Trials in Sleep Apnea and Stroke

Abstract

Few randomized controlled trials have evaluated the effectiveness of continuous positive airway pressure (CPAP) in reducing recurrent vascular events and mortality in poststroke obstructive sleep apnea (OSA). To date, results have been mixed, most studies were underpowered and definitive conclusions are not available. Using lessons learned from prior negative trials in stroke, we reappraise prior randomized controlled trials that examined the use of CPAP in treating poststroke OSA and propose the following considerations: (1) Intervention-based changes, such as ensuring that patients are using CPAP for at least 4 hours per night (eg, through use of improvements in CPAP technology that make it easier for patients to use), as well as considering alternative treatment strategies for poststroke OSA; (2) Population-based changes (ie, including stroke patients with severe and symptomatic OSA and CPAP noncompliers); and (3) Changes to timing of intervention and follow-up (ie, early initiation of CPAP therapy within the first 48 hours of stroke and long-term follow-up calculated in accordance with sample size to ensure adequate power). Given the burden of vascular morbidity and mortality in stroke patients with OSA, there is a strong need to learn from past negative trials and explore innovative stroke prevention strategies to improve stroke-free survival.

SLEAP SMART (Sleep Apnea Screening Using Mobile Ambulatory Recorders After TIA/Stroke): A Randomized Controlled Trial

“…In prior studies examining patients with stroke/TIA, expediting diagnosis and treatment of OSA has been shown to improve outcomes. 40 Although all sleep laboratories may not have long wait-times for iPSG, HSAT may also be more convenient and the preferred diagnostic method for patients with stroke/TIA as demonstrated by the number of patients who declined HSAT versus iPSG in our study (9 [7.2%] versus 38 [30.4%], respectively), as well as patients' report of sleep quality that was comparable to sleep at home (89.4% with HSAT versus 31.1% with iPSG). The high rate of patients declining to undergo iPSG highlights stroke/TIA patients' general discomfort and dislike for iPSG, and the need to use better-tolerated ambulatory methods.…”

“…In prior studies examining patients with stroke/TIA, expediting diagnosis and treatment of OSA has been shown to improve outcomes. 40…”

The case for improving the detection and treatment of obstructive sleep apnea following stroke

“…Although studies assessing the impact of CPAP on nonvascular outcomes among patients with post-stroke OSA have shown positive outcomes, trials evaluating whether CPAP can reduce the risk of incident stroke or death have been largely negative. 6 The largest of these trials, the Sleep Apnea Cardiovascular Endpoints (SAVE) trial, 7 randomized 2717 patients with coronary or cerebrovascular disease (including 1432 with ischemic stroke or intracerebral hemorrhage) to receive CPAP or usual care. Although the overall findings showed no significant reduction in risk of vascular events or death, a preplanned post hoc subgroup analysis showed that patients who had good adherence to CPAP had a significantly lower risk of cerebrovascular events than those in the usual care group.…”

“…Furthermore, in future trials, sample sizes and follow-up periods need to be carefully calculated to assure adequate power and outcome assessment. 6 Investigation of sleep disorders, particularly OSA, should be strongly considered for patients who have had a stroke, with the goal of improving nonvascular outcomes, such as daytime sleepiness, mood and functional outcomes. A good argument can be made for treating OSA like any other vascular risk factor.…”

“…5 Randomized controlled trials have shown that treatment of post-stroke OSA using continuous positive airway pressure (CPAP) improves neurologic recovery and quality of life, and reduces daytime sleepiness and depressive symptoms. 6,7 Given that OSA is a well-established risk factor for stroke, with a greater adjusted relative risk for stroke similar to or higher than traditional modifiable vascular risk factors that are commonly managed after stroke, 8 it would make sense that OSA be routinely screened for and treated after stroke. However, a 2019 study suggested otherwise.…”