Abstract 4147314: Contemporary Diagnosis, Management, and Outcomes of Patients With Low-Gradient Severe Aortic Stenosis: A Multi-Center Analysis

Background: The American College of Cardiology/American Heart Association guidelines recommend assessing aortic stenosis (AS) using American Society of Echocardiography-endorsed parameters and referring patients with severe symptomatic AS for treatment. Yet, multi-site real-world assessment of guideline adherence is lacking. Methods: We assessed consecutive echocardiographic reports for patients >18 years of age from 30 US institutions with appropriate permissions between January 2018–March 2024 (egnite Database; egnite, Inc.). Completeness of echocardiographic evaluation of AS was assessed. Patients with severe AS were stratified into high- and low-gradient (HG, mean aortic gradient [MG] ≥40 mm Hg; LG, MG <40 mm Hg). Rates of Heart Team evaluation within 60 days and aortic valve replacement (AVR) within 6 months were assessed via the Kaplan-Meier method. Results: Of 2,829,095 echocardiographic reports, V max , MG, aortic valve area (AVA), stroke volume index, left ventricular ejection fraction (LVEF), and AS severity were missing in 25%, 30%, 35%, 83%, 5%, and 36%, respectively. Of 1,189,382 patients with available AS severity assessment, 45,967 had an AVA ≤1.0 cm 2 and/or V max ≥4.0 m/s with only 52% being diagnosed with severe AS and 20% being diagnosed as <moderate AS. Of 26,903 patients (2.3%) diagnosed with severe AS, there was a greater proportion of LG cases (LG: 52%, HG: 48%). Regardless of LVEF or symptoms, a lower proportion of severe LG AS patients were evaluated by a Heart Team within 60 days (LG: 37%, HG: 53%) and received an AVR within 6 months (LG: 35%, HG: 61%). Patients not evaluated by the Heart Team were older and more likely to be female and non-White than those who were evaluated, despite a comparable history of heart failure. A greater number of mortality events was observed among LG vs HG patients seen (877/10,241 vs. 381/9304) and not seen (2679/10,121 vs. 914 / 3453) by the Heart Team. Conclusions: Key parameters needed to diagnose the severity of AS are often missing in echocardiographic reports. Compared to HG, severe LG AS patients have lower Heart Team evaluation rates, with racial, sex, and age disparities, as well as lower AVR rates and more observed mortality events. Further work is needed to enhance guideline adherence for the diagnosis and management of patients with severe LG AS.