Factors associated with sleep apnoea prevalence in patients with stroke: a systemic review and meta-analysis

Abstract

Introduction: Recent meta-analyses have noted a high prevalence (~70%) of sleep disordered breathing in patients with transient ischaemic attack (TIA) and stroke. However, heterogeneity between studies was high and did not appear to be accountable by phase of stroke. We conducted an updated meta-analysis and aimed to explore whether stroke characters could account for some of the unexplained heterogeneity. Methods: We searched Medline, Embase, CINAHL and Cochrane Library (until 1 July 2020) for clinical studies in English that have reported the prevalence of sleep apnoea in TIA/stroke patients using polysomnography devices. We used a random-effects model to calculate the pooled prevalence by apnoea hypopnea index (AHI) ≥5/h, 10/h and 15/h. We performed meta-analysis and subgroup analysis to evaluate the impact of stroke characters on overall prevalence. Results: We included 75 studies describing 8753 stroke patients in this meta-analysis. The pooled prevalence of sleep apnoea was 72.7% (95% confidence interval [CI]=67.5%-77.4%) by AHI ≥5/h, 68.3% (95% CI=64.9%-71.5%) by AHI ≥5 to 15/h, and 26.7% (95% CI=23.1%-30.7%) by AHI ≥30/h. The high heterogeneity is partially explained by stroke subtype (1.8%) and stroke phase (6.0%). Overall prevalence defined by AHI ≥5 to 15/h was higher in patients with haemorrhagic than ischaemic stroke (82.7% [95% CI=64.4%-92.7%] vs 67.5% [95% CI=63.2%-71.5%]), higher in supratentorial stroke than infratentorial stroke (69.0% [95% CI=57.8%-78.3%] vs 51.1% [95% CI=42.2%-60.0%]), higher in strokes due to cardioembolism (74.0% [95% CI=56.5%-86.2%]) than other etiological subtypes. Prevalence in infratentorial stroke was homogenous (I2=0) compared with supratentorial stroke (I2 =76%). Conclusion: Stroke subtype, phase, location and aetiology may play important roles in the mechanism linking sleep apnoea with stroke. These factors are recommended to be reported in future cohort studies.