Egbe AC, Vojjini R, Badawy M, et al. - Researchers determined if rises in pulmonary artery wedge pressure (PAWP) in patients experiencing congenital heart disease (CHD) would be more strongly associated with ventricular interdependence vs patients with isolated left-heart disease such as heart failure with preserved ejection fraction (HFpEF). They evaluated ventricular interdependence by the link between PAWP and right-atrial pressure (RAP), RAP/PAWP ratio, and the left-ventricular (LV) eccentricity index. Among CHD patients, 49% had elevated PAWP (≥15 mm Hg). A very strong correlation was evident between RAP and PAWP in CHD that greatly exceeded the respective correlation in HFpEF. In CHD, higher RAP/PAWP ratio and LV eccentricity index were observed, relative to HFpEF. Death/transplant was independently predicted by RAP (but not PAWP). Overall, patients with right-sided CHD were often found to have elevated left-heart filling pressures but this was shown to be associated mainly with right-heart failure and enhanced ventricular interdependence instead of left-heart disease. These revelations strengthen the importance of treatment interventions targeted to the right heart.