Role of Inferior Vena Cava Dynamics for Estimating Right Atrial Pressure in Congenital Heart Disease

Background: Inferior vena cava (IVC) size and collapsibility (IVC dynamics) are used for estimating right atrial pressure (RAP). However, the diagnostic performance of the American Society of Echocardiography IVC criteria for estimating RAP in patients with congenital heart disease are unknown. The purpose of this study was to assess the role of IVC dynamics for estimating RAP in adults with congenital heart disease. Methods: We conducted a retrospective study of adults with congenital heart disease that underwent cardiac catheterization and echocardiogram at Mayo Clinic (2003–2019). IVC diameter was measured at inspiration (IVC min ) and end-expiration (IVC max ), and IVC collapsibility index (IVC CI ) was calculated. Results: Based on 918 patients, we observed a good correlation between IVC max and invasive RAP ( r =0.56, P <0.001); IVC min and RAP ( r =0.58, P <0.001); and IVC CI ( r =−0.72, P <0.001). There was excellent correlation between invasive RAP and estimated RAP using IVC CI ( r =0.80, P <0.001). We observed that IVC CI <60% had superior diagnostic performance as compared with American Society of Echocardiography criteria (IVC max >2.1 cm, area under the curve difference 0.15, P <0.001; IVC CI <50%, area under the curve difference 0.09, P =0.008; combination of IVC max >2.1 cm; and IVC CI <50%, area under the curve difference 0.06, P =0.02). Estimated RAP >10 mm Hg based on IVC CI had comparable prognostic performance as invasive RAP but superior prognostic performance as the American Society of Echocardiography criteria. Conclusions: IVC CI <60% was the best criterion to identify patients with elevated RAP. IVC CI was comparable to invasively measured RAP in its relation to prognosis. Further studies are required to determine whether the use of IVC CI in clinical decision-making will improve clinical outcomes in this population.