Quantitative investigation of cardiomyocyte hypertrophy and myocardial fibrosis over 6 years after cardiac transplantation

AT Armstrong, PF Binkley, PB Baker… - Journal of the American …, 1998 - jacc.org
AT Armstrong, PF Binkley, PB Baker, PD Myerowitz, CV Leier
Journal of the American College of Cardiology, 1998jacc.org
Objectives. This study was performed to determine the degree and time course over 6 years
of cardiomyocyte hypertrophy and myocardial fibrosis of the cardiac allograft in transplanted
patients. Background. Diastolic dysfunction and to a certain extent systolic dysfunction are
common cardiac findings after heart transplantation. The development of posttransplant
cardiomyocyte hypertrophy and myocardial fibrosis likely contributes to these
derangements. Methods. Cardiomyocyte diameter and percent fibrosis were determined in …
Abstract
Objectives. This study was performed to determine the degree and time course over 6 years of cardiomyocyte hypertrophy and myocardial fibrosis of the cardiac allograft in transplanted patients.
Background. Diastolic dysfunction and to a certain extent systolic dysfunction are common cardiac findings after heart transplantation. The development of posttransplant cardiomyocyte hypertrophy and myocardial fibrosis likely contributes to these derangements.
Methods. Cardiomyocyte diameter and percent fibrosis were determined in serial endomyocardial biopsy specimens obtained from 1 month up to 6 years following heart transplantation in 50 patients. Endomyocardial biopsy specimens from 40 patients with primary dilated cardiomyopathy and 11 normal subjects were similarly analyzed for control data. Analyses were performed in a blinded format using a validated computerized image analysis system (Optimas 5.2).
Results. Early (1 month) cardiomyocyte enlargement decreased to the smallest diameter 6 months posttransplant, but thereafter progressively increased by 10% to 20% over the subsequent 5- to 6-year period. Although not statistically established, principal stimuli may include a discrepancy in body size (recipient > donor), coronary allograft vasculopathy and posttransplant systemic hypertension. Percent myocardial fibrosis rose early (1 to 2 months) posttransplant and thereafter remained at the same modest level of severity.
Conclusions. Cardiomyocyte diameter of the transplanted heart gradually increases over time, while percent myocardial fibrosis rises early and remains in a modestly elevated plateau after 2 months posttransplant. These histostructural changes likely contribute to the hemodynamic and cardiac functional alterations commonly observed posttransplant.
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