Most cases of infective endocarditis are associated with an elevated serum C-reactive protein (CRP) concentration. It is important to realize that infective endocarditis can be present in a patient with low serum CRP.
Patient selection: low serum CRP (less than 20 mg/L)
Even in the presence of a low serum CRP concentration there may be significant valvular and perivalvular lesions.
Pathogens associated with low serum CRP endocarditis:
(1) HACEK
(2) Coxiella burnetii
(3) Bartonella henselae
(4) Corynebacterium jeikeium
(5) Streptococcus species
(6) coagulase-negative Staphylococcus species
Other factors associated with low serum CRP concentration:
(1) previous therapy with antibiotics
(2) cardiac device-related infective endocarditis
(3) ? therapy with an anti-inflammatory agent
Indications to transesophageal echocardiography (TEE) when transthoracic echocardiography (TTE) is negative or indeterminate:
(1) unexplained heart failure
(2) new valvular regurgitation
(3) cardioembolic stroke
