 847 vs >847 ng/L) improved the prediction of 1-year mortality (hazard ratio 2.80 for both variables increased vs both low, P < 0.001). After adjustment for cardiovascular risk factors in multivariable Cox proportional hazard analysis, increases in MPO contributed significantly toward the prediction of 1-year mortality (hazard ratio 1.51, P = 0.045). CONCLUSIONS MPO is an independent predictor of 1-year mortality in AHF, is additive to BNP, and could be helpful in identifying patients with a favorable prognosis despite increased BNP concentrations.

Central venous pressure and impaired renal function in patients with acute heart failure

To determine the relationship between central venous pressure (CVP) and renal function in patients with acute heart failure (AHF) presenting to the emergency department.

Effect and Clinical Prediction of Worsening Renal Function in Acute Decompensated Heart Failure

We aimed to establish the prevalence and effect of worsening renal function (WRF) on survival among patients with acute decompensated heart failure. Furthermore, we sought to establish a risk score for the prediction of WRF and externally validate the previously established Forman risk score. A total of 657 consecutive patients with acute decompensated heart failure presenting to the emergency department and undergoing serial creatinine measurements were enrolled. The potential of the clinical parameters at admission to predict WRF was assessed as the primary end point. The secondary end point was all-cause mortality at 360 days. Of the 657 patients, 136 (21%) developed WRF, and 220 patients had died during the first year. WRF was more common in the nonsurvivors (30% vs 41%, p = 0.03). Multivariate regression analysis found WRF to independently predict mortality (hazard ratio 1.92, p <0.01). In a single parameter model, previously diagnosed chronic kidney disease was the only independent predictor of WRF and achieved an area under the receiver operating characteristic curve of 0.60. After the inclusion of the blood gas analysis parameters into the model history of chronic kidney disease (hazard ratio 2.13, p = 0.03), outpatient diuretics (hazard ratio 5.75, p <0.01), and bicarbonate (hazard ratio 0.91, p <0.01) were all predictive of WRF. A risk score was developed using these predictors. On receiver operating characteristic curve analysis, the Forman and Basel prediction rules achieved an area under the curve of 0.65 and 0.71, respectively. In conclusion, WRF was common in patients with acute decompensated heart failure and was linked to significantly worse outcomes. However, the clinical parameters failed to adequately predict its occurrence, making a tailored therapy approach impossible.

Copeptin and risk stratification in patients with acute dyspnea.

IntroductionThe identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of Copeptin, the C-terminal part of the vasopressin prohormone alone and combined to N-terminal pro B-type natriuretic peptide (NT-proBNP) in patients with acute dyspnea.MethodsWe conducted a prospective, observational cohort study in the emergency department of a university hospital and enrolled 287 patients with acute dyspnea.ResultsCopeptin levels were elevated in non-survivors (n = 29) compared to survivors at 30 days (108 pmol/l, interquartile range (IQR) 37 to 197 pmol/l) vs. 18 pmol/l, IQR 7 to 43 pmol/l; P < 0.0001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.83 (95% confidence interval (CI) 0.76 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for Copeptin, NT-proBNP and BNP, respectively (Copeptin vs. NTproBNP P = 0.21; Copeptin vs. BNP P = 0.002). When adjusted for common cardiovascular risk factors and NT-proBNP, Copeptin was the strongest independent predictor for short-term mortality in all patients (HR 3.88 (1.94 to 7.77); P < 0.001) and especially in patients with acute decompensated heart failure (ADHF) (HR 5.99 (2.55 to 14.07); P < 0.0001). With the inclusion of Copeptin to the adjusted model including NTproBNP, the net reclassification improvement (NRI) was 0.37 (P < 0.001). An additional 30% of those who experienced events were reclassified as high risk, and an additional 26% without events were reclassified as low risk.ConclusionsCopeptin is a new promising prognostic marker for short-term mortality independently and additive to natriuretic peptide levels in patients with acute dyspnea.

ΔF508 mutation results in impaired gastric acid secretion

The cystic fibrosis transmembrane conductance regulator (CFTR) is recognized as a multifunctional protein that is involved in Cl– secretion, as well as acting as a regulatory protein. In order for acid secretion to take place a complex interaction of transport proteins and channels must occur at the apical pole of the parietal cell. Included in this process is at least one K+ and Cl– channel, allowing for both recycling of K+ for the H,K-ATPase, and Cl– secretion, necessary for the generation of concentrated HCl in the gastric gland lumen. We have previously shown that an ATP-sensitive potassium channel (KATP) is expressed in parietal cells. In the present study we measured secretagogue-induced acid secretion from wild-type and ΔF508-deficient mice in isolated gastric glands and whole stomach preparations. Secretagogue-induced acid secretion in wild-type mouse gastric glands could be significantly reduced with either glibenclamide or the specific inhibitor CFTR-inh172. In ΔF508-deficient mice, however, histamine-induced acid secretion was significantly less than in wild-type mice. Furthermore, immunofluorescent localization of sulfonylurea 1 and 2 failed to show expression of a sulfonylurea receptor in the parietal cell, thus further implicating CFTR as the ATP-binding cassette transporter associated with the KATP channels. These results demonstrate a regulatory role for the CFTR protein in normal gastric acid secretion.

Plasma neutrophil gelatinase-associated lipocalin for the prediction of acute kidney injury in acute heart failure

IntroductionThe accurate prediction of acute kidney injury (AKI) in patients with acute heart failure (AHF) is an unmet clinical need. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel sensitive and specific marker of AKI.MethodsA total of 207 consecutive patients presenting to the emergency department with AHF were enrolled. Plasma NGAL was measured in a blinded fashion at presentation and serially thereafter. The potential of plasma NGAL levels to predict AKI was assessed as the primary endpoint. We defined AKI according to the AKI Network classification.ResultsOverall 60 patients (29%) experienced AKI. These patients were more likely to suffer from pre-existing chronic cardiac or kidney disease. At presentation, creatinine (median 140 (interquartile range (IQR), 91 to 203) umol/L versus 97 (76 to 132) umol/L, P < 0.01) and NGAL (114.5 (IQR, 67.1 to 201.5) ng/ml versus 74.5 (60 to 113.9) ng/ml, P < 0.01) levels were significantly higher in AKI compared to non-AKI patients. The prognostic accuracy for measurements obtained at presentation, as quantified by the area under the receiver operating characteristic curve was mediocre and comparable for the two markers (creatinine 0.69; 95%CI 0.59 to 0.79 versus NGAL 0.67; 95%CI 0.57 to 0.77). Serial measurements of NGAL did not further increase the prognostic accuracy for AKI. Creatinine, but not NGAL, remained an independent predictor of AKI (hazard ratio (HR) 1.12; 95%CI 1.00 to 1.25; P = 0.04) in multivariable regression analysis.ConclusionsPlasma NGAL levels do not adequately predict AKI in patients with AHF.

Interleukin family member ST2 and mortality in acute dyspnoea

Abstract.  Socrates T, deFilippi C, Reichlin T, Twerenbold R, Breidhardt T, Noveanu M, Potocki M, Reiter M, Arenja N, Heinisch C, Meissner J, Jaeger C, Christenson R, Mueller C. (Department of Internal Medicine, University Hospital Basel, Basel, Switzerland; University of Maryland, School of Medicine, Baltimore, MD, USA). Interleukin family member ST2 and mortality in acute dyspnoea. J Intern Med 2010; 268: 493–500.

Impact of a high-dose nitrate strategy on cardiac stress in acute heart failure : a pilot study

Abstract.  Breidthardt T, Noveanu M, Potocki M, Reichlin T, Egli P, Hartwiger S, Socrates T, Gayat E, Christ M, Mebazaa A, Mueller C (University Hospital, Basel, Switzerland, University Paris, Paris, France, and Klinikum Nürnberg, Nürnberg, Germany). Impact of a high‐dose nitrate strategy on cardiac stress in acute heart failure: a pilot study. J Intern Med 2010; 267: 322–330.

Pathophysiology of Lower Extremity Edema in Acute Heart Failure Revisited

BACKGROUND The pathophysiology and key determinants of lower extremity edema in patients with acute heart failure are poorly investigated. METHODS We prospectively enrolled 279 unselected patients presenting to the Emergency Department with acute heart failure. Lower extremity edema was quantified at predefined locations. Left ventricular ejection fraction, central venous pressure quantifying right ventricular failure, biomarkers to quantify hemodynamic cardiac stress (B-type natriuretic peptide), and the activity of the arginine-vasopressin system (copeptin) also were recorded. RESULTS Lower extremity edema was present in 218 (78%) patients and limited to the ankle in 22%, reaching the lower leg in 40%, reaching the upper leg in 11%, and was generalized (anasarca) in 3% of patients. Patients in the 4 strata according to the presence and extent of lower leg edema had comparable systolic blood pressure, left ventricular ejection fraction, central venous pressure, and B-type natriuretic peptide levels, as well as copeptin and glomerular filtration rate (P=NS for all). The duration of dyspnea preceding the presentation was longer in patients with more extensive edema (P=.006), while serum sodium (P=.02) and serum albumin (P=.03) was lower. CONCLUSION Central venous pressure, hemodynamic cardiac stress, left ventricular ejection fraction, and the activity of the arginine-vasopressin system do not seem to be key determinants of the presence or extent of lower extremity edema in acute heart failure.

AMP-activated protein kinase : a physiological off switch for murine gastric acid secretion

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) has been shown to be a metabolic energy regulator in various cells. Activation is a direct result of rising AMP concentration coupled with falling adenosine triphosphate (ATP). AMPK activation during metabolic stress consequently reduces cellular ATP consumption. The gastric parietal cell has a large abundance of mitochondria per cell volume due to the numerous energy-dependent transporters and channels responsible for acid secretion. We identified AMPK in the parietal cell as a metabolic energy regulator that can switch acid secretion off as cellular ATP levels fall. AMPK presence in murine gastric glands was evaluated by immunofluorescent localization. We used a digital imaging system to monitor acid secretion as observed by proton efflux from parietal cells in hand-dissected gastric glands loaded with the pH-sensitive dye 2′,7′-bis-(2-carboxyethyl)-5-(and 6)-carboxyfluorescein. Individual murine gastric glands were exposed to histamine, pentagastrin, or carbachol. AMPK was pharmacologically activated with 5-aminoimidazole-4-carboxamide-1-β-d-riboside (AICAR) monophosphate or inhibited with 6-[4-(2-piperidin-1-yl-ethoxy)-phenyl)]-3-pyridin-4-yl-pyyrazolo[1,5-a] pyrimidine (compound C) or ATP. Acid secretion was evaluated under these conditions as the rate of intracellular pH recovery. In addition, whole-stomach pH measurements were performed. Immunofluorescent localization confirmed the presence of AMPK in gastric mucosa. Exposure to AICAR monophosphate significantly reduced secretagogue-induced acid secretion; addition of compound C or ATP restored acid secretion. Our results indicate that secretagogue-induced acid secretion could be significantly reduced with AMPK activation and restored with its deactivation. We therefore propose the AMPK as a cellular metabolic off switch for gastric acid secretion.