Transcript Sleep Apnea and Cardiovascular Disease

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.
Sleep Apnea and Cardiovascular Disease
• Sleep-related breathing disorders are highly prevalent in
patients with established cardiovascular disease.
• Obstructive Sleep Apnea (OSA) affects 15.000.000 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)
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.
Sleep Apnea and Cardiovascular Disease
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
Sleep Apnea and Cardiovascular Disease
Sleep Apnea and Cardiovascular Disease
Sleep Apnea and Cardiovascular Disease
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
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
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
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)
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
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
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.
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
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):291-304
CHEST 2008; 133:793-804
Proc Am Thorac Soc 2008; 5:200-206
Sleep Apnea and Cardiovascular Disease
Postgrad Med J 2008; 84:15-22
OSA is an independent risk for
hypertension
OSA and Hypertension:
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
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
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
OSA and Hypertension
Some Numbers
• ~40% of people with OSA have HTN while
awake
• 40-80% of people with non-controlled HTN
have OSA
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
OSA and Coronary Artery Disease
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
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
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
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
OSA and Heart Failure
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 “mildmoderate OSA” than in “no OSA”
Postgrad Med J 2008; 84:15-22
OSA and Heart Failure:
Why does it happen?
• Hypertension
• Left ventricular diastolic dysfunction
• Atrial fibrillation
CHEST 2008; 133:793–804
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
Sleep Apnea and Cardiovascular Disease
OSA and Cardiac Arrhythmias
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
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; 5:200-206
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; 5:200-206
Sleep Apnea and Cardiovascular Disease
OSA and Strokes
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
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
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
SLEEP, Vol. 30, No. 3, 2007
Sleep Apnea and Cardiovascular Disease
SLEEP, Vol. 30, No. 3, 2007