Although right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP) are correlated in heart failure, in a sizeable minority of patients, the RAP and PCWP are not tightly coupled. The basis of this variability in the RAP/PCWP ratio, and whether it conveys prognostic value, is not known.

We analyzed the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial database. Baseline characteristics, including echocardiographic assessment of right ventricular (RV) structure and function, and invasively measured hemodynamic parameters, were compared among tertiles of the RAP/PCWP ratio. Multivariable Cox proportional hazard models assessed the association of RAP/PCWP ratio with the primary ESCAPE outcome (6-month death or hospitalization [days]) adjusting for systolic blood pressure, blood urea nitrogen, 6-minute walk distance, and PCWP. The RAP/PCWP tertiles were 0.27 to 0.4 (tertile 1); 0.41 to 0.615 (tertile 2), and 0.62 to 1.21 (tertile 3). Increasing RAP/PCWP was associated with increasing median right atrial area (23, 26, 29 cm², respectively; P<0.005), RV area in diastole (21, 27, 27 cm², respectively; P<0.005), and pulmonary vascular resistance (2.4, 2.9, 3.6 woods units, respectively; P=0.003), and lower RV stroke work index (8.6, 8.4, 5.5 g·m/m² per beat, respectively; P<0.001). RAP/PCWP ratio was associated with death or hospitalization within 6 months (hazard ratio, 1.16 [1, 1.4]; P<0.05).

Increased RAP/PCWP ratio was associated with higher pulmonary vascular resistance, reduced RV function (manifest as a larger right atrium and ventricle and lower RV stroke work index), and an increased risk of adverse outcomes in patients with advanced heart failure.