Infective Endocarditis: how many ultrasonography studies are necessary to reach the diagnosis? A real world scenario (2008-2017)

Abstract

Background: The central role of echocardiography in the diagnosis, prognosis, and management of infective endocarditis (IE) has been clearly established. Both echocardiograpy and blood cultures are the major criteria to reach the diagnosis of IE. Although 2D transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have complementary roles, TEE has more sensitivity and specificity especially in the presence of intracardiac device. Sometimes, however, in spite of a high clinical suspicion, the first study that is carried out does not contribute with elements that confirm this suspicion and many expert and guidelines suggest to repeat the study in a relatively short time. To analize the role of repeated echoes in the diagnosis of definite IE. Methods & Materials: Retrospective, observational study of consecutives cases of Definite IE according to modified Duke Criteria, in adults patients admitted in a single cardiovascular referral center. Results: From January/2008 to June/2017, 148 definite EI (43 native valve, 72 prosthetic valve, 33 pacemaker-associated IE) were included. All ptes underwent TTE and TEE. The first echoe was made a median of 2 d since the hospitalization day (range = 0-13 d; SD +/- 2) and showed images suggesting IE in 106/148 pts (71.6%). A 2nd echoe was performed in 18 pts in a median time of 7 days and showed images not seen in the previous echoe in 11/18 pts (61%). Considering only “valvular IE” (n = 115) the first echo was “positive” for IE in 76.5% and 86% in the 2nd echoe: native valve IE 81.4% vs 83.7%; PVIE 73.6% vs 87.5% (early PVIE - n: 32 - 75% vs 90%) respectively. Conclusion: Ultrasonography is unequivocally the mainstay of diagnostic imaging in IE. Repeat the study in the case of a high clinical suspicion could notably increase the possibility of achieving the diagnosis of IE, especially when intracardiac device (e.g: prosthetic valves) are probably involved.