D-dimer as a prognostic biomarker for mortality in chronic obstructive pulmonary disease exacerbation.

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 = 1.271-6.426, 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.