Prognostic significance of systemic arterial stiffness evaluated by cardio-ankle vascular index in patients with idiopathic pulmonary hypertension

Abstract

Background: In a previous study, the cardio-ankle vascular index (CAVI) was increased significantly in idiopathic pulmonary arterial hypertension (IPAH) patients compared to the healthy group and did not much differ from one in systemic hypertensives. In this study the relations between survival and CAVI was evaluated in patients with IPAH. Patients and Methods: We included 89 patients with new-diagnosed IPAH without concomitant diseases. Standard examinations, including right heart catheterization (RHC) and systemic arterial stiffness evaluation, were performed. All patients were divided according to CAVI value: the group with CAVI ≥ 8 (n = 18) and the group with CAVI < 8 (n = 71). The mean follow-up was 33.8 ± 23.7 months. Kaplan–Meier and Cox regression analysis were performed for the evaluation of our cohort survival and the predictors of death. Results: The group with CAVI≥8 was older and more severe compared to the group with CAVI< 8. Patients with CAVI≥8 had significantly reduced end-diastolic (73.79±18.94 vs 87.35±16.69 mL, P<0.009) and end-systolic (25.71±9.56 vs 33.55±10.33 mL, P<0.01) volumes of the left ventricle, the higher right ventricle thickness (0.77±0.12 vs 0.62 ±0.20 mm, P < 0.006), and the lower TAPSE (13.38±2.15 vs 15.98±4.4 mm, P<0.018). RHC data did not differ significantly between groups, except the higher level of the right atrial pressure in patients with CAVI≥ 8–11.38±7.1 vs 8.76±4.7 mmHg, P<0.08. The estimated overall survival rate was 61.2%. The CAVI≥8 increased the risk of mortality 2.34 times (CI 1.04–5.28, P = 0.041). The estimated Kaplan–Meier survival in the patients with CAVI ≥ 8 was only 46.7 ± 7.18% compared to patients with CAVI < 8-65.6 ± 4.2%, P = 0.035. At multifactorial regression analysis, the CAVI reduced but saved its relevance as death predictor-OR = 1.13, CI 1.001–1.871. Summary: We suggested the CAVI could be a new independent predictor of death in the IPAH population and could be used to better risk stratify this patient population if CAVI is validated as a marker in a larger multicenter trial.