FRCA Notes

Cardiovascular Risk Assessment

The curriculum asks us to describe 'methods of risk assessment and stratification relevant to the provision of perioperative care '.

Resources

  • Multiple cardiovascular risk factors are present in 45% of surgical inpatients ≥45yrs old
  • Perioperative cardiovascular complications are a major source of mortality (0.5 - 1.5%), morbidity and are associated with prolonged inpatient stay and higher healthcare costs
  • The proportion of surgical inpatients with elevated cardiovascular risk is increasing; nearly 8% have a RCRI ≥3
  • The aim of risk assessment is to identify those having non-cardiac surgery at risk of major adverse cardiovascular events (MACE); non-fatal MI, stroke and cardiac death
  • Multiple perioperative physiological changes increase cardiovascular risk:
    • The surgical stress response increases myocardial oxygen demand via sympathetic activation
    • Haemodynamic stresses intra- and post-operatively directly increase risk, and further compromise myocardial oxygen demand/supply balance
    • Altered coagulation profile
    • Inter-compartmental fluid shifts
  • Other events in the perioperative period can also impact on risk of cardiovascular events:
    • Interruption of regular medications
    • Use of sympathomimetic or anti-cholinergic drugs

  • The initial Goldman risk criteria were proposed by Goldman et al. in 1977
  • They were subsequently modified in 1986 and then again in 1999, resulting in the (Lee) Revised Cardiac Risk Index criteria

Revised (Lee) Cardiac Risk Index

  • The index is composed of six items, the presence of which gains one point
  • The sum total of points corresponds to the risk of perioperative cardiac events occurring; MI, pulmonary oedema, VF/cardiac arrest and complete heart block
  • High risk surgical procedures include intraperitoneal, supra-inguinal vascular or intrathoracic procedures
Item
High-risk surgical procedure
History of ischaemic heart disease
History of cerebrovascular disease
History of congestive cardiac failure
Diabetes mellitus requiring insulin
Pre-operative creatinine ≥177μmol/L

Score Lee Class Risk of perioperative MACE
0 1 0.4%
1 2 0.9%
2 3 6.6%
≥3 4 11%

Benefits Limitations
Quick Data from a single hospital undergoing non-emergent operations
Simple Not generalisable to lower risk populations undergoing minor procedures
Non-invasive Not generalisable to higher risk populations undergoing emergency surgery
Data may be out-of-date with respect to current practice


  1. Does the patient have known cardiovascular risk factors, symptoms suggestive of cardiac disease or diagnosed cardiovascular disease?
    • If no, proceed to surgery

  2. Is the patient undergoing emergency surgery?
    • If yes, proceed to surgery
    • Manage as per recommendations for cardiac patient undergoing non-cardiac surgery

  3. Does the patient have acute cardiovascular disease e.g. acute coronary syndrome, unstable arrhythmia or decompensated heart failure?
    • If yes, manage the acute condition, including cardiology team input
    • Options include deferring surgery, opting for less- or non-invasive interventional techniques, or cancelling surgery

  4. Estimate perioperative risk
    • Use risk assessment tools e.g. RCRI, ACS-NSQIP
    • Risk modifiers not necessarily captured by risk assessment tools:

    Risk modifiers
    Valvular heart disease
    Pulmonary hypertension
    Cardiac device
    Frailty
    History of congenital cardiac disease

  5. Risk-stratify according to results:
    1. No risk modifiers and low risk → proceed with surgery
    2. No risk modifiers but elevated risk → perform ECG + proceed to functional capacity assessment
    3. Risk modifiers present and elevated (any) risk
      • 12-lead ECG
      • TTE
      • MDT discussion regarding timing of surgery vs. further perioperative investigation/management
      • Proceed to functional capacity assessment
    4. In cases where elevated cardiovascular risk is established, refer to GP for long-term cardiovascular risk reduction strategies

  6. Assess functional capacity
    1. DASI >34, METs >4 or reassuring CPET → proceed with surgery
    2. DASI <34, METs <4 or concerning CPET but further optimisation not possible or won't influence perioperative care:
      • Consider proceeding to surgery
      • Explore alternative options e.g. deferring surgery, opting for less- or non-invasive interventional techniques, or cancelling surgery
    3. DASI <34, METs <4 or concerning CPET → proceed to biomarker risk assessment with NT-pro-BNP and Troponin

  7. Are biomarkers normal?
    • If yes, proceed to surgery
    • If no:
  • If further investigations yield low risk then consider proceeding to surgery
  • If further investigations demonstrate higher risk then consider alternative options e.g. deferring surgery, opting for less- or non-invasive interventional techniques, or cancelling surgery