Diagnostic and prognostic value of dobutamine thallium-201 single-photon emission computed tomography after heart transplantation

Background: Cardiac allograft vasculopathy (CAV) is a major cause of mortality in heart transplant recipients. We investigated the diagnostic and prognostic value of dobutamine thallium-201 ((TI)-T-201) single-photon emission computed tomography (SPECT) in heart transplant recipients. Methods: We studied 47 patients (age 51.6 +/- 11.7 years, 37 men), at a mean of 34.0 +/- 21.4 months after heart transplant, who received dobutamine (TI)-T-201 SPECTI, echocardiography and coronary angiography within 1 month of each other. SPECT was considered abnormal in the presence of reversible or fixed defects in >= 2 segments. Significant CAV was defined as >= 50% luminal stenosis. Results: Coronary angiograms were normal in 37 patients. Non-significant CAV was detected in 1 patient and significant CAV in 9 patients. The sensitivity, specificity, positive predictive value and negative predictive value of SPECT for the detection of significant angiographic CAV were 89%, 71%, 42% and 96%, respectively. Large reversible perfusion defects (>= 6 segments) always indicated significant CAV. In patients with normal left ventricular function, a lung/heart ratio (LHR) of >= 0-37 during stress was also an independent predictor of significant CAV (odds ratio 15.5, p = 0.04). A higher stress LHR was associated with greater vessel involvement (r = 0.516, p = 0.0002). Patients with impaired left ventricular function also had higher stress and resting LHR. Over 40.3 +/- 21.9 months after the first SPECT, 1 patient developed significant angiographic CAV and another 4 had cardiac death. Large reversible perfusion defect was a significant predictor of cardiac death (p = 0.002). Conclusions: Dobutamine (TI)-T-201 SPECT is a useful method for detecting patients with significant CAV and assessing prognosis. It is reasonable and safe to design individualized surveillance intensity of coronary angiography for post-transplant patients on the basis of non-invasive monitoring of dobutamine (TI)-T-201 testing. J Heart Lung Transplant 2005;24:544-50. Copyright (c) 2005 by the International Society for Heart and Lung Transplantation.