BACKGROUND: Surgeons may leave a residual atrial-level communication during complete repair of tetralogy of Fallot (TOF) in anticipation of restrictive right ventricle physiology or as routine practice. We investigated the impact of closing the interatrial communication at the time of definitive TOF repair. METHODS: We retrospectively reviewed TOF patients who underwent definitive repair at age <
12 months between June 2000 and January 2023. Propensity score matching identified 82 patients with a patent interatrial communication and 50 patients with no interatrial communication on postoperative echocardiography (as-treated analysis). The primary endpoint was maximum vasoactive-inotropic score (VIS) as a surrogate for low cardiac output syndrome. RESULTS: A total of 132 patients (median age, 3.5 months
interquartile range [IQR], 1.8-5.8 months) were matched. There was no difference in maximum VIS (patent interatrial communication: 5.0 [IQR, 4.8-9.0] vs no interatrial communication: 6.0 [IQR, 5.0-8.0]
P = .78). Additionally, the duration of inotrope therapy (3.0 [IQR, 2.0-4.0] days vs 3.0 [IQR, 1.3-4.0] days
P = .57), peak lactate (2.2 [IQR, 1.9-3.0] mmol/L vs 2.3 [IQR, 1.9-3.2] mmol/L
P = .58), time to lactate clearance (0.2 [IQR, 0.0-0.3] days vs 0.1 [IQR, 0.0-0.3] days
P = .57), chest tube duration (4.0 [IQR, 3.0-6.0] days vs 4.0 [IQR, 3.0-5.0] days
P = .23), and length of intensive care unit stay (5.0 [IQR, 3.0-7.0] days vs 5.0 [IQR, 3.0-7.0] days
P = .71) were similar in the 2 groups. The median duration of follow-up was 5.5 years (IQR, 2.7-9.9 years). Among patients with a residual communication, patency rates were 93.6% at discharge and 53.7% at latest follow-up, with most having bidirectional shunting across the defect. CONCLUSIONS: Closure of the atrial-level communication during complete TOF repair does not significantly impact the immediate postoperative course or mid-term outcomes. Further investigation is warranted to better understand how patency influences long-term outcomes.