Cardiovascular outcomes in COPD, obstructive sleep apnoea and the overlap syndrome.

RATIONALE: COPD and obstructive sleep apnoea (OSA) are both independently associated with an increased risk of cardiovascular disease. It is not clear whether this risk is further increased in COPD-OSA overlap. We aimed to determine whether COPD-OSA overlap has a higher cardiovascular burden compared with COPD or OSA alone. METHODS: This was a matched cohort study using electronic health records from the Clinical Practice Research Datalink Aurum database (England). Exposures of interest were a diagnosis of COPD, OSA or both based on validated code lists. Our primary outcome of interest was cardiovascular mortality defined using ICD-10 codes. Our secondary outcomes of interest included: all-cause mortality, incident acute coronary syndrome (ACS), incident stroke and incident heart failure. RESULTS: The initial study cohort consisted of 365 667 people with COPD (mean±sd) age 68±11 years, 59 526 with OSA age 57±11 years and 11 040 with COPD-OSA age 65±10 years. Cardiovascular mortality was significantly higher in patients with COPD-OSA overlap compared with OSA alone (adjusted hazard ratio 1.72 (1.58-1.88); p<0.001) but not compared with COPD alone. People with COPD-OSA overlap had 27% and 58% increased risk of developing ACS compared with COPD and OSA alone respectively, and 69% and 101% increased risk of developing heart failure compared with COPD and OSA respectively. CONCLUSIONS: We have demonstrated that people with COPD-OSA overlap have a significantly higher cardiovascular burden compared with COPD or OSA alone with real-world implications. Earlier and targeted treatment with cardiovascular optimisation can potentially reduce downstream sequelae.