Table 2

Long-term radiation-induced heart disease, diagnostic modalities and management

Cardiac effects (prevalence)DescriptionScreening/diagnosisManagement
Pericardial disease (6–30%)
  • Pericarditis (acute or chronic)

  • Pericardial effusion

  • Pericardial constriction

Most common manifestation of radiation-induced heart disease and a diagnosis of exclusion. Occurs due to fibrinous exudates to the pericardial surface, fibrotic changes to the parietal pericardium. Acute pericarditis is often self-limiting. Chronic pericarditis is often effusive–constrictive
  • Diagnosis of exclusion after other causes of pericardial disease have been ruled out

  • Echocardiogram

  • Cardiac MRI

  • Cardiac CT

  • Anti-inflammatory drugs for pericarditis

  • Pericardiocentesis for large effusions or tamponade

  • Pericardial window for recurrent pericardial effusions

  • Pericardial stripping for constrictive pericarditis

Coronary artery disease (up to 85%)
  • Microvascular CAD

  • Macrovascular CAD

Due to capillary network/epicardial coronary arteries damage and sustained inflammation via NF-κB. Usually occurs ≥10 years post-radiation therapy. Involves the LM, ostial LAD and RCA. Lesions are longer, smoother, concentric and tubular. Incidence increased by standard CV risk factors
  • Stress echocardiography (could also screen for other causes of RIHD, other than CAD) or stress perfusion imaging

  • Cardiac CTA

  • Possible role for coronary calcium screening

  • As for CAD in patients not treated with radiation: medical therapy, percutaneous coronary angioplasty and coronary artery bypass graft (challenging surgical due to fibrosis of pericardium and mediastinum)

  • Aggressive CV risk factor modification

Valvular heart disease
  • At 10 years (26% AI, 39% MR, 16% TR and 7% PI)

  • At 20 years: (60% AI (16% Aortic Stenosis (AS)), 52% MR, 26% TR and 12% PI)

The mean time interval of 12 years. Diffuse fibrosis of the valvular cusps or leaflets, with or without calcification; no post-inflammatory changes noted. Left-sided valves > right-sided valves. Initial regurgitation related to valve retraction > later stenosis related to thickening/calcification
  • Echocardiogram

  • Cardiac MRI

  • Serial monitoring with timing of surgery as in ACC/AHA guidelines

  • Valve replacement is preferred over valve repair which is associated with worsened valve disease and heart failure

  • Consider TAVR, if mediastinum and cardiac anatomy is not amenable to open heart surgery

Conduction system abnormalities
  • A–V nodal block (including high-degree block)

  • Bundle branch block (RBBB > than LBBB)

  • Fascicular block

  • Tachycardias

  • Prolonged QTc

Not very common. Tachycardias can be persistent and is usually a result of autonomic dysfunction, similar to denervated hearts. Persistent tachycardia could increase the risk of tachycardia-induced cardiomyopathy
  • ECG

  • Telemetry/ambulatory Holter monitor

  • Permanent pacemaker as indicated for high-degree A–V block

  • ICD as indicated for life-threatening arrhythmia, sudden death or secondary prevention

  • Consider subpectoral approach for device implantation, if there is subcutaneous involvement of thoracic radiation

Cardiomyopathy
  • Diastolic dysfunction >systolic dysfunction

  • Right ventricle >left ventricle

Due to increased fibrosis in all three layers of the ventricular walls (epicardium, myocardium and endocardium). May lead to restrictive cardiomyopathy and rarely to systolic dysfunction. In addition, fibrosis of the right ventricle is usually more extensive than of the left ventricle
  • Echocardiogram

  • Cardiac MRI

  • Possible role for biomarkers (BNP, troponin)

  • Slow upward titration of ACE-I, beta blockade and aldosterone inhibitors in patients with reduced LV systolic function

  • Optimise risk factors for diastolic dysfunction

  • Exercise training

  • Inotropic support, VAD and heart transplantation, as indicated*

  • *Consider heart transplantation for the small group of patients with biventricular dysfunction, calcified cardiac skeleton, prior open heart surgery and/or restrictive/constrictive haemodynamic status.

  • ACC, American College of Cardiology; AHA, American Heart Association; AI, aortic insufficiency; BNP, brain natriuretic peptide; CAD, coronary artery disease; CTA, CT angiography; CV, cardiovascular; ICD, implantable cardioverter defibrillator; LAD, Left Anterior Descending artery; LBBB, left bundle branch block; LM, Left Main coronary artery; MR, mitral regurgitation; NF-κB, Nuclear Factor-κB; PI, pulmonic insufficiency; RBBB, right bundle branch block; RCA, Right Coronary Artery; RIHD, Radiation Induced Heart Disease; TAVR, transcatheter aortic valve replacement; TR, tricuspid regurgitation; VAD, Ventricular Assist Device.