Fenótipos tomográficos, achados espirométricos e clínicos em fumantes com alta carga tabágica : um estudo transversal

Abstract

Objective: To evaluate CT phenotypes, airflow limitation and exacerbation-like episodes in heavy smokers. Methods: This cross-sectional study enrolled 172 smokers, with > 30 pack-years exposure, who underwent pulmonary function tests (PFTs) and quantitative computed tomography (QCT). Subjects were classified by presence or absence of airflow limitation according to the current GOLD criteria of post-bronchodilator FEV1/FVC < 0,7. QCT analysis of data in Airway Inspector software resulted in the establishment of two disease-predominant phenotypes groups: emphysema-predominant (EP) (>6 % of pixels < -950 HU) and non-emphysema-predominant (NEP) (<6 % of pixels < -950 HU). Results: The overall mean age was 63.39 ± 6.04 years, 58% were men, mean packyears smoking history was 70.7 ± 34.32 and mean body mass index (BMI) was 26.96 (±5.69). Most of the 58% of male subjects were distributed in the airflow limitation group, which had also a higher mean pack-years smoking history (77.20 ± 38.03 vs. 60.53 ± 24.50, p=0.009) and mean emphysema index (17.01 ± 9.96 vs. 4.52 ± 3.55, p<0.001), than the group without airflow limitation. About 8.9% of those subjects with no airflow limitation had exacerbation-like episodes, and 23,8% show emphysemapredominant phenotype. According to QTC analysis, the EP group exhibited worse FEV1/FVC mean ratio (55.62 ± 13.3) compared to the NEP (79.10 ± 9.78), p<0.001. Conclusions: Despite of no persistent airflow limitation, 8,9% of the heavy smokers had exacerbation-like episodes and QCT findings of emphysema. Those in the EP phenotype group, had worse PFTs values, higher smoking history, male predominance and also experienced more exacerbation-like episodes than NEP.