Diagnosis and Management of Infective Endocarditis in Patients with Post-Obstructive Pneumonia

Introduction to Infective Endocarditis Diagnosis

The American College of Cardiology recommends that all patients with unexplained fever and risk factors for infective endocarditis (IE), including those with bacteremia, should have blood cultures obtained, and positive cultures with typical IE organisms warrant echocardiographic evaluation 1.
The European Heart Journal suggests that transthoracic echocardiography (TTE) is recommended as the first-line imaging modality in all cases of suspected IE 2, 3, 1.

The American College of Cardiology states that TTE should be performed in all cases of suspected IE, as it can identify vegetations, characterize hemodynamic severity of valvular lesions, assess ventricular function and pulmonary pressures, and detect complications 1, 2, 3, 6, 7.
The European Heart Journal notes that TTE has reasonable sensitivity for native valve endocarditis (approximately 60-70%) but lower sensitivity for prosthetic valves and complications like abscesses 2, 8, 5.

The American College of Cardiology recommends that for patients with S. aureus bacteremia without a known source, transesophageal echocardiography (TEE) is reasonable (Class IIa) to diagnose possible IE 1, 4.
The European Heart Journal suggests that patients with S. aureus bacteremia represent a special high-risk population, and TEE might be considered (Class IIb) but is not mandatory if the pneumonia is clearly the source 2, 4, 1.

The American College of Cardiology recommends starting with TTE in all suspected IE cases, and proceeding to TEE if any of the following apply: TTE is nondiagnostic or negative but clinical suspicion remains high, TTE is positive but assessment for complications is needed, the patient has intracardiac devices, or the organism is S. aureus, enterococcus, or fungal species 1, 3, 6, 7.
The Circulation journal notes that if initial TEE is negative but clinical suspicion persists, repeat TEE in 3-5 days, as vegetations may be too small initially or abscesses may appear only as nonspecific perivalvular thickening that becomes recognizable as they expand 3, 6, 7.

The American College of Cardiology states that the gram stain showing GPC is sufficient to trigger echocardiographic evaluation, and not to delay until speciation and sensitivities return 1.
The European Heart Journal suggests that the presence of an obvious extracardiac source (pneumonia) does not exclude concurrent IE, and approximately 30% of IE patients present with embolic events as the initial manifestation 2, 1, 4.

The American College of Cardiology recommends that TTE should be performed in all cases of suspected IE (Class I recommendation), and TEE should follow if TTE is nondiagnostic or if complications are suspected (Class I recommendation) 3, 1, 6, 7.
The Circulation journal notes that for S. aureus bacteremia without known source, TEE is reasonable (Class IIa recommendation) 1, 4.