Abstract 17945: Abnormal Left Ventricular Torsion Assessed by Speckle Tracking Echocardiography in Orthotopic Heart Transplant Patients as Early Predictor of the Acute Myocardial Rejection

Abstract

Background LV torsion is a critical aspect of cardiac biomechanics and hold promise for better understanding the ventricular dysfunction. The aim of this study was to determine whether LV torsion assessed by 2D-speckle tracking imaging can predict rejection in transplanted hearts. Methods From Oct 2010 to Feb 2011, patients who had transplant and underwent echocardiogram as well as RV biopsies in our Center, were analyzed. The echocardiograms and RV biopsies were done within 3 days of each other. Patients who did not have any prior cardiac surgeries or valvular heart disease were analyzed for comparison (controls). Torsion measurements were performed off-line using commercially available software. Basal and apical short-axis views were used for measurement of torsion. LV torsion was calculated as (apical LV rotation minus basal LV rotation)/LV diastolic longitudinal length. By speckle tracking echocardiography, global longitudinal strain was also calculated in all the patients. LVEF was assessed using modified Simpson's method. Patients with incomplete data were excluded. Results 14 transplant patients were compared with 6 matching controls. 4 transplanted patients had a biopsy-confirmed rejection. Torsion, global strain and LVEF were all reduced in patients with rejection as compared to those without rejection and with controls. When mean value of torsion in controls was applied as a normal threshold to the study population, 75% (3/4) of the patients with rejection had an abnormal torsion despite normal LVEF. Torsion analysis provided a sensitivity and specificity of 75% and 70% for detecting rejection in transplant patients. Conclusion To our knowledge this is the first study to demonstrate the value of LV torsion in predicting rejection in patients post heart transplant. In patients with rejection, abnormal LV torsion at initial presentation can be utilized as an early non-invasive predictive marker to help in identification of these patients.