Head-to-head comparison of the cardio-ankle vascular index between patients with acute coronary syndrome and stable angina pectoris.

We aimed to evaluate whether there was a difference in the arterial stiffness assessed by the cardio-ankle vascular index (CAVI) between patients with acute coronary syndrome (ACS) and those with stable angina pectoris (SAP). A total of 199 consecutive patients, 79 with ACS and 120 with SAP, who underwent emergency or elective coronary revascularization were enrolled. The CAVI was measured within 2 days after the procedures, and was compared between the ACS and SAP patients. As parameters related to arteriosclerosis, carotid intima-media thickness (IMT) and number of stenotic coronary vessels were also evaluated. Although IMT was significantly greater in SAP patients (2.1±1.1 vs. 2.4±0.9; P=0.022), CAVI was significantly higher in ACS patients (10.0±1.7 vs. 9.3±1.3; P=0.0012). After an adjustment for the clinical parameters with a significant difference between the two patient groups, CAVI remained significantly higher in ACS patients than in SAP patients (odds ratio 1.92, 95% confidence interval 1.30-3.02; P=0.0023). A multiple linear regression analysis revealed that age (β=0.44; P<0.0001) and ACS (β=0.3; P<0.0001) were the independent determinants of CAVI. A significant decrease in CAVI was observed at 6 months of follow-up as compared with the acute phase in 18 patients with ACS (10.9±1.6 vs. 10.0±1.5; P=0.019). In conclusion, CAVI was significantly and independently higher in patients with ACS than in those with SAP, which might result from a transient increase in the CAVI caused by acute myocardial ischemia.