Abstract Th0086: Improvement of Cardiovascular Prognostic Value of Endothelial Function Test (EndoPAT) by Repeated Measurements

Background: EndoPAT, a peripheral arterial tonometry device (Itamar Medical, Caesarea, Israel) is effective in predicting the prognosis of cardiovascular disease, and a reactive hyperemia index (RHI) of less than 1.67 is considered to indicate abnormal microvascular function. However, when different values are measured each time, interpretation can be difficult. Objective: We sought to determine whether two repeated measurements improve predictive performance compared with a single measurement. Methods: We enrolled 170 patients with diabetes or hypertension who participated in the FMD-J B study (a multicenter study of vascular testing in Japan) from our hospital in 2010-2011. After enrollment, EndoPAT-RHI was measured twice, 1.5 years later (first time) and 3 years later (second time). Patients were divided into two groups: patients with RHI < 1.67 at both time points and the rest (including patients who were measured only once). 44% of patients had RHI < 1.67 at the first measurement, 43% at the second measurement, and 35 (20%) patients had RHI < 1.67 at both measurements (Figure 1). We could follow-up health status of the 165 patients until November 2024. Results: Over a 9.9 ± 2.5-year period, 11 all-cause mortality (7%), 5 cardiac deaths (3%), 21 MACEs (12%), and 12 hospitalizations due to heart failure (7%) occurred. Log-rank analysis of single measurements for each occasion showed differences in all-cause mortality (Figure 2A,2B) and heart failure (Figure 2D,2E), but the prognostic value was not significant in COX analysis. However, patients with RHI < 1.67 twice had a significantly increased risk of all-cause mortality [HR 5.377 (CI 1.484-19.483), p = 0.010] (Figure 2C) and heart failure [HR 4.200 (CI 1.262-13.972), p = 0.019] (Figure 2F) in COX multivariate analysis adjusted for age, sex, lifestyle-related diseases, and renal function. Furthermore, patients with an RHI of 1.67 or higher for both measures had less MACE [HR 0.363 (0.149-0.884), p = 0.026] (Figure 3), even after excluding the effects of other factors. Conclusion: EndoPAT-RHI may have increased cardiovascular prognostic value with repeated measurements.