Doxorubicin Cardiomyopathy: Evaluation by Phonocardiography, Endomyocardial Biopsy, and Cardiac Catheterization

Right ventricular endomyocardial biopsy, right heart catheterization, and systolic time intervals were done in 33 adult patients receiving doxorubicin (AdriamycinTM). Doxorubicin administration was associated with a dose-related increase in the degree of myocyte damage, and 27 of 29 patients biopsied at doses greater than or equal to 240 mg/m2 had doxorubicin-associated degenerative changes identified on biopsy. The pre-ejection period to left ventriculr ejection time ratio (PEP/LVET) showed a threshold phenomenon and did not begin to increase until a total dose of 400 mg/m2 had been reached. Seven patients with catheterization-proven heart failure had a significantly greater amount of myocyte damage on biopsy than dose-matched control subjects (P less than 0.01). Preveious mediastinal radiation appeared to potentiate the doxorubicin-associated degenerative process. Mediastinal radiation and age greater than or equal to 70 years appeared to be risk factors for doxorubicin-associated heart failure. Dose limitation by combined clinical, noninvasive, invasive, and morphologic criteria offered an advantage over empirical dose limitation or dose limitation by PEP/LVET alone.