Transthoracic echocardiography was deemed to have been "appropriate" according to appropriate use criteria in nearly 92% of 535 cases in a single-center retrospective study reported online July 22 in JAMA Internal Medicine.
However, the TTE findings led to an active change in care in only 32% of those cases. In nearly half (47%) of cases, the TTE results resulted in simple continuation of current care, and there was no change in care for the remaining 21% of cases, said Dr. Susan A. Matulevicius and her associates at the University of Texas Southwest Medical Center, Dallas.
Dr. Susan Matulevicius
"The discrepancy between appropriateness and clinical impact is striking and suggests that the appropriate use criteria guidelines as currently implemented are unlikely to facilitate optimal use of TTE," the investigators noted.
The use of TTE has doubled during the past decade and now comprises half of all cardiac imaging services among Medicare beneficiaries. That represents more than $1.1 billion of the total Medicare expenditures for diagnostic imaging during one year, they said.
The American College of Cardiology, American Society of Echocardiography, and other professional groups developed appropriate use criteria for TTE in 2007 (J. Am.Coll. Cardiol. 2007;50:187-204) and updated them in 2011 (J. Am. Soc. Echocardiogr. 2011;24:229-67), but to date, no large study has assessed whether these efforts, or indeed whether the TTE results themselves, actually affect clinical care. Dr. Matulevicius and her colleagues said.
They reviewed the electronic health records for all TTEs performed during 1 month (April 2011) at their medical center, to assess the appropriateness and the clinical impact of the procedures.
The study population was 59% female and 41% male, and the mean age was 58 years. Approximately 55% of the subjects were white, 21% were black, and 8% were Hispanic.
Two general cardiologists who were blinded to the TTE results and to the patients’ clinical course independently reviewed the 535 cases, classifying them as appropriate (91.8%), inappropriate (4.3%), or uncertain (3.9%), according to the updated appropriate use criteria.
Two other noninvasive cardiologists who were blinded to these classifications independently assessed the clinical impact of each TTE and categorized the results as prompting an active change in care (32%), a continuation of current care (47%), or no change in care (21%).
The results of the TTE prompted an active change in clinical care in only 32% of cases. The most common changes were further diagnostic testing (29% of cases) and subspecialty consultation (26%), Dr. Matulevicius and her associates said (JAMA Intern. Med. 2013 July 22 [doi:10.1001/jamainternmed.2013.8972]).
In addition, there was no significant difference between the proportion of appropriate TTEs that led to a change in clinical care (32%) and the proportion of inappropriate TTEs that led to a change in clinical care (22%).
The researchers also conducted an exploratory analysis to determine, by consensus of the reviewing cardiologists, whether the TTEs that led to active change had been very useful, useful, neutral, not useful, or misused as guides to patient care.
Only 19% of all TTEs were judged to be very useful or useful. Another 6% were deemed not useful or misused. The majority (about 75%) were categorized as neutral in this analysis.
These findings are in line with those of previous small studies at other institutions. They suggest that the appropriate use criteria have failed to have much impact on physician decision making and have not curbed the massive growth of TTE use, the investigators added.
"In our study, 114 TTEs in 1 month led to no change in care, which equates to more than 1,300 TTEs on an annual basis. If our findings are corroborated in other settings and centers, 21% (or $230 million) of the $1.1 billion of Medicare expenditures on echocardiography could have been saved if these TTEs had not been performed.
"Better metrics for identifying patients or scenarios when TTE is likely to result in no change in care must be developed," they said.
Certain common indications that at present are considered to be appropriate but have minimal impact on clinical care should be targeted. "For example, initial evaluation of reasonably suspected valvular or structural heart disease (appropriate use criteria 34) and serial reevaluations in a patient undergoing therapy with cardiotoxic agents (appropriate use criteria 91) were the most common "appropriate" TTE indications but resulted in active change in care in fewer than 15% of studies.
"Alternative strategies, including performance of limited echocardiography or screening with plasma biomarkers, such as sensitive troponin and natriuretic peptide levels, may help to improve efficiency of TTE screening for these indications," Dr. Matulevicius and her associates said.