O046 PAP therapy on cardiac remodelling and cardiovascular risk in COPD-OSA-overlap.

Abstract Introduction Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) overlap syndrome (OVS) have increased cardiovascular mortality compared to COPD alone. This study aimed to assess changes in cardiac structure and function using magnetic resonance imaging (CMRI) following treatment with positive airway pressure (PAP) therapy in patients with OVS. The effects of PAP therapy was also assessed on cardiac biomarkers including high-sensitivity troponin (HS-trop), high-sensitivity C-reactive protein (CRP) and brain natriuretic peptide (BNP); arterial stiffness; 6-minute walk distance (6MWD). Methods 7 patients with OVS underwent CMRI, cardiac biomarker testing, pulse wave velocity (PWV) and 6-minute walk test. Investigations were repeated after 3 months of PAP therapy. Results All participants were male, median age 67.7 (IQR 61.0-71.5) years, AHI 48.9/hr (IQR 38.3-71.8/hr). Median FEV1%predicted was 64% (IQR 49.5-71.5%). Baseline RV volume was 146 mL and LV volume was 118 mL and this increased to 152 mL and 129 mL respectively after CPAP (not statistically significant). The presence of late gadolinium enhancement (LGE) did not change after PAP therapy. HS-trop and BNP were lower after CPAP treatment and 6MWD was longer, although statistically not significant. There was no difference in arterial stiffness or 6MWD. AHI improved significantly from 48.9/hr to 6.9/hr on CPAP (95%CI -71.8--28.9), median CPAP compliance 6.5 hrs/night. Conclusion These preliminary results showed that PAP therapy did not result in significant change in cardiac structure or function. Possible reasons include small sample size, short treatment duration and presence of LGE in 42.8% of patients suggesting diseased myocardium not reversible with PAP.