This patient is presenting for elective orthopaedic surgery with increased risk factors for coronary artery disease.
His risk factors for underlying coronary disease and increased cardiac risk factors are:
- Active smoking
- Hypertension
- Hyperlipidaemia
- Type 2 diabetes
- Lack of physical activity
In addition to identifying pre-existing cardiac disease it is also important to define the severity of the disease, its stability and the need for prior treatment and optimisation. The patient’s medication history would also need to be taken under consideration. Unfortunately, there is no information about this.
In general, my mayor aim for this patient pre operatively would be to assess his peri operative risk factors for major cardiac events and to optimise him as much as possible.
To ensure prudent investigation and management, I would follow the ACC/ACHA perioperative guidelines (1) (Figure 1).
Figure 1: ACC/ACHA perioperative guidelines
Estimate perioperative risk of major adverse cardiac events (MACE) based clinical and surgical risk
In my initial history I would aim to assess signs of major clinical predictors of perioperative risk such as:
- Unstable coronary syndrome
- Decompensated heart failure (2)
- Significant arrhythmias resulting in haemodynamic compromise (3)
- Severe valvular disease (4-6)
I would assess these with interrogations about the following:
- Orthopnoea and dyspnoea on exertion (7)
- Paroxysmal nocturnal dyspnoea (7)
- Chest pain in the past
- Palpitations
- Syncope and fainting
This patient is at elevated risk of suffering from major adverse cardiac events (MACE) due to his history of smoking, hyperlipidaemia, hypertension, diabetes, advanced age and type of surgery.
Patients 62 years of age and over are at a significantly higher risk for perioperative strokes and hospital complications in general (8). A history of previous stroke(s) in this patient would be an additional predictor of MACE peri operatively (9).
Additionally, he is presenting for elective major orthopaedic surgery, which in itself is considered a procedure of moderate risk for perioperative cardiac events (1).
Assessment of functional status
The functional status of a patient is considered a sound predictor of perioperative and long-term cardiac events and is often expressed in terms of metabolic equivalents (METs) (1). METs can be classified from excellent (>10 METS) to poor (<4 METs).
It has been shown that patients with reduced functional status of less than 4 METs before surgery are at an increased risk of complications and vice versa. Examples of activities of more than 4 METs are the ability of climbing a flight of stairs, walking uphill and performing heavy work around the house or garden. Examples of activities of less than 4 METs are slow ballroom dancing, walking slowly, or golfing with a cart.
The functional status of this patient is difficult to impossible to assess by considering a history alone. His exercise capacity is decreased due to severe hip pain. This might mask an underlying decrease in functional capacity and with that an increase of risks of underlying coronary artery disease.
Investigations
Blood tests
- Complete blood count including screening for iron deficiency anaemia
- Biochemical blood test, including electrolytes, liver and renal function. An increase in creatinine is further increasing the risk of perioperative MACEs.
- Blood sugar including HbA1c
- Coagulation capacity
- Group and Hold
Chest X-ray
As and assessment for signs of underlying heart and/or lung disease.
12-lead ECG
The 12 lead ECG has prognostic information relating to short and long term morbidity and mortality in patients with established coronary heart disease. Multiple observational studies have identified that certain electrocardiographic abnormalities including arrhythmias, Q-waves, prolonged QTc interval, left ventricular hypertrophy and bundle brunch blocks have some prognostic significance (10-13).
The implications of abnormalities seem to be correlated to patient age and risk factors for coronary heart disease. This patients ECG would also be assessed for signs of previous ischaemia. Due to his history of diabetes, it might be possible that previous ischaemic events have been silent and gone unnoticed.
Additionally a base line pre-operative ECG might be a useful standard against which to measure changes in the peri operative period (14-15).
ECHO
If the history and examination would raise concerns about structural and functional cardiac abnormalities, then I would order a cardiac ECHO.
Assessments would be needed for:
- Valvular abnormalities
- Systolic and diastolic function
- Signs of heart failure
- Signs of pulmonary hypertension
Findings would not only add to the prognostic risk assessment, but also might have implications on the anaesthetic management, type of anaesthetic chosen and the need for additional monitoring peri operatively.
A left ventricle systolic ejection fraction of less than 35% at rest has been associated with a complication risk peri operatively (1).
Stress test
I would order a pharmacologic stress test, as the functional status of this patient is not assessable due to his decreased exercise tolerance. Results of this test might affect the anaesthetic approach including type of anaesthetic used and additional monitoring during this procedure.
Additionally, I would recommend that this patient has his surgery performed in a hospital, which has the possibilities of appropriate peri operative care including postoperative monitored beds.
Optimisations
- Smoking: I would educate this patient about the increased perioperative risks caused by his smoking habit and would offer advice on strategies to stop it.
- Hypertension: I would assess the patient’s current medications and the control of his blood pressure achieved. Recommendations would be depending on information found. Main advice is to continue anti hypertensive medications in the perioperative period, which would be especially important if treated with beta blockers (1, 16-18).
- Hyperlipidaemia: Perioperative use of statins has been shown to reduce the risk of perioperative MACE significantly (1). If the patient is not already treated with statins, then I would commence their use as part of the perioperative assessment (19-21).
- Type 2 Diabetes: Recommendations on perioperative diabetes management depends on medications and their success used for the treatment. Assessment of long-term sugar levels with HbA1c and optimisation of blood sugar treatment are important to decrease perioperative complications.
Overall, multi disciplinary team management including surgical, anaesthetic, endocrine and cardiology advise would be warranted in this patient.