2024 Cardiac Algorithm - Step 4

Functional Capacity Level

Does the patient have good or better functional capacity defined as a Duke Activity Status Index (DASI) score > 34 or the ability to achieve 4+ METs level of exertion without symptoms?  Choose the patient's functional capacity level:

Satisfactory Functional Capacity

Non-emergency surgery
No acute coronary syndrome
Elevated risk surgery and/or risk modifiers
Excellent, moderate, or good functional capacity (≥4 METs, or DASI >34)

Proceed to operating room, no further testing necessary.

Poor or Unknown Functional Capacity
ⓘ how to evaluate functional capacity

Functional capacity evaluates how vigorous a patient is in their normal life activities. 

Previous ACC guidelines used a scheme of activities associated with "metabolic equivalents" (performance on a treadmill stress-test). That scheme remains below. 

ACC now recommends use of a validated standardized structured tool for functional capacity evaluation, and offers the Duke Activity Status Index (DASI) as a tool with outcomes evidence supporting its use as a discriminatory tool. 

The DASI is presented here as a calculator:

Activity: Can you...

Total Score: 0
Assessment: May need further evaluation (≤4 METs)

This is the other, still acceptable scheme for functional capacity based upon METs.

Poor functional cap (1-3 METs) activities:

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    Take care of self
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    Eat, dress, use toilet
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    Walk indoors around the house
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    Walk a block or two on level ground at 2-3 mph
  • -
    cardiac symptoms with higher levels of activity

Good and better (4+ METs) functional capacity activities: 

  • -
    Do light housework, i.e. dusting or washing dishes
  • -
    Climb a flight of stairs or walk up a hill
  • -
    Walk on level ground at 4 mph
  • -
    Run a short distance
  • -
    Do heavy housework, i.e. scrubbing floors, lifting or moving heavy furniture
  • -
    Moderate recreational activities, i.e. golf, bowling, dancing, doubles tennis
  • -
    Strenuous sport, i.e. swim, singles tennis, basketball, skiing.

The question about functional capacity is used to consider which patients might have underlying coronary artery disease which could become symptomatic if not critical during the physiologic stresses of surgery and recovery.

If patients challenge themselves in their regular lives with housework, recreation, maybe even athletics, and these patients are not held back by cardiac symptoms from these activities, it's like they give themselves unofficial cardiac stress tests on a regular basis and pass their own stress tests. These patients do not need to be evaluated with real stress tests. 

Those who do have cardiac symptoms or who don't exert themselves enough to know whether their hearts handle the challenge, these patients may warrant formal evaluation to rule out coronary artery disease in the next step.

Poor functional capacity can be defined as < 4 METs or as ≤ 34 on the Duke Activity Status Index (DASI).