• All-cause mortality [ Time Frame: 5 years ]
  Death due to any cause
• All-cause mortality, myocardial infarction, or stroke [ Time Frame: 5 years ]
  tripe composite endpoint
• Cardiovascular death [ Time Frame: 5 years ]
  Death due to cardiovascular cause
• Cardiovascular death, myocardial infarction, or stroke [ Time Frame: 5 years ]
  tripe composite endpoint
• Ischemic stroke [ Time Frame: 5 years ]
  Stroke is defined as global or focal cerebral, spinal cord or retinal injury resulting in acute neurological dysfunction due to ischemia
• Heart failure hospitalisation [ Time Frame: 5 years ]
  the presence of congestive heart failure being the primary disease process accounting for clinical and physical signs of heart failure, with a need for additional or increased heart failure therapy, requiring at least a 24 hour stay in an inpatient unit or emergency department
• Recurrence of AF after attempts at rhythm control [ Time Frame: 5 years ]
  Recurrence of AF after attempts at rhythm control (pharmacological, catheter, or cardioversion)
• AF Progression [ Time Frame: 5 years ]
  Defined as (1) paroxysmal AF at baseline becoming persistent or permanent at the last follow-up visit or (2) persistent AF at baseline becoming permanent at the last follow-up visit.

The POACH study is part of the Cardiosleep research program. It is a prospective, observational, multicentre study conducted in Singapore. The recruitment target is 1365 patients.

Eligible patients with AF and high cardiovascular risk will be recruited for a home-based sleep study using a FDA-approved portable device. The patients will be divided into 2 groups based on the presence or absence of OSA using apnoea-hypopnoea index ≥ 15 events/hour. The AF will be treated as per local standard practice. Participation in the POACH study will not affect the management of AF. Follow-up will be conducted every 6 months until the median follow-up duration has reached 2 years. The primary endpoint is a four-component composite of all-cause mortality, myocardial infarction, stroke and heart failure hospitalisation.

Antecubital venous blood samples will be taken from the patients in the morning after the sleep study for targeted mass spectrometry which will measure 83 circulating metabolites. Sparse Principal Component Analysis will be used for data reduction. Identification of distinct associations between metabolic perturbations and OSA will be performed.

The overarching objective of the POACH study is to determine the impact of obstructive sleep apnoea (OSA) on cardiovascular outcomes in patients with atrial fibrillation (AF).

AF is the most prevalent sustained arrhythmia. While OSA often co-exists with AF, current management of AF does not take OSA status into consideration. This is partly due to the lack of data on whether OSA is independently associated with cardiovascular events in patients with AF. Besides, metabolomics is an emerging field of 'omics' research focusing on profiling and quantifying low-molecular weight components.

The POACH study is part of the Cardiosleep research program. It is a prospective, observational, multicentre study conducted in Singapore. The recruitment target is 1365 patients.

Eligible patients with AF and high cardiovascular risk will be recruited for a home-based sleep study using a FDA-approved portable device. The patients will be divided into 2 groups based on the presence or absence of OSA using apnoea-hypopnoea index ≥ 15 events/hour. The AF will be treated as per local standard practice. Follow-up will be conducted every 6 months until the median follow-up duration has reached 2 years. The primary endpoint is a four-component composite of all-cause mortality, myocardial infarction, stroke and heart failure hospitalisation. Antecubital venous blood samples will be taken from the patients in the morning after the sleep study for targeted mass spectrometry which will measure 83 circulating metabolites. Sparse Principal Component Analysis will be used for data reduction. Identification of distinct associations between metabolic perturbations and OSA will be performed.

Results of the POACH study will likely impact the care of patients with AF.

• Atrial Fibrillation
• Obstructive Sleep Apnea

• OSA (Watch PAT AHI >/= 15 events per hour)
  Patients found to have OSA by an overnight sleep study
  Intervention: Diagnostic Test: Overnight sleep study
• Non-OSA (Watch PAT AHI < 15 events per hour)
  Patients found NOT to have OSA by an overnight sleep study
  Intervention: Diagnostic Test: Overnight sleep study

Inclusion Criteria:

1. Age 22 or above
2. Known AF, including paroxysmal, persistent or permanent AF

3. High cardiovascular risk, defined as one or more of the following:

   • hypertension
   • diabetes mellitus
   • stroke
   • significant coronary artery disease (at least one stenosis of >50% diameter in at least one major epicardial artery based on CT or conventional coronary angiography, positive stress test [treadmill, myocardial perfusion scan, or stress echocardiography], previous percutaneous coronary intervention, or previous coronary artery bypass surgery)
   • chronic kidney disease (excluding polycystic kidney disease) with an estimated glomerular filtration rate of <60 ml/min/1.73m2,
   • 10-year risk of cardiovascular disease of 15% or greater on the basis of the Framingham risk score, or
   • age of 75 years or older

Exclusion Criteria:

1. Known OSA on regular CPAP treatment
2. Valvular AF (moderate/severe mitral stenosis or mechanical heart valve)
3. Permanent pacemaker implantation
4. Life expectancy less than 1 year based on concomitant medical conditions
5. Unable to give research consent
6. Pregnant or lactating women

• Ng Teng Fong General Hospital
• National University Hospital, Singapore
• Singapore General Hospital
• Tan Tock Seng Hospital
• Sengkang General Hospital