BackgroundEchocardiography has been a popular modality used to aid in the diagnosis of infective endocarditis (IE) with the modified Dukes' criteria. We evaluated the necessity between the uses of either a transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) in patients with a body mass index (BMI) greater than or equal to 25 kg/m2 and less than 25.MethodsA single-centered, retrospective study of 198 patients between the years of 2005 and 2012 diagnosed with IE based on modified Dukes' criteria. Patients were required to be above the age of 18, undergone an echocardiogram study and had blood cultures to be included in the study.This study was conducted at a major hospital in one of the most diverse communities in the United States, providing a cultural and epidemiologically significant advantage. An approved chart analysis using QuadraMed Computerized Patient Record (QCPR) was retrospectively accessed with data-input and calculations formulated in computerized software.ResultsAmong 198 patients, two echocardiographic groups were evaluated as 158 patients obtained a TTE, 143 obtained a TEE, and 103 overlapped with TEE and TTE. 167 patients were included in the study as 109 (65%) were discovered to have native valve vegetations on TEE and 58 (35%) with TTE. TTE findings were compared to TEE results for true negative and positives to isolate valvular vegetations Overall sensitivity of TTE was calculated to be 67% with a specificity of 93%. Patients were further divided into two groups with the first group having a BMI less than or equal to 25 kg/m2 and the subsequent group with a BMI<25. Patients with a BMI less than or equal to 25 that underwent a TTE study had a sensitivity and specificity of 54% and 92, respectively. On the contrary, patients with a BMI<25 had a TTE sensitivity and specificity of 78% and 95, respectively. Furthermore, we obtained the sensitivities of specific valves diseased from vegetations, visualized by TTE (figure 1). Lastly, we were able to demonstrate a correlation between the different modalities of echocardiography used to the specific organism identified on blood cultures (figure 2).ConclusionCalculating a BMI in patients with suspicion for IE may provide benefit in reducing further diagnostic imaging. Our study demonstrated that patients having a BMI <25 kg/m2 with a negative TTE should refrain from further diagnostic studies with TEE, given the findings of increased sensitivities (figure 3). Patients with a BMI less than or equal to 25 may proceed directly to a TEE, possibly avoiding an additional study with a TTE given the low sensitivities identified in this population. Clinicians should be aware that this study has several limitations, one of which a small sample size that may be increased with a multi-centered study. Further investigations with a larger population may improve and possibly provide similar findings, reinforcing the study.
Transthoracic echocardiography using native tissue harmonic imaging: diagnostic alternative to transesophageal echocardiography in patients with suspected infective endocarditis