1. Sleep Apnea and Cardiovascular Disease
Mohammed Fakhry AbdulMohsen, MD, FACC
Associate Professor and Consultant Internist/Cardiologist
University of Dammam and
King Fahd Hospital of the University.

2. Sleep Apnea and Cardiovascular Disease
Sleep-related breathing disorders are highly prevalent in patients with established cardiovascular disease.
Obstructive Sleep Apnea (OSA) affects adult Americans and is present in large number of patients with HTN and other CVD such as CAD, Stroke and AF.
Central Sleep Apnea (CSA) occurs mainly in patients with Heart Failure (HF)

3. Sleep Apnea and Cardiovascular Disease
Objectives:
To describe the types and prevalence of SA and its relevance to individuals who are at risk for or already have established CVD.
To help develop the platform from which with the collaboration with specialist in sleep medicine and related disciplines, such consensus may develop.

4. Sleep Apnea and Cardiovascular Disease

5. Sleep Apnea and Cardiovascular Disease
1. Airway narrowing/obstruction
2. Decreased air flow
3. Increased effort
4. Oxygen saturation swings and
hypoxia
5. Increased BP and HR
6. Disrupted sleep

6. Sleep Apnea and Cardiovascular Disease

7. Sleep Apnea and Cardiovascular Disease

8. Sleep Apnea and Cardiovascular Disease

9. Sleep Apnea and Cardiovascular Disease
Table 1.
Definitions of Terms (5)
Apnea:
Cessation of airflow for 10 s
Hypopnea:
A reduction in but not complete cessation of airflow to 50% of normal,
usually in association with a reduction in oxyhemoglobin saturation
AHI:
The frequency of apneas and hypopneas per hour of sleep; a measure of
the severity of sleep apnea
OSA and hypopnea:
Apnea or hypopnea resulting from complete or partial collapse,
respectively, of the pharynx during sleep

10. Sleep Apnea and Cardiovascular Disease
Table 1.
Definitions of Terms (5)
CSA and hypopnea:
Apnea or hypopnea resulting from complete or partial withdrawal of
central respiratory drive to the muscles of respiration during
sleep
Oxygen desaturation:
Reduction in oxyhemoglobin saturation, usually as a result of an apnea or
hypopnea
Sleep apnea syndrome:
At least 10 to 15 apneas and hypopneas per hour of sleep associated with
symptoms of sleep apnea, including loud snoring, restless sleep, nocturnal
dyspnea, headaches in the morning, and excessive daytime sleepiness

11. Sleep Apnea and Cardiovascular Disease
Table 1. (Cont’d)
Polysomnography:
Multichannel electrophysiological recording of
electroencephalographic, electrooculographic, electromyographic,
ECG, and respiratory activity to detect disturbance of breathing
during sleep
NREM sleep:
Non–rapid eye movement or quiet sleep
REM sleep:
Rapid eye movement or active sleep; associated with skeletal
muscle atonia, rapid movements of the eyes, and dreaming
Arousal: Transient awakening from sleep lasting 10 s

12. Sleep Apnea and Cardiovascular Disease
Table 2:
Obstructive Sleep Apnea Signs, symptoms, and risk factors:
- Disruptive snoring
- Witnessed apnea or gasping
- Obesity and/or enlarged neck size
- Hypersomnolence
- Other signs and symptoms include male gender,
crowded-appearing pharyngeal airway, HTN, morning
headache, sexual dysfunction, behavioral changes
(especially in children)

13. Sleep Apnea and Cardiovascular Disease
Screening and diagnostic tests
- Questionnaires
- Holter monitoring
- Overnight oximetry
- Home-based/ambulatory unattended polysomnography
- In-hospital attended overnight polysomnography.
Treatment options:
- Positional therapy
- Weight loss
- Avoidance of alcohol and sedatives
- Positive airway pressure
- Oral appliances

14. Sleep Apnea and Cardiovascular Disease
Table 3:
Central Sleep Apnea (CSA) Signs, symptoms, and risk factors:
Congestive heart failure
Paroxysmal nocturnal dyspnea
Witnessed apnea Fatigue/hypersomnolence
Other signs and symptoms include male gender, older age, mitral regurgitation, atrial fibrillation, Cheyne Stokes Respiration (CSR) while awake, hyperventilation with hypocapnia

15. Central Sleep Apnea In HF
Figure 2. Schematic outlining possible mechanisms underlying development of
CSA and the possible feedback from CSA resulting in exacerbation of heart
failure.

16. Sleep Apnea and Cardiovascular Disease
Table 3:
Central Sleep Apnea (CSA):
Screening and diagnostic tests:
Overnight oximetry
Ambulatory (unattended) polysomnography
In-hospital (attended) polysomnography
Treatment options:
Optimize treatment of heart failure
Positive airway pressure
Supplemental oxygen

17. Sleep Apnea and Cardiovascular Disease
OSA and Cardiovascular disease:
There is a clear association between OSA and cardiovascular disease
Higher incidence of adverse cardiovascular events in untreated patients with OSA
Postgrad Med J 2008; 84:15-22
SLEEP 2007;30(3):
CHEST 2008; 133:
Proc Am Thorac Soc 2008; 5:

18. Sleep Apnea and Cardiovascular Disease
Postgrad Med J 2008; 84:15-22

19. OSA is an independent risk for
hypertension

20. OSA and Hypertension:

21. OSA and Hypertension, Why does it happen?
OSA can lead to hypoxia (low oxygen levels), repetitive changes in oxygen saturations, and large swings in intrathoracic pressures
These changes are detected by receptors in the brain and in the periphery (carotid bodies)
Stimulate a sympathetic response (“fight or flight response”, “stress” response) increased heart rate and blood pressure
Postgrad Med J 2008; 84:15-22

22. OSA and Hypertension Why does it happen?
Repeated stimulation increased sympathetic tone during the day High blood pressure
Studies have showed:
Increased tonic chemoreflex drive
Abnormalities in HR and BP variabilities during normal awake hours in patients with OSA
Postgrad Med J 2008; 84:15-22

23. OSA and Hypertension Some Numbers
Wisconsin prospective sleep cohort (2000)
709 patients with OSA
Risk of developing HTN over 4 years:
Minimal OSA: 1.42 x normal
Mild-moderate: 2.03 x normal
Moderate-severe: 2.89 x normal
After adjusting for other risk factors

24. OSA and Hypertension Some Numbers
~40% of people with OSA have HTN while awake
40-80% of people with non-controlled HTN have OSA

26. OSA and Hypertension How to treat it?
Effective CPAP therapy can reduce BP
One study showed a fall in systolic BP by 10 mmHg after 4 weeks of CPAP
Improvement in blood pressure correlated with improvement in sleepiness

27. OSA and Coronary Artery Disease

28. OSA and Heart Attacks
People with sleep disordered breathing (SDB) have a high prevalence of coronary heart disease (CHD)
People with CHD have a high prevalence of SDB

29. OSA and Heart Attacks: Why does it Happen?
Multiple nightly stresses on the heart:
Repetitive fluctuations in oxygen levels
Increased blood pressure surges
High sympathetic nervous system tone

30. OSA and Heart Attacks Marin et al. 2005
10 year follow-up study looking at CV events and OSA (including heart attacks and strokes)
Included 264 healthy men, 377 snorers, 403 untreated mild-mod OSA, 235 untreated severe OSA and 372 treated with CPAP

32. OSA and Heart Attacks
Gami et al. looked at 112 patients who underwent a sleep study
Followed them for 5 years
Sudden death from cardiac causes (between midnight and 6 am) occurred in 46% of pts with OSA vs 16% of general population

33. OSA and Heart Failure

34. OSA and Heart Failure
CSA is the SDB most commonly associated with HF. Javaheri 2006→ 49% with CHF have SDB (37% CSA, 12% OSA)
Heart Failure is 2.38 x more common in “mild-moderate OSA” than in “no OSA”
Postgrad Med J 2008; 84:15-22

35. OSA and Heart Failure: Why does it happen?
Hypertension
Left ventricular diastolic dysfunction
Atrial fibrillation
CHEST 2008; 133:793–804

36. OSA and Heart Failure: Effect of treatment
2 randomized studies of CPAP for OSA in CHF, showed some improvement in EF over 1-3 months
Effect of CPAP treatment on mortality/morbidity from heart failure is unknown
CHEST 2008; 133:793–804

37. Sleep Apnea and Cardiovascular Disease

38. OSA and Cardiac Arrhythmias

39. OSA and Cardiac Arrhythmias
Abnormal heart rhythms have been associated with OSA
1983 Guilleminault et al.:
400 pts with OSA
48% had cardiac arrhythmias at night
2% sustained VT, 11% sinus arrest, 8% AV block, 19% PVC
Postgrad Med J 2008; 84:15-22

40. OSA and Cardiac Arrhythmias; Atrial Fibrillation:
Four times increased risk of AF in pts with OSA (AHI>30) (Sleep Heart Health Study 2006)
Onset of >75% of persistent A fib episodes in pts with OSA occur at night (8pm-8am)
A fib recurrence after cardioversion twice as high in untreated OSA
Observational review over 17 yrs suggests that nocturnal hypoxemia influences the onset of A fib
Postgrad Med J 2008; 84:15-22
Proc Am Thorac Soc 2008; 5:

41. OSA and Cardiac Arrhythmias; Ventricular Arrhythmias:
Reported in pts with OSA
Causative role not proven
NEJM 2005, a study observed higher incidence of sudden death during night hours (12am-6am) in pts with OSA, suggesting but not proving a causative effect
Proc Am Thorac Soc 2008; 5:

42. Sleep Apnea and Cardiovascular Disease

43. OSA and Strokes

44. OSA and Strokes OSA is a risk factor for stroke
2 prospective cohort studies following 1022 and 1651 pts found a higher incidence of stroke in OSA
SLEEP, Vol. 30, No. 3, 2007

45. OSA and Strokes: Why does it happen?
Increased CRP (inflammation) and atherogenesis
Increased thrombotic risks (clotting of blood)
Increased blood pressure
Hypoxia
Theoretically PFO?
SLEEP, Vol. 30, No. 3, 2007

46. OSA and Strokes; Treatment effect:
No randomized controlled trials
Observational studies are controversial on whether treatment of OSA would prevent strokes or not
SLEEP, Vol. 30, No. 3, 2007

47. SLEEP, Vol. 30, No. 3, 2007

48. Sleep Apnea and Cardiovascular Disease
SLEEP, Vol. 30, No. 3, 2007

49. Thank you!