Can transthoracic echocardiography with subcostal view predict abdominal aortic atherosclerosis?

Prompt detection of atherosclerosis (ATH) may profoundly impact therapy and patient outcome. During transthoracic echocardiography (TTE), subcostal views may suggest abdominal (ABD) aortic (AO) ATH, but this diagnosis may be inaccurate due to suboptimal images, which may in part relate to use of nonlinear probes. Therefore, we investigated the accuracy of TTE assessment of ABD AO ATH relative to transesophageal (TEE) AO images.

Routine clinical TTE and TEE studies of 100 patients (44 men), aged 30-92 years old, were reviewed retrospectively and blindly. ABD AO ATH by TTE was graded qualitatively as grade (GR) 0 = smooth wall surface; GR 1, 2, and 3 = mild, moderate, and severe irregularities, respectively; and GR 4 = mobile/complex plaque. TEE images were graded quantitatively as the maximal intimal-medial, or plaque thickness, imaged in the AO arch or descending AO, as: GR 0 4 mm, or GR 4 = mobile/complex plaque >4 mm. TTE ability to detect the presence (>GR 0) of ABD AO ATH on TEE was measured in terms of sensitivity (SN), specificity (SP), positive (PPV) and negative (NPV) predictive accuracy-in patients with adequate and suboptimal images-compared to TEE.

TTE image quality was adequate in 75 patients and suboptimal in 25. SP and PPV of grading ATH by TTE were directly related to grading by TEE; however, SN and NPV demonstrated an inverse relationship with increasing grading of ATH. TTE correlated with TEE grading with an r = 0.42 (P = 0.0001) for patients (n = 75) with adequate TTE and r = 0.32 (P = 0.001) for all patients (n = 100), including those with suboptimal TTE images.

Routine TTE imaging is usually correct in predicting ATH on TEE, but with modest error, it should generally not be relied on as a definitive test for ATH. Adequate image quality improves the correlation of TEE and TTE grading of ABD ATH, and more severe ATH on TTE is more predictive of ATH on TEE.