Impact of obstructive sleep apnea treatment in patients with paroxysmal atrial fibrillation.

INTERVENTION: This is a multi centre prospective randomised controlled trial that aims to evaluate the impact of continuous positive airway pressure (CPAP) for 1 year on atrial fibrillation (AF) burden in patients with obstructive sleep apnea (OSA). Following diagnosis of at least moderate OSA, patients randomised to the treatment arm will commence CPAP therapy while patients in the control arm will not. CPAP therapy comprises a mask that is worn while sleeping that provides positive airway pressure. All patients randomized to CPAP therapy will receive CPAP education, hands‐on demonstration, careful mask fitting and acclimatization prior to titration. Pressures are titrated in the range of 4‐20cm H2O until obstructive events are eliminated or maximum CPAP is reach, based on present guidelines for OSA management. The number of visits required for pressure titration will be based on physician clinical judgement. Patients will be followed at 3, 6, 9 and 12 months after enrolment into the study, to assess compliance, efficacy and symptoms. Patients in the control arm will also be followed at these time points for ongoing review. CPAP adherence will be monitored by clinical evaluation and by utilising the remote monitoring function on CPAP machines. CONDITION: Atrial Fibrillation Sleep Apnoea PRIMARY OUTCOME: Change in AF burden (as a percentage of time in AF) assessed by implanted loop recorder or Holter monitor. Change in AF burden (as total time in AF) assessed by implanted loop recorder or Holter monitor. SECONDARY OUTCOME: AF Symptom questionnaires: including Toronto AF severity scale and European Heart Rhythm Association AF symptom scale. Cardiac Structure & Function: Composite outcome assessed using transthoracic echocardiographic measures of left and right atrial size, ventricular dimensions, ventricular hypertrophy, systolic function and diastolic function, including measurements of strain and torsion. Cardiovascular Risk Factors: Composite outcome of blood pressure, blood lipids (triglycerides, LDL‐C, HDL‐C) and glycated haemoglobin (HbA1c) will be quantified by venous sampling. Body mass and height will be measured to determine body mass index. Waist circumference will be measured according to standardised methods. Composite outcome of endothelial function. We will quantify soluble VCAM and ADMA from venous blood samples collected at specified timepoints. Composite outcome of platelet aggregation & thrombotic markers: Given the relationship between AF and embolic stroke, we will quantify circulating thrombotic (fibrinogen, plasminogen activator inhibitor 1) and fibrinolytic markers (tissue‐plasminogen activator) and 2) platelet aggregation from venous blood samples collected at specified timepoints. Digital ECG's to assess P wave duration and dispersion. Inflammation, assessed by composite outcome of of high‐sensitivity C‐reactive protein (hs‐CRP) and Tumour Necrosis Factor Alpha (TNF‐a) from venous blood. Profibrotic Markers: Composite outcome of Tissue Growth Factor (TGF‐beta) and matrix metalloproteinase‐9 (MMP‐9) will be quantified as markers of fibrosis. Sleep questionnaires: The Berlin Questionnaire, The Epworth Sleepiness Scale and the STOP‐BANG questionnaires will be used to assess symptoms of sleep apnoea. INCLUSION CRITERIA: Patients with AF. Patients with at least moderate obstructive sleep apnea defined AHI of 15 or greater.