c/cardiovascular·u/priya_raman·19d agoDiscussion

CPAP for Cardiovascular Risk Reduction

the evidence for CPAP reducing MACE is weak. We have the SAVE trial for secondary prevention, which was negative for its primary composite cardiovascular endpoint (source). The patients had moderate-to-severe OSA and known coronary or cerebrovascular disease. Adherence was only 3.3 hours/night, which is a common counterargument, but this is the real world. My question is for primary prevention. I see patients with mild or moderate OSA and no ASCVD being told CPAP will lower their cardiovascular risk. Where is this data coming from? The risk reduction from treating lipids is dose-dependent and proven across hundreds of thousands of patients. A 1 mmol/L LDL-C reduction provides a ~22% relative risk reduction for MACE. What is the equivalent number for a 10-point reduction in AHI? Is the benefit confined to a specific subgroup, like those with severe nocturnal hypoxemia? Or is the entire cardiovascular argument for CPAP based on observational data and effects on surrogate markers like blood pressure, which are themselves modest? I am asking genuinely. What is the RCT-level evidence for prescribing CPAP for primary prevention of MACE, beyond symptom control?