Exercise In Chronic Heart Failure

Aynsley Cowie

Senior I Physiotherapist, Ayr Hospital

PhD Student, Glasgow Caledonian University

• Exercise intolerance in CHF• Effects of exercise• Evidence for exercise training• PhD• Practical implications & advice

to patients

Overview

Exercise Intolerance in Chronic Heart Failure

Why is exercise tolerance reduced?

Exercise Intolerance

peakVO2, due to:

cardiac output response nutritive blood flow to skeletal

muscles– skeletal muscle abnormalities

%type I fibresmitochondriacapillary densitymuscle fibre size

Exercise Intolerance

Metabolic abnormalities– early dependence on anaerobic metabolism– muscle wasting

AEROBIC METABOLISM

OXYGEN IN CELL

GLUCOSE

ENERGY

PYRUVATE

ENERGY

CO2 & H2O

ANAEROBIC METABOLISM

OXYGEN ABSENT

GLUCOSE

ENERGY

PYRUVATE

NO ENERGY

LACTATE

Exercise Intolerance

Early respiratory muscle de-oxygenation & fatigue– excessive ventilatory effort– inefficient ventilation– V/Q mismatch– higher breathing frequency

Acidity of blood

Early activation of muscle ergoreflex

Health-related Quality of Life

Proposed Effects of Exercise in Chronic

Heart Failure

Effects of Exercise

15-20% peakVO2, due to:

cardiac output response• modest in heart rate & stroke volumediastolic filling at peak exercise

– changes to skeletal musclenutritive blood flow to skeletal musclesO2 extractionmitochondria

Effects of Exercise

Improved metabolic functioning reliance on anaerobic metabolism

ventilatory efficiency

neuro-endocrine activity

sympathetic nervous system activity

Effects of Exercise

Therefore: exercise tolerance symptom severity• improved NYHA class• improved quality of life

……….without: in central haemodynamics unfavourable LV remodelling

But, no clear evidence regarding effects on prognosis

Evidence to Support Exercise Training in

Chronic Heart Failure

Evidence

• Patients historically advised to restrict physical activity to reduce circulatory demands

• Coats et al (1990): first RCT to conclude that exercise actually improves fitness, symptoms and quality of life of those with CHF

Evidence

• NICE 5 (2003): Both aerobic & resistive exercise will improve symptoms, exercise performance & quality of life without deleterious effects on central haemodynamics

• SIGN 57 (2002): Patients with chronic heart failure should considered for comprehensive cardiac rehabilitation if they have limiting symptoms

• European Society of Cardiology (2001): Exercise training…..can increase exercise capacity in compensated stable chronic heart failure patients

Literature Search

Search Criteria:• published in 2000 or more recently• published in English• evaluating a specific programme of

training• including exercise capacity &/or

quality of life outcomes

45 studies found (August 2006)

Literature Search

7 studies were non-controlled, most conducted out with UK

Samples:• Generally small but widely ranging (6-200), mean n=44• Mean age ~60y• Women tended to be excluded• Most included those of NYHA II & III

Location:• Most evaluated hospital-based programmes • Home programmes as effective as hospital programmes• None compared home versus hospital programmes

Literature Search

Mode:• Most trials incorporated cycling in training

• Many very equipment-orientated

• Very few evaluated resistance training

• Those using home walking demonstrated least improvement in exercise capacity

Literature Search

Frequency:• 3 x week or more is required for benefit

Length:• Should be at least 8 weeks• None examine longer programmes / if effects are sustained

Duration:• Conditioning of <30 minutes = least effect on exercise capacity

Intensity:• 60-70% peakVO2 for best effect on exercise capacity

Literature Search

Conclusion:• Small samples, excluding elderly and women• Home walking programmes were least effective• None compared effects of home- & hospital-based

exercise• Training mode was equipment-orientated• Most evidence advocates training at least 3 x week for

at least 30 minutes (plus warm-up and cool-down)• Best outcomes achieved if intensity set to 60-70%

peakVO2

• Few evaluated resistance training

A Study Comparing Effects of Home andHospital-based Exercise on Exercise Capacity and Quality of Life of Patients with Chronic Heart Failure

Aims:

To determine effects of hospital- versus home-based exercise training (versus “usual care”) on exercise capacity and quality of life of patients with CHF

To determine patients’ perceptions of the effects of home- versus hospital-based exercise training

Design

Pre-test measurement of exercise capacity &

quality of life

Randomisation

Hospital-based exercise

Home-based exercise

Control group

Post--test measurement of exercise capacity &

quality of life

Focus groups to examine

perceptions of effects of training

Sample

n=60 (45)Recruitment from Heart Failure Nurse Liaison Service & Cardiology clinics

Inclusion Criteria:• Diagnosis of LVSD by echo• Sufficiently clinically stable for exercise (3-4 weeks)• Willing to participate

Exclusion Criteria:• Other life threatening illness• Unable to participate due to major cognitive impairment

Contraindications

Absolute• Progressive worsening of exercise tolerance / SOB over

past 3-5 days• Significant ischaemia at low work rates• Uncontrolled diabetes• Acute systemic illness or fever• Recent embolism / thromboembolism• Active pericarditis / myocarditis• Moderate to severe aortic stenosis• Regurgitant valvular heart disease requiring surgery• MI within past 3 weeks• New onset AF

(European Society of Cardiology, 2001)

Contraindications

Relative• >1.8kg in body mass over previous 1-3 days• Concurrent dobutamine therapy• Decrease in SBP with exercise• NYHA class IV• Complex ventricular arrhythmias at rest, or with exertion• Supine resting heart rate >100bpm• Pre-existing co-morbidities• Poorly controlled AF

(European Society of Cardiology, 2001)

Exercise Interventions

Hospital-based:• Physiotherapist led classes

• Home-based:• Prescribed by physiotherapist• DVD & home exercise booklet / diary & Heart rate monitor• 3 follow-up phone calls from physiotherapist

Both:• 8 weeks duration, 2 x week, 1 hour per session• Each session: 15 minute warm-up, 30 minute functional

aerobic circuit exercises (interval training), 10 minute cool-down

Control:• General physical activity advice

Outcomes

Exercise Capacity:• Shuttle / 6 minute walk depending on pilot results

Quality of Life:• Literature suggests generic & disease-specific questionnaire• Minnesota Living with Heart Failure & SF-36 most valid &

reproducible

Perceptions of Effects of Exercise:• Home- and hospital-exercisers kept separate• 2-3 group of each (6-7 participants per group)• Previous exercise experience, expectations, perceived effects of

exercise, barriers / facilitators, future exercise ambitions

Methodologyn=60 participants recruited from Heart Failure Nursing Service &

Cardiology Clinics

Pre-test measurement of exercise capacity (by shuttle/6 minute walk) & quality of life (Minnesota & SF-36)

Randomisation

Hospital-based exercise

Home-based exercise

Control

Post-test measurement of exercise capacity (by shuttle/6 minute walk) &

quality of life (Minnesota & SF-36)

8 weeks

2 or 3 focus groups to examine perceptions of effects of training

2 or 3 focus groups to examine perceptions of effects of training

Plan…...

•Final amendments to be made for ethics•Data collection planned for Spring 2007-Spring 2008

Practical Implications for Patients Attending

Rehabilitation

Advice for Patients

Patient Evaluation

• Referrals from clinics, cardiologists / other consultants, GPs or other health professionals

• Good recruitment protocol with agreed criteria & contraindications

• Heart failure must have been stable for around 3-4 weeks• Patients of NYHA I to III are eligible - ?some stable class IVs • No lower limit to ejection fraction • Don’t wait for optimisation of medications• Any arrhythmias should be as well controlled as possible

Patient Assessment

Subjective:• Gauge “normal” heart failure symptoms• Threshold for ICDs • Status of up-titration• Are they checking their weight regularly?

Objective:• Weight if not self-monitoring• BP and resting heart rate• ?recent ECG • Measurement of functional capacity• Measurement of quality of life

Exercise Session

• Warm-up: 5-15 minutes• Conditioning: 10-30 minutes aerobic

exercise alternated with active recovery• Cool-down: 5-10 minutes • Seated exercises where appropriate• Should be tailored to the individual• Resistance training can be included• Exercises will be symptom limited• Borg RPE rating should be 12-13

Borg RPE

6 No exertion7 Very, very light89 Very light1011 Light

1213 Somewhat hard

1415 Hard1617 Very hard1819 Very, very hard20 Maximum exertion

Exercise Session

• May not be able to achieve target heart rate• Heart rate may have to be adjusted as medications

(blockers) are up-titrated

Common problems• Symptomatic low BP

– check drug dosages / timings• Increase in symptoms

– ?overloaded (weight gain)– ? blockers initiated or up-titrated

Exercise Session

Safety• Higher risk patients - staff ratio should be 1:5• Some patients may require 1:1• SCD common• Rare in CHF English CR programme (Wythenshawe)

N.B.• Good and bad days - exercise prescription may change (erratic attendance)• Remember fluid restriction when encouraging intake • Gout is common 2° to diuretics

Home Exercise

Too unfit for class?• Short daily sessions of 5-15 minutes• Simple programme (?e.g. chair programme / pedals)• As fitness improves, increase duration of session &

reduce frequency to once per day• Start to increase pace to brisk (12-13 on Borg scale)• With further improvement, aim to gradually build up

to accumulation of 30 minutes moderate intensity activity most days

General Physical Activity Advice

• Do any activity that you enjoy & are used to doing, unless you have been told otherwise

• Physical activity is safe if you start slowly & build up gradually

• Always exercise within limits of your symptoms• If you use GTN spray or tablets for relief of angina,

keep this to hand• If you wish to try a new activity, it’s probably best

to check with a health professional first

General Physical Activity Advice

• Remember you may have good & bad days• Avoid sudden bursts of intense activity • Always start & end your exercise at a lower pace• Take care when exercising in extremes of temperature,

or windy weather• Avoid exercising directly after a large meal

General Physical Activity Advice

• Rest if you have a sore throat, cold, flu, infection / temperature, or if your heart failure suddenly worsened

• Restart your programme at an easier pace• If you experience severe chest pain, undue shortness of

breath, palpitations, nausea, dizziness, or excessive tiredness during exercise, do not continue - speak to your GP or nurse about this!

Swimming

• Head-up immersion & hydrostatically-induced volume shift

LV volume loading & heart volume• Physiological effects for easy paced swimming =

intense cycling• 2001 guidelines state that patients should refrain• More recent advice: compensated patients can swim • Swim if they are stable & are used to swimming -

highlight that abilities may be reduced in water (build up gradually)

Thank You

Any Questions?

References &Bibliography

ACPICR (2006) Standards for the Exercise Component of Phase III CardiacRehabilitation. London: ACPICR

European Society of Cardiology (2001) Recommendations for Exercise Training in Chronic Heart Failure Patients. European Heart Journal 22: 125-135

Coats et al (1990) Effect of Physical Training in Chronic Heart Failure. The Lancet 335: 63-66

National Institute for Clinical Excellence (2003) Chronic Heart Failure. London:Clinical Guideline No. 5

Scottish Intercollegiate Guidelines Network (2002) Cardiac Rehabilitation.Edinburgh: SIGN 57

Pilot Study

A Study Comparing Validity & Reproducibility of the Shuttle Walk Test and 6-minute Walk Test in Chronic Heart Failure

Why?• Inconsistent research examining validity and

reproducibility of the walking tests

• Literature lacks standardisation of methodology• Most studies conducted out with United Kingdom • Studies use small samples, excluding women and elderly

Pilot - Methodologyn=28 participants recruited from Heart Failure Nursing Service

Randomly familiarised with 1 walking test

Treadmill cardio-pulmonary exercise test - STEEP protocol

6 x walking tests (3 x shuttle, 3 x 6 minute walk) - 1 per week

Participants undertake walking test familiarised with first

Comparisons between data

from walking tests & treadmill

Comparisons between data from 3 attempts of each

walking tests

Comparisons between reproducibility of tests

familiarised with - against those not

ANALYSES OF WALKING TESTS’

VALIDITY

ANALYSES OF WALKING TESTS’

REPRODUCIBILITY

ANALYSES OF EFFECTS OF

FAMILIARISATION

Pilot - Sample

Recruitment from Heart Failure Nurse Liaison Service

Inclusion Criteria:• Diagnosis of LVSD by echo• Sufficiently clinically stable for exercise• Willing to participate

Exclusion Criteria:• Other life threatening illness• Unable to participate due to major cognitive impairment

Progress so far…..

• Recruitment slow!• Patients need to be optimised on medication• Problems with treadmill testing criteria - LBBB• Patients reluctant to enrol in “serial testing”, reluctant

to travel, reluctant to attend after 4.30pm• Recruitment extended to include those attending

Cardiology clinics & attending for echo

Data on 7 patients collated to date!

Hope++ to complete by Spring 2007