BRCA1 Reflects Myocardial Adverse Remodeling in Idiopathic Dilated Cardiomyopathy.

BACKGROUND: The role of BRCA1 in chronic ischemic episodes seems to be pivotal for adverse remodeling and development of ischemic cardiomyopathy, because of its role in DNA repair and apoptosis. The aim of this study was to investigate the role of BRCA-1 in idiopathic dilated cardiomyopathy (IDCM). MATERIAL AND METHODS: The study group (IDCM) comprised myocardial samples from hearts explanted before transplantation owing to IDCM in 10 males (age 44 ± 5.3 years) without clinical symptoms of ischemic heart disease. The control group consisted myocardial fragments taken from 10 male heart valve and pulmonary artery donors with diagnosed cerebral death (age 40 ± 2.3 years). BRCA1 was detected immunohistochemically with rabbit anti-BRCA1 polyclonal antibody. The intensity of BRCA1 expression was semiquantitatively assessed for cardiocytes, small vessels including capillaries, and interstitial cells. The significances between groups were estimated using the Mann-Whitney U test. RESULTS: All IDCM cases were positive and presented nonuniform BRCA1 expression: hypertrophied cardiocytes showed very intense staining and typical cardiomyopathic cardiocytes were stained weakly forming mosaic. Control cases showed weak-to-moderate uniform staining. Intensity of staining was significantly higher in IDCM cardiocytes, whereas small vessels and interstitial were stained similarly in both groups. CONCLUSIONS: IDCM adverse remodeling results in more intense but nonuniform BRCA1 expression. This phenomenon seems to reflect IDCM biology: lower BRCA1 expression in myocytes with lower anti-apoptotic and DNA damage repair activity, with the opposite in hypertrophied myofibers.

Fractal analysis of heart graft acute rejection microscopic images.

BACKGROUND: Endomyocardial biopsy to evaluate rejection in the transplanted heart is accepted at the "gold standard." The complexity of microscopic images suggested using digital methods for precise evaluating of acute rejection episodes with numerical representation. The aim of the present was study to characterize digitally acute rejection of the transplanted heart using complexity/fractal image analysis. MATERIAL AND METHODS: Biopsy samples harvested form 40 adult recipients after orthotropic heart transplantation were collected and rejection grade was evaluated according to the International Society for Heart and Lung Transplantation (0, 1a, 1b, or 3a) at transverse and longitudinal sections. Fifteen representative digital microscope images from each grade were collected and analyzed after Sobel edge detection and binarization. RESULTS: Only mean fractal dimension showed a progressive and significant increase and correlation based on rejection grade using longitudinal sections. Lacunarity and number of foreground pixels showed unequivocal results. CONCLUSION: Mean fractal diameter could serve as auxiliary digital parameter for grading of acute rejection in the transplanted heart.

Paradox of advanced glycation end-products in late cardiac biopsies of heart transplant recipients.

BACKGROUND: A pilot study of orthotopic heart transplant (OHT) recipients showed that advanced glycation end-product (AGE) deposits were related to acute rejection episodes among subjects with diabetes mellitus (DM); in contrast, among non-DM patients it was associated with prolonged freedom from coronary artery vasculopathy (CAV). However the number of observations in non-diabetic subjects was low. The aim of the current study was to establish the role of AGEs in late endomyocardial biopsies (EMBs) among a larger group of non-diabetic patients. MATERIAL AND METHODS: Elective EMBs were performed at 3 years post OHT in 62 subjects with DM, namely, 57 males and 5 females of overall mean age of 50±8 years versus 92 free of DM, including 79 males and 13 females of mean age 51±13 years. We localized AGEs in myocardial paraffin sections using monoclonal mouse anti-AGE antibodies. The presence of AGEs in cardiomyocytes, stromal cells, capillaries, and arterioles was described with a semiquantitative scale. RESULTS: All-cause deaths, CAV, and CAV-related events were observed in 28% versus 23%, 27% versus 29%, and 15% versus 19% of non-DM versus DM patients (P=NS). The occurrence of AGEs was significantly more frequent among non-DM than DM subjects: cardiocytes, 100% versus 69% (P<.0001); stroma, 54% versus 31% (P=.0037); capillaries, 67% versus 31% (P<.0001); and arterioles, 26% versus 3% (P=.0002; chi-square). Among the DM group, mean EMB score correlated with AGE presence in cardiomyocytes (n=0.29; P<.05, Spearman test) AGE presence had no impact on survival or CAV development. CONCLUSION: AGE presence was more common in late EMB from non-diabetic than diabetic OHT recipients; they had no impact on survival or CAV in non-diabetic patients.

Differences in antiapoptotic, proliferative activities and morphometry in dilated and ischemic cardiomyopathy: study of hearts explanted from transplant recipients.

BACKGROUND: Antiapoptotic as well as replacement and proliferative mechanisms take place in the myocardium in dilated cardiomyopathy (DCM) and ischemic heart disease (IHD). We sought to estimate antiapoptotic, proliferative and replacement activities in cardiomyopathies. MATERIALS: The study groups included seven hearts with DCM and eight with IHD, which had been explanted at the time of transplantation. The comparator group consisted of cases of myocardial hypertrophy and the control group, donor fragments. METHODS: Antiapoptotic and proliferative responses were determined immunohistochemically as Bcl-2 and Ki67 expression by semiquantitative assessment of the intensity of staining. We also measured and statistically analyzed the integrative morphometric measurements of the fraction of fibrosis area, the nucleosarcoplasmic ratio, and cardiocyte diameter. RESULTS: No Bcl-2 expression was observed in the controls. The strongest reaction was seen in the DCM group, then in the IHD, and in the comparator group of myocardial hypertrophy. Proliferative activity was seen only in endocardial and interstitial fibroblasts in DCM and IHD cases. The cardiocyte diameter showed no statistical association between myocardial hypertrophy and IHD, or IHD and DCM, whereas the nucleosarcoplasmic ratios were significantly different from control groups for all comparisons. Myocardial fibrosis showed the highest values in DCM and IHD. Discriminant analysis showed the value of interstitial fibrosis and cardiocyte diameter to categorize the analyzed groups. CONCLUSIONS: Antiapoptotic Bcl-2 activity seemed to play an important role in cardiocyte preservation, while proliferative activity was resticted to interstitial connective tissue cells as a replacement process. Myocardial Bcl-2 expression, the extent of myocardial fibrosis, and cardiocyte diameter may serve as additional diagnostic tools to differentiate cardiomyopathies.

Pivotal karyometric measurements in different types of cardiomyopathic morphology: study of hearts explanted from transplant recipients.

BACKGROUND: Morphometric studies based on the measurement of cardiocyte nuclei have focused on progressive hypertrophy rather than shape, which is a deciding factor for the diagnosis of hypertrophy in myocardial diseases. The aim of this research was to demonstrate how the digital morphology of cardiocyte nuclei change correlated with the type of myocardial pathology. MATERIALS AND METHODS: The study groups encompassed 7 hearts with dilated cardiomyopathy (DCM) and 8 hearts with ischemic heart disease (IHD) which were explanted. A comparative group consisting of myocardial hypertrophy was contrasted with a control group of donor heart fragments. Cardiocyte nuclei were evaluated morphometrically on histologic slides. We calculated the nuclear area, length, breadth, perimeter, roundness, elongation, fullness factors, and nuclear chromatin mean gray level. The results were subjected to discriminant analysis. RESULTS: All karyometric measurements analyzed by backward discriminant analysis showed only 2 powerful factors: nuclear breadth and chromatin mean gray level. The Mahalanobis distance showed the proximity of control and hypertrophy groups, whereas differences between IHD and DCM were nonsignificant. CONCLUSION: The lack of karyometric differences between IHD and DCM suggested a common morphologic response for long-lasting progressive injury. The main morphologic differences were dependent on nuclear chromatin activity/stainability and nuclear breadth, suggesting darker and thinned nuclei in normal and adaptative stages and irregular brighter nuclei in cardiomyopathies.

Different role of advanced glycation end products in pathology of transplanted heart in patients with or without diabetes mellitus type 2.

BACKGROUND: Aim of the study was to localize advanced glycation end products (AGEs) in late endomyocardial biopsies (EMBs) of orthotopic heart transplant (OHT) recipients with and without diabetes mellitus (DM) to correlate their presence with acute rejection episodes (ARE) and cardiac allograft vasculopathy (CAV). MATERIALS AND METHODS: Elective EMBs were performed at 3 years post-OHT in 64 subjects, with DM (59 M/5 F), of overall mean age of 49 +/- 8 years and 24 patients, without DM (21 M/3 F), of overall mean age of 42 +/- 10y. Localization of myocardial AGEs in paraffin sections was assessed immunochemically using mouse monoclonal anti-AGE antibodies (clone 6d12) on cardiomyocytes, stromal cells, connective tissue elements and capillaries. RESULTS: The occurrence of AGEs was similar in DM versus non-DM subjects: namely, cardiocytes 73% versus 63%, stroma 33% versus 33%, connective tissue 13% versus 9%, and capillaries 31% versus 33%, respectively. Only in the DM group. The acute rejection episodes and mean EMB score significantly correlated with AGE presence in cardiomyocytes (r = 0.29/0.3; P = .02/.02; Spearman). There was no relation between AGE occurrence and CAV diagnosis among DM subjects, while the time free from angiographically confirmed CAV or a CAV-related event was significantly shorter among non-DM recipients without AGEs in capillaries and/or cardiocytes (P = .014/.017/.014/.03, respectively; log-rank). CONCLUSION: AGE occurrence in OHT recipients with DM was related to ARE, but not to CAV; in contrast, among non-DM patients it was not correlated with ARE, but their absence predicted CAV.

Microvasculopathy observed in early or late endomyocardial biopsies is not related to angiographically confirmed transplanted heart coronary vasculopathy.

INTRODUCTION: The aim of the study was to examine the potential relation between microvasculopathy observed in endomyocardial biopsies (EMBs) and clinical coronary vasculopathy (CAV) after orthotopic heart transplantation (OHT). MATERIALS AND METHODS: We preformed a retrospective analysis involving 68 OHT patients in whom the procedure was performed before 1999. The CAV(+) group consisted of 37 subjects (35 males/2 females) of overall mean age of 45 +/- 11 years. Ischemic cardiomyopathy was the diagnosis in 57% of the cohort that displayed CAV established by angioplasty, myocardial infarction, or CAV-related death. The control group contained 31 subjects (24 male/7 female) of overall mean age of 43 +/- 16 years. The pretransplant diagnosis was ischemic c-pathy in 39%. These subjects displayed negative coronary angiography at 10 years after OHT. Based upon studies early after OHT 55 subjects were divided based on the myocardial blush grade (MBG) upon coronary angiography performed between 4th and 6th week after surgery: one cohort of six individuals showed decreased MBG (6 males) of mean age 52 +/- 7 years. There was prior ischemic c-pathy in 50%. In contrast, 49 subjects showed a normal MBG (43 males/67 females) of overall mean age of 45 +/- 12 years. Ischemic c-pathy had been present in 39%. Microvasculopathy was defined as the presence of prominent endothelial cells, vacuolation of the endothelium, thickening of the basal membrane and/or muscle layer, the presence of lymphocytes in the arteriolar wall, periarteriolar fibrosis, or stenotic arteriolar lumenia in the 12- and 36 month EMB (CAV groups) or the 4-week EMB (MBG groups). RESULTS: Rejection grades were comparable in CAV(+) and CAV(-) groups, but decreased in normal MBG group. The only significant difference was observed in the occurrence of basal membrane thickening, which was present in 22% of subjects from the CAV(+) group and 3% of individuals from the CAV(-) group in the 12-month EMB. CONCLUSION: Microvasculopathy observed early or late after OHT was not related to angiographically confirmed CAV.

Cytomegalovirus infection does not accelerate microvasculopathy development in heart transplant recipients.

BACKGROUND: Clinical studies with intravascular ultrasound have suggested that even subclinical cytomegalovirus (CMV) infections increase intimal hyperplasia in transplanted heart coronary arteries after 1 year. The potential influence of CMV on microvasculopathy development is not known. The Aim of our study was to compare the occurrence of microvasulopathy in endomyocardial biopsies (EMBs) of heart transplant recipients with versus without CMV infection. MATERIALS AND METHODS: We performed a case-controlled, retrospective study of 58 subjects diagnosed with CMV infection by the presence of pp65 antigen. The 49 men and 91 women of overall age 49 +/- 8 years showed ischemic cardiomyopathy in 52%. We matched a control cohort of 58 subjects without CMV disease. Microvasculopathy was assessed using 4-degree grading system developed by Hiemann et al for elective EMBs performed at 1 and 12 months after transplantation. RESULTS: Significant acute rejection episodes were observed among 22% versus 21% of 1-month EMBs, and 3% versus 5% of 12-month EMBs for CMV(+) versus control group subjects respectively. The commonest microvasculopathy was nonstenotic thickening (grade B) 60% versus 59% (35 versus 34 patients) among 1-month EMBs; and 50% versus 60% (29 vs 35 patients) among 12-month EMBs, respectively. Progression of microvasculopathy score between 1- and 12-month EMB was observed in 40% versus 41% of subjects, and regression occurred in 22% versus 21%, respectively. None of differences was significant. CONCLUSION: Our data do not support the thesis that CMV infection promotes microvasculopathy development among heart transplant recipients.

Advanced glycation end products in the development of ischemic and dilated cardiomyopathy in patients with diabetes mellitus type 2.

INTRODUCTION: Hyperglycemia intensifies nonenzymatic glucose coupling to tissues, resulting in myocardial stiffness and formation of advanced glycation end products (AGE). The aim of this study was to assess seeking AGE in the myocardium from patients with type 2 diabetes (DM2) subjected to orthotopic heart transplantation (OHT), seeking to establish whether AGE play a role in the development of cardiomyopathies leading to OHT. MATERIAL: The 2 studied groups consisted of 11 hearts explanted from patients with ischemic cardiomyopathy+DM2 (ICM+DM2, 55 +/- 6.5 years) and 8 from dilated cardiomyopathy+DM2 (DCM+DM2, 49.6 +/- 4.5 years). Comparative subgroups were composed of nondiabetic explanted hearts, 41 with ICM (52.8 +/- 5.8 years) and 41 with DCM (52.7 +/- 4.2 years). All patients were males. METHODS: We examined immunohistochemical localization of AGE using a semiquantitative scale of reaction intensity in cardiomyocytes, fibroblasts, capillaries, arterioles, and arteries. Additionally, we calculated the scores for cardiocytes (AGE(Cardiocyte)) and all left ventricular components (AGE(LV)). RESULTS: The cytoplasmic AGE deposits in cardiomyocytes were predominantly diffuse-granular in DM2 groups, whereas nondiabetic groups showed a lack of a reaction or a diffuse pattern. There were no differences in the reaction intensity between the 2 studied groups, or 2 comparative groups. All myocardial constituents showed higher AGE intensity in DM2 than nondiabetic groups. Only in the ICM+DM2 group did the DM2 duration correlate with AGE staining in selected myocardial layers and with AGE(Cardiocyte) and AGE(LV). CONCLUSIONS: The presence of AGE in the hearts of patients requiring transplantation was related to the duration of DM2. The deposition of AGE in left ventricular myocardium was enhanced by DM2 particularly in patients with ICM.

Cardiocyte nuclear chromatin density correlates with transplanted heart left ventricular mass.

INTRODUCTION: Cardiocyte hypertrophy is accompanied by polyploidy, seen as a decrease in chromatin density in the enlarged nucleus. Repeated biopsies of a transplanted heart offer the possibility of a dynamic evaluation of these phenomena. The aim of this work was an evaluation of cardiocyte nuclear chromatin density in transplanted hearts during long-term follow-up. MATERIALS AND METHODS: The material encompassed myocardial biopsy specimens taken during the first week, first month, and then on an annual basis up to 10 years after surgery. Only biopsy specimens with no rejection were considered (grade "0" International Society for Heart and Lung Transplantation [ISHLT] 122 biopsy specimens). The control group consisted of 7 donor heart specimens. We evaluated the optical density-mean gray level-of cardiomyocyte nuclear chromatin. We determined correlations of this index with the nuclear area, and with left ventricle ultrasound measurements, using correlation analysis. RESULTS: The chromatin mean gray level decreased with time, correlating positively with interventricular septum thickness, left ventricle posterior wall diameter, and left ventricular mass. Analysis of individual periods showed a significant positive correlation of the mean grey level with the cardiocyte nuclear surface in year 3, 4, and 9 after transplantation, thereby suggesting the occurrence of polyploidy at those times. The significant negative correlation of these values (1 week and 1 year) indicated normalization of early cardiocyte hypertrophy. CONCLUSIONS: With the passage of time chromatin condenses, leading to pyknosis. The activity of cardiocyte chromatin correlated with left ventricular hypertrophy. Compensatory cardiomyocyte polyploidy is a periodical phenomenon.

Thymoglobulin administered early after heart transplantation reduces early myocardial hypertrophy assessed by morphometric studies.

UNLABELLED: The aim of this study was to assess the effects of early thymoglobulin administration on cardiocyte nuclear status in orthotopic heart transplant (OHT) recipients. MATERIAL AND METHODS: We investigated endomyocardial biopsies (EMBs) from 31 OHT recipients and 10 control cases. OHT patients were divided into the standard group who were treated without thymoglobuline; an ATG group who received thymoglobulin electively, and a standard+ATG group who were administered thymoglobulin upon a drop in renal function. We evaluated only EMBs obtained at 1 and 4 weeks after OHT showing no significant rejection (ISHLT grades 0 to 1B). The morphometric studies were performed using a computerized, automated Quantimet image analysis system. Overall, 1750 cardiocyte nuclei were quantitated for area, length, breadth, perimeter, chromatin median grey level, and fullness factor. Statistical analysis was performed using the Mann- Whitney U test, the Wilcoxon test, and discriminant analysis. RESULTS: All OHT groups showed significantly higher values (indicating nucleus enlargement) than the control group. All factors suggesting myocardial hypertrophy were significantly higher in the standard group; however, they decreased significantly with time. In contrast, the nuclear geometric parameters were significantly lower and stable throughout the study in the ATG group. The results of the standard+ATG group were intermediate, and their normalization as incomplete at the week 4 examination. Discriminant analysis revealed the closest Mahalanobis distance between control and ATG groups both at and weeks 1 and 4 after OHT. CONCLUSION: Thymoglobulin administered early after surgery protected cardiocyte hypertrophy in heart transplant recipients, mitigating graft ischemic damage.

Remodeling of human transplanted myocardium in ten-year follow-up: a clinical pathology study.

UNLABELLED: Remodeling taking place in transplanted myocardium leads to a change in the number of cardiocytes. Ultrasound measurements and biopsy evaluation should reflect their loss and compensation. We sought to evaluate the morphology of the transplanted heart upon long-term follow-up. MATERIAL AND METHODS: Myocardial biopsies were obtained in the first week, first month, and then annually for 10 years from transplantation that did not show rejection (grade "0" ISHLT, 122 biopsies). The control group encompassed 7 donor heart fragments. Proliferation in biopsies was evaluated with Ki67 (M7240, DAKO), cardiocyte hypertrophy by measuring their diameter, the surface area of the nuclei, nuclear-sarcoplasmic index, and stromal fibrosis evaluated as the surface area fraction. Ultrasound measurements included diastolic thickness of the interventricular septum, posterior wall of the left ventricle, and left ventricular mass. The correlation of measurements with time from transplantation was evaluated using Spearman's test. RESULTS: A positive Ki67 reaction was observed in fibroblasts and endothelial cells. The increased cardiocyte nuclear area correlated with the time elapsed since transplantation (r = 0.2; P < .05) with a simultaneous decrease in cardiocyte thickness (r = -0.3; P < .05), without changes in the nuclear-cytoplasmic index (r = 0.02; P > .05). Stromal fibrosis also increased (r = 0.1; P < .05). Ultrasound measurements of the left ventricle showed a decreased tendency with the passage of time (r = -0.2 to -0.3; P < .05). CONCLUSION: A transplanted heart does not undergo hypertrophy but rather fibrous atrophy with apparent compensatory hypertrophy of the cardiomyocytes.

Transplanted heart cardiomyocytes reveal continuous expression of antiapoptotic Bcl-2 protein.

BACKGROUND: Apoptotic mechanisms take place in cardiocyte death during acute heart graft rejection and remodeling by the mitochondrial pathway. This process is suppressed by Bcl-2 protein. Besides that, knowledge about cardiocyte antiapoptotic responses after heart transplantation is scanty. We sought to estimate Bcl-2 expression in the absence of rejection. MATERIAL: The study group included endomyocardial biopsies taken at 1 week, 1 month, 1 through to 10 years after heart transplant, which showed rejection grade "0"; the control group were donor heart fragments. METHOD: Bcl-2 expression was determined immunohistochemically by NP030 antibody (DAKO) and Envision-DAB. The intensity of staining was assessed semiquantitatively. RESULTS: No Bcl-2 expression was seen in the controls; in the posttransplant groups, the significantly strongest sarcoplasmic reaction was observed at 1 week after heart transplant. Thereafter, the reaction decreased, and was weakest in the 3- and 5-year groups. From this time, Bcl-2 expression increased albeit without statistical significance. The intensity of the reaction showed no correlation with the time elapsed from heart transplant (Spearman r = 0.05; P > .05). CONCLUSION: The expression of antiapoptotic Bcl-2 protein occurs during the entire posttransplant period, being probably a preservative and adaptative response.

Cardiocyte nucleus shape as an indicator of heart graft aging.

UNLABELLED: Morphometric publications based on the measurement of cardiocyte nuclei indicated their progressive hypertrophy ignoring, however, their shape, which is a deciding factor for the microscopic-based diagnosis of hypertrophy. We sought was to demonstrate how the shapes of cardiocyte nuclei change over time and correlate them with the thickness of the interventricular septum, (IVS) the biopsy site. MATERIAL: We evaluated myocardial biopsies taken in the first week, first month, and then annually until posttransplant year 10. Only biopsies with no rejection were considered: grade "0" ISHLT (122 biopsies). The control group encompassed fragments from seven donor hearts. METHODS: Cardiomyocyte nuclei were evaluated morphometrically. We calculated the length, breadth, perimeter, roundness, elongation, and fullness factors for correlation with the IVS thickness, and selected indices. The relationships between karyometry and IVS thickness (measured by ultrasound) as well as time were calculated by Spearman's correlation test. RESULTS: Among the examined indices, only nuclear length did not correlate significantly with follow-up time. Among the remaining indices, the strongest correlations with time were observed with regard to breadth (r = 0.214), perimeter (r = 0.150), roundness (r = -0.06) and fullness (r = 0.06), and finally elongation (r = 0.02). The decreasing thickness of the interventricular septum (r = -0.31) showed a weak correlation only with the cardiocyte nuclear length (r = -0.05). CONCLUSION: Graft aging imitates hypertrophy inasmuch as cardiocyte nuclei become wider despite the decreased thickness of the interventricular septum. Therefore, karyometric measurements do not reflect myocardial morphology.

Nuclear mean gray level and chromatin distribution changes in cardiomyocytes of heart transplant recipients suffering from acute cellular rejection.

BACKGROUND: Distribution and staining of the nuclear chromatin are sensitive indicators of changes in physiology and pathology of cells. However, their use in heart transplant recipients is rare. The aim of this study was to compare cardiomyocyte status in heart transplant recipients suffering from moderate acute cellular rejection and subjects without signs of active cellular rejection. MATERIALS AND METHODS: One hundred twenty-nine endomyocardial biopsy samples from 43 heart transplant recipients (no later than 6 months after surgery) were evaluated. Overall, 3235 cardiomyocytic nuclei were analyzed using the Quantimet image analysis system to assess the mean gray level: 1584 nuclei were found in biopsies without signs of rejection or with nonsignificant rejection (ISHLT grades 0, 1A, and 1B), whereas the remaining 1651 nuclei were measured from biopsies showing ISHLT grade 3A (significant rejection). Additionally, the chromatin distribution was assessed in all eligible nuclei. RESULTS: The mean gray level was markedly increased in nuclei from biopsy samples with significant rejection (182.6 vs 112.5, P < .001, Mann-Whitney U test). Moreover, the analysis of chromatin distribution revealed significantly more frequent chromatin marginalization and irregular distribution in rejecting subjects (P < .001, chi-square test). CONCLUSION: Inflammatory stimulation of cardiomyocytes during acute cellular rejection of the transplanted heart influences the chromatin distribution in the nuclei, which may have an additional value, when assessing the severity of rejection.

Pathologic assessment of cardiomyocytes in heart transplant recipients treated with rapamycin or cyclosporine.

The aim of this study was to compare cardiomyocytes and stromal pathology in heart transplant recipients treated with rapamycin (RAPA) versus cyclosporine (CyA). We analyzed elective biopsies obtained during first 3 months after heart transplantation in four patients treated with RAPA (24 biopsies) and seven patients receiving CyA (49 biopsies). Additional medications in both groups consisted of mycophenolate mofetil or azathioprine and prednisone. The intensity of rejection was assessed using the ISHLT scale; it was comparable in both groups based upon the number of results showing significant rejection and the average biopsy scores. Each slide was also examined under high-power magnification to sarcoplasmic and nuclear changes. Sarcoplasmic vacuolation, premyocytolysis and myocytolysis, nuclear staining, stromal fibrosis and edema, presence of vasculopathy, and lymphocytes infiltrating the myocardium occurred more frequently in the CyA group. The difference in the degree of hyperchromasia of the nuclei was highly significant (67% versus 10%, P <.00001). Our findings suggest that despite comparable levels of rejection as assessed using the ISHLT scale, patients treated with RAPA display fewer signs of cardiomyocytic alterations early after heart transplantation.