Perioperative Cardiac Evaluation and Management

Extent of investigation and management plan depends on urgency of the surgery. Key timing thresholds:

Preoperative Management

Involves:

Risk Stratification

  • Patients ⩾45 years of age, or 18-44 with known significant cardiac disease are most likely to benefit from thorough pre-operative risk assessment
  • Patients with a perioperative MACE rate of <1% are considered low risk
    Do not require perioperative evaluation.

Pre-operatively:

  • All patients should have cardiac risk assessed
  • Assess functional capacity with the Duke Activity Status Index (DASI)
    Useful thresholds:
    • Personal ADLs
      1 MET.
    • Walk up a flight of stairs or on level ground at 6km/hr
      4 METS.
    • Do heavy housework or two flights of stairs
      4-10 METS.
    • Strenuous sports
      ⩾10 METS.
  • Can be performed using either:
    • Revised Cardiac Risk Index (RCRI)
      • Evaluates six major risk factors:
        • High risk surgery
        • IHD
          Evidenced by MI, positive stress test, ischaemic CP, nitrate use, ECG with Q waves.
        • Cardiac failure
        • Cerebrovascular disease
        • DM on insulin
        • Cr ⩾177μmol/L
      • Calculates risk of:
        • Cardiac death, MI, cardiac arrest:
          • 0 risk factors: 0.4%
          • 1 risk factor: 1%
          • 2 risk factors: 2.4%
          • ⩾3 risk factors: 5.4%
        • Rate of MI, pulmonary oedema, VF, cardiac arrest, CHB:
          • 0 risk factors: 0.5%
          • 1 risk factor: 1.3%
          • 2 risk factors: 3.6%
          • ⩾3 risk factors: 9.1%
    • National Surgical Quality Improvement Program (NSQIP)
      RCRI preferred.
  • Dividing patients into:
    • Low risk
      ⩽1% chance of perioperative MI or death.
    • High risk
      Consider:
      • Investigations
        Echocardiography, stress testing.
      • Cardiology consultation
      • Perioperative troponin monitoring
        Pre-operatively, as well as 24 and 72 hours post-operatively.

Other predictors:

  • Heart failure
    Correlates with poor outcome, even if well managed.

Investigations:

BNP/
* Independently associated with death and nonfatal MI at 30 days after non-cardiac surgery
* BNP >92mg/L or NT-proBNP >300ng/L
22% vs 4.9%.

ECG:

  • Preoperative resting ECG reasonable for patients undergoing other than low-risk surgery:
    • CAD
    • Murmur
    • Arrhythmia
    • Peripheral arterial disease
    • Cerebrovascular disease
    • Structural heart disease
  • Should be performed within 3 months for stable patients

Echocardiography: > * LVEF <30% is an independent contributor to perioperative morbidity > * Routine assessment is not recommended

  • Reasonable in dyspnoea of unknown origin
  • Reasonable in known cardiac failure and:
    • Worsening dyspnoea or change in clinical status
    • Consider if no assessment of LV function in previous 12 months
  • New murmur and any cardiac symptom
    e.g. Breathlessness, presyncope, syncope, chest pain.
  • Valvular disease
    Moderate or greater stenosis or regurgitation and:
    • Significant change in clinical status or exam findings
    • No echo within the last 1 year

Stress testing:

  • Routine noninvasive stress testing is not useful
  • Patients with >10 METS do not require further exercise testing
  • Reasonable to perform pharmacological stress testing in patients at elevated risk and who have <4 METS functional capacity and it would change management
    e.g. Preoperative coronary revascularisation, medical management, or a change in surgical approach.

Angiography:

  • Routine perioperative angiography is not recommended

Management of Specific Conditions

Cardiac diseases influencing perioperative management include:

  • IHD/
  • Cardiac failure
  • Valvular disease
  • Arrhythmias

CAD/IHD

Management of antiplatelet agents in stents is covered under antiplatelets in coronary artery stents.

Previous MI:

  • ⩾60 days should elapse after MI before non-cardiac surgery performed, in absence of coronary intervention, in order to reduce MACE risk
  • MI within 6 months is an independent risk factor for perioperative stroke
    8× ↑ in mortality.

Revascularisation:

  • Revascularisation is only recommended if indicated by other existing guidelines
    • CABGs should be performed before elective surgery if otherwise indicated
    • PCI should be limited to:
      • Left main disease not amenable to CABG
      • STEMI or NSTEACS
        BMS recommended in urgent or time-sensitive surgery.
    • Timing relating to operation:
  • No difference in long-term outcome with revascularisation unless:
    • Left main disease
    • LVEF <20%
    • Severe AS

Cardiac Failure

Heart failure is:

  • Prevalent and ↑
  • A significant perioperative risk factor
    • Active heart failure greater risk than CAD for perioperative morbidity and mortality
    • Outcomes improved for patients with stable symptoms/controlled failure

Valvular Heart Disease

  • Valvular intervention is recommended for patients who meet criteria prior to elective surgery
  • Elevated risk elective noncardiac surgery is reasonable to perform with appropriate intraoperative and postoperative haemodynamic monitoring in patients with :
    • Asymptomatic severe AS
    • Asymptomatic severe MS if not favourable for percutaneous commissurotomy
    • Asymptomatic severe MR
    • Asymptomatic severe AR with a normal LVEF

Arrhythmias

Management of anticoagulation for AF is covered elsewhere.

Heart Block:

  • High-grade cardiac conduction abnormalities may require temporary or permanent transvenous pacing
  • Interventricular conduction delay without high-grade conduction block or symptoms does not require evaluation, but should be taken into account when considering beta blockade

Ventricular Arrhythmias:

  • Asymptomatic ventricular arrhythmias are not associated with an ↑ in cardiac complications
    Don’t require evaluation unless:
    • Associated with structural abnormality
    • Symptomatic
  • Frequent ventricular ectopics are a risk factor for arrhythmia but not MI or death
  • VT should be evaluated by a cardiologist
    • LV function
    • CAD
  • Intraoperative VT or NSVT should prompt cardiology referral

Post-Operative

Myocardial Injury After Noncardiac Surgery

MINS is:

  • Defined as elevated cardiac troponin ⩾99th percentile
  • Likely a supply-demand mismatch in the majority of cases
  • Complicates 8-19% of non-cardiac surgery
    • 40% of these are true MI
  • Associated with significant ↑ in short and long-term perioperative mortality
    22.5% vs 9.3%.

Screening:

  • Should be performed in high risk patients
    Defined as:
    • RCRI >1%
    • Elevated BNP/
    • Age 45-64 with significant VBS disease
    • Age >75
  • Pre-operatively: Troponin and ECG
  • Repeat ECG in PACU
  • Repeat high-sensitivity troponin at 6-12 hours, and on days 1-3

Management of myocardial injury without MI:

  • Aspirin
  • Statin
  • Consideration of beta-blockade

References

  1. Duceppe E, Parlow J, MacDonald P, Lyons K, McMullen M, Srinathan S, et al. Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery. Canadian Journal of Cardiology. 2017 Jan 1;33(1):17–32.
  2. Wijeysundera DN, Pearse RM, Shulman MA, Abbott TEF, Torres E, Ambosta A, et al. Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study. The Lancet. 2018 Jun;391(10140):2631–40.
  3. Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery. Circulation. December 2014. https://www.ahajournals.org/doi/abs/10.1161/CIR.0000000000000106. Accessed December 29, 2019.