Introduction: Chronic obstructive pulmonary disease (COPD) is a risk factor for cardiovascular disease (CVD). Increased arterial stiffness is one proposed mechanism linking COPD to CVD. Carotid-femoral pulse wave velocity (cf-PWV) is a non-invasive measure for assessing arterial stiffness. However, its reliability has not been established in COPD. We aimed to assess the between day reproducibility of cf-PWV in stable patients with COPD.

Method: The Assessment of Risk in Chronic Airways Disease Evaluation (ARCADE) is a longitudinal study of up to 1500 patients with COPD confirmed with spirometry. Thirty patients free from CVD underwent height and weight measurements before assessing the arterial stiffness using the SphygmoCor device (AtCor medical). This was repeated after mean (range) 7(1) days.

Results: Carotid-femoral PWV was measured on two visits. Mean ± SD age was 67±8 years, BMI 27.2±4.7 kg/m2. Mean cf-PWV at visit 1 was 9.7±2.2 m/s and 9.7±2.2 m/s on the second visit. Repeated measures ANOVA showed no significant difference between subject measurements (F=1.00 and p=0.326). The interclass correlation coefficient (ICC) was 0.93. The Bland and Altman plot showed a mean difference of 0.01 m/s and an upper limit of +1.62 m/s and a lower limit of −1.62 m/s. The plot revealed no systematic bias with slight random error and two clear outliers. (Figure1)

Figure 1

Bland and Altman plot showing between days difference in Pulse Wave Velocity (PWV) in patients with COPD.

Conclusion: Carotid-femoral PWV is a reproducible measure using the SphygmoCor machine in patients with COPD. This may be used as a useful measure to assess cardiovascular risk and monitor therapy in clinical practice.