Use of the Valve Visualization on Echocardiography Grade Tool Improves Sensitivity and Negative Predictive Value of Transthoracic Echocardiogram for Exclusion of Native Valvular Vegetation

Background: Transesophageal echocardiography (TEE) remains the preferred test to rule out infective endocarditis (IE) but is resource intensive and carries risk. Multiple studies report low sensitivity of transthoracic echocardiography (TTE) for detection of IE; however, these studies did not account for TTE quality. We test the validity of a simple valve visualization grading tool to stratify TTEs by quality and determine whether a high-quality TTE may be used to exclude valvular vegetation and forgo the need for TEE. Methods: The Valve Visualization on Echocardiography Grade (VEG) tool scores the TTE from 0 to 10 based on leaflet visualization and valve leaflet clarity. The tool was retrospectively applied to 309 sequential patients who underwent both TTE and TEE at an academic teaching hospital between 2011 and 2015. The TEE report was the gold standard for presence or absence of vegetation. Patients with prosthetic valves and pacemaker wires were excluded. Sensitivity of TTE for detecting vegetation was calculated at each VEG score, and the optimal cutoff was identified. Results: A total of 309 patients were included in the analysis. Among the 216 negative TTEs, 19 (9%) had a positive TEE. The median VEG score was 4. A VEG score cutoff >6 provided optimal sensitivity and was used as the cutoff. Overall, 75 (25%) patients had a VEG score >6, and 234 (75%) had a score ≤6. Sensitivity and negative predictive value for IE were higher in the VEG >6 versus VEG ≤6 group (sensitivity 96% vs 66%, negative predictive value 97.5% vs 90%; P < .05). The false-negative rate was lower (2.5% vs 10%; P = .04) in VEG > 6 versus VEG ≤ 6 groups, respectively. Conclusions: Leaflet visualization and valve leaflet clarity are important components in the TTE evaluation of patients with suspected IE. This study demonstrates that the better the valve leaflets are visualized on TTE (as represented in this population by a score >6), the higher the confidence one can have that the TTE will not be falsely negative for vegetation(s) when vegetation(s) are not noted on these TTEs. If validated in future prospective studies, this may reduce the need to perform an invasive TEE in selected patients undergoing evaluation for native valve IE.