title: Assessment of the myocardial changes in heart transplant recipients without evident acute myocardial rejection by integrated backscatter: comparison with simultaneous dobutamine stress echocardiography and (201)thallium spect.
abstract: Cardiomyocyte hypertrophy and interstitial fibrin deposition develop in cardiac allografts and contribute to the functional changes of transplanted hearts. We hypothesized that integrated backscatter (IBS) can detect these myocardial changes. A total of 32 heart transplant recipients with either no or mild acute rejection (International Society of Heart and Lung Transplantation grade IA) were enrolled in this study. IBS data of myocardium were collected immediately before simultaneous dobutamine stress echocardiography (DSE) and (201)thallium imaging. Coronary angiography and endomyocardial biopsy were also performed. Coronary angiography showed diffuse narrowing in 1 patient who also had abnormal results of IBS, DSE, and thallium results. In the other 31 patients with patent coronary arteries, there were 3 patients (10%) with abnormal DSE results, 19 patients (61%) with abnormal IBS patterns, and 16 patients (52%) with reversible thallium perfusion defects. Of the patients, 44% had cardiomyocyte hypertrophy and 56% interstitial fibrin deposition. There were significant differences in the prevalence of (201)thallium perfusion defects and serum cyclosporine levels between patients with and without abnormal IBS patterns. Pathologic changes were also associated with abnormal IBS patterns (p = 0.01). However, there was no association between abnormal IBS and DSE results. By multiple logistic regression analysis, the abnormal IBS patterns were associated inversely with serum cyclosporine level (p = 0.028). In conclusion, abnormal IBS patterns are associated significantly with perfusion heterogeneity and pathologic changes in heart transplant recipients without evident acute myocardial rejection. There is no association between abnormal IBS patterns and dobutamine-induced dyssynergy in these patients. IBS provides a noninvasive approach for detection of myocardial changes in transplanted hearts without evident acute rejection.
authors.affiliation: Department of Internal Medicine (Cardiology), National Taiwan University Hospital, No. 7, Chung-Shan S. Road, Taipei, Taiwan.
authors.forename: Y L
authors.initials: YL
authors.lastname: Ho
authors.forename: C L
authors.initials: CL
authors.lastname: Chen
authors.forename: R B
authors.initials: RB
authors.lastname: Hsu
authors.forename: L C
authors.initials: LC
authors.lastname: Lin
authors.forename: R F
authors.initials: RF
authors.lastname: Yen
authors.forename: C M
authors.initials: CM
authors.lastname: Lee
authors.forename: M F
authors.initials: MF
authors.lastname: Chen
authors.forename: P J
authors.initials: PJ
authors.lastname: Huang
mesh_terms: D006328:Cardiac Catheterization; D002316:Cardiotonic Agents; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004280:Dobutamine; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D002316:Cardiotonic Agents; D013794:Thallium Radioisotopes; D004280:Dobutamine