Adrenomedullin in patients at high risk for pulmonary hypertension.
BACKGROUND
Adrenomedullin is a newly identified peptide with profound hypotensive effects. We investigated perioperative adrenomedullin levels among patients with congenital heart disease with and without pulmonary hypertension.


METHODS
Levels of plasma adrenomedullin, endothelin-1, and nitric oxide metabolites were measured in three groups: (1) low pulmonary flow (n=11); (2) high flow/low pulmonary arterial pressure (less than 60% systemic pressure) (n=9); and (3) high flow/high pressure (n=10). Samples were obtained preoperatively, on and off pump, and 3, 6, and 12 hours after bypass.


RESULTS
Adrenomedullin levels were highest in the low pulmonary flow group (189.7+/-15 pg/mL low flow versus 103.1+/-9.5 pg/mL high flow/low pulmonary and 139+/-17.5 pg/mL high flow/high pressure at 12 hours; p < or = 0.05). The arterial pressure/systemic pressure remained significantly lower in the high flow/low pulmonary pressure compared with the high flow/high pressure group (0.37+/-0.08 versus 0.62+/-0.11; p < 0.005). Perioperative endothelin-1 and nitric oxide levels remained low in the low pulmonary flow group but increased progressively in both high flow groups.


CONCLUSIONS
Circulating plasma adrenomedullin appears to affect baseline vascular tone in patients with intact endothelial function. It may interact with nitric oxide and endothelin-1 to help regulate blood pressure perioperatively in patients with congenital heart disease.
Vijay
P
P
Section of Cardiothoracic Surgery, Indiana University School of Medicine, Indianapolis 46202-5125, USA. pvijay@iupui.edu
Szekely
L
L
Sharp
T G
TG
Miller
A
A
Bando
K
K
Brown
J W
JW
D053607:Adrenomedullin; D001794:Blood Pressure; D002675:Child, Preschool; D019332:Endothelin-1 / Q000097:blood; D005260:Female; D006330:Heart Defects, Congenital / Q000097:blood / Q000150:complications* / Q000601:surgery; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology*; D008297:Male; D009569:Nitric Oxide / Q000097:blood; D010455:Peptides / Q000097:blood*; D011652:Pulmonary Circulation / Q000502:physiology; D012307:Risk Factors
D019332:Endothelin-1; D010455:Peptides; D053607:Adrenomedullin; D009569:Nitric Oxide