Evaluation of the potential role of color-coded tissue Doppler echocardiography in the detection of allograft rejection in heart transplant recipients

Background: Color-coded tissue Doppler (TD) echocardiography can noninvasively quantify alterations in left ventricular (LV) systolic and diastolic function. The objective of this study was to test the hypothesis that TD may play a role in the detection of LV dysfunction associated with allograft rejection in heart transplant recipients. Methods and Results: Seventy-eight consecutive transplant recipients underwent 89 TD studies of posterior wall myocardial velocity gradient and mitral annular velocity within 1 hour of endomyocardial biopsy. Color TD echocardiographic images were digitized for semiautomated computer analysis. Histologic analysis revealed no significant rejection in 75 biopsies and significant rejection in 14. TD posterior wall peak systolic and diastolic velocity gradients were reduced significantly with rejection: 3.9 ± 2.0 s^-1 versus 2.6 ± 0.9 s^{- 1} and 5.4 ± 2.4 s^-1 versus 3.5 ± 1.6 s^-1, respectively (P < .05 vs the nonrejecting group). Peak systolic and diastolic mitral annular velocities by TD were also reduced with rejection: 63 ± 14 mm/s versus 49 ± 12.4 mm/s and 90 ± 23 mm/s versus 60 ± 21 mm/s, respectively (P < .001 vs the nonrejecting group). A TD peak-to-peak mitral annular velocity > 135 mm/s had 93% sensitivity, 71% specificity, and 98% negative predictive value for detecting rejection. Although TD was unable to discriminate between rejection and other causes of low velocity values, high TD velocity values were supportive of excluding rejection. Conclusions: These data suggest that color-coded TD may play a potential role as a screening test to exclude rejection in heart transplant recipients. Although this method has the potential to decrease the number of biopsies, further testing in a larger series of transplant recipients with rejection is warranted.