In Reply We appreciate Dudzinski and colleagues’ thoughtful letter and generally agree with the points they raise. Appropriate use criteria (AUC) are a strong step by multiple societies to address the clinical use of transthoracic echocardiography (TTE). However, we caution against using the relative prevalence of major new abnormalities on appropriate vs inappropriate TTEs as a surrogate for their relative clinical utility. Appropriate TTEs are expected to have a higher prevalence of major abnormal findings owing to the inherent bias present in the definition of appropriate vs inappropriate AUCs. An appropriate indication, such as “reevaluation of known heart failure to guide therapy,” will by construction have a high prevalence of major TTE abnormalities. In contrast, an inappropriate indication, such as “initial evaluation of ventricular function with no symptoms or signs of cardiovascular disease,” will yield few abnormal findings. Furthermore, the clinical impact of TTE does not solely depend on the detection of TTE abnormalities. A normal TTE for an indication like “hypotension or hemodynamic instability of uncertain or suspected cardiac etiology” may result in the pursuit of noncardiac diagnoses and therapies. Similarly, an indication like “initial evaluation when there is a reasonable suspicion of valvular or structural heart disease” may detect moderate aortic stenosis, but if the patient has a terminal illness and/or refuses or is not a candidate for future surgical or percutaneous valve interventions, care may not change.
Matulevicius SA, Das SR, Reimold SC. Assessing the Clinical Impact of Appropriate Echocardiograms—Reply. JAMA Intern Med. 2014;174(7):1196–1197. doi:10.1001/jamainternmed.2014.1437