Noninvasive estimation of left atrial (LA) pressure (LAP) is essential for the diagnosis and risk stratification of heart failure (HF).1 The 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) recommendations introduced a multiparametric, rule-based framework combining early diastolic transmitral velocity (E), early diastolic mitral annular velocity (e′) and the E/e′ ratio, tricuspid regurgitant jet velocity (TR-V), and left atrial volume index (LAVi).2 Although this framework improved consistency, a large proportion of patients remained classified as “indeterminate,” limiting clinical decision-making and prognostic discrimination.3, 4, 5 Conceptually, the 2016 algorithm prioritized left ventricular (LV) diastolic dysfunction grading rather than a hierarchical evaluation of LAP itself, contributing to ambiguous classifications, especially in borderline or partially incomplete studies.

To address these limitations, the 2025 update introduced a simplified 2-step algorithm for LAP assessment.6 Step 1 applies 3 core Doppler indices (e′, E/e′, and peak TR-V) to classify LAP when findings are concordant. Step 2 adjudicates discordant or incomplete cases using any one of several secondary markers of elevated filling pressure (pulmonary vein systolic/diastolic ratio [PV S/D] ≤0.67, LA reservoir strain (LARS) ≤ 18%, or LAVi > 34 mL/m2),7, 8, 9, 10 thus replacing the former “indeterminate” category with a deterministic decision pathway. In external validation, this stepwise strategy reduced the number of cases in the indeterminate category and improved diagnostic accuracy against invasive reference standards.9

However, routine adoption of LARS remains limited by vendor dependence and implementation challenges. In contrast, PV Doppler and LAVi are more widely obtained and reproducible, while LARS is measurable only in a subset of patients, reflecting real-world practice.11, 12, 13, 14 Importantly, the 2025 framework was designed to remain decisive even when LARS is unavailable, allowing adjudication based on PV S/D and/or LAVi rather than defaulting to “indeterminate.” Against this background, we applied the updated 2025 algorithm to test whether it reduced indeterminate classifications and improved prognostic stratification compared with the 2016 standard, using the composite end point of HF hospitalization and all-cause mortality.