Background: Echocardiography is an essential evaluation in the diagnosis of infectious endocarditis (IE). Transthoracic echocardiography (TTE) is a portable study that is widely available and non-invasive. Though transesophageal echocardiography (TEE) is traditionally known for higher sensitivity and specificity, it is speculated that improvements in modern TTE imaging could produce higher diagnostic yield than previously thought. This study seeks to evaluate diagnostic prowess of modern TTE compared to TEE in a single large academic medical center.
Methods: Inpatient TEE exams performed between January 1, 2017 and December 31, 2017 for bacteremia, suspected endocarditis, and stroke were reviewed. TEE exams for valvular heart disease, TEE-guided cardioversion, intraoperative TEE’s and TEE exams determined to be for stroke without infectious concerns were excluded.
Results: One hundred thirty-one TEE exams were identified. We analyzed ninety-four (71.8%) of these subjects who underwent TTE prior to TEE. Diagnosis of IE was defined by presence of vegetation on TEE exam. The sensitivity and specificity of TTE was 65% and 79% respectively. TTE had a false positive rate of 21%, on the basis of valve abnormality classified as possible IE, later refuted. The interclass correlation coefficient was 0.37(p<0.001), which is suboptimal. The false negative rate, or missed diagnosis rate, of TTE was 35%. There were no reported complications due to TEE.
Conclusions: TTE performed poorly as a diagnostic test for IE with inadequate sensitivity, unacceptable false positive rate, and ultimately poor correlation with TEE result. TEE was performed without patient complications. TEE is a more invasive but well justified approach to evaluate suspected IE in inpatients and may be the more appropriate initial diagnostic approach.