Myocardial infarction mortality risk after treatment for Hodgkin disease: a collaborative British cohort study

Abstract

Background: Myocardial infarction is a major cause of excess long-term mortality in survivors of Hodgkin disease, but limited information exists on the effects of specific chemotherapy regimens used to treat these patients on their risk of death from myocardial infarction.

Methods: We followed a cohort of 7033 Hodgkin disease patients who were treated in Britain from November 1, 1967, through September 30, 2000, and compared their risk of myocardial infarction mortality with that in the general population of England and Wales. All statistical tests were two-sided.

Results: A total of 166 deaths from myocardial infarction occurred in the cohort, statistically significantly more than expected (standardized mortality ratio [SMR] = 2.5, 95% confidence interval [CI] = 2.1 to 2.9), with an absolute excess risk of 125.8 per 100,000 person-years. Standardized mortality ratios decreased sharply with older age at first treatment, but absolute excess risks of death from myocardial infarction increased with older age up to age 65 years at first treatment. The statistically significantly increased risk of myocardial infarction mortality persisted through to 25 years after first treatment. Risks were increased statistically significantly and independently for patients who had been treated with supradiaphragmatic radiotherapy, anthracyclines, or vincristine. Risk was particularly high for patients treated with the doxorubicin, bleomycin, vinblastine, and dacarbazine regimen (SMR = 9.5, 95% CI = 3.5 to 20.6). Risk at 20 or more years after first treatment was particularly great for patients who had received supradiaphragmatic radiotherapy and vincristine without anthracyclines (SMR = 14.8, 95% CI = 4.8 to 34.5).

Conclusions: The risk of death from myocardial infarction after treatment for Hodgkin disease remains high for at least 25 years. The increased risks are related to supradiaphragmatic radiotherapy but may also be related to anthracycline and vincristine treatment.