According to an abstract reported by Dr. Ming Hui Chen at the annual scientific sessions of the American Heart Association, there is a high prevalence of occult cardiovascular disease among Hodgkin’s lymphoma survivors who had mediastinal radiation therapy.
Dr. Hui and colleagues carried out a systematic examination of 182 Hodgkin's patients at Boston-area hospitals between 1967 and 2006. The patients were asymptomatic for heart disease and had no history of it. All patients underwent transthoracic and stress echocardiographic examinations, and those with findings suggestive of ischemic coronary disease also underwent confirmatory angiography.
They found that among patients with no prior history of heart disease, 47 (26%) showed signs of "significant" coronary artery disease (CAD), valvular disease, or left ventricular systolic dysfunction with screening echocardiography done at least five years and an average of 15 years after finishing radiation therapy.
The average age of the affected patients was 43, with ranges from a low of 21 up to 65—in many cases far too young to have cardiovascular disease.
The patients had received an average total radiation dose of 3,960 Gy.
The question that remained unanswered for Hui was this:
"Does radiation directly cause [CAD or valve disease] or does it do so indirectly through hypertension and other cardiac risk factors? Does the hypertension reflect an interaction with arterial stiffness caused by radiation itself?"