Impact of frequent exacerbations in patients with COPD

Exacerbations are important events in the natural history of chronic obstructive pulmonary disease (COPD). The higher the number of COPD exacerbations, the worse are the clinical and economical consequences. Objectives: To determine the influence of the number of exacerbations on the evolution and severity of COPD patients. Methods: A retrospective study of COPD patients admitted to our hospital and outpatients followed for COPD over a period of 22 years. The patient is considered frequent exacerbator if the number of exacerbations is greater than or equal to 2/year. Results: The study included 1300 COPD patients (97% male; mean age 66+/-10 years), among whom 883 (68%) were frequent exacerbators and 417 infrequent exacerbators (32%). No relationship was seen between age, gender, smoking history (pack-years) and the frequency of exacerbations. Frequent exacerbators had lower FEV1 (1.1 L versus 1.52 L for infrequent exacerbators, p<0,001) and a lower PaO2 (67.5 vs 75.4 mmHg, p<0,001). Frequent exacerbations accelerate lung function decline. FEV1 decline was significantly faster in frequent exacerbators (-55 vs -43 ml/year, p=0,045). Frequent exacerbators had a higher number of severe exacerbations (1.27 vs 0.48 severe exacerbations/year, p<0,001), are those also most likely to be admitted to hospital, with higher number of hospitalisation in the ICU, more frequent use of MV, NIV and home oxygen (p<0,001) than infrequent exacerbators. Conclusion: Compared to infrequent COPD exacerbators, frequent COPD exacerbators have severe deterioration of lung function with frequent hospitalisations and an accelerated decline in FEV1, contributing to increased exacerbation susceptibility and perpetuation of the frequent exacerbator phenotype.