Association between DLCO index and the severity of heart failure: a cross-sectional study

Abstract

Background The prognostic role of diffusing capacity of the lung for carbon monoxide (DLCO) in heart failure has not been thoroughly investigated. Therefore, this study aimed to evaluate DLCO variation in different systolic and diastolic heart failure stages. Methods This was a prospective cross-sectional study on 51 patients with systolic (reduced LVEF) or diastolic (preserved LVEF) chronic heart failure (CHF). All patients underwent a standard DLCO test. The associations between the severity of heart failure and reduced carbon monoxide transfer factor (TLCO), carbon monoxide transfer coefficient (KCO), and alveolar volume (VA) were investigated. Data were analysed using SPSS software version 16. p-Values below 0.05 were considered statistically significant. Results The mean age of participants was 59.29 ± 14.91 years, with 72% of the study population being male. Systolic heart failure was observed in 47% of patients, diastolic heart failure in 18%, and a mixed systolic and diastolic pattern in 35%. There were significant differences between TLCO percentage in patients with CHF types and the New York Heart Association (NYHA) functional classes (p = 0.042). Overall, an ejection fraction (EF) of less than 25% correlated with 3%, 53%, and 0.78 declines in TLCO, KCO%, and KCO index, respectively. Conclusion Despite the lack of statistically significant differences between DLCO indices and CHF severity, decreased DLCO parameters correlated with reduced EF. Therefore, DLCO testing might be helpful to predict HF severity.