The Role Of Adrenomedullin And Angiotensin Ⅱ In Pulmonary Hypertension Associated With Congenital Heart Disease

Objective: Adrenomedullin (ADM) is a novel hypotensive peptide that was isolated from human phenochromocytoma. It was demonstrated that ADM levels were increased in patients with congestive heart failure, hypertension, and renal failure etc. But the relation between ADM and pulmonary hypertension (PH) associated with congenital heart disease (CHD) has not been fully understood. The present study was to investigate the changes of plasma ADM and angiotensinâ…¡ (Angâ…¡) levels in patients with CHD, to study the correlation between plasma ADM and Angâ…¡.Methods: Plasma ADM and Angâ…¡ levels were determined by radioimmunoassay in 32 patients with CHD and 14 healthy control subjects. The patients with CHD were divided into four groups according to pulmonary artery systolic pressure /system artery systolic pressure (PASP/SAP): high pulmonary flow group (n=8), mild-PH group (n=8), moderate-PH group (n=8), severe-PH group (n=8) and healthy control group (n=14). Samples were obtained on admission and before cardiopulmonary bypass.Results: 1. Plasma ADM and Angâ…¡ level in high pulmonary flow group H were apparently higher than those of control group ,respectively ( P<0.05); Plasma ADM and Angâ…¡ in cases of mild-PH were markedly higher those of high pulmonary flow group ( P<0.05) ; Plasma ADM and Angâ…¡ level in cases of moderate or severe-PH group were apparently higher than those of mild-PH ( P<0.05) ; Plasma ADM level in cases of severe-PH group were apparently higher than those of moderate-PH ( P<0.05); but plasma Angâ…¡ level in cases of severe-PH group were apparently lower than those of moderate-PH ( P<0.05). 2. Plasma ADM of pulmonary artery in cases of CHD positively correlated with PASP/SAP. (r = 0.951, P<0.01). 3. Plasma ADM level of pulmonary artery was apparently higher than that of pulmonary vein (P<0.05). 4. Plasma Angâ…¡level of pulmonary vein was apparently higher than that of pulmonary artery (P<0.05). 5. Plasma ADM of elbow vein (except severe-PH group) positively correlated with plasma Angâ…¡ of elbow vein (except severe-PH group) (r=0.946, P<0.01).Conclusion: During the progression of PH in cases of CHD plasma ADM and Angâ…¡ played an important role in the development of PH. ADM might be involved in protective mechanism against further increase of pulmonary arterial pressure. ADM could be used as a reliable indicator of the severity of PH associated with CHD.