Attenuation of cardiac remodelling by endocardial injection of erythropoietin: ultrasonic strain-rate imaging in a model of hibernating myocardium.
OBJECTIVE
The aim of this study was to investigate whether erythropoietin (EPO) has cardioprotective effects in a chronic myocardial ischaemia model regarding strain-rate imaging parameters during dobutamine stress echocardiography (DSE).


RESULTS
An ameroid constrictor was placed around the circumflex artery in 13 pigs to induce hibernating myocardium by a chronic vessel occlusion. The pigs were randomized 14 days later: seven pigs receiving 10,000 U EPO and six pigs receiving placebo injected into the ischaemic region using a NOGAtrade mark-guided transendocardial catheter. At weeks 2 and 6, animals were examined by DSE, electromechanical mapping, and coronary angiography. During incremental dobutamine infusion, regional radial function was monitored by measuring peak systolic strain-rates (SRsys), systolic strains (epsilonsys), and post-systolic strains (epsilonps). At week 6, the animals were pathohistologically investigated. Echocardiography revealed 2.2+/-0.8 hypokinetic segments in the EPO-treated animals in comparison with 3.3+/-0.9 akinetic segments per animal in the controls. The mean ejection fraction was reduced in the control group (55+/-3 vs. 66+/-4%, P=0.057). Strain-rate imaging revealed ischaemic myocardium in EPO-treated animals and non-viable myocardium in the controls (P=0.0001). Histological analysis of the ischaemic region revealed a reduction of myocardial fibrosis (8+/-1 vs. 27+/-5%) in the EPO-treated group. The transmural extension of fibrosis and the echocardiographic deformation data correlated in the posterior walls (EPO group): epsilonsys at rest r=0.83; peak SRsys during dobutamine stimulation r=0.92, P=0.01.


CONCLUSIONS
Endocardial EPO injection may induce cardioprotective effects in chronic ischaemic myocardium and helps to obtain the myocardial contractile reserve, objectified by ultrasonic strain-rate imaging.
Schneider
Carsten
C
Department of Cardiology, Asklepios Klinik, St. Georg II. Med. Abteilung (Kardiologie), Lohmühlenstrasse 5, 20099 Hamburg, Germany. dr_c_schneider@hotmail.com
Jaquet
Kai
K
Malisius
Rainer
R
Geidel
Stephan
S
Bahlmann
Edda
E
Boczor
Sigrid
S
Rau
Thomas
T
Antz
Matthias
M
Kuck
Karl-Heinz
KH
Krause
Korff
K
D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003250:Constriction; D003327:Coronary Disease / Q000503:physiopathology; D004298:Dopamine / Q000494:pharmacology*; D004452:Echocardiography; D004921:Erythropoietin / Q000494:pharmacology*; D015552:Injections, Intralesional; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011897:Random Allocation; D011994:Recombinant Proteins; D013314:Stress, Mechanical; D013552:Swine; D013599:Systole; D020257:Ventricular Remodeling / Q000187:drug effects*
D002316:Cardiotonic Agents; D011994:Recombinant Proteins; D004921:Erythropoietin; D004298:Dopamine