Radiation-Induced Heart Disease: An Under-Recognized Entity?

Abstract

Radiation-induced heart disease (RIHD) represents a spectrum of cardiovascular disease in patients who have undergone mediastinal, thoracic, or breast radiotherapy (RT). RIHD may involve any cardiac structure and is a major cause of morbidity and mortality in cancer survivors. While large cohort studies have demonstrated that symptomatic RIHD is a common late finding in this population, the incidence of asymptomatic disease is likely to be even higher. Long-term follow-up with regular screening for RIHD plays an important role in the management of cancer survivors who have undergone RT. Aggressive modification of traditional cardiovascular risk factors such as hypertension, dyslipidemia, and cigarette smoking is essential in patients at risk for RIHD, as these have been shown to potentiate the risks of radiation. In patients with symptomatic RIHD, medical and/or percutaneous therapies are often preferable to surgical interventions in view of the increased surgical risk associated with radiation damage to surrounding tissues. Percutaneous revascularization should generally be favored over surgical revascularization. Transcatheter valve replacements have not been widely used in this population but may offer an alternative to high-risk surgical valve procedures. Pericardiectomy is usually associated with extremely poor short-term and long-term outcomes in patients with RIHD and should be avoided in most cases. Heart transplantation is also higher risk in patients with RIHD than in patients with other etiologies of heart failure, but may be considered in young patients without other comorbidities.

Cardiotoxicity of anticancer treatments

“…91 Pericardiectomy, or stripping of the pericardium might be required; the procedure is associated with considerable morbidity and mortality. 92 Modern radiation techniques have reduced the incidence of post radiation ischaemia and contractile dysfunction, but the numerous patients treated with chest irradiation in the past will remain an ongoing challenge for the physicians responsible for their long-term follow-up.…”

Tetrahydrobiopterin Protects against Radiation-induced Growth Inhibition in H9c2 Cardiomyocytes

“…[1] However, radiation therapy can cause many complications[1] such as second malignant neoplasms, endocrine disorders, cardiopulmonary dysfunction, cardiovascular complications, and cognitive and psychosocial problems,[2] among which radiation-induced heart disease (RIHD) is one of the most difficult complications. RIHD may manifest as pericardial disease, myocardial disease, valvular disease, conduction abnormalities, coronary artery disease, or cardiovascular death.…”

Long-term Cardiac Mortality After Hypofractionated Radiation Therapy in Breast Cancer

“…One of the main theories of radiation related HF is therefore that myocyte damage results from indirect toxicity caused by microvascular changes (137). Damage to the microvasculature via inflammatory and thrombotic pathways lead to increased capillary permeability and subsequent loss of vasculature, focal ischemia and interstitial fibrosis (136;138).…”