MYOCYTE NUCLEAR-AREA AS A MEASURE OF LEFT-VENTRICULAR HYPERTROPHY IN TRANSPLANT PATIENTS

Transplanted hearts have been reported to increase in size/weight in t he first few months after transplant and to remain stable thereafter. An indirect way of assessing the changes in heart weight is through th e changes in the area of the myocyte nucleus (MNA). We studied 20 pati ents who had undergone orthotopic heart transplantation more than 12 m onths previously; 10 had become hypertensive, and the remaining 10 wer e normotensive. Myocardial biopsies taken the first week after transpl ant and 6, 12, 24, and 52 weeks after transplant were assessed. Myocyt e nuclear area was measured in 200 myocytes/biopsy with an image analy zer. Individual measurements showed a wide variation in MNA, with sign ificant overlaps among the different biopsies. Assessment of MNA at on e year showed increased MNA in 4/10 patients in the hypertensive group and 5/10 in the normotensive group. The remaining patients showed eit her no statistically significant changes in MNA or a significant (p < 0.0001) decrease in MNA. The presence of systemic hypertension was not a predictive factor for significant hypertrophy and, in some cases, n ot even for hypertrophy itself. We conclude that although there is oft en an increase in MNA of the transplanted heart at one year posttransp lant, this increase is not systematic, and isolated morphometric resul ts should be viewed cautiously.