In previous studies, the cardio-ankle vascular index (CAVI) was increased significantly in idiopathic pulmonary arterial hypertension (IPAH) patients compared with the healthy group and did not differ much from that in systemic hypertensives. In this study, the relationship between survival and CAVI was evaluated in patients with IPAH.
We included 89 patients with newly 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 analyses were performed for the evaluation of our cohort survival and the predictors of death.
The group with CAVI ≥ 8 was older and more severe compared with the group having 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, higher right ventricle thickness (0.77 ± 0.12 vs. 0.62 ± 0.20 mm, P < 0.006) and lower tricuspid annular plane excursion (13.38 ± 2.15 vs. 15.98 ± 4.4 mm, P < 0.018). RHC data did not differ significantly between groups, except for the higher level of 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%. CAVI > 8 increased the risk of mortality by 2.34 times (confidence interval 1.04–5.28, P = 0.041). The estimated Kaplan–Meier survival in patients with CAVI ≥8 was only 46.7 ± 7.18% compared with patients having CAVI < 8 (65.6 ± 4.2%, P = 0.035). At multifactorial regression analysis the CAVI reduced but retained its relevance as a predictor of death (odds ratio = 1.13, confidence interval 1.001–1.871).
We suggest that CAVI could be a new independent predictor of death in the IPAH population and could be used to risk stratify this patient population better if CAVI is validated as a marker in a larger multicentre trial.
KEY CONTRIBUTORS
G. D. Radchenko, I. O. Zhyvilo, E. Y. Titov., Y. M. Sirenko State institution ‘National Scientific Center “Institute of Cardiology named after M. D. Strazhesko”’ of National Academy of Medical Science, Kyiv, Ukraine
