The Connection Between Cardiovascular Disease and Sleep Apnea: An Expert Interview
There is growing evidence to support a relationship between sleep apnea and CVD.
A growing body of research has examined the relationship between sleep-disordered breathing and cardiovascular disease (CVD). Various findings have demonstrated that obstructive sleep apnea (OSA) is linked with a higher incidence of atrial fibrillation (AF), CVD, stroke, and heart failure, while central sleep apnea associated with Cheyne-Stokes respiration (CSA-CSR) is predictive of AF and heart failure.1
A high prevalence of sleep apnea has been noted in cardiology patients, and researchers are increasingly focusing on OSA and CSA as potentially modifiable risk factors for CVD. However, the clinical studies in this area thus far have produced mixed results. For example, a 2015 meta-analysis of randomized trials concluded that treatment of OSA with continuous positive airway pressure (CPAP) was associated with significant increases in body mass index (BMI) and weight, rather than the expected weight loss.2
Numerous other trials have investigated the impact of CPAP on blood pressure, and the overall findings indicate a modest reduction, particularly in patients with resistant hypertension.3-5 In trials assessing the effects of OSA treatment on surrogate CV risk markers, including arterial stiffness, cardiac ejection fraction, and inflammatory markers, the “evidence is generally consistent with a positive effect of CPAP on vascular and metabolic functions and components of the atherosclerotic process,” according to a new white paper published in Circulation.1, 6-10,
In a large multicenter trial, patients assigned to OSA treatment with CPAP did not experience a significant decrease in hypertension or CV events, although further analysis revealed a significant reduction in the combined end points in adherent users (patients who used CPAP for ≥4 hours a night; incidence density ratio, 0.69; 95% CI, 0.50-0.94).11
“[O]ur current knowledge of primary prevention of cardiovascular disease with CPAP is limited to surrogate end points, combined end points, and observational data,” the white paper authors concluded.1
In addition, research into the effect of OSA treatment on outcomes in patients with existing CVD (and receiving standard care) has not indicated significant CV benefits, and CPAP was not shown to increase survival in patients with heart failure and CSA-CSR.1