Direct left ventricle-to-coronary artery stent restores perfusion to chronic ischemic swine myocardium.
BACKGROUND
Direct left ventricle (LV)-to-coronary artery shunts (VSTENT) have been proposed as an alternative means of myocardial revascularization. The goal of this study was to examine quantitative changes in myocardial perfusion and possible mechanisms of revascularization with an LV-to-coronary shunt.


METHODS
Ameroid occluders were implanted on the proximal left anterior descending coronary artery (LAD) of 6 pigs to create chronic ischemia. Four weeks later, a VSTENT was placed to directly connect the distal LAD with the LV chamber. Animals survived for an additional 3 weeks and received periodic bromodeoxyuridine (BrdU) injections to identify dividing cells to identify and quantify angiogenesis. Regional myocardial perfusion (RMP) was measured with color microspheres under adenosine vasodilatory stress before and 3 weeks after VSTENT implantation. Vascularity was assessed histologically by an overall vascularity index and a growth index reflecting the density of BrdU-positive vascular cells.


RESULTS
Three weeks after VSTENT placement, RMP improved from 38.4% +/- 19.6% of non-ischemic flow to 86.8% +/- 13.7% in treated animals (P < .05). This benefit was accompanied by histological evidence of increased vascularity and vascular proliferation. Four of 5 animals had patent and functional devices at the end of the study.


CONCLUSIONS
Chronic VSTENT placement improves RMP and may promote arterial remodeling in chronically ischemic porcine myocardium.
Yi
Geng-Hua
GH
Department of Surgery, Division of Cardiothoracic Surgery, Columbia University College of Physicians and Surgeons, New York, New York, USA.
George
Isaac
I
He
Kun-Lun
KL
Lee
Myung Jea
MJ
Cahalan
Patrick
P
Zhang
Geping
G
Gu
Anguo
A
Klotz
Stefan
S
Burkhoff
Daniel
D
Wang
Jie
J
D000818:Animals; D002908:Chronic Disease; D003331:Coronary Vessels; D004195:Disease Models, Animal; D005260:Female; D006352:Heart Ventricles; D008297:Male; D017202:Myocardial Ischemia / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods*; D018919:Neovascularization, Physiologic; D015607:Stents; D013552:Swine