Appropriate Use of Echocardiography

Introduction

Echocardiography is an important tool in the diagnosis and management of cardiovascular disease. The detailed cardiac structural and functional information that echocardiography provides, coupled with its portability and lack of ionizing radiation, has established this imaging modality as a critical tool in the care of patients with known or suspected cardiovascular disease. However, there has been concern in recent years regarding the rapid growth of echocardiography utilization, which was estimated at 6%–8% per year in the early 2000s. Although the widespread use of echocardiography has been in keeping with the overall growth in cardiac imaging services, geographic variation and concerns regarding appropriate use have helped stimulate a drive for improved utilization of clinical echocardiography services.

Development of Appropriate use Criteria

The American College of Cardiology Foundation (ACCF), along with other subspecialty societies, developed Appropriate Use Criteria (AUC) in an effort to promote more effective utilization of diagnostic testing and procedures in cardiovascular medicine, and echocardiography has been a focus of the AUC. The AUC were developed primarily out of concern regarding an increase in the use of noninvasive cardiac imaging services and Medicare spending between 1995 and 2006, and the ACCF published its first AUC document in 2005. AUC are distinct from clinical practice guidelines, as guidelines are intended to inform clinicians when a diagnostic test or procedure should or should not be performed. In contrast, AUC delineate clinical scenarios in which ordering a test or procedure may be considered appropriate or less appropriate.

Initial AUC for transthoracic (TTE) and transesophageal (TEE) echocardiography were published in 2007 and stress echocardiography (SE) AUC were released in 2008. The AUC are based on a number of common clinical scenarios in which echocardiography is most often used. Revised and updated AUC covering adult TTE, TEE, and SE were published in 2011; however, this document does not address the use of perioperative TEE. AUC for initial outpatient pediatric echocardiography were published in 2014. The 2011 revised AUC for adult echocardiography incorporated data and recommendations provided by interval clinical data and standards documents published after the release of the initial AUC in 2007 and 2008. Additionally, the revised AUC clarified areas in which omissions or lack of clarity existed in the original criteria. The approach for the revised 2011 AUC for adult echocardiography was to create five broad types of clinical scenarios regarding the possible use of echocardiography: (1) for initial diagnosis; (2) to guide therapy or management, regardless of symptom status; (3) to evaluate a change in clinical status or cardiac exam; (4) for early follow-up without change in clinical status; and (5) for late follow-up without change in clinical status. Certain specific clinical scenarios were addressed with additional focused indications. The evaluation of heart failure provides an example of the main types of clinical scenarios found in the AUC for TTE ( Fig. 47.1 ).

The scenarios are rated by a panel with a broad array of expertise (i.e., including not only echocardiographers) to evaluate the “appropriateness” of echocardiography in each situation. AUC ratings are created by applying the validated, prospectively based modified RAND (Research and Development) appropriateness method. Briefly, this process involves: (1) the development of a list of clinical indications, assumptions, and definitions by a writing group; (2) a review of indications and feedback from a review panel; and (3) two rounds of indication ratings by a rating panel (first round, no interaction among panel members; second round, panel interaction) and determination of a composite appropriate use score ( Fig. 47.2 ).

An appropriate imaging study is defined as “one in which the expected incremental information, combined with clinical judgment, exceeds the expected negative consequences by a sufficiently wide margin for a specific indication that the procedure is generally considered acceptable care and a reasonable approach for the indication.” Ratings are made on a scale of 1–9, in which a score of 9 indicates highly appropriate use of testing. Using the iterative modified Delphi exercise process describedpreviously, a final rating score is established for each indication, and grouped as A, a score of 7–9, indicating an appropriate test for the specific indication (the test is generally acceptable and is a reasonable approach for the indication); U, a score of 4–6, indicating uncertainty for the specific indication (the test may be generally acceptable and may be a reasonable approach for the indication); and I, a score of 1–3, indicating an inappropriate test for that indication (the test is not generally acceptable and is not a reasonable approach for the indication).

The AUC methodology has subsequently evolved over time. Importantly, the terminology used to describe the three appropriateness categories has changed. As mentioned previously, studies for specific clinical indications were initially divided into appropriate, uncertain, or inappropriate categories. The revised terminology specifies “appropriate care,” “may be appropriate care,” and “rarely appropriate care.” It is therefore more explicitly recognized that a rarely appropriate study may be correct for a specific patient at a specific time; therefore, the goal for rarely appropriate studies is not necessarily zero.