Estimated carotid-femoral pulse wave velocity has similar predictive value as measured carotid-femoral pulse wave velocity

OBJECTIVE: Carotid-femoral pulse wave velocity (cfPWV) adds significantly to traditional cardiovascular (CV) risk prediction, but is not widely available. Therefore, it would be helpful if cfPWV could be replaced by an estimated carotid-femoral pulse wave velocity (ePWV) using age and mean blood pressure and previously published equations. The aim of this study was to investigate whether ePWV could predict CV events independently of traditional cardiovascular risk factors and/or cfPWV.

DESIGN AND METHOD: cfPWV was measured and ePWV calculated in 2366 apparently healthy subjects from four age groups of the Danish MONICA10 cohort. Additionally, the subjects were divided in four CV risk groups based on Systematic COronary Risk Evaluation (SCORE) or Framingham risk score (FRS). In 2006 the combined CV endpoint (CEP) of CV death, non-fatal myocardial infarction, stroke and hospitalization for ischemic heart disease was registered. Most results were retested in 1045 hypertensive patients from a Paris cohort.

RESULTS: Bland Altman plot demonstrated a relative difference of -0.3 % (95% confidence interval (CI) -15-17%) between ePWV and cfPWV. In Cox regression models in apparently healthy subjects, ePVW and cfPWV (per standard deviation) added independently to SCORE in prediction of CEP (HR [95% CI] = 1.38[1.09-1.76] and HR [95% CI] = 1.18[1.01-1.38]) and to FRS (HR [95% CI] = 1.33[1.06-1.66] and HR [95% CI] = 1.16[0.99-1.37]). If healthy subjects with ePWV and/or cfPWV ≥ 10 m/s were reclassified to a higher SCORE risk category, net reclassification index (NRI) was 10.8%, P < 0.01 (Table 1). These results were reproduced in the Paris cohort.

CONCLUSIONS: ePWV predicted major CV events independently of SCORE, FRS and cfPWV indicating that these traditional risk scores have underestimated the complicated impact of age and blood pressure on arterial stiffness and CV risk.