Majority of TTEs appropriate but may not change management, study finds

Most transthoracic echocardiograms (TTEs), even those done for appropriate clinical indications, have little effect on patient management, according to a new study.

Researchers in Texas retrospectively reviewed medical records of TTEs at one medical center and classified them according to appropriate use criteria developed in 2011 and assessed clinical impact. The two cardiologists who judged appropriate use criteria were blinded to clinical impact, and the two cardiologists who assessed clinical impact were blinded to appropriate use criteria. When the cardiologists disagreed and could not reach consensus on either clinical impact or appropriate use, a third cardiologist, also blinded, adjudicated. A TTE could be classified as leading to an active change in care, continuation of current care, or no change in care. The study's main outcome measures were prevalence of appropriate, inappropriate and uncertain TTEs based on appropriate use criteria and the prevalence of the three clinical impact categories. The results were published online July 22 by JAMA Internal Medicine.

All TTEs ordered at University of Texas Southwestern Medical Center from April 1 through April 30, 2011, were reviewed and 535 were included in the analysis. Most of the study patients were women (58.7%); 55.3% were white, 21.1% were African American and 8.2% were Hispanic. The mean age was 58 years. Fifty-seven percent of TTEs were ordered for inpatients, and general internists (38.5%) and cardiologists (31.2%) were the specialists most likely to order the tests.

The researchers found that 31.8% of TTEs led to an active change in care, 46.9% led to continuation of current care and 21.3% led to no change in care. Based on the 2011 appropriate use criteria, 91.8% of TTEs were appropriate, 4.3% were inappropriate, and 3.9% were of uncertain appropriateness. A similar proportion of appropriate and inappropriate TTEs led to active change in care (32.2% vs. 21.7%, respectively; P=0.29). Outpatient TTEs were slightly less likely than inpatient ones to be judged appropriate (86.5% vs. 95.7%, respectively; P<0.001).

The study was limited by its reliance on electronic medical records, which may have provided incomplete information and led to misclassification of clinical impact, the authors noted. They also pointed out that they were unable to assess patient satisfaction and that their results may not be generalizable to other practice settings, among other limitations. They concluded, however, that while almost all TTEs in their study were considered appropriate by 2011 criteria, fewer than one-third led to an active change in care. In addition, almost half led to continuation of current care and approximately 21% resulted in no change in care.

“The discrepancy between appropriateness and clinical impact is striking and suggests that the [appropriate use criteria] as currently implemented are unlikely to facilitate optimal use of TTE,” they wrote. They called for further research examining the necessity of TTE in medical care.

The author of one of two invited commentaries said that while the existing appropriate use criteria are “meticulous,” the evidence on how and when to best use echocardiography is slim. The current study, he said, “demonstrates that the concepts of appropriateness and usefulness may diverge considerably. Transthoracic echocardiograms cost more than $1 billion per year to Medicare alone, and many TTE procedures performed by the book may still not lead to improved outcomes.” He called for additional randomized trials of diagnostic testing focusing on specific clinical scenarios. “Such trials may cost more than collecting observational data, but for common tests and indications, their results may be definitive, eventually saving far more money,” he wrote.

The second invited commentary noted the limitations of a retrospective review of electronic medical records and said that the results should be confirmed prospectively before major conclusions are drawn. “Certainly, the [appropriate use criteria] are not without remaining flaws and ideally should result in a categorization scheme that can be demonstrated to have a consistent, but necessarily invariable, effect on medical decision making,” the authors wrote. “This retrospective study points the way for further prospective studies looking at the impact of echocardiography and how it affects physician decision making.”