Abstract 12693: Invasive Derivation, Validation, and Prognostic Association of a Quantitative Echocardiographic Estimate of Pulmonary Artery Wedge Pressure

Abstract

Background: Grading of diastolic dysfunction (DD) commonly leads to indeterminate classifications and provides little information on treatment effect or disease progression. A quantitative non-invasive estimate of LV filling pressures would have clinical utility. Aim: To invasively derive and validate a quantitative echocardiographic estimation of pulmonary artery wedge pressure (PAWP), and to compare its prognostic performance with diastolic dysfunction grading. Methods: Echocardiographic measures were used to estimate PAWP (ePAWP) using multivariable linear regression in patients undergoing right heart catheterization (RHC). Prognostic associations were analyzed in the National Echocardiography Database of Australia (NEDA). Results: In patients who underwent both RHC and echocardiography within two hours (n=90), ePAWP was derived using left atrial volume index (LAVi), mitral peak early velocity (E), and pulmonary vein peak systolic velocity (PVs). In an external validation cohort (n=53), ePAWP showed good agreement with invasive PAWP (mean±SD difference 0.5±5.0 mmHg) and good diagnostic accuracy for estimating PAWP >15mmHg (area under the curve [95% confidence interval] 0.94 [0.88-1.00]). Among patients in NEDA (n=38,856, median [interquartile range] follow-up 4.8 [2.3-8.0] years, 2,756 cardiovascular deaths), ePAWP associated with cardiovascular death even after adjustment for age, sex, and diastolic dysfunction grading (hazard ratio (HR) 1.08 [1.07-1.09]) and provided incremental prognostic information to diastolic dysfunction grading (C-statistic: 0.68 vs. 0.65, p<0.001). Increased ePAWP associated with worse prognosis across all grades of diastolic function (HR normal: 1.07 [1.06-1.09]; indeterminate: 1.08 [1.07-1.09]; abnormal: 1.08 [1.07-1.09]. Conclusion: Echocardiographic ePAWP is an easily acquired continuous variable with good accuracy that associates with prognosis beyond diastolic dysfunction grading.