Dou S, et al. - It was hypothesized that the co-existence of COPD and bronchiectasis may be associated with relative pulmonary artery enlargement [main pulmonary artery to aorta diameter ratio (PA:A ratio) >1]. In this current study, it was shown that bronchiectasis in COPD was independently related to relative pulmonary artery enlargement.

• Researchers performed a retrospective study, wherein they enrolled COPD patients from 2012 through 2016.
• They collected demographic and clinical data.
• They used Bhalla score to determine the severity of bronchiectasis.
• Also, they analyzed patient characteristics in two ways: the high (PA:A >1) and low (PA:A ≤1) ratio groups; and COPD with and without bronchiectasis groups.
• They used logistic regression analysis to evaluate risk factors for high PA:A ratios.

• This study included a total of 480 COPD patients, of whom radiographic bronchiectasis was present in 168.
• Poorer nutrition (albumin, 35.6±5.1 vs 38.3±4.9, P<0.001), lower oxygen partial pressure (74.4±34.5 vs 81.3±25.4, P<0.001), more severe airflow obstruction (FEV1.0, 0.9±0.5 vs 1.1±0.6, P=0.004), and a higher frequency of bronchiectasis (60% vs 28.8%, P<0.001) were documented as the presenting features in patients with pulmonary artery enlargement, compared with patients in the low ratio group.
• Higher levels of systemic inflammation (erythrocyte sedimentation rate, P<0.001 and fibrinogen, P=0.006) and PA:A ratios (P<0.001) were observed in patients with both COPD and bronchiectasis.
• Findings demonstrated that a higher PA:A ratio was significantly closely correlated with a higher Bhalla score (r=0.412, P<0.001).
• Researchers noted that patients with both COPD and bronchiectasis with high ratios presented higher levels of NT-proBNP (P<0.001) and systolic pulmonary artery pressure (P<0.001).
• In addition, bronchiectasis was identified as an independent risk factor for high PA:A ratios in COPD patients (OR =3.707; 95% CI =1.888–7.278; P<0.001) in multiple logistic analyses.