Abstract 16929: Defining Thresholds for Meaningful 30-day Health Status Changes Following Transfemoral Carotid Artery Stenting

Introduction: Carotid artery stenosis treatment trials have focused on clinical endpoints such as stroke, death, and MI, but evidence of carotid revascularization’s impact on health status is limited. This study aims to establish minimal clinically important differences (MCIDs) to assess clinical improvement or worsening from the perspectives of patients with carotid artery stenosis undergoing transfemoral carotid artery stenting (TF-CAS). Methods: We studied patients in the multicenter Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) registry who underwent TF-CAS between 2010 and 2014 and who completed either the EQ-5D-3L or SF-36, two generic health-related quality-of-life surveys. Distribution-based MCIDs were calculated as 0.5 standard deviations for 30-day changes in health status scores post-TF-CAS for the EQ-5D-3L index value and visual analog scale (VAS) subscales and the SF-36 mental and physical component summary (MCS and PCS) subscales. We then stratified this analysis by symptom status (presence or abscence of prior stroke or TIA). Results: The study included 3,930 patients (27.7% symptomatic) who completed the EQ-5D-3L and 3,018 (30.5% symptomatic) who completed the SF-36. The MCIDs for the overall cohorts were 0.09, 11.02, 4.73, and 5.39 for the EQ-5D-3L index value, EQ-5D-3L VAS, SF-36 MCS, and SF-36 PCS, respectively. All MCIDs are summarized in Table 1. The MCIDs for each subscale were similar between asymptomatic and symptomatic subpopulations. Conclusions: Distribution-based thresholds for improvement and worsening of health status in patients undergoing TF-CAS were established for commonly-used generic health status instruments. These reference values can be used in both symptomatic and asymptomatic disease and will be important for interpreting future trial results focusing on the benefit of TF-CAS from patients’ perspectives.