USE OF EXERCISE ELECTROCARDIOGRAPHY, TECHNETIUM-99M-MIBI PERFUSION TOMOGRAPHY, AND 2-DIMENSIONAL ECHOCARDIOGRAPHY FOR CORONARY-DISEASE SURVEILLANCE IN A LOW-PREVALENCE POPULATION OF HEART-TRANSPLANT RECIPIENTS

Background: Coronary artery disease has been reported to be a signific ant cause of long-term morbidity and mortality after heart transplanta tion. However, the diagnosis of coronary disease by means of noninvasi ve procedures has shown disappointing accuracy, and many centers curre ntly recommend an annual surveillance coronary angiogram. Methods: We prospectively studied the accuracy and feasibility of a symptom-limite d upright bicycle exercise, combined with computerized electrocardiogr am analysis, echocardiography, and perfusion scintigraphy in 37 consec utive heart transplant recipients at 2.8 +/- 1.4 years after transplan tation for routine follow-up coronary angiography. Results: No patient had any hemodynamically significant (> 50% diameter) coronary stenosi s, but luminal irregularities were detectable in four patients. The ex ercise electrocardiogram was interpretable in only 22 patients (59%), and two of the remaining patients (9%) had false-positive results. The feasibility of perfusion tomography (100%) and two-dimensional echoca rdiography (97%) were greater than for stress electrocardiogram (p < 0 .001 and p < 0.01 respectively). False-positive results were obtained at stress echocardiography in one patient (3%), and at scintigraphy in six patients (16%, p = not significant). None of these methods detect ed coronary artery stenoses of less than 50% diameter. Conclusions: Bo th exercise perfusion tomography and two-dimensional echocardiography are feasible and can be used with adequate specificity for the noninva sive diagnosis of coronary artery disease in heart transplant recipien ts. However further studies are needed to determine their respective s ensitivity.