Exercise-based cardiac rehabilitation in patients with chronic heart failure: a Dutch practice guideline

Rationale To improve the quality of exercise-based cardiac rehabilitation (CR) in patients with chronic heart failure (CHF) a practice guideline from the Dutch Royal Society for Physiotherapy (KNGF) has been developed. Guideline development A systematic literature search was performed to formulate conclusions on the efficacy of exercise-based intervention during all CR phases in patients with CHF. Evidence was graded (1–4) according the Dutch evidence-based guideline development criteria. Clinical and research recommendations Recommendations for exercise-based CR were formulated covering the following topics: mobilisation and treatment of pulmonary symptoms (if necessary) during the clinical phase, aerobic exercise, strength training (inspiratory muscle training and peripheral muscle training) and relaxation therapy during the outpatient CR phase, and adoption and monitoring training after outpatient CR. Applicability and implementation issues This guideline provides the physiotherapist with an evidence-based instrument to assist in clinical decision-making regarding patients with CHF. The implementation of the guideline in clinical practice needs further evaluation. Conclusion This guideline outlines best practice standards for physiotherapists concerning exercise-based CR in CHF patients. Research is needed on strategies to improve monitoring and follow-up of the maintenance of a physical active lifestyle after supervised CR.

deterioration of CHF and prevents recurrence of cardiac events. [3,4] Exercise training, usually conducted by physiotherapists, constitutes an important part of CR aiming to improve exercise capacity and quality of life (QoL) both in the short and long term. The mechanisms underlying these beneficial effects involve improvement of muscle perfusion, muscle metabolism, ventilatory efficiency, neurohormonal regulation and cardiac function [4][5][6].
The exact content of exercise-based CR programs in CHF patients in the Netherlands is not well established. Within Dutch CR centres, there is considerable variation in the methods for determination of exercise intensity training, training intensity and volume. [7] A possible explanation is that guidelines and position statements lack clear practical guidance for physiotherapists. [8][9][10][11][12][13][14] Therefore, a clinical practice guideline on exercise-based CR was developed by the Dutch Royal Society for Physiotherapy (KNGF), describing optimal exercise-based CR, including assessment, treatment and evaluation in CHF patients. This clinical practical guideline and the guideline for exercise-based CR in patients with coronary artery disease [15] can be considered as a supplement to the Dutch Multidisciplinary Guideline for CR [9].

Guideline development process
This guideline has been systematically developed according to the method of Physiotherapy Development in the Netherlands, [16] which is in line with international methods of guideline development [17].
Recommendations for exercise-based CR were, if they existed, based on systematic reviews or meta-analyses, and if available completed with more recent randomised-controlled trials (RCTs) and otherwise based on RCTs only. Methodological quality of RCTs was scored using the physiotherapy evidence database (PEDro) scale. [19] Only studies with a score of more than 5 out of 10 points were included. If there was insufficient scientific evidence, recommendations were based on consensus within the guideline development group (GDG).
The level of evidence was categorised on the basis of Dutch national agreements on evidence grading for guideline development (EBRO/CBO) (Table 1).

Comments, modification and financing
The guideline is written by the GDG, consisting of the following disciplines: physiotherapists representing the KNGF, movement scientists, epidemiologists, a representative of the Dutch multidisciplinary CR guideline committee and a cardiologist representing the CR section of the Dutch Society of Cardiology. An external group, consisting of a clinical exercise physiologist, a physician, and two physiotherapists, reviewed the draft versions of the guideline. The members of the guideline GDG and the external members have declared that they have no conflict of interest. This study was funded by the KNGF.

Clinical and research recommendations
The CR process is divided into the following phases: This guideline focuses mainly on the outpatient CR phase (phase II). Postoperative pulmonary complications (such as obstructive pulmonary diseases) are treated if necessary (as indicated by the pulmonologist or other medical specialist) at the CCU or ICU. Perioperative treatment involves teaching the patient techniques to improve ventilation and to mobilise and cough up sputum (breathing, huffing and coughing techniques) and advising the patient.
The clinical mobilisation should include functional exercises, such as exercises related to activities of daily living (ADL) and walking at an early stage of this phase. Exercise should be discontinued or intensity should be decreased if patients show signs of excessive strain/cardiac overload. The physiotherapist explains the aetiology and/or the treatment (e.g. medication, surgery), ways of coping with CHF and other complaints during daily life (i.e. how to 'respond to the demands of life', and how to recognise signs of excessive strain), and how to gradually increase the intensity of activities at home. Table 2 lists the referral information provided before the mobilisation starts, signs of excessive strain/ cardiac overload and outcome criteria.

Outpatient CR phase (phase II)
Patients with CHF will be referred to the CR team by their cardiologist when they have returned to a stable state (in terms of filling volume, medication use and functional classification) after a clinical admission or after a routine outpatient check-up. The outpatient CR consists of an intake / assessment procedure, a treatment phase and an evaluation, which will be discussed chronologically in the following sections.
Intake / assessment procedure At the start of the outpatient CR phase, all eligible patients should be referred for an intake procedure, carried out by a member of the CR team, in many cases the CR coordinator/ nurse, preferably by using a clinical algorithm for patient needs in CR (Fig. 1) [22].
Based on the results of the assessment procedure, the CR coordinator/nurse, in consultation with the patient, decides what type of care or what interventions are indicated. The patient then goes through a specific assessment for each of the relevant disciplines, after which they start one or more CR programs (Fig. 1.).
If the patient has no contraindications for physical training (Table 3), an additional assessment should be performed by the physiotherapist to define the content of the training program.
The aim of the physiotherapist's assessment is to assess the nature and severity of patients' health problems in relation to their physical functioning (in terms of movements) and to assess the extent to which this can be modified. Fig. 2 shows a flowchart of the assessment procedure.
The assessment focuses on identifying impairments of bodily functions, limitations of activities, restrictions of participation and health problems that may influence the choice of exercise activities to be included in the training program. Limitations of activities may regard their nature, duration and/or quality. The physiotherapist analyses the performance of problematic activities that were identified using the patient-specific complaints instrument. [23] The physiotherapist assesses the quality of the patient's aspects of physical performance (including endurance, strength, speed, agility and coordination) and the degree to which the patient is able to use them. The physical performance during activities perceived as problematical can be scored in terms of duration and intensity, perceived fatigue (Borg Rating of Perceived Exertion (RPE) scale 6-20) [24] and in terms of anxiety, chest pain and dyspnoea (Borg 1-10). If requested by the patient's physician, the physiotherapist can monitor the patient's heart rate and blood pressure during these activities. The modified Shuttle Walk Test (SWT) [25][26][27] is used to determine patients' functional exercise capacity. The MET method and the Specific Activity Scale (SAS) [28] can be used to estimate whether any discrepancy between the actual performance level and the target level can be eliminated with a suitable training program. The physiotherapist measures patients' maximum inspiratory pressure (Pimax) using a Pimax meter. Based on the results of the assessment procedure, rehabilitation goals will be defined.

Treatment phase
The treatment during the outpatient CR phase comprises three modalities: information/advice, a tailored training program and a relaxation program (Fig. 3). The physiotherapist systematically evaluates the rehabilitation goals, during and at the end of the treatment. Typically, the treatment phase should last for a period 8 to 12 weeks in order to obtain the optimal treatment result.

Information / advice
Information and advice must be given in a multidisciplinary context. The physiotherapist offers the patient assistance (guidance, coaching), information and advice, geared towards their personal goals. Patient education about the disorder and the importance of treatment are required to enable the patient to cope effectively with CHF.
Aims of information and advice may include: ADL activities of daily living, CHF chronic heart failure a In some exceptional cases, patients may not have met these goals at the time of discharge from hospital, due to psychosomatic, social or severe physical problems (e.g. comorbidities). These patients may be referred for clinical admission to a specialised multidisciplinary CR centre for more intensive care

Tailored training program
The training program is intended for patients who are: & Referred by a cardiologist and have no contraindications for training (Table 3); & Functionally stable (i.e. no change in NYHA class) and on optimal medication for at least 3 weeks; & NYHA Class II or III; weeks before the start of the training • Atrial fibrillation with rapid ventricular response at rest (>100 bpm) • Serious cognitive problems (memory, attention and concentration) • Weight gain of >3 kg within a few days, whether or not accompanied by increased dyspnoea at rest a Symmetrical functional movements below the patient's pain threshold (with comfortable rather than forceful movements and controlled breathing) can be started within 6 weeks after surgery (which can also help to prevent the development of a frozen shoulder) + The physiotherapist should consult the patient's pulmonologist or cardiologist to decide on the minimum individual saturation value Based on the individual goals, patients' preferences and limitations established during the assessment procedure in combination with results of the maximum or symptomlimited exercise test with respiratory gas analysis and safety criteria (Table 3), a definite training program is composed. It is important to realise that a substantial number of CHF patients do not respond to training in terms of an increase in VO 2 peak [29,30].
The physiotherapist observes the patient's training intensity, individual response, tolerance of the exercise load and their overall clinical status. Also the patient's response during the recovery phase after exercise is monitored. The exercise session must be terminated when safety criteria are exceeded, or if there are any reasons for excessive strain (Table 3).
During the first 2-4 weeks of the training program, the physiotherapist systematically measures the patient's blood pressure and heart rate (and rhythm) before, during and after the training session. This supervised period is extended if any arrhythmias, ischaemia, angina, blood pressure abnormalities or supraventricular or ventricular ectopy occur during exercising. Patients with documented ischaemia or arrhythmias may need to have their cardiac rhythm monitored by ECG, if indicated by their cardiologist. In the case of comorbidities, the GDG recommends starting the training program, based on the exercise principles, relating to the exercise limiting factor, and/ or the most restrictive pathology or disorder. A low-intensity start is recommended in case of doubt.
The tailored training program may comprise practising skills and activities (to enable patients to utilise their general or strength endurance in motor activities), aerobic interval/ endurance training, strength endurance training (inspiratory muscle training and peripheral muscle training), practising functions/activities, and/or (aerobic) training to reduce cardiovascular risk factors (if atherosclerosis is the underlying case of CHF).

Recommendation 2. Aerobic endurance and/or interval training
Aerobic endurance or interval training increases the exercise capacity and QoL in patients with CHF (NYHA Classes II-III) and is therefore recommended. The mechanisms underlying these beneficial effects involve improvement of patients' muscle perfusion, muscle metabolism, breathing efficiency, neurohormonal regulation and cardiac pump function (Level 1) [4][5][6].
It is assumed that high-intensity interval training (HIT) results in a better improvement of left ventricular function than moderate-intensity training (Level 2) [31].
HIT may result in a greater improvement of the aerobic endurance capacity than moderate-intensity training (Level 2) [32].
The research concerning the effectiveness of HIT training is conducted in relatively low-risk CHF patients; therefore the GDG advises to be cautious in patients with a high risk of cardiac overload (Level 4). If HIT is applied, the cardiologist should be informed and safety criteria (Table 3) should be closely adhered to.
Training should be individually directed and functionally geared toward personal goals. If the goal is to improve endurance capacity, aerobic exercise can be gradually increased from 50 to 80 % of VO 2 peak/ heart rate reserve, preceded by warming up and followed by cooling down. HIT can involve interval blocks of 4 times 4 min at 80-90 % of VO 2 peak / heart rate reserve, with active recovery for 3 min at 40-50 % of VO 2 peak / heart rate reserve (as determined by the maximum or symptom-limited exercise test with respiratory Fig. 2 Flowchart of the assessment procedure performed by the physiotherapist gas analysis). During both endurance or interval training and HIT, the program should preferably start with a 2-week introductory period in which the patient trains at an intensity of 40-50 % of VO 2 peak / heart rate reserve. Patients with a VO 2 peak >10.5 mL/kg/min, but <17.5 mL/kg/min (3-5 METs/40-80 W) appear to benefit most from 1 to 2 training sessions a Fig. 3 Flowchart of the physiotherapy process day for 15 min, focusing on aerobic interval training. Patients with a VO 2 peak >17.5 mL/kg/min (≥5 METs / ≥80 W) can limit their training to 2-3 sessions a week, for 20-30 min per training session [9].
If the goal is to improve patients' endurance capacity, training intensity should be based on the results of a maximum or symptom-limited exercise test with respiratory gas analysis (Table 4), preferably on a percentage of VO 2 peak, VO 2 reserve (the difference between the VO 2 max and the VO 2 at rest) or the ventilatory or anaerobic threshold, converted into heart rate (or work rate, Watt). If no respiratory gas analysis has been done, the maximum heart rate attained can be used to calculate the training zone. In both cases, the Karvonen formula is used to calculate the training heart rate as a percentage of the heart rate reserve, added to the resting heart rate. [33] If the patient's heart rate does not rise sufficiently during the maximum or symptom-limited exercise test with respiratory gas analysis, the training intensity should be based on a percentage of the maximum capacity expressed in Power (Watt) or METs, and/or the Borg score (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20).

Recommendation 3. Submaximal strength training
Strength training increases muscle strength and endurance, and is recommended in preparation for, or as an adjunct to, aerobic exercise training for patients with stable CHF (Level 1) [5,34].
This type of exercise training is particularly suitable for patients who experience strength-related limitations in activities of daily living and during social participation. The GDG advises caution with strength training in the CHF patient (research has only been conducted in relatively low-risk CHF patients), especially in patients with a left ventricular function <35 % (Level 4).
Strength training should be functional and directed toward personal goals and individual restrictions in daily life. The strength training starts with a 2-week 'pre-training' period, involving 2-3 series of 10 repetitions against a low resistance estimated at <30 % of 1 repetition maximum (RM). After this pre-training period, the resistance level for strength training can be estimated on the basis of 10 RM. If the goal is to improve the patient's muscle strength, the external resistance can be gradually raised from 40 to 65 % of the 1RM. Training the large muscle groups is recommended, at a frequency of 2-3 times a week, in 10-15 repetitions of 2-3 series.

Recommendation 4. Inspiratory muscle training (IMT)
IMT increases Pimax and reduces the sensation of dyspnoea and is therefore recommended in CHF patients with a Pimax <70 %predicted (Level 2) [35][36][37] or a ventilatory impairment according to the maximum or symptom-limited exercise test with respiratory gas analysis (i.e. insufficient or absent breathing reserve) (Level 4). Table 4 Information to determine training intensity • The patient's current physical condition, based on the maximum or symptom-limited exercise test with gas analysis (spiro-ergometry) • Protocol used • The referring physician's evaluation of the electrocardiogram before, during and after exercise (criteria for cardiac ischaemia, arrhythmias and the practical consequences of the findings) • Heart rate at rest, the maximum heart rate and recovery heart rate (especially during the first minute) • Maximum VO2max and wattage achieved (and the percentage of the predicted value) • Blood pressure changes at rest, during exercise and during the recovery phase • The reason for terminating the test and the level of the impairment (central or peripheral) • Medication use (type and dosage) • The patient's subjective symptoms during the test (angina/ dyspnoea) and his/her Borg score • Spiro-ergometry: gas exchange parameters such as maximum oxygen uptake (VO2max), the percentage of predicted VO2max, O2 pulse, maximum respiratory minute volume (VE) (tidal volume and respiratory rate), respiratory exchange rate, anaerobic or ventilatory threshold, VE/VCO2 ratio, saturation and any other relevant parameters (e.g. VO2 oxygen uptake efficiency slope and the presence of respiratory oscillations) • The maximum voluntary ventilation, which may be derived (37.5× the forced expiratory volume (FEV1)) Table 5 Situations that may prevail in the final evaluation at the conclusion of the CR program a • The patient has attained his/her goals at an optimum level • The patient has partially attained his/her goals, and it seems likely that he/she will be able to continue the training activities elsewhere, under supervision, and thus eventually attain these goals • The patient has not attained his/her goals and it seems likely that he/she has attained their maximum achievable level. Not all patients will improve their endurance capacity and therefore need for example to spread their energy expenditure and to deal with their dyspnoea in a functional way a After the outpatient CR phase, all patients with CHF are referred to aftercare activities (Phase III); in exceptional cases they may be referred to a specialised CR centre for clinical rehabilitation High-intensity IMT may produce better results than lowintensity IMT, however in practice the high load training is not suitable for patients with dyspnoea during low ADL effort (Level 4).
Low-intensity IMT should be performed against a resistance of 20-40 % of Pimax for 30 min/day or 2 times 15 min/ day, on 3-4 days a week, preferably for a period of 8-12 consecutive weeks, and high-intensity IMT against a Patient is familiar with the relaxation program and is able to relax resistance of 60-70 % of Pimax for 4-5 times 5-10 min/day, 3-4 days a week, preferably 10 consecutive weeks, using a threshold device.
A relaxation program in combination with aerobic training is superior to training alone (Level 3) [40].
The CHF patient should attend two sessions to try out the relaxation program. If the program proves beneficial, they attend a further 6-8 sessions lasting 60-90 min each. An important goal of the relaxation program is to teach the patient to calm their mind and to breathe more slowly. In addition, the program may address cognitive themes such as understanding the value of rest, the balance between work and rest, the influence of psychological factors on physical functioning and differentiating between cardiac factors in relation to stress, anger, depression and pressure of time. Instructions for relaxation can be given during exercising (active relaxation) or at rest (passive relaxation), partly in the context of warming up and cooling down, and partly as a separate relaxation program.

Evaluation
In addition to a 'continuous' evaluation over the entire course of the training program, more comprehensive interim evaluations should be carried out at least every 4 weeks, as well as at the end of the CR program. Final evaluation criteria that may prevail are listed in Table 5. Table 6 shows the intended outcomes for the CR goals, the relaxation program and patients' acquired knowledge about CHF and lifestyle, as well as recommendations for assessment and evaluation.
The physiotherapist should report to the multidisciplinary CR team about the treatment process, the treatment outcomes and the recommendations (aftercare). This should happen at least at the end of the treatment, but preferably also during the treatment period. In addition, the physiotherapist informs the patient's cardiologist, family physician and, if applicable, their rehabilitation physician or company doctor.
Post-CR phase (phase III)

Recommendation 6. Continuation of a physically active lifestyle
Patients are recommended to continue exercise, as part of an active lifestyle, for the rest of their lives after the outpatient CR period has ended, at a physiotherapy practice, at a certified exercise facility or independently (Level 1-2) [49][50][51].
Monitoring by secondary care professionals to check if CHF patients maintain their exercise capacity and an active lifestyle in order to identify relapses at an early stage and intervene is advisable (Level 3) [52].
Patients with an indication to attend high-intensity maintenance training (≥60 % VO 2 peak) should be referred to a physiotherapy practice or a certified exercise facility (registered with the Dutch cardiac association), where professional supervision is available. Patients should preferably continue their training activities in a setting that participates in a local network which includes the hospital or rehabilitation centre where the CR program took place, as this implies easy access and frequent contacts. Patients requiring low-or moderateintensity maintenance training (<60 % of VO 2 peak) can choose to do this independently, or at a certified exercise facility. If patients who are advised to attend low-to moderate-intensity maintenance training are deemed likely to soon relapse into an inactive lifestyle, they should be referred to a training program at a primary care physiotherapy practice, under professional supervision.

Applicability and implementation issues
This guideline outlines best practice standards for physiotherapy, in terms of efficacy, efficiency and tailored care, for CHF patients who are eligible for CR. Implementation of the guideline in clinical practice needs further evaluation. [53] Adherence to the guideline needs to be stimulated by, for example, adopting it into a decision supporting system/ flowchart, for example the Dutch clinical algorithm for patient needs in CR [22].
This guideline is the first guideline for physiotherapists that provides practical guidance on how to tailor an exercise training program with respect to intensity and duration individually, using results of a maximum or symptom-limited exercise test with respiratory gas analysis. This guideline and also the guideline for exercise-based CR in patients with coronary artery disease [15] aims to reduce the considerable practice variation which has recently been reported in Dutch CR centres, [7] and thereby, to increase quality of exercise-based CR in the Netherlands [54].
Further research is needed on strategies to improve monitoring and follow-up of the maintenance of a physically active lifestyle after supervised CR; for example by implementing activity monitoring devices combined with telemonitoring, or by web-based coaching platforms to guide patients. [55] Exercise-based CR may also be followed by relatively brief maintenance programs and booster sessions, including behavioural techniques and focusing on incorporating lifestyle changes into daily life, in order to improve long-term adherence to lifestyle modifications. [56] Finally, more research is needed into characteristics and modalities of physical activity and exercise training in CHF in the long term.