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 (IVCmin) and end-expiration (IVCmax), and IVC collapsibility index (IVCCI) was calculated.
Results: Based on 918 patients, we observed a good correlation between IVCmax and invasive RAP (r=0.56, P<0.001); IVCmin and RAP (r=0.58, P<0.001); and IVCCI (r=-0.72, P<0.001). There was excellent correlation between invasive RAP and estimated RAP using IVCCI (r=0.80, P<0.001). We observed that IVCCI <60% had superior diagnostic performance as compared with American Society of Echocardiography criteria (IVCmax >2.1 cm, area under the curve difference 0.15, P<0.001; IVCCI <50%, area under the curve difference 0.09, P=0.008; combination of IVCmax >2.1 cm; and IVCCI <50%, area under the curve difference 0.06, P=0.02). Estimated RAP >10 mm Hg based on IVCCI had comparable prognostic performance as invasive RAP but superior prognostic performance as the American Society of Echocardiography criteria.
Conclusions: IVCCI <60% was the best criterion to identify patients with elevated RAP. IVCCI was comparable to invasively measured RAP in its relation to prognosis. Further studies are required to determine whether the use of IVCCI in clinical decision-making will improve clinical outcomes in this population.
Keywords: atrial pressure; catheterization; diagnosis; heart failure; hypertension.