Socioeconomic disparity in utilization of transcatheter aortic valve replacement

Abstract

Abstract Introduction Transcatheter aortic valve replacement (TAVR) is a major therapeutic option, rapidly replacing surgical aortic valve replacement (SAVR) in patients with aortic stenosis (AS) in recent years. However, the use of TAVR may vary with the socioeconomic status (SES) since new technologies are more likely to have the lower accessibility in some medico-social environments. In South Korean patients with AS, we investigated the difference in the use of TAVR based on SES and whether the difference influences clinical outcomes of patients with AS. Methods Between 2010 and 2020, 30,142 patients newly diagnosed with AS in a tertiary or regional center were investigated through the Korean National Health Insurance System (KNHIS). Patients were received either medical, SAVR or TAVR therapy for AS. The patients were categorized into 3 groups based on the insurance premium level (IPL) of the KNHIS (IPL1, <100 KW; IPL2, 100-249 KW; IPL3, ≥250KW). AS-related death was defined as death by AS, heart failure or ventricular arrhythmia. Cardiovascular (CV) death was defined as AS-related death or death by myocardial infarction or stroke. The study period was divided at year 2015, when the partial coverage for TAVR was implemented by the KNHIS. Results The numbers of patients referred to the tertiary/regional centers have continuously grown for the 11 years but the referring rate has grown even faster since 2015. The proportions of TAVR has increased while that of SAVR has decreased since 2015. TAVR was more frequently chosen by patients with a higher IPL (5.5%, 8.0% and 12.5%, respectively in the IPL1, IPL2 and IPL3, p<0.001), whereas the medical therapy appeared not affected by the IP levels. The patients in the IPL2 (odd ratio [OR] 1.33 [1.20-1.47]) and IPL3 (OR 1.65 [1.45-1.86]) had a higher chance to undergo TAVR than those in the IPL1 whereas the patients in the IPL3 was a lower chance to undergo SAVR than those in the IPL1 (OR 0.86 [0.78-0.94]). In patients with severe AS, the disparities between the IPL1 and IPL3 exaggerated (OR 1.99 [1.70-2.33]) (Figure 1). Higher IPLs were associated with lower risks of CV death and AS-related death. Time-varying Cox proportional hazard models showed that TAVR was associated with a lower risk of CV death than both medical therapy and SAVR in the entire study period and in year 2015 or later, whereas TAVR was associated with a lower risk of AS-related death than the both only in year 2015 or later, after adjustment of relevant covariates including the IPL (Figure 2). The choice of TAVR significantly medicated the associations between IPLs and the risk of CV death (responsible for 3.0% in the IPL2 and 4.1% in the IPL3). Conclusion The SES based on the IPL is independently associated with the choice of TAVR in patients with AS and the association has become stronger since 2015. The disparity in use of TAVR could mediate more frequent CV deaths in patients with the lower IPL.Figure 1Figure 2