Pulmonary vascular resistance and pulmonary artery compliance in a large cohort of patients with sinus venosus septal defect

Abstract Background Left-to-right shunt in patients with sinus venosus septal defect (SVSD) may affect resistive (pulmonary vascular resistance – PVR) and elastic (pulmonary artery compliance-PAC) properties of the pulmonary arteries. This study aimed at evaluating (1) changes in hemodynamics over time and (2) the relationship between PVR and PAC in a large cohort of patients with SVSD. Methods Data of 136 patients with SVSD (median age at diagnosis 14 (IQR 5–48) years, 47% male) were included. Catheterization data was available in 87 patients. Pressures were measured and cardiac output evaluated using the Fick principle. PVR (mean pulmonary artery pressure (mPAP)-wedge pressure/cardiac output) and PAC (stroke volume/pulse pressure) were calculated and indexed for body surface area. Results Ninety percent had abnormal pulmonary venous connection. Median shunt ratio was 2.5 (IQR 2.0–2.9). 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, 19 (14%) atrial arrhythmia, 6 (4%) sick sinus syndrome and 7 (5%) required pacemaker implantation. PVR indexed and PAC indexed was 3.5 (IQR 2.4–7.5) WU·m2 and 1.8 (IQR 1.3–2.5) mL/mmHg·m2. There was an inverse, hyperbolic relationship between PVR and PAC with an RC time of 6.6 (IQR 4.4–8.9) sec. When comparing patients with age at catheterization 50 years, shunt ratio (2.5±0.6 vs 2.5±0.8 vs 2.5±0.6; p=0.836) and PVR indexed (2.9 (2.3–3.4) vs 3.1 (2.0–9.0) vs 6.6 (3.6–8.8) WU·m2; p=0.132) were not statistically different, whereas mPAP (19 (16–22) vs 21 (16–24) vs 28 (22–34) mmHg; p=0.002); wedge (6 (4–8) vs 13 (8–16)vs 14 (10–19) mmHg; p