Role of preoperative cardiac CT in the evaluation of infective endocarditis: comparison with transesophageal echocardiography and surgical findings

Abstract

Background: Significant improvement of computed tomography (CT) technology in the last decade has led to more use of this modality for evaluating infective endocarditis (IE) especially since the introduction of high resolution electrocardiogram (ECG) synchronized multiphasic (4D) acquisition. While there are a number of reports on the accuracy and value of 4D CT for evaluation of IE, there is no published data regarding the performance of single-phase ECG gated CT for assessment of IE. The purpose of this study is to evaluate the sensitivity and specificity of preoperative single-phase ECG-gated CT imaging versus transesophageal echocardiography (TEE) in the assessment of complications related to IE, with comparison to surgical findings.

Methods: Among 899 patients with surgically proven IE in our database, 122 underwent contrast-enhanced ECG cardiac CT and were included in the study; 84 of these patients also underwent TEE.

Results: Overall, there was no significant difference between CT and TEE in the identification of pseudoaneurysm/abscess and dehiscence. For the detection of pseudoaneurysm/abscess in prosthetic valves, CT demonstrated higher sensitivity (81% vs. 64%) and specificity (75% vs. 33%) in patients with mechanical aortic valves; TEE demonstrated marginally higher sensitivity (72% vs. 63%) and specificity (80% vs. 73%) in patients with bioprosthetic aortic valves, although the differences are not statistically significant. TEE demonstrated significantly higher sensitivity (85% vs. 16%) in identifying vegetation in all patients (P<0.0001), including patients with prosthetic valves (sensitivity, 78% vs. 19%). The combined imaging findings of CT and TEE demonstrated improved sensitivity in identifying pseudoaneurysm/abscess and slightly improved detection of prosthesis dehiscence.

Conclusions: Preoperative single-phase gated CT can be seen as complementary to TEE in assessing complications of suspected IE or may be substituted for TEE when vegetation or dehiscence is depicted on transthoracic echocardiography and the patient has a contraindication to TEE.

Keywords: Computed tomography (CT); endocarditis; transesophageal echocardiography (TEE).

Figure 1

Study protocol.

Figure 2

Endocarditis complicated by periaortic abscess [yellow arrow on CT image (A)] and pseudoaneurysm [short yellow arrow on CT (B) and orange arrows on TEE without color Doppler (C) and with color Doppler (D)]. Intraoperative image demonstrates extensive periaortic soft tissue thickening with diffuse inflammation posteriorly (E). Surgical images reprinted with permission from Elsevier (12). RCA, right coronary artery; LVOT, left ventricular outflow tract; CS, coronary sinus; CFB, central fibrous body.

Figure 3

Dehiscence of a bioprosthetic aortic valve in setting of endocarditis complicated by pseudoaneurysm (red and yellow arrows from three chamber (A) and short axis (B) CTA reformats, yellow arrow from TEE (D). Vegetation noted as well (C). Explanted partially dehisced bioprosthesis (E) infected with Staphylococcus aureus. Surgical images reprinted with permission from Elsevier (12). TEE, transesophageal echocardiography.

Figure 4

Vegetations associated with endocarditis noted on native aortic and mitral valve leaflets [short and long yellow arrows on CT images (A,B), short and long orange arrows on TEE image (C)]. Excised aortic valve cusps (D) with vegetations and cusp degeneration. Surgical images reprinted with permission from Elsevier (12). TEE, transesophageal echocardiography.

Figure 5

The sensitivity and specificity of detecting pseudoaneurysm/abscess, vegetation, and dehiscence in the overall patient population with CT, TEE, and CT + TEE combined. TEE, transesophageal echocardiography.

Figure S1

The sensitivity and specificity of detecting pseudoaneurysm/abscess, vegetation, and dehiscence in patients with prosthetic valves with CT, TEE, and CT + TEE combined. CT, computed tomography; TEE, transesophageal echocardiograph.

Figure S2

The sensitivity and specificity of detecting pseudoaneurysm/abscess, vegetation, and dehiscence in patients with prosthetic valves in the aortic position with CT, TEE, and CT + TEE combined. CT, computed tomography; TEE, transesophageal echocardiograph.