d -dimer as a Prognostic Biomarker for Mortality in Chronic Obstructive Pulmonary Disease Exacerbation

Abstract Background A major barrier to chronic obstructive pulmonary disease (COPD) research and management is lack of easily obtained biomarkers that are predictive of clinically important outcome measures. Objectives We sought to investigate in patients admitted for acute exacerbation of COPD (AECOPD) the association of d -dimer (fibrin degradation product) obtained upon admission with in-hospital mortality and postdischarge prognosis. Methods Clinical and laboratory data were evaluated in 61 patients admitted for AECOPD in whom d -dimer levels were obtained and in whom venous thromboembolism/ pulmonary embolism was excluded. Receiver operating characteristics curve was used to determine the optimal cutoff level for d -dimer that discriminated survivors versus nonsurvivors during index hospitalization, and during follow-up that extended to a median observation period of 62.6 months. Results Mean (± SD) age of the study cohort was 71.2 ± 10.5 years. Mean d -dimer level in nonsurvivors (n = 12) was significantly higher than in survivors (n = 49): 3.18 ± 0.97 mg/L versus 1.45 ± 1.18 mg/L, respectively, P = 0.0006. d -dimer level > 1.52 mg/L predicted in-hospital mortality with a sensitivity and specificity of 100% and 63.6%, respectively. After discharge, median survival of patients with d -dimer above and below 1.52 mg/L were 9.6 and 62.6 months, respectively (hazard ratio = 2.636; 95% confidence interval = 1.2716.426, P = 0.0111). Conclusions Elevated d -dimer is a reliable prognostic marker for both short-term and long-term survival in patients admitted for AECOPD. Prospective studies are required to further establish the appropriate role of d -dimer as a prognostic biomarker in patients with COPD.