Is Acute Exacerbation of COPD (AECOPD) Related to Viral Infection Associated with Subsequent Mortality or Exacerbation Rate?

BACKGROUND: There is a growing interest in better defining risk factors associated with increased susceptibility to exacerbation in patients with COPD. INTRODUCTION: The aim of the study was to determine whether identification of a respiratory virus during a severe acute exacerbation of COPD (AECOPD) increases the risk of subsequent exacerbations and mortality during a one-year followup. METHODS: Secondary analysis of 86 COPD patients admitted for AECOPD between June 2007 and December 2008 at Geneva’s University Hospital who were followed up for 1 year. Fifty-one percent of index AECOPD were related to viral infection. Rate of AECOPD, time to next AECOPD, and all-cause mortality were compared between patients with vs without viral index AECOPD. RESULTS: Eighty-one cases were included in this secondary follow-up analysis. Mean exacerbation rate was 1.9 AECOPD per person-year for patients with viral index AECOPD vs 4.0 AECOPD per person year for those with non-viral index AECOPD. Incidence rate ratio (IRR) for subsequent AECOPD during one year follow up was lower for patients with viral index AECOPD (IRR 0.57; [CI 95% 0.39-0.84]), after controlling for previous exacerbations, and was strongly associated with the number of exacerbations in the year preceding the index AECOPD. During the one-year follow-up period, 16 patients (19%) died. In a Cox regression model, patients with a proven viral infection did not have a higher mortality (HR 0.56 [CI 95% 0.20 -1.58]). CONCLUSION: Viral AECOPD was not associated with a higher rate of subsequent exacerbations or mortality during the following year.