1. Screening for Sleep Apnoea in Cardiac Rehabilitation
2 December 2018
Screening for Sleep Apnoea in Cardiac Rehabilitation
Dr Frances WISE1, 2 Mary-Anne BEER1 Robyn SHEPPARD1
CARDIAC REHABILITATION UNIT, CAULFIELD HOSPITAL, ALFRED HEALTH
EPWORTH MONASH REHABILITATION MEDICINE UNIT
This morning, I would like to present to you the outcomes from a quality improvement program we introduced into our Cardiac Rehab Unit at Caulfield Hospital back in 2016 using a screening tool for obstructive sleep apnoea.

2. Obstructive Sleep Apnoea
2 December 2018
Obstructive Sleep Apnoea
So what is obstructive sleep apnoea?

3. Obstructive Sleep Apnoea
2 December 2018
Obstructive Sleep Apnoea
A disorder in which breathing is repetitively interrupted during sleep due to collapse of the upper airway resulting in hypoxia and sleep fragmentation.
Sleep 1999
Obstructive sleep apnoea is disorder in which breathing is repetitively interrupted during sleep, due to collapse of the upper airway resulting in hypoxia and sleep fragmentation. It is associated with daytime sleepiness and is categorised as mild moderate or severe sleep apnoea when diagnosed using polysomnography or a sleep study. So why are we in the Cardiac Rehab Unit interested in obstructive sleep apnoea?

4. 2 December 2018
Background
Obstructive Sleep Apnoea (OSA) affects 25% of men and 9% of women in Australia Snore Australia
Sleep apnoea affects 25% of men and 9% of women Australia wide, but it’s not only associated with daytime sleepiness, although this does have implications for work, safety and social interactions.

5. 2 December 2018
Background
Obstructive Sleep Apnoea is associated with significant chronic diseases
Sleep apnoea is also associated with other chronic diseases including hypertension, AMI, stroke, diabetes, depression and may lead to early death. The associations of OSA are very similar to the risk factors of our patients with coronary artery disease and heart failure.

6. The relationship with cardiac risk factors
2 December 2018
The relationship with cardiac risk factors
Prevalence of Obstructive Sleep Apnoea in Populations With Cardiovascular Disorders (CVD)
Condition %
Hypertension
30–83
Ischemic heart disease
30–58
Stroke
43–91
HF, with reduced ejection fraction
12–53
HF, with preserved ejection fraction 40
Hypertrophic cardiomyopathy
Atrial fibrillation
25–80
End-stage renal disease
40–60
The relationship between OSA and cardiovascular disease is significant, as you can see on this table. The Australia wide figures for OSA I showed earlier are still considerably lower than their prevalence in patients with cardiovascular conditions, such as heart failure and IHD, but notably hypertension, stroke and atrial arrhythmias.
There is also an increasing awareness of the importance of OSA’s role in the causation or promotion of these conditions.
Floras 2014

7. 2 December 2018
Thus, not surprisingly, OSA is recognised as a predictor of premature cardiovascular death.
Floras 2014
So, it’s not surprising that OSA is a predictor of premature cardiovascular death.

8. WHY - did we undertake this study?
2 December 2018
“Patients with untreated sleep apnoea may experience significantly worse outcomes during their cardiac rehab and recovery” Sharma Parker 2011
OSA is underdiagnosed and undertreated in Cardiac Rehabilitation patients
Why did we undertake this study? It has been documented that patients with untreated OSA may experience worse outcomes during their cardiac rehab and recovery. However, this condition is underdiagnosed and undertreated in our patient group.

9. HOW – did we perform this study?
2 December 2018
HOW – did we perform this study?
431 cardiac rehabilitation patients completed:
the Berlin Sleep Questionnaire (BSQ),
We also measured:
Hospital Anxiety and Depression Scale
6 Minute Walk Test (6MWT).
Body Mass Index (BMI),
Body Fat % and
Risk factor history
So what did we do?
We gave the Berlin Sleep Questionnaire to 431 of our Cardiac Rehab patients on their admission to the unit. Each patient completed the Hospital Anxiety and Depression Scale Questionnaire and 6MWT on admission and discharge. We looked at their BMI and body fat percentage and each patient had a risk factor profile completed.

10. HOW – did we perform this study?
2 December 2018
HOW – did we perform this study?
Berlin Sleep Questionnaire Netzer 1999
The Berlin Sleep Questionnaire is a 10 point self report questionnaire, divided into 3 categories. It covers snoring, daytime fatigue and the final category covers both hypertension and obesity. If a patient scores high in 2 or more of these categories, they are considered high risk for Obstructive Sleep Apnoea

11. HOW – did we perform this study?
2 December 2018
HOW – did we perform this study?
Score ≥ 2 on the BSQ = letter to GP to suggest FURTHER INVESTIGATION
Berlin Sleep Questionnaire
and their GP was sent a letter requesting they consider a referral for further investigation, or referral to a sleep clinic.

12. 2 December 2018
Next Steps?
The Berlin Sleep Questionnaire is only one screening tool that is freely available for screening for OSA.
The Berlin Sleep Questionnaire is only one screening tool that is freely available, and should others consider screening for OSA there are other options available, but the Berlin was our screening tool of choice.
So what did we find?

13. 2 December 2018
WHAT – were the results?
38% (n = 164) of patients scored highly on BSQ & needed referral to a sleep clinic for follow up
So what did we find?
We found that 38% or 164 of our original 431 patients scored high risk on the Berlin Sleep Questionnaire.
High Scorers
Low Scorers
AGE, MEAN
63.7
63.6
SEX, MALE, %
72.2 77
SMOKER, %
13.4* 9
HYPERTENSION, %
68.9* 42
DIABETES, %
28.4*
17.7
BMI, MEAN
30.2*
26.9
% BODY FAT, MEAN
31.2*
27.1
WAIST MEASURE, MEAN, CM
104.5* 97
HADS, % WITH ANXIETY
35.5*
21.7
HADS, % WITH DEPRESSION
32.2*
13.8
EXERCISE >150MINS/WEEK, %
54.2
57.7
6 MINUTE WALK, M, ADM
478*
501
6 MINUTE WALK, M, DC
634.7*
717

14. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE, MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI, MEAN
30.2 *
26.9
% BODY FAT, MEAN
31.2 *
27.1
WAIST CM, MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE >150 Mins/WK %
54.2
57.7
6 MWT MEAN ADM
478 *
501
6 MWT MEAN DISCH
634.7 *
717
These 431 patients all have a cardiac history and associated risk factors, however, when we compared these high risk sleep apnoea patients or “high scorers” with those who had a lower risk or “low scorers”, it revealed some interesting results. There is no statistical difference between age or gender in either group. The age and gender mix are comparable to that of our usual cardiac rehab population at Caulfield.

15. WHAT – were the results? Smoking is an independent risk factor for OSA
2 December 2018
WHAT – were the results?
Smoking is an independent risk factor for OSA
Smokers have a THREE fold increase in risk of developing OSA compared to non smokers
Prevalence of smoking in sleep apnoea patients may be as high as 35%
Kashyap 2001
“Where there’s smoke, there’s sleep apnoea!” Krishnan et al 20
We are all aware of the significant risk smoking poses to our cardiovascular health, but smoking is also an independent risk factor for OSA. In fact smokers also have a risk 3 times greater than non smokers of developing OSA. One study also showed the prevalence of smoking in sleep apnoea patients to be as high as 35%. To quote one researcher who claimed “Where there’s smoke, there’s sleep apnoea!”

16. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
Prevalence of Risk Factors in High Scorers
High Scorers (164)
Low Scorers (267)
AGE, MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI, MEAN
30.2 *
26.9
% BODY FAT, MEAN
31.2 *
27.1
WAIST CM, MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE >150 Mins/WK %
54.2
57.7
6 MWT MEAN ADM
478 *
501
6 MWT MEAN DISCH
634.7 *
717
As you can see, our data supports this as the greater percentage of our patients who are current smokers also have a significantly higher risk of having sleep apnoea.

17. WHAT – were the results? Hypertension is a key risk factor for CVD
2 December 2018
WHAT – were the results?
Hypertension is a key risk factor for CVD
In the medical literature a third or more of individuals with hypertension also will have OSA Floras 2015
Hypertension too is a key risk factor for CVD. In the medical literature, a third or more of individuals with hypertension will also have OSA

18. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE, MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI MEAN
30.2 *
26.9
% BODY FAT MEAN
31.2 *
27.1
WAIST CM, MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE >150 Mins/WK %
54.2
57.7
6 MWT MEAN ADM
478 *
501
6 MWT MEAN DISCH
634.7 *
717
Our results too reflect this. In fact 68.9% of our high scorers had diagnosed hypertension compared to 42% the low scorer group.

19. 2 December 2018
WHAT – were the results?
Intermittent hypoxia and sleep fragmentation can lead to insulin resistance
Hamilton Naughton 2013
Large published studies indicate that OSA is a predictor of diabetes, with OSA patients 30% more likely to develop diabetes.
Kendzerska et al 2014
Patients with diabetes have an increased risk of developing OSA
Intermittent hypoxia and sleep fragmentation can lead a whole host of metabolic conditions including insulin resistance. Large studies indicate that OSA is a predictor of diabetes with OSA patients 30% more likely to develop diabetes. Conversely, patients with diabetes have an increased risk of developing OSA.

20. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE, MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI, MEAN
30.2 *
26.9
% BODY FAT, MEAN
31.2 *
27.1
WAIST CM, MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE >150 Mins/WK %
54.2
57.7
6 MWT MEAN ADM
478 *
501
6 MWT MEAN DISCH
634.7 *
717
As you can see, 28.4% of our high scorers were also found to have diabetes compared to 17.7% of low scorers.

21. 2 December 2018
WHAT – were the results?
The external and internal neck circumferences and the degree of obesity are important predictors of sleep apnoea Katz 1989
In general, the physical examination is normal in patients with OSA, aside from the presence of obesity (body mass index: >30 kg/m2), an enlarged neck circumference (men: >43 cm [17 in]; women: >37 cm [15 in]).
Downey 2018
It has been well documented that neck circumference is a relevant factor in the diagnosis of OSA. The combination of obesity and a neck circ of greater than 43cm in men and greater than 37 cm in women are considered predictive.

22. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI MEAN
30.2 *
26.9
% BODY FAT MEAN
31.2 *
27.1
WAIST CM MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE > 150 MINS/WK%
54.2
57.7
6 MWT ADM MEAN
478 *
501
6 MWT DISCH MEAN
634.7
717
Again our data supports this with our high scorers measuring a mean neck circumference of 40.9 cm compared to 38.5 cm in the low scorers.

23. 2 December 2018
WHAT – were the results?
Obesity is a major risk factor for both cardiovascular disease and OSA
Wong et al 2018
A 10% weight gain can lead to a SIX fold increase in the chances of developing OSA
Peppard Young Palta 2000
Obesity is also a major risk factor for both cardiovascular disease and OSA, with one study identifying a 10% weight increase may lead to a 6 fold increase in the chances of developing OSA.

24. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE, MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CIRCUMFERENCE CM MEAN
40.9 *
38.5
BMI MEAN
30.2 *
26.9
% BODY FAT MEAN
31.2 *
27.1
WAIST CM MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE > 150 MINS/WEEK %
54.2
57.7
6 MWT ADM
478 *
501
6 MWT DISCH
634.7 *
717
As you can see from the mean BMI, mean body fat percentage and corresponding mean waist measurement, our obese patients have a statistically significant increase in risk for OSA compared to our lower weight patients.

25. 2 December 2018
WHAT – were the results?
Sleep disturbance is strongly associated with depressive symptoms and health related quality of life
Banack 2014
Patients with both depression and OSA have an increased risk of death/adverse events following myocardial infarction, more than either depression or OSA alone.
Hayano et al 2012
Sleep disturbance is strongly associated with depressive symptoms and health related quality of life and Patients with both depression and OSA have an increased risk of death/adverse events following myocardial infarction, more than either depression or OSA alone.

26. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI MEAN
30.2 *
26.9
%BODY FAT MEAN
31.2 *
27.1
WAIST CM MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE > 150 MINS/WEEK %
54.2
57.7
6 MWT ADM
478 *
501
6 MWT DISCH
634.7 *
717
The percentage of our patients with increased anxiety and depression indicating a poorer health related QoL, were also significantly represented in the high scorer category.

27. 2 December 2018
WHAT – were the results?
Health related quality of life influences both compliance with medical treatments and program adherence
Banack 2014
OSA is associated with impaired exercise capacity and lower peak VO2.
Beitler et al 2014
Health related quality of life influences both compliance with medical treatments and program adherence, which is particularly important for our patients in the CRU as they manage their risk factors. For example exercise…OSA is associated with impaired exercise capacity and lower peak VO2.

28. WHAT – were the results? Prevalence of Risk Factors in High Scorers
2 December 2018
High Scorers (164)
Low Scorers (267)
AGE MEAN
63.7
63.6
GENDER MALE %
72.2 77
SMOKER %
13.4 * 9
HYPERTENSION %
68.9 * 42
DIABETES %
28.4 *
17.7
NECK CM MEAN
40.9 *
38.5
BMI MEAN
30.2 *
26.9
%BODY FAT MEAN
31.2 *
27.1
WAIST CM MEAN
104.5 * 97
HADS ANXIETY %
35.5 *
21.7
HADS DEPRESSION %
32.2 *
13.8
EXERCISE > 150 MIN/WEEK %
54.2
57.7
6 MWT ADM
478 *
501
6 MWT DISCH
634.7 *
717
Whilst not statistically significant, there was a trend towards fewer exercise minutes completed per week by our high scorers than our low scorers. What is significant however, is the improvement on 6 MWT from admission to discharge, where our low scorers had a mean improvement of 216 metres, whilst the high scorers, had a mean improvement of only 157 metres on discharge.

29. WHAT – were the results? To Summarise: HIGH SCORERS:
2 December 2018
WHAT – were the results?
To Summarise:
HIGH SCORERS:
Were significantly more likely to have a history of smoking, hypertension or diabetes.
Had Higher BMI, body fat % and neck circumference higher prevalence of depression and anxiety.
Had Lower Exercise Tolerance and there was less improvement in 6MWT by discharge.
In summary, our high risk patients were significantly more likely to have a history of smoking, hypertension or diabetes. They had higher BMI, body fat percentage neck circumference. There was also an increased prevalence of anxiety and depression. They also had poorer outcomes on their 6MWT on discharge.

30. WHAT – were the results? Of our 164 high scorers,
2 December 2018
WHAT – were the results?
Of our 164 high scorers,
only 5 patients were referred by their GPs for further investigation.
Unfortunately, of our 164 high scoring patients, only 5 of these high scorers were referred by their GP to a sleep clinic.

31. 2 December 2018
Our Unit is developing a protocol to initiate direct referral to sleep clinics, with examination of outcomes including Quality of Life, fat mass and mood.
Next Steps?
As a result, our team in the CRU are developing a protocol to directly refer these patients to a sleep clinic to help improve their outcomes and their quality of life.

32. 2 December 2018
THANK YOU!