CHICAGO—Although nearly nine in 10 transthoracic echocardiograms (TTEs) met appropriate use criteria (AUC) by 2011, fewer than one-third resulted in a change in care, according to a single-center study presented March 26 as a scientific poster at the 61st annual American College of Cardiology (ACC) scientific session.
Prior studies have shown that the majority of TTEs performed meet AUC; however, the association between AUC and clinical impact “remains unknown,” Susan A. Matulevicius, MD, a cardiologist at the University of Texas Southwestern Medical Center in Dallas, said during an interview. “There have been hints that, even with appropriate use, the clinical impact may not change.”
For the study, she and her colleagues retrospectively reviewed the charts of 200 consecutive patients who had an inpatient or outpatient TTE at their academic medical center. They excluded 29 studies because they were without any post-TTE documentation or were conducted in patients with left ventricular assist devices or post-cardiac transplant. Other patients were eliminated for various reasons, leaving a final cohort of 166 patients.
Each of the remaining TTEs was classified according to 2011 AUC by a cardiologist blinded to clinical impact and was assessed for clinical impact by two independent cardiologists blinded to AUC classification. Matulevicius said that they attempted to remain “liberal in terms of giving credit to assessments, so as to avoid an overly judgmental bias.”
Clinical impact was assigned to one of three categories:
- Active change in care;
- Reassurance: when it was documented that a caregiver followed up with the patient; or
- No impact: when certain actions were taken regardless of the echo, or the information gathered from the echo was already known.
When disagreements in assigned clinical impact occurred, they were resolved by consensus, according to Matulevicius.
According to the 2011 AUC, the researchers classified 88 percent of the TTEs as appropriate, 8 percent as inappropriate and 4 percent as uncertain.
Appropriately 63 percent of the studies were conducted in the inpatient setting. The researchers found a difference between appropriateness for the inpatient and outpatient settings—with “the majority of the inpatient studies being appropriate and only 33 percent of the studies were appropriate in the outpatient setting.” Also, of the 4 percent of studies deemed uncertain, 67 percent took place in the outpatient setting.
However, the researchers found that 70 percent of all TTEs resulted in no active change in care. Of these, 69 percent were categorized as reassurance and 31 percent as no impact. “The clinical impact of inappropriate TTEs was similar to that of appropriate TTEs, although the absolute number of inappropriate TTEs was small,” Matulevicius noted.
“These findings warrant further investigation in light of the current emphasis on containing medical costs and efficiently using limited medical resources,” she concluded.