High Prevalence of Clinically Important Echocardiographic Abnormalities in Patients with a Normal Electrocardiogram Referred for Transthoracic Echocardiography

Association Between Transthoracic Echocardiography Appropriateness and Echocardiographic Findings

BACKGROUND

The association between appropriate use criteria and echocardiographic findings in patients with chronic cardiovascular diseases is unknown.

METHODS

As a substudy of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial, 9,230 transthoracic echocardiographic (TTE) examinations from six Ontario academic hospitals were linked to a registry of echocardiographic findings. The TTE studies were rated appropriate), rarely appropriate, or may be appropriate according to the 2011 appropriate use criteria. TTE findings of appropriately ordered examinations were compared with those of rarely appropriate examinations for specific disease subsets, including heart failure and valvular heart disease.

RESULTS

There were 7,574, 1,087, and 569 TTE examinations ordered for appropriate, rarely appropriate, and may be appropriate indications, and of the 7,574 appropriate studies, 6,399 were ordered for specific indications and 1,175 for general indications. TTE examinations ordered for general indications had lower rates of left ventricular dysfunction (19.6% vs 9.1%, P < .001) and moderate to severe aortic stenosis (15.5% vs 2.6%, P < .001). Of the 2,395 TTE examinations ordered for patients with heart failure, appropriately ordered studies were more likely to result in left ventricular segmental abnormality (37.0% vs 24.9%, P = .012) but similar rates of right ventricular dilatation (15.4% vs 14.7%, P = .79), right ventricular dysfunction (14.8% vs 11.3%, P = .22), and moderate to severe mitral regurgitation (12.1% vs 9.2%, P = .35). Of the 2,859 studies ordered to assess valvular heart disease, appropriately ordered studies were significantly more likely to find moderate to severe valvular pathology, including aortic stenosis (30.4% vs 24.6%, P = .008), aortic regurgitation (8.9% vs 1.6%, P < .001), mitral stenosis (6.7% vs 3.1%, P = .002), and mitral regurgitation (16.1% vs 6.1%, P < .001), but similar rates of tricuspid regurgitation (11.2% vs 13.0%, P = .60).

CONCLUSIONS

Overall, appropriately ordered TTE examinations for heart failure and valvular heart disease were significantly more likely to have abnormal findings than rarely appropriate examinations. TTE studies ordered for general indications had fewer, although still a significant proportion, of abnormalities compared with studies ordered for specific indications.