PROGRESSIVE HETEROGENEITY OF MYOCARDIAL PERFUSION IN HEART-TRANSPLANTRECIPIENTS DETECTED BY TL-201 MYOCARDIAL SPECT

Progressive graft atherosclerosis is a serious complication in long-te rm survivors after heart transplantation. Coronary angiography is inse nsitive with regard to the early and characteristic alterations. We ev aluated the progression of these abnormalities and the influence of fo rmer rejection episodes. Methods: Early after transplantation, 43 pati ents (34 men, mean age 53.7 +/- 10.7 yr) underwent stress and redistri bution Tl-201 myocardial SPECT after treadmill exercise. Twenty patien ts were followed-up to the second postoperative year, and 13 patients to the third postoperative year. Thallium-201 distribution and kinetic abnormalities were documented in a scheme enclosing 20 myocardial seg ments. Additionally a score was developed that measured the degree of inhomogeneity of Tl-201 distribution and the severity of perfusion def ects, respectively. Results: Regarding scintigraphy, pathologic result s could be found in 40% of segments (redistribution, 25%; reverse redi stribution, 30%; persistent defects, 49%). Score values in heart trans plant recipients differed significantly from normal controls (p < 0.00 1) and were comparable to patients with single vessel disease of their native hearts. Thallium-201 inhomogeneity in recipients after treatab le rejection episodes did not differ from results in recipients withou t any biopsy-proven rejection. The follow-up of cardiac transplant pat ients revealed a significant increase of score values up to the third year after transplantation (p < 0.02), despite reproducible normal ang iography. There was no direct correlation between score values and IVU S results, although there was a parallel trend in 10 of 12 follow-ups. Conclusion: Despite normal coronary angiography, Tl-201 myocardial SP ECT frequently revealed pathologic results in heart transplant recipie nts. Scintigraphic results did not correlate with intimal thickening o f epicardial coronary arteries accessible to intravascular ultrasonogr aphy in the early phase after transplantation. The presented score of inhomogeneity might reveal progressive disease possibly caused by smal l vessel alterations.