One-year worsening of cardio-ankle vascular index predicts cardiovascular events in adults younger than 65 years

Background The cardio-ankle vascular index (CAVI) is an indicator of vascular function based on the measurement principles of pulse wave velocity. However, the association between its longitudinal changes and cardiovascular events remains unclear. Purpose The aim of this study was to investigate the association between longitudinal changes in CAVI and cardiovascular events. Methods A total of 4,032 participants (mean age 68± 11 years; 51% male) who were enrolled in the Coupling Study and had CAVI measurements at baseline and after one year were included. Based on a guideline-derived CAVI cutoff of 9 [1], participants were classified into four groups:Good group: baseline CAVI < 9 / 1-year CAVI < 9 (N = 1,841)Improved group: baseline CAVI ≥ 9 / 1-year CAVI < 9 (N = 268)Worsened group: baseline CAVI < 9 / 1-year CAVI ≥ 9 (N = 407)Poor group: baseline CAVI ≥ 9 / 1-year CAVI ≥ 9 (N = 1,516) The primary endpoint was major cardiovascular events, including stroke, coronary heart disease, sudden death, heart failure, and aortic dissection. Analyses were further stratified by age (<65 / ≥65 years). Results During a median follow-up of 5.0 years (20,844 person-years), 167 events (4.0%) occurred. In the overall cohort, the incidence of events tended to be higher in the worsened group (hazard ratio [HR] 1.55; 95% confidence interval [CI]: 0.90–2.67) and the poor group (HR 1.27; 95% CI: 0.82–1.95) compared with the good group, although these differences were not statistically significant. Among participants aged <65 years, event incidence was significantly higher in the worsened group (HR 3.66; 95% CI: 1.23–10.88) and the poor group (HR 3.18; 95% CI: 1.32–7.66) compared with the good group. No significant differences were observed among the four groups in participants aged ≥65 years (Figure). Conclusions In individuals younger than 65 years, worsening CAVI over one year was significantly associated with an increased risk of cardiovascular events. These findings suggest the clinical utility of repeated vascular function assessment in relatively younger populations.