Influence of valve replacement on plasma endothelin-1 level in mitral stenosis.
OBJECTIVE
The rise of pressure in the pulmonary circulation during the course of mitral stenosis leads to pathomorphological changes and a reduction in vascular compliance. Endothelial dysfunction is also promoted, with increased expression of endothelin. This aim of this study was to evaluate whether the increase in endothelin-1 levels in pulmonary hypertension due to advanced mitral stenosis is reversible after valve replacement.


METHODS
Thirty-nine patients with isolated, longlasting post-rheumatic mitral stenosis were enrolled. During preoperative Swan-Ganz catheterization blood samples were withdrawn from the pulmonary artery and capillaries for measurement of endothelin-1 (ET-1). Similar examinations were performed six months after mitral valve replacement. Hemodynamic parameters were measured also during 25-W exercise effort.


RESULTS
The mean preoperative hemodynamic parameters of the pulmonary circulation were moderately increased. Mean plasma levels of ET-1 were about three-fold higher than normal. Capillary levels of ET-1 were significantly higher than those in the pulmonary artery (1.78+/-1.22 versus 1.03+/-1.16 pg/ml, p <0.05). There was no significant correlation between ET-1 level and any hemodynamic or clinical parameters, except NYHA functional class. After surgery, pulmonary capillary levels of ET-1 fell significantly, but were still high (1.78+/-1.22 versus 1.41+/-1.00 pg/ml); ET-1 levels in the pulmonary artery were unchanged. Patients with persistently high ET-1 levels had significantly worse exercise hemodynamic parameters, especially of pulmonary arterial compliance.


CONCLUSIONS
In patients with long-lasting, severe mitral stenosis, ET-1 levels remained increased and the ET-1 concentration gradient across the pulmonary circulation persisted for six months after valve replacement. High ET-1 capillary levels are correlated with poor exercise tolerance and poor exercise compliance of the pulmonary vessels.
Snopek
G
G
II Clinic of Valvular Heart Disease, National Institute of Cardiology, Warsaw, Poland.
Pogorzelska
H
H
Korewicki
J
J
D019332:Endothelin-1 / Q000097:blood*; D004730:Endothelium, Vascular / Q000503:physiopathology; D017079:Exercise Tolerance; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D008946:Mitral Valve Stenosis / Q000097:blood* / Q000503:physiopathology / Q000601:surgery; D011446:Prospective Studies
D019332:Endothelin-1