Association of elevated D-dimer with disease severity, length of stay and in-hospital mortality among patients admitted for acute exacerbation of chronic obstructive pulmonary disease: A real-world cohort study from a tertiary centre in Karachi, Paki

Objective: To quantify the prevalence of elevated D-dimer levels, explain their link with clinical severity, hospital length of stay (LOS), and all-cause in-patient mortality, and compare our findings to current international research. Material and Methods: A total of 146 patients diagnosed with AECOPD to Jinnah Postgraduate Medical Centre (JPMC) between February 10 and August 9, 2023 were included. AECOPD severity was categorized as moderate or severe. The major exposure was an admission D-dimer of > 0.985 mg/L. The outcomes included illness severity, LOS, and in-hospital death. Frequencies were compared using χ²/Fisher's exact tests, and LOS using independent t-test. Results: The results showed that D-dimer was increased in 125 (85.6%). Among patients with elevated D-dimer levels, 103 (82.4%) had moderate AECOPD and 22 (17.6%) had severe AECOPD. However, among those with normal D-dimer levels, 20 (95.2%) had moderate AECOPD and only 01 (4.8%) had severe AECOPD. Although there was higher proportion of severe cases in the elevated D-dimer group, while there was not statistically significant association found between AECOPD Severity and D-dimer levels as p value= 0.199. Conclusions: Although almost 90% of Pakistani AECOPD patients had D-dimer levels above the diagnostic threshold, in this real-world cohort, the marker provided no independent distinction for bedside risk stratification. Large multicenter trials using venous thromboembolic imaging and longitudinal follow-up are needed. Keywords: D-dimer, Mortality, AECOPD, COPD