Behavior of Unrepaired Perimembranous Ventricular Septal Defect in Young Adults

The number of adolescents and young adults with congenital heart defects, including ventricular septal defect (VSD), increases continuously. We evaluated the mid-term outcome of small and unclosed perimembranous VSDs (pmVSDs). All patients with a known unrepaired pmVSD at 16 years of age were selected from our database. The clinical, electrocardiographic, and echocardiographic changes between baseline and the latest follow-up examination were compared. A total of 220 patients (119 males, median age 18 years, interquartile range 7) could be included. During a median follow-up of 6 years (interquartile range 4, range 38), 2 patients died (1%; 1 from sudden death and 1 from end-stage heart failure). Endocarditis occurred in 8 patients (4%). One patient required pacemaker implantation (0.5%) and one required implantable cardioverter-defibrillator implantation (1%). Fifteen patients (7%) required a closing procedure. In 8 patients (4%), the pmVSD closed spontaneously. In the remaining 203 patients (93%), the QRS morphology changed in 5% and 1% lost sinus rhythm (p = 0.0001 and p = 0.015, respectively). The left ventricular ejection fraction and stroke volume index increased from 62 ± 7% to 67 ± 8% and from 41 ± 11 to 44 ± 15 ml/m² (p = 0.0001 and p = 0.035, respectively), the end-systolic diameter decreased, and the end-diastolic diameter did not change. Finally, patients with an open pmVSD developed more pulmonary arterial hypertension during follow-up (from 3% to 9%, p = 0.002). In conclusion, mid-term follow-up of adolescents and young adults with a small and unrepaired pmVSD was not uneventful. Some patients required intervention, but in others, spontaneous closure occurred. Electrocardiographic and structural changes were noticed, for which the clinical significance needs to be determined.