24th June 2026

Epidemiology

Risk factors for the development of IE are:

• Structural heart disease (including HOCM, ASD, VSD, PDA, ToF)
• Valvular heart disease (including previous rheumatic fever)
• Presence of a prosthetic valve (including TAVI)
• Poor dental hygiene
• Age >60
• Male sex (three times more common in men)
• Immunosuppression (including cytotoxic medications, HIV)
• Intravenous drug use (IVDU)
• Previous IE
• Indwelling intravascular devices
• Presence of implantable cardiac devices
• Chronic haemodialysis

IE may be classified as right-sided (tricuspid and pulmonary valves) or left-sided (aortic and mitral valves). It may affect the patient’s own valves (native-valve IE) or a prosthetic valve. Left-sided IE is more common than right-sided. Right-sided IE is particularly associated with IVDU, and the tricuspid valve is particularly vulnerable in these cases. One in six patients with a prosthetic valve will develop IE, and this population makes up approximately 20% of all cases of IE.