Aortic stenosis (AS) is one of the most prevalent valvular heart diseases, which primarily affects older adults.1,2 Untreated patients with symptomatic severe AS have a high risk of mortality, more than 50% within one-year.3,4 The advent of surgical aortic valve replacement (SAVR) in the 1960s and then transcatheter aortic valve replacement (TAVR) in the 2000s have resulted in a steady decline in morbidity and mortality for AS over decades.5, 6, 7, 8, 9, 10, 11 TAVR, in particular, initially provided a new option for patients deemed to be poor candidates for SAVR 3, with indications for TAVR now expanded to include low-surgical-risk patients.12, 13, 14 The advent of TAVR has correlated with increased survival for all patients with AS.15 Despite this growth, some recent data suggest that many patients with symptomatic severe AS remain untreated, raising the potential need for improved awareness, patient engagement and referral for shared decision making (SDM) with Heart Valve Specialists when indicated.16, 17, 18, 19

To optimize care delivery for patients with aortic stenosis, it is crucial that patients who are likely to benefit from aortic valve replacement (AVR) are referred for a thorough evaluation in a timely manner. Prior studies suggest that AVR is not always used in managing symptomatic severe AS even in patients that appear to have strong indications for AVR.16, 17, 18, 19 This could be due to various reasons: 1) under-recognition of patients who would benefit from AVR; 2) recognition but under-referral; or 3) appropriate lack of referral/utilization in patients who either have preferences to avoid AVR and/or contraindications because of competing comorbidities. Distinguishing between these potential explanations is critically important to inform the design of systems of care that promote appropriate utilization of AVR for patients who are likely to benefit. However, quantitative results are inadequate for distinguishing between these possibilities. As such, detailed clinical adjudication and chart review are needed.

The American Heart Association (AHA) and American College of Cardiology (ACC) issued guidelines that highlight the crucial role of a multidisciplinary Heart Valve Team in managing patients with severe valvular heart disease (VHD) when intervention is being considered, which is classified as a class I recommendation in both the 2014 and 2022 AHA/ACC guidelines.20,21 Additionally, the guidelines suggest that even asymptomatic patients with severe VHD be referred to a Heart Valve Team for further evaluation and management, with as a class IIa recommendation.20,21

Despite these recommendations, recent evidence suggests that many patients with symptomatic severe AS are still not receiving AVR, raising questions about effective implementation of the guidelines.4,16,22. To provide insight about the potential role of referrals in this gap that could lead to the redesign of clinical care systems, this study was conducted across two hospitals to investigate the impact of patients' clinical characteristics and process-related parameters on referral to Heart Valve Specialists and utilization of AVR. Through a physician-led chart review, the study aimed to uncover the reasons for the potential under-referral of patients with symptomatic severe AS and to identify areas for clinical practice improvement.