Influence of pulmonary rehabilitation in patients with Chronic Obstructive Pulmonary Disease exacerbator phenotype.

Objective To verify if there are differences in Chronic Obstructive Pulmonary Disease (COPD) patient exacerbator and non-exacerbator phenotypes undergoing a Pulmonary Rehabilitation Program (PRP). Methods A real life retrospective study included outpatients with COPD from public primary care who completed a 12-weeks PRP, three times a week. All were assessed before and after PRP using the six-minute walk test (6MWT), the modified Medical Research Council (mMRC) dyspnea index, quality of life and Body-mass Index, airflow Obstruction, Dyspnea and Exercise (BODE index). Results A total of 151 patients were analyzed and mean age was 65.0 ± 8.1 years and mean Forced Expiratory Volume (FEV) 1% of predicted was 39.8 ± 15.9. The predominant gender was male (66.9%). Of these patients 31 (20.5%) were exacerbator phenotype There was a significant improvement in the mean distance in the 6MWT in both groups, with the largest change observed in the exacerbator group [mΔ (95% CI): 84.9 (57.1-112.6) vs. 48.6 (37-60.2) p= 0.018]. Significant reduction in dyspnea on the mMRC scale occurred in both groups, with the highest intensity in the exacerbator group [mΔ (95% CI): - 0.8 (-1.11 to 0.51) vs. -1.6 (-2.20 to -1.13) p = 0.006]. Improvement in the BODE index occurred in both groups, but the mean variation was also significantly greater in the exacerbator group [mΔ (95% CI): -1.44 (-2.17 to -0.70) p= 0.045]. Conclusion Patients with COPD exacerbator phenotype had a greater magnitude of response to PRP (36 meters) when compared to non-exacerbator phenotype regardless the severity of airflow obstruction, also showing improvement in prognosis measured by the BODE index.