The last five years have seen a paradigm shift in healthcare: new minimally invasive treatments are now available that can effectively replace surgery for elderly, comorbid patients. The most striking example is Transcatheter Aortic Valve Replacement (TAVR), the first major minimally invasive structural heart disease treatment to be disseminated nationally. TAVR is a life-saving option for the approximately 87,000 Veterans nationwide who suffer from severe aortic stenosis, and thereby face a 50% mortality rate within two years if left untreated. Preliminary data suggest that the novel complexities associated with TAVR diffusion significantly impact vulnerable patient populations. Based on prior data, one key mechanism for these disparities may be that vulnerable patient populations are less equipped to make informed decisions about treatment. Driven by the hypothesis that vulnerable Veteran populations experience unequal treatment with TAVR, but that decision support to routinely assess appropriateness and reduce barriers to care for Veterans can reduce these differences, the aims of this proposal are to: (1) Identify patient level factors that influence cardiovascular procedural treatment on the spectrum from minimally invasive (newer: TAVR and older: PCI) to invasive (older: CABG, SAVR) within the VA, categorizing high and low access groups, with non- VA data comparison. Multivariate, hierarchical logistic regression will be used to determine the association of patient level factors, including demographic and VA-specific contextual factors (e.g., percent service connection, proximity to VA procedure site, use of Veterans Choice or Medicare) with procedural use, identifying “low” and “high” access profile groups. I hypothesize that older, established cardiovascular procedures will show fewer inequities in care compared to the newest paradigm of care, TAVR. (2) Identify decisional needs and barriers to achieving appropriate TAVR treatment from the perspectives of Veterans (stratified into low and high access groups as defined by Aim 1) and their healthcare providers. I will use an explanatory mixed methods design to conduct semi-structured interviews with a stratified sample of low and high access profile Veterans referred for TAVR from multiple states and their providers to inform development of a pilot intervention in Aim 3. I hypothesize that poor understanding of individualized risks and benefits are a major limitation to appropriate TAVR referrals, with geographic barriers and difficulty using Veterans Choice options particularly identified among low access profile Veterans. (3) Build and pilot a novel individualized decision-making tool and patient facing website to improve both appropriateness and access to care, along with a strategy for implementation into routine VA care. Using TAVR as a model, I will develop and validate the feasibility of a prototype physician-facing decision aid for incorporation into routine VA care that predicts i...