Cardio-ankle vascular index as a predictor of major adverse cardiovascular events in metabolic syndrome patients

Abstract

Background: Arterial stiffness, as reflected in the cardio-ankle vascular index (CAVI), is a risk factor for major adverse cardiovascular events (MACEs). Hypothesis: Combining CAVI and metabolic syndrome (MetS) may enhance prediction of MACEs in a general adult population. Methods: A total of 3807 employees of the Electricity Generating Authority of Thailand were enrolled in a longitudinal health study during 2007-2008. Baseline characteristics were collected and CAVI determined. Subjects with previous coronary artery disease or stroke were excluded from analysis. MetS was defined using the modified NCEP-ATP III for Asians. The primary study endpoint was occurrence of a MACE (myocardial infarction, stroke, or cardiovascular death). Results: MetS was present in 39.2% at study baseline. The prevalence of CAVI > 9 was higher in subjects with MetS compared to those without (33.7% vs. 28.5%, P = 0.001). During the 12.4 ± 0.6 years follow-up, 227 participants developed MACEs and 350 died. MetS was more common in patients who developed a MACE (8.2% vs. 5.0%, p < 0.001) than was non-MetS, but it was not a significant risk after adjusting covariables. Participants with CAVI > 9 had greater risk for MACEs 1.34 (95% CI: 1.01, 1.79) relative to those with CAVI < 9. Participants with both MetS and CAVI > 9 had the worst outcomes, with the highest frequency of MACEs, among the four groups. Conclusion: Arterial stiffness assessed by CAVI may enhance prediction of future MACEs, adding to the null predictive power of MetS. This index can be used to motivate MetS patients to modify their life-styles for prevention.