*5.5.2 Development of infective endocarditis*

VSDs even when not hemodynamically significant carry a lifetime risk of developing infective endocarditis (IE). The incidence of IE in unrepaired VSDs is 1.5 to 2.4 per 1000 patient-years, especially if associated with aortic insufficiency or with left ventricle-to-right atrial shunt [21]. Based on a Swedish registry study, risk of IE in adult VSD patients without previous intervention is 20–30 times higher than the general population [22]. The second natural history study reported risk of IE is twice as likely in unrepaired defects as compared to after surgical repair. However, the incidence of IE after closure of VSD was still higher than normal risk curve [23, 24]. Based on the 2007, AHA guidelines, prophylaxis for IE is not recommended on patients with isolated VSDs. The exceptions are VSDs within 6 months of surgical or intervention closure, with ES, with residual defects after surgery or patients with previous history of IE [25].
