Infective Endocarditis Risk in Ventricular Septal Defect

Risk Stratification by VSD Status

• The European Society of Cardiology reports IE occurring in up to 2 per 1000 patient-years in patients with small residual VSDs 1
• At least 22% of patients with surgically repaired VSDs who developed IE had known residual VSD leaks 2
• Corrective surgery with no residual defect eliminates the attributable risk for endocarditis 6 months after surgery 3, 4, 5
• The risk before surgical closure is more than twice that of surgically closed VSDs 2

Important Clinical Context

Mortality and Morbidity Considerations

• The presence of aortic regurgitation independently increases the risk of IE in patients with VSD, whether managed medically or surgically 2

Risk Factors That Amplify IE Risk

• Residual defects at or adjacent to prosthetic patches that inhibit endothelialization remain high-risk 2
• Unrepaired cyanotic congenital heart disease carries substantially higher IE risk than isolated VSDs 2, 3
• The predominant organism in VSD-associated IE is viridans streptococcus, with the incidence rate nearly 35-fold the population-based rate 2

Critical Pitfalls to Avoid

• Do not assume all "repaired" VSDs have equal risk—carefully assess for residual shunts, as these patients retain elevated IE risk comparable to unrepaired defects 2