2024 Cardiac Algorithm - Step 3

Estimate Perioperative Risk

Two parts to this step now...

(1) Does the patient have low or elevated perioperative risk of major adverse cardiac event (MACE) per a validated risk calculator?

(2) Does the patient have any risk modifiers

Low Calculated Risk, No Modifiers

Non-emergency surgery
No acute coronary syndrome
Low risk for MACE, no modifiers

Proceed to operating room, no further testing necessary. 

Any Calculated Risk, Modifiers Present

Non-emergency surgery
No acute coronary syndrome
Any risk for MACE, risk modifiers present

ACC recommends consideration of appropriate team-based consultation regarding timing of non-cardiac surgery (i.e. whether to delay) and perioperative diagnostic testing and management. This represents an off-ramp or at least a pause to consider the impact and optimization of any modifying risk factor.

ACC also notes recommendations for EKG in patients with CVD or symptoms, and echocardiography when suspecting mod-severe valvular disease, new dyspnea, or suspected new/worsening ventricular function.
The next step considers functional capacity.

The next step considers functional capacity.

Proceed to Step 4, Functional Capacity.

ⓘ risk levels & calculators


The ACC guideline recommends use of a validated tool in order to assess for risk of major adverse cardiac events (MACE) during and after surgery. Such tools include factors about the patient's health as well as factors about the surgery's known risks, in order to come to an overall impression of risk. 

For patients with a low risk of perioperative MACE, and without risk modifiers, no further cardiac evaluation is recommended and surgery may proceed. 

For patients with an elevated risk and/or risk modifiers, further cardiac consideration ensues in Step 4 of the decision tree. 

The ACC guideline offers seven evaluation tool options:

1) The RCRI is simplest and is included here in its entirety owing to its concise nature below. A score of 0 or 1 on the RCRI indicates low risk of MACE. 1 point each for:

  • -
    creatinine ≥ 2.0 mg/dL
  • -
    heart failure
  • -
    insulin dependent diabetes
  • -
    suprainguinal vascular surgery, intrathoracic surgery, or intraabdominal surgery
  • -
    history of stroke or TIA
  • -
    ischemic heart disease

2) The American College of Surgeons NSQIP Surgical Risk Calculator can be found online here:

 ACS NSQIP risk calculator 

3) The American College of Surgeons NSQIP MICA (MI or Cardiac Arrest) calculator can be found as a spreadsheet download or online calculator here:

 ACS MICA calculator 

... and can also be found as the "Gupta [lead author Circulation 2011] Perioperative Cardiac Risk" calculator in the iOS (and Android) multi-calculator app, MDCalc, and web version linked above. 

These first 3 evaluation tools were endorsed in the 2014 ACC guideline. Additional tools now endorsed include (in chronological order): 

  • -
    Goldman Index of Cardiac Risk (1977)
  • -
    Surgical Outcome Risk Tool (2014)
  • -
    NSQIP Geriatric-Sensitive Perioperative Cardiac Risk Index (2017)
  • -
    AUB-HAS2 Cardiovascular Risk Index (2019)

The general goal is determine whether the patient has a risk of >1% for MACE. The ACC points out that there is variation on how each scheme might predict risk of any patient. Schemes include differing endpoints in their derivation studies. Thus the 2024 ACC guideline points out that as of yet data is lacking to recommend one system over another. 

What about cataract surgery? The risk calculators might make a typical cataract surgery patient (e.g. 78 y.o., CAD, CKD, DM) seem to have elevated MACE risk. However, the current guideline points out that some surgeries, ophthalmologic and plastic surgery are named, have very low risk of MACE even for high risk patients. And the previous ACC guideline of 2007 explicitly identified low risk procedures (endoscopic, superficial, cataract, breast, and "ambulatory" procedures) as having less than 1% total cardiovascular morbidity and mortality rates even in high risk patients. Thus there is basis for clinicians to forego further cardiac evaluation steps for cataract patients and the like.

ⓘ more about modifiers

More details on several of the modifiers, especially because this issue is new in the 2024 guideline

Severe valvular disease
- suspected or known severe valvular disease warrants attention prior to non-cardiac surgery, and ACC makes several recommendations
- ACC offers numerous recommendations regarding patients with aortic and mitral valvular disease of both stenosis and regurgitation, and patients who have undergone prior interventions such as transcatheter valve replacement

Severe pulmonary hypertension

Elevated-risk congenital heart disease
- ACC breaks adult congenital heart disease (ACHD) into 3 categories: low, intermediate, and elevated risk. The preop guideline identifies examples of each in long lists.
- ACC recommends that those with intermediate and elevated risk conditions receive specialist evaluation prior to surgery

Prior coronary stents/CABG
- those with CAD and these interventions are on antiplatelet regimens which must be carefully considered
- note that this modifier would send an RCRI patient with but a single point for CAD and intervention onwards for functional capacity evaluation despite an RCRI score < 2, which is new in the 2024 guideline

Recent stroke or TIA
- ACC recommends a delay of non-cardiac surgery of ≥ 3 months after most recent cerebrovascular event (see timing section of app)

Cardiovasc Implantable Electronic Devices
- ACC offers recommendations regarding patients with devices such as pacemakers and ICD's

Frailty
- new topic of discussion in 2024 guideline
- frailty has significant impact on risk and recovery
- ACC identifies several frailty assessment tools which can be used to identify those at risk of adverse outcomes 

Elevated cardiac risk is generally defined as >1% MACE in perioperative period as determined on a validated risk estimation tool.

The risk modifiers, especially the cardiopulmonary ones, can be off-ramps to pause the progress to the operating room. All warrant consideration, some warrant evaluation and optimization.