CPAP

1. August 28,2016

2. • Obstructive sleep apnea causes –
1. Episodic hypoxemia
2. Nocturnal sympathetic nervous system activation
3. Elevates blood pressure and
4. Markers of oxidative stress, inflammation.

3. • Large negative intrathoracic pressure swings also
impose mechanical stress on the heart and great
vessels.
• Various cohort studies have shown an association
between obstructive sleep apnea and cardiovascular
events, particularly stroke.

4. • Randomized, controlled trials have shown that
treatment with continuous positive airway pressure
(CPAP)
1. Lowers SBP by 2 to 3 mm Hg in patients with OSA
2. by 6 to 7 mm Hg in patients with resistant
hypertension,
3. improves endothelial function,
4. increases insulin sensitivity.

5. • Observational clinical studies have shown that the
use of CPAP is associated with
1. lower rates of cardiovascular complications
2. death from cardiovascular causes, especially among
patients who are adherent to treatment.
• SLEEP APNEA CARDIOVASCULAR ENDPOINTS (SAVE)
STUDY, a secondary prevention trial - designed to
evaluate the effectiveness of CPAP in reducing the
rate of cardiovascular events among patients with
OSA.

6. METHODS

7. STUDY DESIGN
• The SAVE study was an:
1. international,
2. multicenter,
3. randomized,
4. parallel-group,
5. with blinded end-point assessment.

8. INCLUSION CRITERIA
• Patients were recruited at 89 clinical centers in 7
countries;
1. an age between 45 and 75 years,
2. a diagnosis of coronary artery disease or
cerebrovascular disease,
3. a diagnosis of moderate-to-severe obstructive
sleep apnea

9. MODERATE-TO-SEVERE
OBSTRUCTIVE SLEEP APNEA
• Defined as an apnea hypopnea index of ≥ 30 per
hour of sleep, as an oxygen desaturation (the
number of times per hour during the oximetry
recording that the blood oxygen saturation level
drops by ≥4 percentage points from baseline) ≥ 12
per hour, was established with the use of a home
sleep study screening device.

10. EXCLUSION CRITERIA
1. Patients reporting severe daytime sleepiness
(Epworth Sleepiness Scale score >15);
2. Patients having an increased risk of an accident
from falling asleep,
3. Patients having very severe hypoxemia (oxygen
saturation <80% for >10% of recording time),
4. Patients having pattern of Cheyne–Stokes
respiration on the nasal pressure recording.

12. • Potential participants were required to have a
minimum level of adherence to CPAP therapy, which
was defined as an average of 3 hours per night,
during a 1-week run-in period in which CPAP was
used.

13. RANDOMIZATION AND INTERVENTIONS

14. "Usual care" consisted of advice on healthy sleep habits and lifestyle changes along
with cardiovascular risk management.

15. • Concomitant management of cardiovascular risk
factors were performed.
• All participants were given advice on healthful sleep
habits and lifestyle changes to minimize obstructive
sleep apnea.
• Clinic visits were scheduled for all participants at 1, 3,
6, and 12 months and annually thereafter.

16. STUDY MEASURMENTS
• At randomization and at each follow-up visit,
participants’ BP and HR was measured.
• Among the participants in the CPAP group, data on
adherence to the use of the CPAP device were
recorded.
• At randomization, at 6 months, and at 2 and 4 years,
anthropometric measurements were obtained in all
participants.

17. STUDY END POINTS
• The primary end points were composite of death
from any cardiovascular cause;
1. myocardial infarction (including silent myocardial
infarction),
2. stroke,
3. hospitalization for heart failure, acute coronary
syndrome (including unstable angina), or transient
ischemic attack.

18. • Secondary cardiovascular end points included:
1. Revascularization procedures,
2. New-onset atrial fibrillation,
3. New-onset diabetes mellitus,
4. Death from any cause.

19. RESULTS

21. The mean duration of follow-up was 3.7 years.

22. INTERVENTION ADHERENCE, MEDICATIONS,
AND LIFESTYLE FACTORS
• The mean duration of use of the CPAP device during
the 1-week run-in phase was 5.2 hours per night.
• In the CPAP group, the mean duration of adherence
to CPAP therapy in the first month of treatment was
4.4±2.2 hours per night, which decreased to 3.5±2.4
hours per night by 12 months and remained
relatively stable thereafter(mean adherence during
follow-up, 3.3±2.3 hours).

23. • The residual apnea–hypopnea index during CPAP use,
averaged 3.7 events per hour, which indicated good
control of OSA with CPAP.
• Of the 1346 patients in the CPAP group, 566 (42%) had
good adherence to treatment (≥4 hours per
night)during follow-up.
• No significant differences were observed between the
two groups in the use of medications for diabetes
mellitus and cardiovascular conditions, in lifestyle
factors including diet and smoking, and in body-mass
index from baseline to the end of the study.

27. Conclusion
• In a large group of adults with both cardiovascular
disease and moderate-to severe OSA, the use of
CPAP therapy had no significant effect on the
prevention of recurrent serious cardiovascular
events.
• Though it significantly reduced sleepiness and other
symptoms of OSA and improved quality-of-life
measures.

28. Faleminderit!