Dagmar Kunz

brain natriuretic peptide levels predict functional capacity in patients with chronic heart failure.

OBJECTIVES The goal of this study was to determine if brain natriuretic peptide (BNP) levels are associated with exercise capacity in patients with chronic heart failure (HF). BACKGROUND Plasma levels of BNP are increased subject to the degree of systolic and diastolic left ventricular dysfunction in patients with chronic HF. Exercise testing is useful to assess functional capacity and prognosis in chronic HF. METHODS We prospectively studied 70 consecutive patients with chronic HF (60.3 +/- 10.4 years, 51 men) referred for cardiopulmonary exercise testing. Resting BNP was obtained after 10 min of supine rest before symptom-limited bicycle exercise testing. RESULTS In patients with chronic HF, BNP levels correlated with oxygen uptake (VO(2)), both at anaerobic threshold (VO(2)AT: r = -0.54, p < 0.001) and peak exercise (peak VO(2): r = -0.56, p < 0.001). Impairment of ventilatory efficiency (EqCO(2): r = 0.43, p < 0.001) and maximum exercise level (W % predicted: r = -0.44, p < 0.05) correlated less well with BNP. There was a significant inverse correlation between left ventricular ejection fraction and BNP (r = -0.50, p < 0.05). Brain natriuretic peptide discriminated well chronic HF patients with a peak VO(2) <10 ml/min/kg (area under the receiver operating characteristic [ROC] 0.93) or <14 ml/min/kg (area under the ROC 0.72). A BNP >316 pg/ml was associated with a risk ratio of 6.8 (95% confidence interval, 2.3 to 19.8) for a reduced exercise capacity with a peak VO(2) <14 ml/min/kg. CONCLUSIONS Brain natriuretic peptide is clearly associated with exercise capacity in chronic HF. Brain natriuretic peptide levels show a significant correlation with the impairment of VO(2) at peak exercise and anaerobic threshold. Brain natriuretic peptide is able to differentiate between chronic HF patients with moderately and severely impaired exercise capacity.

Brain natriuretic peptide predicts right heart failure in patients with acute pulmonary embolism

BACKGROUND Plasma levels of brain natriuretic peptide (BNP) are increased in patients with left heart failure. In patients with severe pulmonary embolism (PE), primary right ventricular (RV) dysfunction is frequent. Little is known about BNP secretion in acute RV failure. METHODS We prospectively studied 50 consecutive patients with confirmed PE (age range, 57 +/- 19 years; 36 men). PE was confirmed with pulmonary angiography, spiral computed tomography, or echocardiography and subsidiary analyses. On admission, echocardiography and BNP measurements were performed in all patients. RESULTS Patients without RV dysfunction had significantly lower BNP levels than patients with RV dysfunction (55 +/- 69 pg/mL vs 340 +/- 362 pg/mL, P <.001). There was a significant correlation between RV end-diastolic diameter and BNP (r = 0.43, P <.05). BNP discriminated patients with or without RV dysfunction (area under the receiver operating characteristic curve, 0.78; 95% CI, 0.64-0.92). A BNP >90 pg/mL was associated with a risk ratio of 28.4 (95% CI, 3.22-251.12) for the diagnosis of RV dysfunction. All patients without LV systolic dysfunction who had syncope necessitating cardiopulmonary resuscitation had normal BNP levels. Patients with RV dysfunction had significantly more in-hospital complications (cardiogenic shock, inotropic therapy, mechanical ventilation). However, BNP levels were not predictive of mortality or in-hospital complications. CONCLUSIONS BNP levels are frequently increased in patients with PE who have RV dysfunction, whereas patients without RV dysfunction show reference range BNP levels in the absence of left ventricular dysfunction. In acute PE, BNP elevation is highly predictive of RV dysfunction, but not of in-hospital complications and mortality.

Usefulness of brain natriuretic peptide release as a surrogate marker of the efficacy of long-term cardiac resynchronization therapy in patients with heart failure

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Evaluation of serum levels of solubilized adhesion molecules and cytokine receptors in coronary heart disease

OBJECTIVES The diagnostic importance of circulating solubilized tumor necrosis factor-alpha receptor II (sTNF-alphaRII) and interleukin-2 receptor in coronary heart disease (CHD) was evaluated. In addition, these variables were correlated with solubilized adhesion molecule levels (i.e., intracellular adhesion molecule [ICAM], vascular cell adhesion molecule [VCAM], and E-selectin). BACKGROUND Atherosclerosis is considered to be a chronic inflammatory process. Because the immunologic network presents an abundance of positive and negative feedback mechanisms, information obtained from different immunologic variables might be highly redundant. METHODS In a cross-sectional study design, 60 patients with angiographically proven CHD were compared with 60 individuals who had undergone coronary angiography but in whom no evidence of stenosis could be found (control subjects). Angiography was performed at least one year before the study. Cytokine levels were determined by enzyme-linked immunosorbent assay technique and evaluated by univariate and multivariate statistical methods. RESULTS All immunologic variables except E-selectin (p = 0.08) significantly discriminated between patients and control subjects. Coronary artery bypass graft surgery after angiography did not lead to significant differences in the variables investigated in the patients with bypass surgery as compared with the subjects without bypass surgery. Receiver-operating characteristics analysis showed comparable test accuracy for solubilized adhesion molecules and cytokine receptors. Multivariate logistic regression analysis, including age, revealed that only ICAM and sTNF-alphaRII were independently correlated with the presence of CHD. Patients belonging to the third tertile of at least one of these two variables demonstrated a 1.6- to 2-fold increased relative risk for the presence of CHD. CONCLUSIONS We concluded that both circulating ICAM and TNF-alphaRII should be further evaluated as markers for atherosclerotic changes in the coronary system.

Urotensin II in patients with chronic heart failure

Human Urotensin II (hU‐II) is the most potent vasoconstrictor known to date. HU‐II receptors are predominant in the human heart and arterial vessels, suggesting hU‐II to be of importance as a cardiovascular mediator.

[12] Functional imaging of mitochondrial redox state

Publisher Summary The use of intrinsic fluorophores allows evaluation of the function of mitochondrial oxidative phosphorylation without having the phototoxic side effects of the various fluorescent mitochondrial dyes. To detect the changes of the mitochondrial redox state in response to alterations of oxidative phosphorylation (OxPhos) at the single cell level, the fluorescence changes of the α-lipoamide dehydrogenase flavin moiety by confocal microscopy is investigated. Functional imaging of the mitochondrial redox state can be performed by microscopic detection of the flavoprotein fluorescence of the mitochondrially localized α-lipoamide dehydrogenase, which is in tight redox equilibrium with the mitochondrial NAD system. Direct detection of the NAD(P)H fluorescence signal for mitochondrial NAD redox state determinations can be performed in digitonin-permeabilized cells or saponin-permeabilized muscle fibers at considerably higher sensitivity. The procedure is applicable for cultured cells having low mitochondrial content. For the determination of putative heterogeneities of the mitochondrial redox state in permeabilized muscle fibers, the application of Fp/NAD(P)H ratio imaging is advantageous, because it offers an increased sensitivity with respect to metabolic alterations of the fluorescence signals. In sum, the monitoring of intrinsic fluorophores allows one to obtain insights into the mitochondrial function of single living cells, avoiding the problems of phototoxicity and photobleaching.