Background: Pulmonary artery wedge pressure (PAWP) is often elevated in patients with right-sided congenital heart disease (CHD), raising the possibility of coexisting left-heart disease, but pressure-volume relationships in the left and right sides of the heart influence one another through interdependence, which may be amplified in patients with CHD.
Methods: We hypothesized that increases in PAWP in patients with CHD would be more strongly related to ventricular interdependence compared with patients who have isolated left-heart disease such as heart failure with preserved ejection fraction (HFpEF). Ventricular interdependence was assessed by the relationship between PAWP and right-atrial pressure (RAP), RAP/PAWP ratio, and the left-ventricular (LV) eccentricity index.
Results: PAWP was elevated (≥15 mm Hg) in 49% of patients with CHD (n = 449). There was a very strong correlation between RAP and PAWP in CHD (r = 0.81, P < 0.001) that greatly exceeded the respective correlation in HFpEF (n = 160; r = 0.58, P < 0.001; P < 0.001 between groups). RAP/PAWP ratio and LV eccentricity index were higher in CHD than HFpEF (1.26 ± 0.18 vs 1.05 ± 0.14, P = 0.007) and (0.80 ± 0.21 vs 0.59 ± 0.19, P < 0.001), respectively. RAP (but not PAWP) was an independent predictor of death/transplant (hazard ratio 1.86 per 5 mm Hg, 95% confidence interval, 1.39-2.45, P = 0.002).
Conclusions: Left-heart filling pressures are commonly elevated in right-sided CHD, but this is related predominantly to right-heart failure and enhanced ventricular interdependence rather than left-heart disease. These data provide new insight into the basis of abnormal left-heart hemodynamics in patients with CHD and reinforce the importance of therapeutic interventions targeted to the right heart.
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