Importance of aggressive evaluation in patients with Staphylococcus aureus bacteremia

Abstract

Staphylococcus aureus is almost uniquely capable of ausing infective endocarditis (IE) on apparently noral cardiac valves. Already a leading cause of bactereia and IE, rates of S aureus bacteremia (SAB) have ncreased dramatically in the past several years. This ncreasing frequency, coupled with rising rates of antiiotic resistance, has amplified the clinical threat osed by this serious, common, and virulent pathogen. lthough the possibility of underlying IE arises in virtully every patient with SAB, only a minority of patients ith bacteremia will actually have cardiac involveent. Distinguishing patients with S aureus IE from hose with uncomplicated SAB is essential, but often ifficult. In this issue of the American Heart Journal, braham et al address the unresolved issue of echocariography to identify endocarditis among patients with AB. During a 3-year period, the echocardiographic eatures of 104 patients with 2 blood cultures with ositive results for S aureus who underwent either a ransesophageal echocardiography (TEE) for suspected E or who had positive results on a transthoracic echoardiogram (TTE) at Grady hospital were evaluated. heir investigation yielded several key observations. First, the rate of IE among patients with SAB is high. his study adds to the growing body of evidence emhasizing that IE is common and potentially unsusected in patients with SAB. For example, 55% of 119 anish patients with S aureus IE from 1976 to 1981, 2% of 260 Danish patients with S aureus IE identified rom 1982 to 1991, and 18% of 172 Brazilian patients ith IE, most of whom had hospital-acquired SAB, ere not clinically suspected and were only diagnosed ith IE at a post-mortem examination. The availability f echocardiography in general, and TEE in particular, as aided in identifying IE. The current investigation