What are the Appropriate Use Criteria (AUC) for Echocardiography?

Appropriate Use Criteria for Echocardiography

The Appropriate Use Criteria (AUC) for echocardiography define specific clinical scenarios where echocardiography is considered reasonable based on medical evidence and expert opinion, with the goal of avoiding both under- and over-utilization to improve patient outcomes and healthcare resource allocation. 1

Definition and Purpose

• AUC define patient subgroups where medical evidence and expert opinion are combined to assess whether the benefits of echocardiography outweigh risks in specific clinical situations 1
• The intent is to guide rational use of echocardiography, avoiding both under- and over-utilization, leading to improved outcomes, optimal healthcare delivery, and justifiable healthcare expenditures 1
• AUC serve as educational and quality improvement tools to identify patterns of care and reduce inappropriate testing 2

Rating System

• Clinical scenarios are rated on a scale of 1 to 9 by an independent technical panel 3:
  • Appropriate (A): Score 7-9 - Test is generally acceptable and reasonable approach
  • Uncertain (U): Score 4-6 - Test may be acceptable and may be reasonable approach
  • Inappropriate (I): Score 1-3 - Test is not generally acceptable and not a reasonable approach 3

Key Appropriate Indications for Transthoracic Echocardiography (TTE)

• Initial evaluation of symptoms potentially caused by suspected cardiac etiology 1
• Evaluation after prior testing concerning for heart disease 1
• Evaluation of valvular heart disease 1
• Evaluation of heart failure 1
• Perioperative evaluation in specific scenarios 1
• Assessment for device therapy 1
• Evaluation in specialized care programs (e.g., solid organ transplantation) 1

Key Appropriate Indications for Transesophageal Echocardiography (TEE)

• Evaluation to facilitate clinical decision making regarding anticoagulation, cardioversion, and/or radiofrequency ablation in atrial fibrillation/flutter 1
• Evaluation of cardiovascular source of embolus with no identified noncardiac source 1
• TEE shows higher appropriate use rates (94-97%) compared to TTE, possibly because the operator is more involved in the decision to perform TEE 1

Key Appropriate Indications for Stress Echocardiography

• Evaluation of ischemic equivalent (nonacute) with:
  • Low pretest probability of CAD with uninterpretable ECG or inability to exercise 1
  • Intermediate pretest probability of CAD regardless of ECG interpretability 1
  • High pretest probability of CAD regardless of ECG interpretability 1
• Evaluation of possible acute coronary syndrome with:
  • No ischemic changes on ECG or with LBBB/paced rhythm 1
  • Various combinations of TIMI risk scores and troponin levels 1

Implementation Studies Findings

• Most clinical scenarios (84-89%) for which echocardiograms were ordered could be classified by AUC 1
• For TTE, 87-91% of classifiable studies were appropriate, with 9-13% inappropriate 1
• For TEE, 94-97% of classifiable studies were appropriate 1
• For stress echocardiography, 66-71% of classifiable studies were appropriate 1
• Outpatient settings showed lower appropriate rates (74%) compared to inpatient settings (94.4%) 4
• Studies outside the US showed similar results, with approximately 1 in 10 scans potentially avoidable 4

Common Pitfalls and Caveats

• Higher proportion of unclassified studies in outpatient settings, likely because many original AUC indications specifically address symptoms or "change in clinical status" 1
• Routine testing when there is no change in clinical status or when results are unlikely to modify management is more likely to be inappropriate 3
• The most common inappropriate indication for TTE is "initial evaluation for a murmur/click without symptoms/signs of structural heart disease" 4
• Different specialties show varying rates of appropriate ordering, with cardiac surgeons having the lowest appropriate rate (60%) in some studies 4

Evolution of AUC

• The 2011 AUC document combined and updated the original separate documents for TTE/TEE (2007) and stress echocardiography (2008) 1
• More recent AUC have been developed for multimodality imaging in specific conditions:
  • Congenital heart disease (2020) 2
  • Nonvalvular heart disease (2019) 5
• AUC implementation has helped moderate utilization of echocardiography over the past decade 6

Clinical Impact

• AUC effectively stratify the clinical practice of echocardiography as they predict important echo abnormalities and impact optimal patient care 6
• Application of AUC may help identify true variations in care delivery by supplementing claims data with clinical data 1
• New technologies have demonstrated feasibility of applying AUC at the point of care 6