[Detection of acute rejection by Doppler echocardiography in orthotopic cardiac transplantation. Prospective comparative study with endomyocardial biopsy].

In a prospective study of 23 patients who had undergone orthotopic heart transplantation we tried to assess the value of doppler-echocardiography in the detection of acute graft rejection. For this purpose, 220 echocardiographic records were compared with the results of endomyocardial biopsies performed at an interval of less than 12 hours. The parameters investigated by TM and two-dimensional echocardiography were: morphological parameters (including septal echodensity), left ventricular mass and systolic function parameters. Diastolic parameters (isovolumetric relaxation time [IVR], transmitral gradient half-decrease time [T 1/2] and proto-end-diastolic mitral velocity ratio [E/A] were measured by TM echocardiography and pulsed doppler velocimetry. The best doppler-echocardiographic criteria for graft rejection were a more than 15 ms reduction of IVR, a more than 15 p. 100 increase of myocardial mass, and a more than 30 p. 100 increase of teh E/A ratio, the corresponding sensitivities for histological rejection being 82, 76 and 74 p. 100 respectively. In contrast, T 1/2 and systolic function studies seemed to be disappointing. Finally, the increase of septal echodensity enabled rejection to be diagnosed with an excellent (92 p. 100) specificity but an insufficient sensitivity. Thus, none of the parameters measured were sensitive enough, taken separetely, to replace endomyocardial biopsy. However, the combined use of the most sensitive of them should make it possible to reduce the frequency of systematic biopsies.