From the Guidelines
Obstructive sleep apnea (OSA) is a significant risk factor for coronary artery disease (CAD), with a 70% relative increased risk of cardiovascular morbidity and mortality, as reported in the 2012 European guidelines on cardiovascular disease prevention in clinical practice 1. The relationship between OSA and CAD can be attributed to several pathophysiological mechanisms, including repetitive bursts of sympathetic activity, surges of blood pressure, and oxidative stress brought on by pain and episodic hypoxaemia associated with increased levels of mediators of inflammation, which promote endothelial dysfunction and atherosclerosis 1. Some key points to consider include:
- OSA affects an estimated 9% of adult women and 24% of adult men, making it a significant public health concern 1
- The risk of CAD correlates with the apnoea–hypopnea index in men between 40 and 70 years, highlighting the importance of screening and treating OSA in this population 1
- Screening for and treating OSA in patients with chronic coronary artery disease and hypertension may result in decreased cardiac events and cardiac death, emphasizing the need for early intervention 1
- The severity of OSA is directly related to the risk of CAD, with more severe OSA associated with greater CAD risk, underscoring the importance of prompt and effective treatment 1
From the Research
Relationship Between OSA and CAD
- Obstructive sleep apnea (OSA) is common in patients with coronary artery disease (CAD) and has been identified as a potential risk factor for CAD 2.
- Studies have shown that OSA is associated with an increased risk of cardiovascular events, including myocardial infarction and stroke, in patients with CAD 2, 3.
- The pathophysiological mechanisms that link OSA with CAD are complex and can influence the broad spectrum of conditions caused by CAD, from subclinical atherosclerosis to myocardial infarction 4.
Effects of CPAP Therapy on CAD
- Continuous positive airway pressure (CPAP) therapy has been shown to reduce the risk of cardiovascular events in patients with OSA and CAD, particularly in those with an apnea-hypopnea index (AHI) less than 30 events/h 3.
- A post hoc analysis of a prospective clinical trial found that CPAP-related protection against adverse cardiovascular outcomes was associated with a greater pretreatment pulse rate response to respiratory events (ΔHR) 5.
- However, not all studies have found a significant reduction in cardiovascular risk with CPAP therapy in patients with OSA and CAD, highlighting the need for further research in this area 6.
Clinical Implications
- The high prevalence of OSA among patients with CAD highlights the importance of screening for OSA in this population 2.
- Treatment of OSA with CPAP therapy may have a beneficial effect on cardiovascular outcomes in patients with CAD, particularly in those with moderate to severe OSA 3, 5.
- Further studies are needed to fully understand the relationship between OSA and CAD, and to determine the optimal treatment strategies for patients with both conditions 4.