Increased QT dispersion is associated with reduced overall survival in patients with acute exacerbations of chronic obstructive pulmonary disease

Abstract

Objectives: Chronic obstructive pulmonary disease (COPD), especially acute exacerbations of COPD, are associated with increased cardiovascular mortality, including sudden cardiac death. Previous studies have reported that ECG abnormalities are common in stable COPD patients. However, the prognostic utility of ECG taken at the time of AECOPD is not known. In this study we sought to address this gap in knowledge pertaining to ECG parameters at time of AECOPD and overall survival. Methods: We conducted a retrospective cohort study of patients admitted to our institution with a primary diagnosis of AECOPD. Standard 12-lead ECG obtained at the time of initial presentation was evaluated. The primary outcome was overall survival. Results: Two hundred and eleven AECOPD patients were considered for the study. Death had occurred in 42 (20%) patients at follow-up. Among the different ECG parameters evaluated, the QT Dispersion (QTD) and corrected QT Dispersion (QTcD) were significantly associated with increased mortality. Receiver Operator Characteristic analysis identified QTcD >48msec had a sensitivity of 90% and specificity of 55% in predicting death and QTcD >48msec was also associated with worse overall survival (months) (mean ± SD: 26 ± 1.0 vs. 30 ± 0.7, p = 0.001). Conclusion: QTcD ≥48msec is associated with increased mortality. Further research is required to better understand this association and potentially identify reversible factors that if appropriately addressed, may ultimately improve the prognosis of patients with COPD.