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Pneumologie 2009; 63 - A4
DOI: 10.1055/s-2009-1242144

Plasma big-endothelin in pre- versus postcapillary pulmonary hypertension

S Braun 1, A Schmeisser 2, G Hoeffken 1, M Halank 1
  • 1Medical Clinic I/Pneumology, Universitiy Hospital Carl Gustav Carus, Dresden
  • 2Medical Clinic/Cardiology, University Hospital Otto-von-Guericke, Magdeburg

Objective: Big-ET-1 seems to correlate with severity and prognosis in patients with precapillary pulmonary arterial hypertension as in patients with congestive left heart failure (CHF). While endothelin-receptor-antagonists (ERAs) became a milestone in medical therapy of PAH, ERAs failed to improve long-term clinical outcome in CHF patients. The objective of this case series is to compare plasma big-ET-1 levels in patients with precapillary pulmonary hypertension versus patients with CHF with and without postcapillary pulmonary hypertension and to correlate big-ET-1 plasma levels to hemodynamic parameters of right heart function.

Methods: Plasma big-ET-1 levels were obtained during right heart catheterization was performed in 24 patients with precapillary pulmonary hypertension and regular left ventricular function, in 37 patients with CHF and postcapillary pulmonary venous hypertension (PVH), in 14 patients with severe systolic left heart failure but without PVH and in 10 controls.

Results: Mean-big-ET-1 levels were 1.0 ± 0.1 fmol/ml in controls, 2.1 ± 0.5 fmol/ml in PAH, 2.7 ± 0.6 in CHF without PVH and 3,4 ± 0,5 fmol/ml in CHF with PVH. Big-ET-levels were significantly lower in controls compared to all other groups (p < 0.001). Despite significant higher pulmonary vascular resistance and pulmonary artery pressure in patients with precapillary PH big-ET-1 levels were significantly higher in CHF with postcapillary PH compared to the group with precapillary PH and compared to the group with CHF without PVH. No significant difference was found between the precapillary PH group and the CHF group without PVH. In PVH the correlation coefficient between big-ET-1 was 0.4 for PAPmean, 0,1 for TPG, 0.3 for PVR, 0.6 for RAP, 0.5 for RVEDP and -0.6 for SvO2 and CI. In pulmonary arterial hypertension the correlation coefficient between big-ET-1 was 0.3 for PAPmean, 0.15 for TPG, 0.27 for PVR, 0.8 for RAP, 0.7 for RVEDP and -0.6 for SvO2 and -0.5 for CI.

Conclusion: Despite higher pulmonary vascular resistance and pulmonary artery pressure in precapillary pulmonary hypertension we found significantly higher big-ET-1 levels in patients with chronic left heart failure with pulmonary venous hypertension. In pre- and postcapillary pulmonary hypertension correlations of plasma big-ET-1 levels were significantly lower to PVR and meanPAP compared to right heart filling pressures, cardiac index and mixed venous oxygen saturation (SvO2).