Pulmonary Artery Abnormalities in Ex-smokers with and without Airflow Obstruction

Abstract

Pulmonary vascular disease is a common complication of chronic obstructive pulmonary disease (COPD), and an important risk factor for COPD exacerbations and death. We explored the relationship between pulmonary artery volumes measured using thoracic computed tomography (CT) and lung structure-function measured using spirometry, CT and magnetic resonance imaging (MRI) in 124 ex-smokers with (n = 68) and without (n = 56) airflow obstruction, and a control group of 35 never-smokers. We observed significantly greater main (p = .01), right (p = .001) and total (p = .003) pulmonary artery volumes in ex-smokers with airflow obstruction as compared to ex-smokers without airflow obstruction. There were also significantly greater pulmonary artery volumes in both ex-smoker subgroups, compared to the never-smoker subgroup (p = .008). For all participants, there were significant correlations for pulmonary artery volumes with the ratio of the forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), the diffusing capacity of the lung for carbon monoxide (DLCO%pred), airway count, MRI ventilation defect percent and MRI apparent diffusion coefficients. In ex-smokers, ventilation defect percent was significantly correlated with right (r = 0.27, p = .02) and total (r = 0.25, p = .03) pulmonary artery volumes. Multivariate zero-inflated Poisson regression analysis showed that FEV1%pred (p = .004), DLCO%pred (p = .03), the six minute walk distance (p = .04) and total pulmonary artery volume (p = .03) were significant predictors of acute exacerbations of COPD, while the number of previous exacerbations was not. In conclusion, pulmonary artery enlargement measured using thoracic CT was observed even in ex-smokers without airflow obstruction and was predictive of COPD exacerbations in ex-smokers with airflow obstruction.

Determination of vascular alteration in smokers by quantitative computed tomography measurements

“…[25] However, other researchers challenged this hypothesis by evidencing that pulmonary vascular abnormalities were also found in smokers without chronic hypoxia. [26] These conclusions are consistent with our results in smokers. The cigarette smoke reached the lung vessels by their inner and outer exposure to cigarette smoke.…”

Cardiopulmonary and Muscular Interactions: Potential Implications for Exercise (In)tolerance in Symptomatic Smokers Without Chronic Obstructive Pulmonary Disease

“…Impaired ability in recruiting pulmonary vessels during exercise has been demonstrated in light smokers (Rizzi et al, 2016) or second-hand smokers (Arjomandi et al, 2012). Moreover, a large population-based study showed the presence of pulmonary artery enlargement on HRCT in smokers without COPD (Lindenmaier et al, 2016). Overall, compensatory increases in minute ventilation are likely useful to maintain alveolar ventilation and arterial blood gas homeostasis in symptomatic smokers but this might hasten dynamic mechanical constraints thereby contributing to dyspnea and exercise intolerance.…”

Implications of the pulmonary artery to ascending aortic ratio in patients with relatively mild chronic obstructive pulmonary disease

“…Moreover, the calculation metric of the PA-A ratio has good inter-observer and intra-observer agreement (22). Additionally, a recent report showed a three-dimensional (3D) approach to quantify the pulmonary artery volume predicted COPD exacerbations in ex-smokers with modest airflow limitation (23). It suggests that 3D total pulmonary artery volume measurement may be more sensitive than the PA-A ratio, by advancing more easy methods and validating on boarder range of patients.…”