Identification and prospective validation of clinically relevant chronic obstructive pulmonary disease (COPD) subtypes
Judith Garcia-Aymerich, Federico P Gómez, Marta Benet, Eva Farrero, Xavier Basagaña, Àngel Gayete, Carles Paré, Xavier Freixa, Jaume Ferrer, Antoni Ferrer, Josep Roca, Juan B Gáldiz, Jaume Sauleda, Eduard Monsó, Joaquim Gea, Joan A Barberà, Àlvar Agustí, Josep M Antó, PAC-COPD Study Group, Josep M Antó, Judith Garcia-Aymerich, Marta Benet, Jordi de Batlle, Ignasi Serra, David Donaire-Gonzalez, Stefano Guerra, Joaquim Gea, Eva Balcells, Àngel Gayete, Mauricio Orozco-Levi, Ivan Vollmer, Joan Albert Barberà, Federico P Gómez, Carles Paré, Josep Roca, Robert Rodriguez-Roisin, Àlvar Agustí, Xavier Freixa, Diego A Rodriguez, Elena Gimeno, Karina Portillo, Vall D'Hebron, Jaume Ferrer, Jordi Andreu, Esther Pallissa, Esther Rodríguez, Sant Pau, Pere Casan, Rosa Güell, Ana Giménez, Eduard Monsó, Alicia Marín, Josep Morera, Eva Farrero, Joan Escarrabill, Antoni Ferrer, Jaume Sauleda, Bernat Togores, Juan Bautista Gáldiz, Lorena López, José Belda, Judith Garcia-Aymerich, Federico P Gómez, Marta Benet, Eva Farrero, Xavier Basagaña, Àngel Gayete, Carles Paré, Xavier Freixa, Jaume Ferrer, Antoni Ferrer, Josep Roca, Juan B Gáldiz, Jaume Sauleda, Eduard Monsó, Joaquim Gea, Joan A Barberà, Àlvar Agustí, Josep M Antó, PAC-COPD Study Group, Josep M Antó, Judith Garcia-Aymerich, Marta Benet, Jordi de Batlle, Ignasi Serra, David Donaire-Gonzalez, Stefano Guerra, Joaquim Gea, Eva Balcells, Àngel Gayete, Mauricio Orozco-Levi, Ivan Vollmer, Joan Albert Barberà, Federico P Gómez, Carles Paré, Josep Roca, Robert Rodriguez-Roisin, Àlvar Agustí, Xavier Freixa, Diego A Rodriguez, Elena Gimeno, Karina Portillo, Vall D'Hebron, Jaume Ferrer, Jordi Andreu, Esther Pallissa, Esther Rodríguez, Sant Pau, Pere Casan, Rosa Güell, Ana Giménez, Eduard Monsó, Alicia Marín, Josep Morera, Eva Farrero, Joan Escarrabill, Antoni Ferrer, Jaume Sauleda, Bernat Togores, Juan Bautista Gáldiz, Lorena López, José Belda
Abstract
Background: Chronic obstructive pulmonary disease (COPD) is increasingly considered a heterogeneous condition. It was hypothesised that COPD, as currently defined, includes different clinically relevant subtypes.
Methods: To identify and validate COPD subtypes, 342 subjects hospitalised for the first time because of a COPD exacerbation were recruited. Three months after discharge, when clinically stable, symptoms and quality of life, lung function, exercise capacity, nutritional status, biomarkers of systemic and bronchial inflammation, sputum microbiology, CT of the thorax and echocardiography were assessed. COPD groups were identified by partitioning cluster analysis and validated prospectively against cause-specific hospitalisations and all-cause mortality during a 4 year follow-up.
Results: Three COPD groups were identified: group 1 (n=126, 67 years) was characterised by severe airflow limitation (postbronchodilator forced expiratory volume in 1 s (FEV(1)) 38% predicted) and worse performance in most of the respiratory domains of the disease; group 2 (n=125, 69 years) showed milder airflow limitation (FEV(1) 63% predicted); and group 3 (n=91, 67 years) combined a similarly milder airflow limitation (FEV(1) 58% predicted) with a high proportion of obesity, cardiovascular disorders, diabetes and systemic inflammation. During follow-up, group 1 had more frequent hospitalisations due to COPD (HR 3.28, p<0.001) and higher all-cause mortality (HR 2.36, p=0.018) than the other two groups, whereas group 3 had more admissions due to cardiovascular disease (HR 2.87, p=0.014).
Conclusions: In patients with COPD recruited at their first hospitalisation, three different COPD subtypes were identified and prospectively validated: 'severe respiratory COPD', 'moderate respiratory COPD', and 'systemic COPD'.
Source: PubMed