Pulmonary hemodynamics and outcome in a large cohort of patients with sinus venosus septal defect

Background: Left-to-right shunt in sinus venosus septal defect (SVSD) may affect resistive (pulmonary vascular resistance–PVR) and elastic (pulmonary artery compliance-PAC) pulmonary artery properties. This study aimed at evaluating (1) impact of age, (2) pulmonary hemodynamics, and (3) outcome in a large cohort of SVSD patients. Methods: This study included 136 patients with SVSD (median age at diagnosis 14 (IQR 5–48) years, 47% male) of which 87 underwent catheterization. Pressures were measured and cardiac output was evaluated using the Fick principle at diagnosis. PVR, PAC and their product (RC time) were calculated. Results: Surgical repair was performed in 128 (94%) at a median age of 13 (IQR 5– 43) years. During a median follow-up time of 31 (IQR 17–55) years, 12 (9%) patients died, 13 (10%) developed heart failure, 4 (3%) Eisenmenger syndrome, 19 (14%) atrial arrhythmia, 6 (4%) sick sinus syndrome and 7 (5%) required pacemaker implantation. In those who underwent catheterization, median shunt ratio was 2.5 (IQR 2.0–2.9). Thirty (34%) had mean PA pressure ≥25 mmHg. PVR indexed, PAC indexed, and RC time was 3.5 (IQR 2.4–7.5) WU.m², 1.8 (IQR 1.3–2.5) mL/mmHg.m² and 0.39 (0.26–0.53) sec with an inverse hyperbolic relationship between PVR and PAC. Mean PA pressure (P < 0.0001); wedge pressure (P = 0.001), PVR indexed (P = 0.002) and PAC indexed (P = 0.002) changed significantly with age at diagnosis, but shunt ratio did not. Conclusion: SVSD has good long-term outcome, albeit with late morbidities. Thirty-four percent has mean PA pressure ≥25 mmHg, but Eisenmenger syndrome is rare (3%). PVR and PAC are inversely related and change significantly with older age.