Percutaneous coronary intervention (PCI)

Percutaneous coronary intervention (PCI) refers to minimally invasive procedures undertaken to restore coronary artery blood flow.  In this procedure, the coronary arteries are accessed via a catheter inserted into either the femoral or radial artery.  Balloon angioplasty is undertaken to dilate the vessel, commonly followed by deployment of coronary stents. 

Most patients can resume physical activity within a few days of their PCI, and cardiac rehabilitation may commence within 2 weeks, unless obvious problems are evident.  

When prescribing exercise to patients following PCI, the following should be considered:

• Underlying cardiac pathology
• Type of PCI and the risk of restenosis
• Any complications associated with the procedure
• Discomfort at rest or on exertion at, or distal to, the site of peripheral artery cannulation
• Presence of angina symptoms at rest or on exertion
• The patient's compliance with anti-platelet medications.

Surgery involving median sternotomy

Procedures such as coronary artery bypass graft (CABG) surgery and open valve surgery are usually performed via surgical division of the sternum (i.e., median sternotomy). This type of surgery involves sternal closure and approximation of the two sternal halves using stainless steel wires, or less commonly, by plates or cables at the completion of the surgical procedure. Only minimal motion of the two sternal halves should be present in the early weeks following this procedure.  Consolidation evident on Xray or ultrasound imaging of the sternum may take anywhere from 4 weeks to 6 months. 

Post-operative complications may include musculoskeletal problems related to the incisional scar such as post-sternotomy pain, thoracic or shoulder pain. In a small but significant number of patients sternal instability and non-union. Thorough assessment and timely management of these post-surgical factors facilitates better patient outcomes and recovery.

Objective testing of exercise capacity may be contraindicated in some patients, such as those presenting with unstable angina and arrhythmia, at this time. It is important to check with the cardiologist or cardiac surgeon on the safety of attempting objective assessment of exercise capacity and consider ECG-monitoring throughout and after the assessment.

Self-paced tests such as the 6-minute walk test (6MWT) and the 6-minute bike test (6MBT) may be preferable than externally paced tests, such as the incremental shuttle walk test (ISWT). Safety of the 6MWT in patients awaiting CABG has not been established and if there are concerns it may be substituted with a 2-minute walk test or a modified 6-minute walk assessment.

Note factors that may reduce exercise capacity such as anaemia, pain, deconditioning, fatigue, cardiac and respiratory function. 

If the patient is haemodynamically stable and there are no other contraindications, sitting out of bed and gentle ambulation should commence within the first 24 hours following surgery. All patients should undertake a progressed walking program throughout the inpatient stay.

ECG monitoring (e.g., via telemetry) is often continued for at least 4 days post procedure to monitor for bradycardia, AF or other changes in heart rhythm which may occur following CABG or combined CABG and valve procedures. Patients with AF, particularly with rapid ventricular response (>100 beats per minute) are at risk of haemodynamic compromise during exercise. Blood pressure should be measured prior to mobilising and the patient monitored for signs of hypotension, dizziness, and fatigue.

Intermittent or continuous peripheral oxygen saturation SpO₂ should be measured during exercise using a portable pulse oximeter. Supplemental oxygen should be strongly considered during exercise if resting oxygen saturation is below 92%, or if the SpO₂ drops by 5% or more during exercise. Note that accurate measures of SpO₂ may be difficult in patients with AF. Almost all patients experience respiratory dysfunction to varying degrees after cardiac surgery. Supplemental oxygen will often be needed during exercise in the first 48 to 72 hours.

Other considerations include the following:

• Instruct patients to "Keep Your Move in the Tube" See Resuming functional activity following median sternotomy surgery
• Walking aids can be used safely to progress mobilisation if warranted.  Patients should be encouraged to use equal and even pressure through both arms. A single walking stick can also be used for support if care is taken not to weight bear predominantly through one side.
• Some patients may be able to commence moderate intensity exercise using large muscle groups (such as walking or cycling) during the inpatient stay. Supervised moderate intensity walking (RPE 11-12 on the 6-20 scale) has been shown to be safe and effective for improving functional capacity and distance walked at hospital discharge.  Stationary cycling may provide an alternative for those unable to walk without an aid, provided the patient can mount and sit comfortably. Stationary bikes also allow ease of telemetry and blood pressure monitoring.
• Upper limb and thoracic (trunk) exercises has been reported to reduce post-sternotomy pain. For specific recommendations on thoracic and upper limb exercises that can be commenced during the acute post-operative phase and in the weeks following hospital discharge, see section on Prevention of musculoskeletal complications

“Keep Your Move in the Tube” is a simple framework that guides patients to move safely following median sternotomy surgery. The concept encourages short lever arms during load-bearing upper limb movements to facilitate safe bed mobility, transfers, and activities of daily living during the recovery period. As demonstrated in the figure below, the green tube represents favourable movements whilst unfavourable movements are demonstrated by the red tube.

By moving within the green tube, there is minimal movement at the sternal bone edges so no other precautions or restrictions are needed.  Ideally this method should be taught and practiced pre-operatively.

Keep Your Move in the Tube

Image to follow

Reproduced with permission from Bayler Scott & White Health, USA

Following surgery, movement of the cervical and thoracic spine and shoulders may be reduced in the early post-operative phase. Range of motion should be assessed before surgery, during the inpatient stay and throughout the post-discharge phases of rehabilitation.

In addition to a walking program, patients should commence thoracic, neck and upper limb exercises whilst in hospital, with the aim to i) restore range of movement, ii) reduce pain and iii) prevent deconditioning in the first 3-4 weeks following surgery.  In some patients, additional therapies such as joint mobilisations, trigger point massage, ice and heat, may be required to manage symptoms. These may be initiated during the hospital admission and continued throughout the cardiac rehabilitation phase. At times patient may require referral to outpatient or private practice physiotherapy beyond discharge from hospital to assess and manage their specific musculoskeletal problems.

Refer to Exercises following cardiac surgery for examples of specific neck and chest wall exercises that may be commenced following surgery involving median sternotomy. Patients should be encouraged to use the principles of “Keep Your Move in the Tube”, when performing these exercises.

Sternal instability results from infection and /or disruption of the wires connecting the surgically divided sternum resulting in separation, pain and excessive motion of the sternal edges. Factors that significantly increase the risk of sternal infection or instability in patients following median sternotomy include: female gender with large breasts, diabetes mellitus, obesity, bilateral internal mammary artery harvesting, reoperation procedures, increased blood product requirement and excessive coughing.

Sternal instability is often reported by patients as a clicking, clunking or increased movement of the sternum that results in pain and discomfort with activities of daily living (ADL) such as reaching, rolling over in bed and getting up out of a chair. The clinical sequence of sternal instability is illustrated below. As sternal non-union may lead to mediastinitis or deep sternal wound infection, early detection and management are essential.

Sternal stability assessment

The diagnosis of sternal instability can be reliably made by Real-Time Ultrasound Imaging, or physical assessment of the sternum employing the Sternal Instability Scale (SIS).

As part of the assessment process, clinicians should ask patients about the following:

• Pain quality and location– intermittent/constant, dull/sharp, hot/cold, deep/superficial
• Feelings of instability or excessive motion – e.g., patient reports that their chest 'feels like it is going fall open'
• Sounds – ‘clicking’, ‘clunking’
• Activities that provoke symptoms (‘unstable feeling’, pain, clicking or crepitus)
• State of the wound or scar including the colour, sensitivity to temperature, discharge (serous or coloured), hypersensitivity, and presence of keloid scarring or adhesions

Modified Sternal Instability Scale (SIS)

The Modified Sternal Instability Scale (SIS), (see table below), is a reliable scale for physical assessment of the sternum for stability. This scale prompts health professional to assess and grade sternal instability to ensure consistent in reporting of this complication and to prompt timely referral and management to the cardiac surgeon if warranted.

Assessment procedure:

The upper and lower regions of the sternum should be assessed separately as the lower sternum is often more unstable than the upper region.  Palpate between the sternal halves using the 2nd, 3rd and 4th digits (as shown in the figure below) during:

• Shoulder flexion (unilaterally and/or bilaterally)
• Trunk lateral flexion and/or rotation
• Coughing and deep inspiration/expiration

Select the grade that corresponds with the findings of the physical examination.  If the SIS grade is 2 or 3, notify the medical practitioner to ensure timely medical management if required (e.g., surgical re-wiring).

It is recommended that the sternum be assessed i) 3 to 5 days post-cardiac surgery, ii) at the commencement of cardiac rehabilitation (3 to 6 weeks post surgery) and iii) prior to commencing exercise involving upper limb advanced stretches and weights or pulleys (unilateral). Patients diagnosed with sternal instability will need monitoring every 3 to 4 weeks.

Figure: Physical assessment of sternal instability

Management of Sternal Instability

For those with established sternal instability, a return to theatre for surgical re-wiring is often necessary. At times, this option is not available if bone quality is poor or confounding risk factors for re-operation exist.

Patients with sternal instability should continue to follow the “Keep Your Move in the Tube” method to ensure safe performance of transfers and daily tasks.

A medication review may be necessary for those with a dry, non-productive cough secondary to medications (e.g., ACE inhibitors) to minimise risk of sternal instability.

In some instances, external bracing, such as the “Qualibreath” (see figure below), may be recommended to:  

• Provide an interim measure prior to surgical repair
• Minimise symptoms of pain
• Prevent the progression of a minimally unstable sternum

All women should be encouraged to wear a supportive bra, with wide straps and no underwire, early in the post-operative period to ensure support for their breasts and to minimise undue stress on the healing sternum and associated wound. Whilst many women use a standard firm fitting sports bra, commercial options which are specifically designed for this purpose, are available.  An example of this is the “Qualibra” (shown below).

"Qualibreath" below

"Qualibra" below

Reproduced with permission from HjorthHealth Pty Ltd, 2012

The table below summarises recommended management approaches for patients with sternal instability.

Cardiac rehabilitation, where available, should be recommended to patients following cardiac surgery, with exercise training prescribed using the principles of “Keep Your Move in the Tube.” Patients should be encouraged to participate in individually prescribed and progressed, moderate intensity endurance training, aiming for an intensity of 13 -14 on the 6-20 RPE scale.

Early resistance training is safe for patients following median sternotomy, and results in no increase in pain, adverse events or sternal complications. Early resistance training also appears to enhance cognitive recovery in these patients [#pengelly-j-royse-c-williams-g-et-al]. This is important because 40% of patients who present for cardiac surgery have mild cognitive impairment and are more susceptible to further decline and progression to dementia compared to the general population.

Following implantation of an implantable cardioverter defibrillator (ICD) or permanent pacemaker PPM), patients are encouraged to avoid elevating the arm above shoulder level for a period of time to prevent lead dislodgement. This time frame may vary depending on the cardiologist so clinicians should abide by their local protocols. Limited evidence is available regarding resistance training following device implantation.  However, overhead loaded activities such as shoulder presses, should generally be avoided to reduce the risk of “subclavian crush” (due to narrowing of the space between the clavicle and first rib), and ultimately lead fracture.

Patients with ICDs are at risk of receiving inappropriate shocks during exercise if the HR increases to the zone at which therapies are programmed. Therefore, exercise should be planned to maintain the HR at least 10-15 beats per minute below the threshold. Contact sports must be avoided; it is particularly important to remind young people of this.

Ventricular assist devices (VADs) are implanted to increase circulating blood flow for patients with very poor cardiac function. In Australia, VADs are used as a bridge to transplant and occasionally for destination therapy.  Exercise prescription for these patients is highly specialised and clinicians should have a thorough understanding of the physiology imposed by different devices, and the patient’s response to exercise Most VADs rely on adequate preload thus requiring patients to be well hydrated. Blood pressure is generally measured by doppler and should be within a defined range, determined by the medical team, to safely exercise.

Whilst VAD hardware (controllers, batteries, drive lines) may restrict certain activities, most activities can be modified to accommodate these. The exercise specialist should be familiar with the VAD alarm systems and their implications for exercise training, and should know what do in any given alarm situation. VAD parameters should generally be recorded before and after each exercise session. The medical team/VAD coordinator should be made aware of any alarms that are triggered during the exercise session and these should also be documented. In some circumstances, the VAD settings may require alteration, necessitating close liaison with the medical team/VAD coordinator. Patients with a VAD cannot swim for exercise.

Exercise training is essential to optimise functional ability and fitness prior to transplant surgery, and to accelerate recovery in the post-operative phase. The pre-transplant phase may require shorter duration activities and greater rest periods, as per guidelines for exercise in heart failure. Exercise training, particularly for the quadriceps muscle, also helps offset the effects of immunosuppressive medication (muscle atrophy, bone demineralisation, increased adiposity) and assists return to routine life following transplantation.

Exercise should be prescribed and progressed according to altered physiology (e.g. cardiac denervation), individual circumstances and clinical presentation (e.g. post-surgical complications, episodes of cardiac transplant rejection and infection risk) to enhance continued and prolonged adherence to exercise.