Cardiologists need to join the sleep community in completing clinical trials evaluating the treatment of obstructive sleep apnea (OSA) among patients at risk for developing cardiovascular disease (CVD), as well as patients with symptomatic CVD. The following are points to remember from this review of CV consequences from OSA:

Simple Facts:

1. Severe OSA has been associated with increased CV mortality.
2. Central sleep apnea (CSA) is rare in the population, but is common among patients with heart failure and opioid use.
3. Despite being a major risk for OSA, only 20-40% are obese.

Mechanisms and Studies Linking OSA and CVD:

1. Continuous positive airway pressure (CPAP) may reduce only one mechanism causing hypertension (increased sympathetic drive) and not the salt, obesity, volume overload – all of which are not affected by CPAP.
2. Falls in blood pressure readings seen with CPAP are associated with severity of OSA and hours of use of CPAP. The minimum threshold to adhere to CPAP is at least 4 hours/night, but optimally closer to 6 hours/night.
3. Adaptive servoventilation (ASV) is not recommended as treatment for CSA in reduced ejection fraction heart failure patients after the recent SERVE-HF (Treatment of Predominant Central Sleep Apnoea by Adaptive Servo Ventilation in Patients With Heart Failure) trial.
4. CPAP is a recommended treatment strategy for all atrial fibrillation (AF) patients with OSA. CPAP has been shown to significantly reduce recurrence of AF following cardioversion and ablation strategies among AF patients with sleep apnea.

Non-CPAP Strategies to Treat Sleep Apnea:

1. A meta-analysis of exercise among OSA patients reported a 30% reduction in nocturnal apneic or hypopnea events.
2. Data on supplemental oxygen in heart failure patients with nocturnal hypoxia are mixed. A randomized clinical trial is needed to understand the role of oxygen in this group.
3. Transvenous phrenic nerve stimulation has been studied in 151 CSA patients over 6 months. All patients were randomized to having the device on/off over the study period, and found significant improvements in sleep measures. However, side effects were common, and larger studies are needed.

Keywords: Atrial Fibrillation, Blood Pressure, Catheter Ablation, Continuous Positive Airway Pressure, Electric Countershock, Heart Failure, Hypertension, Obesity, Primary Prevention, Sleep Apnea Syndromes, Sleep Apnea, Obstructive, Sleep Apnea, Central

< Back to Listings