Reduced pulmonary artery pulsatility on dynamic 256-slice CT is associated with severity of emphysema and reduced right ventricular function

Introduction: Pulmonary hypertension is associated with reduced survival in COPD but is difficult to detect. There are major limitations to clinical application of Echocardiography and cardiac MRI in severe COPD. Dynamic CT can overcome these limitations and simultaneously assess lungs, pulmonary vasculature and cardiac function within the same study acquisition. Methods: 37 COPD patients (mean/SD FEV1 48/24% predicted) underwent retrospective ECG-gated contrast enhanced 256-slice multidetector CT following clinical recovery from a hospitalized exacerbation. Main PA cross-sectional area (CSA) was measured (perpendicular to long axis at midpoint between pulmonary valve and PA bifurcation) at 10% intervals from 0-90% of the R-R interval. Pulsatility was calculated from ((maximum CSA – minimum CSA)/minimum CSA x 100)). Cardiac function was determined using images reconstructed at 10% intervals from 0%-90% of the R-R interval. We assessed pulsatility of the main pulmonary artery in severe COPD and its relationship with %LAA (emphysema) and right ventricular function. Results: Mean/SD PA pulsatility was reduced in this patient cohort at 16.9/5.9%. PA pulsatility was significantly correlated with emphysema index (r=-0.365, p=0.031) and with reduced RVEF (r=0.483, p=0.0025). Conclusions: Reduced PA pulsatility is common in severe COPD and related to both severity of emphysema and impaired right ventricular ejection fraction. Impairment of PA pulsatility occurs early in pulmonary hypertension and MDCT may permit earlier case detection in COPD.