Acute effects of 17beta-estradiol on left internal mammary graft after coronary artery bypass grafting.
BACKGROUND
Vasospasm of arterial conduits used for coronary surgical procedures is an important cause of postoperative graft failure. Mounting experimental evidence suggests that estrogen reverses acetylcholine-induced vasospasm of the coronary arteries in animals and humans. Estrogen also affects endothelium-derived constrictor factors. We therefore investigated the in vivo vasomotor responses to transdermal 17beta-estradiol of the left internal mammary artery (LIMA) grafted on the anterior descending coronary artery.


METHODS
We studied 20 women, mean age of 62 +/- 7.2 years (range, 48 to 73 years), who had undergone cardiopulmonary bypass for coronary artery bypass grafting. They received transdermal 17beta-estradiol on the fifth day after operation. The diameter, cross-sectional area, and blood flow of the LIMA graft were measured by transthoracic color Doppler echography before (basal values) and after the transdermal administration of 50 microg of 17beta-estradiol (control).


RESULTS
LIMA graft vasodilation after the administration of 17beta-estradiol was observed. A significant increase in diameter (2.06 +/- 0.4 mm versus 2.37 +/- 0.28 mm; p = 0.035) and cross-sectional area (3.45 +/- 1. 2 mm2 versus 4.24 +/- 1 mm2; p = 0.039) was registered. The LIMA graft mean flow increased by 49% (44.76 +/- 27.19 mL/min versus 56.62 +/- 27.69 mL/min), but this increase was not statistically significant (p = 0.06).


CONCLUSIONS
The acute postoperative transdermal administration of 17beta-estradiol induced a significant increase of LIMA graft diameter and cross-sectional area in postmenopausal women who underwent coronary artery bypass grafting. The LIMA graft vasodilation was also associated with an improvement in LIMA blood flow.
Polvani
Gianluca
G
Department of Cardiac Surgery, University of Milan, Centro Cardiologico Monzino IRCCS, Italy. luca.polvani@cardiologicomonzino.it
Marino
Maria Rosa
MR
Roberto
Maurizio
M
Dainese
Luca
L
Parolari
Alessandro
A
Pompilio
Giulio
G
Di Matteo
Silvia
S
Fumero
Andrea
A
Cannata
Aldo
A
Barili
Fabio
F
Biglioli
Paolo
P
D000279:Administration, Cutaneous; D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods*; D003329:Coronary Vasospasm / Q000000981:diagnostic imaging / Q000188:drug therapy*; D018618:Echocardiography, Doppler, Color; D004958:Estradiol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D014664:Vasodilation / Q000187:drug effects
D004958:Estradiol