Sleep Disordered Breathing: Beware Snoring! Dr T A McDonagh Consultant Cardiologist Royal Brompton Hospital London. UK

Transcription

1 Sleep Disordered Breathing: Beware Snoring! Dr T A McDonagh Consultant Cardiologist Royal Brompton Hospital London. UK

2 Sleep Disordered Breathing in CHF Erratic breathing during sleep known for years e.g. Cheyne Stokes Respiration Advances in sleep medicine, range of disorders under general heading of sleep disordered breathing (SDB) Obstructive sleep apnoea (OSA) Central sleep apnoea (CSA) Cheyne Stokes (periodic breathing) Obstuctive and central hypoventilation

3 Apnoea and Hypopnoea Apnoea: Cessation of airflow > 10 secs Hypopnoea: >50% reduction in airflow for >10 secs associated with: desaturation and/or arousal (various definitions of hypopnoea are used) Syndrome of Sleep disordered Breathing: Apnoea Hypopnoea Index (AHI) > 10-15/ hr Or >5 per hour associated with symptoms of day time sleepiness, nocturnal choking..

4 Obstructive Sleep Apnoea (OSA) Collapse of pharyngeal airway Loss of pharyngeal dilator muscle tone during sleep Central Sleep Apnoea (CSA) Reduced efferent activity to the respiratory pump muscles

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6 Central Apnoea Obstructive Apnoea Airflow Thoracic Effort Abdominal Effort

7 Prevalence of SDB in CHF Patients :47-71% Author, Year Number Patients NYHA Male (%) LVEF (%) SDB Severity (AHI) OSA (%) CSA (%) Lanfranchi, I 89 27(6) >15/hour Ferrier, I-II 77 34(9) >10/hour Javaheri, II (7) >15/hour Oldenburg, >II 80 28(7) >15/hour Schulz, II,III >10/hour Vazir, II (10) >15/hour MacDonald, >II >15/hour Bitter, II-IV 64 >55 >15/hour Prevalence in of OSA in general population 4% men and 2% in women

8 Type of SDB in CHF CSA - prevalence of 40-50% 100 OSA is seems to vary between 8-35% (with more patients with CSA presenting as OSA as they may have high BMI or large neck size) CSA OSA (Vazir et al, EJHF 2006)

9 Pathophysiological consequences of OSA Obstructive sleep apnoea Arousal Hypoxaemia Negative intrathoracic pressure Proinflammatory effects/oxidative stress Sympathetic surge Reduced myocardial O2 delivery Increased LV wall tension and LV O2 demand Increase in HR and BP Cardiac ischaemia Cardiac hypertrophy Cardiac arrhythmias Cardiac failure

10 Pathophysiology of CSA Mechanism for development of Central apnoea in CHF: fall of PaCO 2 below the apnoeic threshold leads to central apnoea Other important factors in the pathophysiology of CSA: Pulmonary congestion hyperventilation (lowers PaCO 2 ) Enhanced chemoreceptor sensitivity to CO 2 Small Lung volumes (rapid changes in alveolar CO 2 are reflected in arterial CO 2 ) Reduced CO 2 reserve (narrowed gap between sleep eupnoeic CO 2 and apnoeic threshold) Prolonged circulation time

11 In the general population, patents with severe OSA (AHI>30) have more fatal CVS events (Marin et al 2005, Lancet)

12 Untreated OSA significantly increases risk of death in patients with heart failure Wang et al JACC 2007

13 CSA patients have a worse prognosis Javaheri et al JACC 2007)

14 Consequences of SDB in CHF Hypersomnolence and accidents (RTA) Fatigue and reduced activity levels CV (increased sympathetic nervous system activation from recurrent hypoxia and arousals): arrhythmia risk and sudden cardiac death accelerated progression of heart failure repetitive hypertensive swings following apnoea in OSA direct haemodynamic stress on the myocardium from inspiratory effort (in OSA) against occluded airway (increased afterload) Increased mortality (but only from small studies in patients with CHF)

15 How do patients with SDB and heart failure present? hypersomnolence (?) obesity snoring fatigue witnessed apnoea paroxysmal nocturnal dyspnoea morning headaches

16 Epworth Sleepiness Score Individual and mean ESS for patients with CHF-SDB v Wisconsin Sleep Cohort P = CHF-SDB Wisconsin Cohort Vazir et al ERS 2004

17 Actigraphy No SDB SDB Longer time in bed Reduced Activity (Hastings, Vazir et al ERJ 2006)

18 How do patients with SDB and heart failure present? Hypersomnolence (?) obesity snoring fatigue witnessed apnoea paroxysmal nocturnal dyspnoea morning headaches

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20 Specific questions Diagnosis of SDB Snoring, witnessed apnoea and day time sleepiness Risk factors high BMI and AF Sleep study Gold standard-detailed poylsomnography (EEG, ECG, chin EMG, chest and abdominal effort sensors, airflow detection, oximetry and periodic limb and snoring monitoring) Usually-pulse oximetry, airflow, respiratory effort, snoring and position monitoring Screening? Justified if effective Rx Good OSA but not CSA Screen by oximetry overnight, HRV, and apnoea detection

21 Treatment of SDB in CHF Optimise HF Rx Weight Loss Postural change during sleep to reduce pulmonary oedema

22 CRT reduced AHI significantly after 17 weeks in 12 CHF patients with CSA significant improvement AHI (19.2 to 4.6 / hour) NYHA class (from ІІІ to ІІ) Exercise capacity Ejection fraction (25 to 35%) Kara T et al Chest Jul;134(1):87-93

23 CRT and OSA in HF Mean LVEF % AHI fell from No iprovement in sleep architecture or symptoms (Stanchina et al Chest 2009;132;433)

24 Specific Treatment of SDB in CHF OSA CPAP CSA Optimal treatment Unclear

25 Treatment OSA in general population with CPAP Reduces -obstructive apnoea -hypopnoeas -arousals -daytime somnolence -daytime BP Reduces risk of complications (fatal CVS events) -IHD -Stroke»

26 In the general population, patents with OSA treated with CPAP have less fatal CVS events than severe untreated OSA (Marin et al 2005, Lancet)

27 Treatment of OSA in CHF with CPAP RCT of one month of CPAP in patients with severe CHF, LVEF<45% and AHI>20 (N= 24) Improvement in LVEF by 9% Reduction in LV End Diastolic Diameter Reduction in daytime HR and BP over 30 days reversal of the mechanical and haemodynamic effects of OSA. (Kaneko et al NEJM 2003)

28 Treatment of OSA in CHF with CPAP RCT in 56 CHF patients of 3 months of CPAP compared to controls: Match for age, sex, LVEF, AHI CPAP group (N= 28): Improved LVEF 5% Improved quality of life Reduction in day time sleepiness Reduced urinary epinephrine levels No change in exercise capacity or NYHA (Mansfield et al AJRCCM Feb 2004)

29 CPAP-OSA and CHF Non randomised data suggests a reduction in mortality in Heart Failure (Kasai et al Chest 2008) Ethically difficult to randomise...

30 Optimal Treatment of CSA in CHF Remains Unclear 1) Oxygen Corrects apnoea related hypoxaemia Decreases NA concentrations Increases effort capacity No effects on LV function or QOL 2) Carbon Dioxide Theory should stabilise periodic breathing Reduces AHI but increases arousals 3) Drug therapy: Theophylline, Acetazolamide, Benzodiazepines and Opiates

31 Types of Nocturnal Non-Invasive Support used to treat CSA CPAP Intial small uncontrolled trials suggested benefit Decrease in VEs 20 patients reduced death or CTX at 5 years Bi-level (not discussed here as small single centre study suggests that it is as good as CPAP) Adaptive Servo-Ventilation (ASV)

32 CANPAP study (CPAP for CSA in CHF) Multi-centre randomized controlled trial N = 258 with CHF and CSA randomized to CPAP treatment every night over 4 years or no treatment (AHI reduced from 40 to 20) -Decrease pulmonary oedema, increase in mean arterial O2 saturation -Reduced Minute ventilation and increased PaCO 2 above apnoeic threshold (Bradley et al, 2005 NEJM)

33 CANPAP study No survival benefit, but CPAP Improved: LVEF by 2% Exercise capacity Therefore not recommend CPAP for the treatment of CSA in CHF

34 Adaptive Servo Ventilation (Autoset CS) and CSA A non-invasive ventilator specifically designed to treat Cheyne Stokes breathing Ventilation at 90% of maximum V T Servo-controlled Designed to smooth out periodic breathing

35 Adaptive Servo Ventilation (Autoset CS) and CSA Pre-treatment Autoset CS Airflow (PET-CO2) Abdominal Thoracic SPO 2 20 s 20 s

36 Adaptive Servo Ventilation (Autoset CS) and CSA 1 night of Autoset CS (N=14, NYHA III) improved overnight breathing pattern + sleep quality, better than nasal oxygen/ CPAP/ Bilevel (Teschler et al AJRCCM 2000)

37 ASV in all types of SDB Single centre study 11 HF patients with mixed SDB treated with ASV versus 8 controls with HF and SDB ASV for 6 months Effectively treated all forms of SDB Improved LV EF by 5% Improved vitality scores Reduced daytime sleepiness Hastings, Vazir et al IJC 2008

38 Adaptive Servo Ventilation (Autoset CS) and CSA 1 month of Autoset N of 30, randomized, double blind control trial 15 therapeutic V 15 Sub-therapeutic Autoset CS Reduce objective daytime sleepiness (but not subjectively) Reduced blood BNP and catecholamine excretion No change in LVEF (Pepperell et al AJRCCM 2003) Randomised controlled trial of ASV has commenced (SERVE-HF)

39 SERVE HF trial Multicentre Randomised controlled trial (NYHA II-IV) Heart failure patients with SDB (predominant CSA) are randomised to either ASV or optimal medical therapy Follow up for 3-4 years Aim for 1200 patients Primary Outcome Measures: 1) All cause mortality or unplanned hospitalization for worsening heart failure 2) Cardiovascular mortality or unplanned hospitalization for worsening heart failure 3) All cause mortality or all cause hospitalization

40 Conclusions SDB occurs in a significant number of CHF patients (>50%), mainly CSA, but significant number have OSA. Significant number of patients have mixed disease CHF with SDB seem not to report excessive daytime sleepiness measured subjectively Beware Snoring SDB in CHF worsens CHF CSA in CHF indicates a poorer prognosis

41 Conclusions OSA in CHF treat with CPAP Optimal Treatment of CSA remains Unclear CANPAP suggests CPAP is not beneficial SERVE HF is under way to assess benefits of ASV Consider treating patients with CSA with a trial of Autoset CS if optimizing treatment of underlying CHF is not sufficient to alleviate CSA. (especially if sleepy with severe CSA)

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