Respiratory parameters predict poor outcome in COPD patients, category GOLD 2017 B

• Published in: International journal of chronic obstructive pulmonary disease Vol. 13; pp. 1037 - 1052
• Main Authors: Brat, Kristian, Plutinsky, Marek, Hejduk, Karel, Svoboda, Michal, Popelkova, Patrice, Zatloukal, Jaromir, Volakova, Eva, Fecaninova, Miroslava, Heribanova, Lucie, Koblizek, Vladimir
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.01.2018; Dove Medical Press Ltd; Dove Medical Press
• Subjects: Age; Analysis; Anoxemia; Body mass index; Bronchitis; Chronic obstructive lung disease; Chronic obstructive pulmonary disease; Classification; COPD; GOLD 2017 Update; Hypercapnia; Hypertension; hypoxaemia; Lung diseases; Medical prognosis; Medical research; Mortality; Online databases; Original Research; Patient outcomes; Patients; Population; Prognosis; Risk factors; Sleep apnea; Survival analysis; mortality; hypoxemia; GOLD 2017 update; hypercapnia; COPD
• ISSN: 1178-2005; 1176-9106; 1178-2005
• DOI: 10.2147/copd.s147262

Respiratory parameters are important predictors of prognosis in the COPD population. Global Initiative for Obstructive Lung Disease (GOLD) 2017 Update resulted in a vertical shift of patients across COPD categories, with category B being the most populous and clinically heterogeneous. The aim of our study was to investigate whether respiratory parameters might be associated with increased all-cause mortality within GOLD category B patients. The data were extracted from the Czech Multicentre Research Database, a prospective, noninterventional multicenter study of COPD patients. Kaplan-Meier survival analyses were performed at different levels of respiratory parameters (partial pressure of oxygen in arterial blood [PaO ], partial pressure of arterial carbon dioxide [PaCO ] and greatest decrease of basal peripheral capillary oxygen saturation during 6-minute walking test [6-MWT]). Univariate analyses using the Cox proportional hazard model and multivariate analyses were used to identify risk factors for mortality in hypoxemic and hypercapnic individuals with COPD. All-cause mortality in the cohort at 3 years of prospective follow-up reached 18.4%. Chronic hypoxemia (PaO <7.3 kPa), hypercapnia (PaCO >7.0 kPa) and oxygen desaturation during the 6-MWT were predictors of long-term mortality in COPD patients with forced expiratory volume in 1 second ≤60% for the overall cohort and for GOLD B category patients. Univariate analyses confirmed the association among decreased oxemia (<7.3 kPa), increased capnemia (>7.0 kPa), oxygen desaturation during 6-MWT and mortality in the studied groups of COPD subjects. Multivariate analysis identified PaO <7.3 kPa as a strong independent risk factor for mortality. Survival analyses showed significantly increased all-cause mortality in hypoxemic and hypercapnic GOLD B subjects. More important, PaO <7.3 kPa was the strongest risk factor, especially in category B patients. In contrast, the majority of the tested respiratory parameters did not show a difference in mortality in the GOLD category D cohort.