Speckle-tracking 2-dimensional strain echocardiography: a new noninvasive imaging tool to evaluate acute rejection in cardiac transplantation.
BACKGROUND
There remains no reliable non-invasive method to detect cardiac transplant rejection. Recently, speckle-tracking 2-dimensional strain echocardiography (2DSE) was shown to be sensitive in the early detection of myocardial dysfunction in various models of cardiomyopathy. We aim to determine if 2DSE-derived functional indices can detect cardiac transplant rejection.


METHODS
Heterotopic rat cardiac transplantation was performed in histocompatible isografts or histoincompatible allografts. Histologic rejection scores were determined. Short-axis, mid-left ventricular (LV) echocardiography was performed on Day 6 after transplantation. Conventional measures of function were measured, (including LV fractional shortening and ejection fraction) as well as 2DSE parameters.


RESULTS
Despite class IIIB rejection in allografts and no rejection in isografts, there was no difference between isografts vs allografts in fractional shortening (15% +/- 3% vs 12% +/- 3%) or ejection fraction (36% +/- 5% vs 26% +/- 6%; both not significant). In contrast, 2DSE revealed decreases between isografts and allografts in global radial strain (12.6% +/- 5.6% vs 1.1% +/- 0.2%, p < 0.05), peak radial systolic strain rate (3.10 +/- 0.74/s vs 0.54 +/- 0.13/s, p < 0.001), and peak circumferential systolic strain rate (-1.99 +/- 0.55 vs -0.43 +/- 0.11/s; p < 0.01).


CONCLUSIONS
Systolic strain imaging using 2DSE differentiates myocardial function between experimental cardiac transplant rejection in allografts and non-rejection in isografts. Therefore, 2DSE may be useful in early non-invasive detection of transplant rejection.
Pieper
Galen M
GM
Department of Surgery (Transplant Surgery), Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. gmpieper@mcw.edu
Shah
Akash
A
Harmann
Leanne
L
Cooley
Brian C
BC
Ionova
Irina A
IA
Migrino
Raymond Q
RQ
D000818:Animals; D004452:Echocardiography / Q000379:methods*; D006084:Graft Rejection / Q000000981:diagnostic imaging*; D016027:Heart Transplantation / Q000276:immunology* / Q000473:pathology / Q000502:physiology; D015778:Minor Histocompatibility Antigens / Q000276:immunology; D017534:Radial Artery / Q000000981:diagnostic imaging; D051381:Rats; D011917:Rats, Inbred Lew; D011920:Rats, Inbred WF; D013314:Stress, Mechanical; D013318:Stroke Volume; D013599:Systole; D014184:Transplantation, Homologous / Q000276:immunology / Q000473:pathology; D014185:Transplantation, Isogeneic / Q000276:immunology / Q000473:pathology; D016277:Ventricular Function, Left
D015778:Minor Histocompatibility Antigens