DOBUTAMINE ECHOCARDIOGRAPHY IN THE DETECT ION OF CORONARY-ARTERY DISEASE OF HEART-TRANSPLANT PATIENTS

The value of Dobutamine stress echocardiography in the detection of co ronary artery disease in heart transplant patients was studied in 64 p atients at control coronary angiography 39 +/- 14 months after transpl antation. Dobutamine was infused at progressively increasing doses (5 to 40 mu g/kg/min) at 5 minute intervals, in order to reach 85% of the theoretical maximal heart rate or an ischaemic event. Echocardiograph y was analysed in the 4 standard views which were digitised allowing c alculation of a regional wall motion score under basal conditions and at peak dosage in 16 left ventricular segments. Coronary angiography i dentified three groups : group I : 29 patients with normal coronary ar teries; group II : 17 patients with non-significant coronary disease ( diffuse or localised stenosis < 50%); group III : 9 patients with sign ificant (> 50%) coronary disease. Dobutamine stress echocardiography s howed regional wall motion abnormalities in 2/29 patients in group I, 13/17 patients in group II and all patients in group III (global sensi tivity : 85%; specificity : 97%). The contractility score was signific antly higher under basal conditions in group III (1.45 +/- 0.54) than in group I (1) and group II (1.17 +/- 0.23). At peak dose, the contrac tility score was unchanged in group I and increased significantly (p < 0.01) in the other two groups. The authors conclude that Dobutamine e chocardiography is a reliable, non-invasive method of detecting corona ry disease in cardiac transplant patients, and is particularly valuabl e for demonstrating myocardial ischaemia related to coronary lesions j udged to be not significant at coronary angiography.