Clinical utility of brachial-ankle pulse wave velocity in the prediction of cardiovascular events in diabetic patients

Background: Brachial-ankle pulse wave velocity (baPWV) is a method to estimate arterial stiffness, which reflects the stiffness of both the aorta and peripheral artery; it would be applicable to general practice, since its measurementis automated. The aim of this study was to evaluate whether baPWV can be predictors of future cardiovascular events (CVE) in diabetic patients. Methods: We prospectively evaluated the association between baPWV or carotid intima-media thickness (carotid IMT) at baseline and new onset of CVE in 1040 type 2 diabetic patients without CVE. The predictability of baPWV and/or carotid IMT for identifying patients at high risk for CVE was evaluated by time-dependent receiver-operating-characteristic (ROC) curve analysis. Results: During a median follow-up of 7.5 years, 113 had new CVD events. The cumulative incidence rates of CVE were significantly higher in patients with high baPWV values (>= 1550 cm/s) as compared to those with low baPWV values (< 1550 cm/s) (p < 0.001, log-rank test). Similarly, the cumulative incidence rate of CVE was significantly higher in patients with higher maximum carotid IMT (maxIMT) values (>= 1.0 mm) as compared to those with lower maxIMT values (< 1.0 mm) (p < 0.001, log-rank test). Subjects with both "high PWV" and "high IMT" had a significantly higher risk of developing CVE as compared to those with either "high PWV" or "high IMT," as well as those with neither. A multivariate Cox proportional hazards regression model revealed that both baPWV (HR = 1.30, [95%CI: 1.07-1.57]; p = 0.009) and maxIMT (HR = 1.20, [95%CI: 1.01-1.41]; p = 0.033) were independent predictors for CVE, even after adjustment for the conventional risk factors. Time-dependent ROC curve analyses revealed that the addition of maxIMT to the Framingham risk score resulted in significant increase in AUC (from 0.60 [95%CI: 0.54-0.67] to 0.63 [95%CI: 0.60-0.82]; p = 0.01). Notably, the addition of baPWV to the Framingham risk score and maxIMT resulted in further and significant (p = 0.02) increase in AUC (0.72 [95%CI: 0.67-0.78]). Conclusions: Evaluation of baPWV, in addition to carotid IMT and conventional risk factors, improved the ability to identify the diabetic individuals with high risk for CVE.