Early, intracoronary growth hormone administration attenuates ventricular remodeling in a porcine model of myocardial infarction.
OBJECTIVE
Ventricular remodeling is a common corollary of myocardial infarction. We hypothesized that this process may be attenuated by growth hormone, administered as a single high-dose, selectively in the infarct zone, early postmyocardial infarction.


METHODS
In 35 pigs (29+/-4 kg), myocardial infarction was generated by inflation of an over-the-wire angioplasty balloon in the circumflex artery for 60 min and 5 further pigs were sham-operated. Ten minutes after reperfusion, the pigs were randomized (2:1) to either growth hormone (1 IU/kg) (n=23) or normal saline (n=12), delivered via the balloon catheter. All survivors were treated with captopril and were sacrificed 4 weeks after myocardial infarction.


RESULTS
Compared to controls, growth hormone-treated animals displayed lower heart weight (4.1+/-0.5 g/kg body weight, versus 3.4+/-0.4 g/kg, respectively, p=0.003) and dimensions (left ventricular short axis diameter 46+/-7 mm versus 37+/-6 mm, p=0.01; right ventricular short axis diameter 38+/-7 mm versus 30+/-5 mm p=0.001). Growth hormone increased wall thickness in the infarct (6.0+/-1.8 in controls versus 9.9+/-3.7 in treated animals, p=0.004) and non-infarct zones (10.6+/-1.8 in controls versus 15.5+/-3.8 in treated animals, p=0.0006) and produced higher (p<0.05) microvascular density in both zones.


CONCLUSIONS
Intracoronary administration of growth hormone attenuates left and right ventricular remodeling by inducing hypertrophy and by enhancing angiogenesis.
Mitsi
A C
AC
Department of Cardiology, University of Ioannina, 1 Stavrou Niarxou Avenue, 45110 Ioannina, Greece.
Hatzistergos
K E
KE
Niokou
D
D
Pappa
L
L
Baltogiannis
G G
GG
Tsalikakis
D G
DG
Papalois
A
A
Kyriakides
Z S
ZS
Malamou-Mitsi
V
V
Kolettis
T M
TM
D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage; D002216:Captopril / Q000008:administration & dosage; D004195:Disease Models, Animal; D013006:Growth Hormone / Q000008:administration & dosage* / Q000378:metabolism*; D006801:Humans; D009203:Myocardial Infarction / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D013552:Swine; D020257:Ventricular Remodeling / Q000187:drug effects*
D000959:Antihypertensive Agents; D013006:Growth Hormone; D002216:Captopril