High Market Competition Hospitals Are Driving Utilization of Transcatheter Aortic Valve Replacement Among Younger Patients in the US

S. Sakowitz¹, S. Bakhtiyar², S. Mallick³, S. Jane. Pereira⁴, S. Hirji⁵, R. Shemin³, P. Benharash^6
1UCLA David Geffen School of Medicine, Los Angeles, California ²University of Colorado, Aurora, Colorado ³UCLA, Los Angeles, California ⁴University of Utah, Salt Lake City, Utah ⁵Brigham and Women's Hospital, Allston, Massachusetts ⁶UCLA Division of Cardiac Surgery, Los Angeles, California

Purpose: Utilization of transcatheter aortic valve replacement(TAVR) has increased dramatically since 2011. Immediately following device approval, surrounding market competition was noted to spur institutional adoption[1-3]. While TAVR marketing to patients, physicians, and hospitals has become ubiquitous, it remains unclear how regional center-level competition may influence TAVR utilization and clinical practice.

Methods: All adult (≥18years) elective TAVR and surgical aortic valve replacement (SAVR) records were tabulated from five 2019 Healthcare Cost and Utilization Project State Inpatient Databases (Arizona, Florida, Maryland, New Jersey, New York). The Herfindahl-Hirschman Index (HHI) was used to assess hospital market competition. For each institution, we identified a variable radius that comprised 75% of total discharges. The HHI was then calculated as the sum of squared market shares for each hospital within that radius. Following prior methodology, institutions were categorized as Low (HHI>2,500), Moderate (HHI 1,500-2,500), and High Competition Centers (HCC) (HHI < 1,500).

Subsequently, multivariable regression models were built to consider the association of increasing market competition with TAVR versus SAVR utilization, accounting for patient factors, urban/rural location, and annual hospital cardiac surgical operative volume. We additionally adjusted for neighborhood socioeconomic disadvantage using the Distressed Communities Index (DCI). Neighborhoods in the top quintile by DCI score were considered Distressed.

Results: Among 144 unique centers, HHI ranged from 0-10,000. Relative to others, HCC were of lower annual cardiac surgical volume (mean 463 vs 545 annual procedures, P< 0.001), but were more frequently located in large metropolitan regions (74 vs 30%, P< 0.001). Interestingly, HCC were less often located in Distressed communities (9 vs 20%, P< 0.001).

Patients treated at HCC were of similar age, sex, and comorbidity burden, compared to those at other hospitals (Table).

Following risk-adjustment, care at HCC was linked with significantly higher odds of receiving TAVR, relative to treatment at other institutions (Adjusted Odds Ratio[AOR] 1.29, 95%Confidence Interval[CI] 1.20-1.39; Model C-Statistic 0.85; FigureA).

Notably, care at HCC was associated with significantly greater likelihood of TAVR for younger patients (FigureB). Specifically, among patients ≤65 years, treatment at HCC was linked with a 47% relative increase in likelihood of TAVR, compared to lower-competition institutions (AOR 1.47, CI 1.22-1.77; FigureC).

Considering patients >65 years, HCC also remained linked with increased TAVR odds (HR 1.25, CI 1.15-1.36).

Other factors associated with greater TAVR likelihood included increasing age (AOR 1.14/year, CI 1.13-1.14), greater Elixhauser comorbidity burden (AOR 1.03/point, CI 1.01-1.05), female sex (AOR 1.76, CI 1.66-1.87), and Medicaid insurance (AOR 1.40, CI 1.16-1.69; Reference: Private).

Conclusion: Greater hospital market competition was linked with significantly increased likelihood of TAVR. This effect appeared to most notably impact the care of younger patients, who faced dramatically elevated TAVR likelihood at high-competition centers. Our findings suggest that regional competition may influence clinical practice in the treatment of aortic stenosis.

Identify the source of the funding for this research project: None