Central pulsatile haemodynamics in COPD: a propensity score-matched evaluation of cohorts

BACKGROUND: Cardiovascular risk is elevated in patients with COPD. Central haemodynamic measurements via wave separation analysis indicate cardiovascular risk independent of well-known limitations of peripheral blood pressure measurements, but have not yet been studied in COPD. We aimed to investigate central haemodynamics and their association with lung function in patients with COPD.

METHODS: In this cross-sectional evaluation of cohort studies, we used propensity score matching to compare COPD patients from the randomised ELASTIC trial (n=80) to subjects without airflow limitation and cardiovascular diseases from the Heinz Nixdorf Recall study (n=2307) and the Heinz Nixdorf Multi-Generation Study (n=2625). Central haemodynamics were measured noninvasively via wave separation analysis. Forward wave amplitude (FWA) and backward wave amplitude (BWA) were compared between patients and controls matched for age, sex, hypertension and smoking, and were assessed for associations with lung hyperinflation.

RESULTS: From the initial study cohorts, we identified 75 pairs of COPD patients and matched controls. We found greater FWA in patients than in matched controls (Cohen's d 0.423, 95% confidence interval (CI) 0.098-0.746). BWA was greater in patients than in unmatched controls (Cohen's d 0.333, 95% CI 0.104-0.562), but did not differ after matching (Cohen's d 0.128, 95% CI -0.193-0.448). On multivariable regression FWA was independently associated with hyperinflation expressed as residual volume to total lung capacity ratio (standardised β -0.188, 95% CI -0.335- -0.037) in patients with COPD.

CONCLUSION: COPD is associated with greater FWA which may contribute to increased cardiovascular risk and appears to be correlated with the degree of hyperinflation in patients with COPD.