The interaction among OSA, CPAP, and medications in patients with comorbid OSA and cardiovascular/cerebrovascular disease: a randomized controlled trial

BACKGROUND: Most patients with comorbid sleep apnea (OSA), cardiovascular (CV) disease, and/or cerebrovascular (CeV) disease simultaneously take medications. Whether OSA and continuous positive airway pressure (CPAP) interact with CV/CeV medications remains unknown. This study aimed to determine the interaction among OSA, CPAP, and CV/CeV medications; the effects of medications on major adverse cardiac and cerebrovascular events, and survival in patients with comorbid OSA and CV/CeV. METHODS: This was a post hoc analysis of the data from one center of the Sleep Apnea Cardiovascular Endpoints Study. Participants (aged 45–75 years) with comorbid OSA and CV/CeV were randomized to receive usual care with or without CPAP from December 2008 to November 2013. The primary endpoint was death and the secondary endpoint was a composite of death, myocardial infarction, stroke, hospitalization for unstable angina, heart failure, and transient ischemic attack. RESULTS: In total, 131 patients were analyzed. Sixty-three were in the CPAP group and 68 were in the usual care group, 41 had good adherence to CPAP (65.1%), and the median follow-up time was 43.0 (35.0, 54.0) months. In Cox regression analysis, ACE inhibitors and nitrates were independent factors for decreased survival in patients with comorbid OSA and CV/CeV (chi-square = 22.932, P = 0.003; ACE inhibitors: OR 7.241, P = 0.048, 95% CI 1.016–51.628; nitrates: OR 18.012, P = 0.011, 95% CI 1.923–168.750). ACE inhibitors increased mortality and secondary endpoints in the CPAP group (chi-square = 4.134, P = 0.042) but not in patients with good CPAP adherence. Clopidogrel and nitrates decreased survival in usual care group (clopidogrel: chi-square = 5.312, P = 0.021; nitrates: chi-square = 6.417, P = 0.011), but not in CPAP group. CONCLUSIONS: OSA may predispose patients with CV/CeV and CV/CeV medications to a negative effect. CPAP treatment may neutralize the negative effects of OSA by relieving chronic intermittent hypoxia. Trial registration ClinicalTrials.gov (NCT00738179, first registration date: 20/08/2008).