Myocardial Deformation Analysis by Echocardiographic Strain Imaging Allows Detection of Patients with Post-Transplant Coronary Stenoses in the Absence of Visible Wall Motion Alterations

Abstract

Background: Non-invasive detection of transplant coronary artery disease (TxCAD) for timing of angiographies is a major goal. However, because diffuse distal coronary narrowing is a major determinant of left ventricular (LV) dysfunction in Tx,CAD, wall motion alterations induced by coronary stenoses are less evident. Because echocardiographic speckle-tracking derived strain imaging reveals alterations in wall motion and myocardial deformation not detectable by conventional echocardiography and allows the distinction between active and passive wall motion, we assessed its reliability to distinguish patients with angiographic TxCAD from those without the disease. Methods: Between 1/2005 and 6/2007, all heart-transplanted patients underwent 2D-strain analyses before routine coronary angiographies. LV radial, circumferential and longitudinal strain and strain-rate were calculated from parasternal and apical views, respectively. Dyssynchrony and dyssynergy indexes were also calculated from strain curves. In patients without visible wall motion alteration and with normal LV ejection fraction, 2D-strain parameters and indexes were tested for relationships to angiographic findings. Results: All 2D-strain and strain-rate parameters were significantly lower in patients with angiographic TxCAD. Except for global peak strain, all systolic parameters showed high negative predictive values for focal epicardial coronary stenoses. However, high positive predictive values for focal coronary stenoses were found only for dyssynchrony and dyssynergy indexes. The systolic dyssynchrony and endsystolic dyssynergy indexes showed the highest positive and negative predictive values for focal stenoses (>50% narrowing). Thus, at certain cut-off values, these indexes showed positive and negative predictive values of 90-95% and 91-98%, respectively. Conclusions: 2D-strain imaging appeared to be reliable not only for prediction of angiographic TxCAD (with and without focal stenoses), but also for differentiation between TxCAD with and without focal proximal coronary stenoses. The high predictive values of systolic strain dyssynchrony and dyssynergy indexes recommend 2D-strain as a non-invasive tool with the potential to facilitate early detection of stenoses and to enable angiographies to be timed, sparing patients frequent routine angiographies.