Radiation-induced coronary artery disease: a difficult clinical conundrum

Abstract

Accelerated coronary artery disease seen following radiation exposure is termed 'radiation-induced coronary artery disease' (RICAD) and results from both the direct and indirect effects of radiation exposure. Long-term data are available from survivors of nuclear explosions and accidents, nuclear workers as well as from radiotherapy patients. The last group is, by far, the biggest cause of RICAD presentation. The incidence of RICAD continues to increase as cancer survival rates improve and it is now the second most common cause of morbidity and mortality in patients treated with radiotherapy for breast cancer, Hodgkin's lymphoma and other mediastinal malignancies. RICAD will frequently present atypically or even asymptomatically with a latency period of at least 10 years after radiotherapy treatment. An awareness of RICAD, as a long-term complication of radiotherapy, is therefore essential for the cardiologist, oncologist and general medical physician alike. Prior cardiac risk factors, a higher radiation dose and a younger age at exposure seem to increase a patient's risk ratio of developing RICAD. Significant radiation exposure, therefore, requires a low threshold for screening for early diagnosis and timely intervention.