Atrial fibrillation is a major cause of stroke in apneic patients: a prospective study

Large prospective studies have established that sleep-disordered breathing (SDB) is associated with an increased incidence of cardiovascular and cerebrovascular diseases. Heterogeneous results have been published about SDB and ischaemic stroke mechanism. The aim of this study was to evaluate the relationship between poststroke apneic syndrome and stroke aetiologies according to the ASCO classification.

A total of 134 patients with acute ischaemic cerebrovascular events were prospectively included. Patients with severe or infratentorial infarctions were excluded. Stroke risk factors and clinical characteristics were recorded in all patients. An overnight polygraphy was recorded (Embletta PDS). Apneic patients were defined if the polygraphy reported an apnea-hypopnea index ≥15. A standardized diagnosis workup, including serum biological investigation, evaluation of extra and intracranial arteries and heart morphology and function, was performed. Stroke mechanism was defined using ASCO and TOAST classifications.

A proportion of 42% (56 of 134) of the patients were diagnosed as having sleep apneas. Apneic patients were older (p < 0.001), had higher BMI (p = 0.02), and more were hypertensive (p < 0.001). Using ASCO classification, a major cardioembolic source of stroke, mainly atrial fibrillation, was more frequently observed in apneic patients (41.1% vs. 20.5%, p < 0.05), while no difference was observed when considering atherosclerosis or small-vessel disease mechanisms. Univariate analysis showed that cardioembolic stroke depends on sex, age, left atrial size and OSA; however, age remained the only significant factor in multivariate analysis.

This study confirms the high prevalence of sleep apneas in stroke-affected patients and identifies atrial fibrillation as a major source of stroke in this population. The strong correlation between age and SDB seems to drive the increased frequency of stroke related to atrial fibrillation in this population.