PLASMA-CONCENTRATIONS OF ADRENOMEDULLIN CORRELATE WITH THE EXTENT OF PULMONARY-HYPERTENSION IN PATIENTS WITH MITRAL-STENOSIS

Objective-To examine the pathophysiological significance of adrenomedu llin in the pulmonary circulation by investigating the relation betwee n plasma concentrations of adrenomedullin and central haemodynamics in patients with mitral stenosis. Methods-Plasma concentrations of adren omedullin in blood samples obtained from the femoral vein, pulmonary a rtery, left atrium, and aorta were measured by a newly developed speci fic radioimmunoassay in 23 consecutive patients with mitral stenosis ( 16 females and seven males, aged 53 (10) years (mean (SD)) who were un dergoing percutaneous mitral commissurotomy. Results-Patients with mit ral stenosis had higher concentrations of adrenomedullin than age matc hed normal controls (3.9 (0.3) v 2.5 (0.3) pmol/l, p < 0.001). There w as a reduction in adrenomedullin concentrations between the pulmonary artery and the left atrium (3.8 (0.2) v 3.2 (0.4) pmol/l, p < 0.001). The venous concentrations of adrenomedullin correlated with mean pulmo nary artery pressure (r = 0.65, p < 0.001), total pulmonary vascular r esistance (r = 0.83, p < 0.0001), and pulmonary vascular resistance (r = 0.65, p < 0.001). Plasma concentrations of adrenomedullin did not c hange immediately after percutaneous mitral commissurotomy; however, t hey decreased significantly one week later. Conclusions-Plasma concent rations of adrenomedullin are increased in patients with mitral stenos is. This may help to attenuate the increased pulmonary arterial resist ance in secondary pulmonary hypertension due to mitral stenosis.