2016 ACC AUC for Coronary Revascularization in ACS

AUC Rating System

The Appropriate Use Criteria (AUC) score ranges from 1 to 9 and categorizes revascularization strategies in ACS:

Score Range	Category	Meaning
7–9	Appropriate	Strong recommendation; benefits generally outweigh risks. Procedure is generally reasonable and acceptable.
4–6	May Be Appropriate	Moderate recommendation; benefits and risks balanced or uncertain. Procedure may be acceptable depending on clinical judgment and patient preferences.
1–3	Rarely Appropriate	Weak recommendation; risks likely outweigh benefits. Procedure is not generally acceptable; alternative strategies preferred.

Key Point: The AUC framework evaluates specific clinical scenarios, not individual patients. Clinical judgment and patient preferences should inform final treatment decisions, even when scenarios are rated as "May Be Appropriate" or "Rarely Appropriate."

Risk Assessment in ACS

Risk stratification guides urgency and intensity of revascularization. Calculate 10-year cardiac mortality risk using standardized scores:

High-Risk Features (NSTEMI/Unstable Angina)

At least 1 of the following indicates high risk for short-term death or nonfatal MI:

Clinical instability: History-accelerating tempo of anginal symptoms in preceding 48 hours, or rest angina
Pulmonary edema: Most likely due to ischemia
New/worsening MR murmur
Hemodynamic changes: SBP <90 mmHg, new cardiogenic shock
Age >75 years
ECG findings: ST-segment deviation >0.5 mm, bundle-branch block (new or presumed new), sustained ventricular tachycardia
Elevated cardiac markers: Troponin or elevated CK-MB

TIMI Risk Score for ACS

Use the TIMI Risk Score to quantify risk. Variables (1 point each): age ≥65, ≥3 CAD risk factors, known CAD, aspirin use in past 7 days, severe angina (≥2 episodes in 24 hours), ST-segment deviation, elevated cardiac markers.

TIMI Risk Groups:

Low-risk (0–2 points): <1% per-year cardiac mortality
Intermediate-risk (3–4 points): 1–3% per-year mortality
High-risk (5–7 points): >3% per-year mortality

GRACE ACS Risk Calculator

For prognostic risk assessment, use the GRACE ACS risk score to estimate in-hospital mortality and 6-month outcomes. Incorporates age, heart rate, SBP, Killip class, creatinine, cardiac biomarkers, and ST-segment changes.

STEMI: Immediate Revascularization by PCI

For STEMI patients presenting within 12 hours of symptom onset or up to 24 hours with ongoing ischemia:

Clinical Scenario	Revascularization of Presumed Culprit Artery by PCI	AUC Score
Primary PCI (Culprit Only)
≤12 hours from symptom onset	Perform primary PCI for all STEMI patients	9
12–24 hours from symptom onset with persistent ischemic symptoms or hemodynamic/electrical instability	Perform primary PCI	8
12–24 hours from symptom onset, stable without ischemic symptoms or hemodynamic/electrical instability	PCI may be considered but is not mandatory	6
Cardiogenic Shock
Shock persisting after PCI of presumed culprit artery; PCI of 1+ additional vessels	PCI of additional vessels may be appropriate	8
Stable patient immediately following PCI of culprit; one or more additional severe stenoses	Staged PCI of additional severe lesions may be appropriate	6
Stable patient immediately following PCI; one or more additional intermediate (50–70%) stenoses	Staged PCI of additional intermediate stenoses may be appropriate	4

Door-to-Balloon Time: Primary PCI is the preferred reperfusion strategy for STEMI when performed within 120 minutes of first medical contact. If door-to-balloon time exceeds 120 minutes AND transfer delay is prolonged, consider fibrinolytic therapy with rescue PCI.

STEMI: Initial Treatment by Fibrinolytic Therapy

Fibrinolytic therapy is appropriate when primary PCI is not available or when door-to-balloon time will exceed 120 minutes from first medical contact:

Clinical Scenario	PCI of Presumed Culprit Artery After Fibrinolysis	AUC Score
Evidence of failed reperfusion after fibrinolysis (e.g., failure of ST-segment resolution, acute HF, myocardial ischemia, or unstable arrhythmias)	Perform rescue PCI (urgent catheterization)	9
Stable after fibrinolysis AND asymptomatic (no HF, ischemia, or arrhythmias) AND PCI performed 3–24 hours after fibrinolytic therapy	Perform PCI as part of routine post-fibrinolytic strategy	7
Stable after fibrinolysis AND asymptomatic (no HF, ischemia, or arrhythmias) AND PCI >24 hours after onset of STEMI	PCI may be considered for conservative management of stable patients after fibrinolysis	5

Timing of PCI After Fibrinolysis: Routine invasive strategy (early cardiac catheterization with intent to perform PCI on infarct-related artery) is appropriate 3–24 hours after successful fibrinolysis. This allows assessment of reperfusion adequacy and identification of residual stenosis requiring intervention.

STEMI: Revascularization of Nonculprit Artery

Management of additional significant stenoses in nonculprit vessels during STEMI hospitalization:

Clinical Scenario	Successful Treatment of Culprit Artery	AUC Score
Nonculprit Vessels
Asymptomatic; findings of ischemia on noninvasive testing; one or more additional severe stenoses	PCI of additional severe nonculprit vessels is appropriate during acute MI	8
Asymptomatic (no additional testing performed); one or more additional severe stenoses	PCI of additional severe nonculprit vessels may be appropriate during acute MI	7
Asymptomatic (no additional testing); one or more additional intermediate (50–70%) stenoses	PCI of additional intermediate stenoses may be appropriate during acute MI	6
Asymptomatic; one or more intermediate (50–70%) stenoses; FFR ≤0.80	PCI of additional intermediate stenoses with abnormal FFR is appropriate during acute MI	7

Key Studies: Multivessel STEMI Treatment Strategies

PRAMI (2015): Immediate multivessel PCI in STEMI was superior to culprit-only PCI (primary endpoint: death, reinfarction, or ischemia-driven revascularization at 12 months)
CVLPRIT (2015): Complete revascularization (culprit + nonculprit) within 48 hours improved outcomes vs. culprit-only in multivessel STEMI
DANAMI3-PRIMULTI (2015): Staged multivessel PCI (nonculprit lesion treatment deferred >3 days) reduced major adverse events in high-risk patients

Pitfall: Do not routinely treat all nonculprit stenoses during primary PCI in hemodynamically unstable patients. Prioritize culprit vessel revascularization and hemodynamic stabilization first; defer staged revascularization when feasible.

NSTEMI/Unstable Angina: Revascularization Strategy

Management of ACS without ST-segment elevation varies based on clinical risk and ischemic burden:

Clinical Scenario	Revascularization by PCI or CABG	AUC Score
Early Invasive Strategy
Evidence of cardiogenic shock; immediate revascularization of 1 or more coronary arteries	Early invasive revascularization (PCI or CABG) is appropriate	9
Patient stabilized; intermediate- or high-risk features for clinical events (TIMI score ≥3–4)	Early invasive revascularization (PCI or CABG) is appropriate	7
Patient stabilized after presentation; low-risk features for clinical events (TIMI score ≤2)	Early invasive revascularization may be considered for conservative management of low-risk patients	5
Ischemia-Guided (Conservative) Strategy
Patient stabilized after presentation; low-risk features; no recurrent symptoms or signs of ischemia on testing	Revascularization may be deferred if ischemia-guided approach chosen and no further testing demonstrates ischemia	5

Timing of Invasive Procedure

Immediate (within 2 hours): Cardiogenic shock, hemodynamic instability, electrical instability, mechanical complication
Early (within 24 hours): High-risk features (TIMI ≥3, elevated troponin, ST-segment deviation, recurrent symptoms, hemodynamic/electrical dysfunction)
Routine (within 72 hours): Intermediate-risk features with stable presentation
Selective (if ischemia evident): Low-risk features; proceed with cardiac catheterization only if noninvasive testing shows ischemia

Use the HEART Score for additional chest pain risk stratification in the acute care setting.

Clinical Decision Algorithm

Simplified decision pathway for ACS revascularization:

Step 1: Determine ACS Type

ST-segment elevation (STEMI)? YES = Proceed to STEMI pathway. NO = Proceed to NSTEMI/UA pathway.

Step 2: STEMI Pathway

Within 12 hours of symptom onset OR 12–24 hours with ongoing ischemia: Perform primary PCI of culprit artery. 9

If PCI not available within 120 minutes: Administer fibrinolytic therapy with intent for rescue PCI if reperfusion fails. 7–9

After culprit revascularization—assess for multivessel disease:

Cardiogenic shock or high-risk patient → PCI of severe nonculprit vessels may be appropriate 8
Stable, asymptomatic, severe nonculprit stenosis → Staged PCI may be appropriate 6–7
Intermediate stenoses (50–70%) → PCI may be appropriate if FFR ≤0.80 7

Step 3: NSTEMI/UA Pathway

Cardiogenic shock or hemodynamic instability: Perform immediate (within 2 hours) invasive revascularization. 9

High-risk features (TIMI ≥3, elevated troponin, ST changes, recurrent symptoms): Perform early (within 24 hours) invasive revascularization. 7

Low-risk features (TIMI ≤2, negative biomarkers, no ST changes): May pursue ischemia-guided (selective) strategy with invasive revascularization only if noninvasive testing shows ischemia. 5

For all NSTEMI/UA: Calculate risk using TIMI or GRACE score to guide timing and aggressiveness of invasive strategy.

Clinical Pearls & Special Scenarios

Left Main Coronary Artery Disease

Revascularization Indication: Significant left main stenosis (≥50% diameter narrowing) identified during ACS catheterization is generally an indication for revascularization by PCI or CABG, depending on anatomic complexity (SYNTAX score) and patient factors. CABG is preferred for complex left main disease; PCI acceptable for simple anatomy with stent technology.

Cardiogenic Shock in ACS

Immediate Revascularization: ACS complicated by cardiogenic shock (SBP <90 mmHg despite support, elevated filling pressures, reduced cardiac index) warrants emergent invasive revascularization of the culprit vessel. PCI of additional severe nonculprit vessels may also be appropriate to maximize myocardial salvage and improve hemodynamics. Use mechanical circulatory support (IABP, left ventricular assist devices) as bridging therapies.

Fractional Flow Reserve (FFR) & Nonculprit Stenoses

FFR-Guided Revascularization: For intermediate (50–70% diameter narrowing) nonculprit stenoses identified during ACS catheterization, FFR measurement can guide revascularization decisions. FFR ≤0.80 indicates hemodynamically significant ischemia and warrants PCI. FFR >0.80 suggests deferral of revascularization is safe.

Right Ventricular Infarction (RVI)

Pitfall—Fluid Management: RVI (usually inferior STEMI with RV involvement) requires careful fluid resuscitation. Avoid aggressive diuretics; maintain preload to preserve right ventricular cardiac output. Hemodynamic monitoring (pulmonary artery catheter) may aid management. Perform revascularization of the right coronary artery as per standard STEMI protocol.

Mechanical Complications

Mitral Regurgitation & Ventricular Septal Defects: Acute severe MR or VSP secondary to MI requires urgent revascularization (PCI or CABG) plus surgical repair. Immediate (within 2–4 hours) cardiac catheterization and revascularization are appropriate, often followed by surgical consultation for structural repair.

Stent Thrombosis

Very Late Stent Thrombosis (>1 year post-stent): Acute stent thrombosis presenting as ACS warrants urgent revascularization. If the culprit is a stent, aspirate thrombotic material and restore flow; consider bailout stenting. Treat as an acute ACS event using standard protocols.

Prior Fibrinolytic Therapy

Timing of Catheterization: Patients initially treated with fibrinolytic therapy should undergo early (3–24 hours) cardiac catheterization with intent to perform PCI on the infarct-related artery. This allows assessment of reperfusion adequacy and identification of residual stenosis requiring intervention.

Related Calculators

Use these tools to quantify risk, guide invasive strategy timing, assess prognosis, and inform revascularization decisions in ACS: