Myocardial perfusion scintigraphy as a screening method for significant coronary artery stenosis in cardiac transplant recipients

Background: Several studies have explored the feasibility of using myocardial perfusion imaging to detect allograft vasculopathy after heart transplantation. We undertook the present prospective consecutive study to comparatively evaluate the role of serial myocardial perfusion single-photon emission computed tomography (SPECT) scanning and coronary arteriography (CAG) in detecting coronary artery stenosis suitable for coronary angioplasty in heart transplant recipients. Methods: Within a 2-week interval during a follow-up period of 5.6 (95% confidence limits 2.1 to 12) years, 255 serial CAGs and myocardial perfusion scintigraphies were performed in 67 patients. Arteriography and scintigraphy were performed once yearly after heart transplantation. We retrospectively analyzed the data. Results: Myocardial scintigraphy showed pathologic reversible defects in 9 out of 67 patients. Four of these patients had significant (>50% and also >70%) focal segmental stenosis in the middle and proximal parts of the coronary arteries (Type A lesions), 1 had diffuse and circumferential narrowing in the distal parts (Type B lesions), whereas CAG showed no lesions in the remaining 4 patients. The patients with significant Type A lesions were revascularized with percutaneous coronary angioplasty. Coronary arteriography showed that 1 patient had extensive Type A and Type B lesions, whereas myocardial perfusion scans detected no. The predictive value of a negative (normal) SPECT was 98% (95% confidence limits 94% to 100%) for the detection of lesions suited for revascularization. Conclusions: Annual myocardial SPECT seems well suited to screen for significant coronary artery stenosis. A SPECT study without reversible defects virtually excludes lesions, suitable for coronary artery revascularization.