Valvular Damage

Abstract

Valvular heart diseases (VHD) may be observed in patients with cancer for several reasons, including preexisting valve lesions, radiotherapy, infective endocarditis, and secondary to the left ventricle dysfunction. The incidence of VHD is especially in younger survivors treated with thoracic radiation therapy for certain malignancies, such as Hodgkin's lymphoma and breast cancer. The mechanism of radiation-induced damage to heart valves is not clear and includes diffuse fibrocalcific thickening of the valve. VHD is commonly diagnosed after a long latent period, in the context of clinical symptoms, or suspected on the basis of a new murmur. The evaluation includes identification of anatomical valve abnormalities, valve dysfunction, and assessing the functional consequences of valve dysfunction on the ventricles. Echocardiography is the optimal imaging technique for diagnostic and therapeutic management. Cardiovascular magnetic resonance and computed tomography (CT) may be used to assess the severity of VHD, but cardiac CT is mainly useful for detecting extensive calcifications of the ascending aorta. Patients exposed to mediastinal radiotherapy and minimal valve dysfunction require follow-up of 2-3 years, with moderate valve disease yearly, with severe, should be assessed for valve surgery.

Keywords: Anthracycline; Hodgkin's lymphoma; breast cancer; echocardiography; mediastinal radiotherapy; valvular heart disease.

Figure 1

Radiation exposure of aortic valve interstitial cells (AVICs), causes upregulation of tissue growth factor-β and osteogenic factors (bone morphogenetic protein-2, osteopontin, alkaline phosphatase, and the transcription factor RUNX2, leading to fibrosis and valve calcification Gujral et al.[33]

Figure 2

Cardiac computed tomography images from a 56-year-old man, 27 years' postmantle irradiation for Hodgkin's disease. Images demonstrate calcified aorto-mitral curtain and aorta (a), and mitral valve annulus (b)

Figure 3

Echocardiographic analysis of a patient with radiation-induced valvular heart disease. Extensive calcifications of the aortic and mitral valve (arrows) and the left ventricle. Significant aortic stenosis and regurgitation

Figure 4

Three-dimensional transesophageal echocardiogram demonstrating the difference between rheumatic valve disease and radiation-induced valve disease. (a) Rheumatic mitral valve with bilateral commissural fusion (black arrows). (b) In contrast in radiation-induced valve disease, there is no commissural fusion (red arrows)

Figure 5

Following this algorithm, patients exposed to mediastinal radiotherapy with structurally abnormal valves (calcification/thickening), but minimal valve dysfunction, require follow-up 2–3 years, patients with moderate valve disease yearly, patients with severe valve dysfunction should be assessed for valve surgery