Increased incidence of infective endocarditis in patients with ventricular septal defect

Ventricular septal defect (VSD) is one of the most common congenital heart anomalies in childhood and there is an increasing prevalence of VSDs in the adult population. The long-term risk of infective endocarditis (IE) is of concern. The aim of this study was to clarify and compare the incidence of IE in adults with repaired and unrepaired VSDs.

Patients with VSDs were identified using the Adult Congenital Heart Disease registry at the National Heart Centre Singapore. Patients were divided into Group 1 (repaired VSD) and Group 2 (unrepaired VSDs). The electronic medical records were searched for hospitalization due to IE during a 10-year period (October 2, 2007-October 1, 2017).

Four hundred seventy-nine patients (53% male) were identified, with a mean age of 35.0 ± 13.7 years. There were 164 patients (34.2%) in Group 1 and 315 patients (65.8%) in Group 2. In total, there were eight episodes of IE from six patients (3 male, mean age of 42.2 ± 20.7 years). Two patients had recurrent IE. The overall incidence of IE was 1.67/1000 y, and this is 11-15-fold higher compared to general adult population. The incidence of IE in Group 2 was 1.90/1000 y. There were no IE cases in Group 1.

Patients with VSDs, especially if unrepaired, carry a substantially increased risk of IE compared to the general population.