Current Concepts in Prevention of Prosthetic Valve Endocarditis

‘�‘ Previously, PVE has been arbitrarily divided into “early” and “late,” based on whether the infection occurred within 60 days of valve replacement or later.� The rationale for this time categorization was based on differing bacteriologic, pathogenetic, and prognostic associations for PVE cases acquired before vs after this 60-day breakpoint.� For example, older studies had confirmed a predominance of coagulase-negative staphylococcal, Gram-negative bacillary and fungal pathogens among early PVE cases, with streptococci being uncommon etiologic ‘� In contrast, the oral and enterococcal streptococci, along with the staphylococci, tended to predominante in the late PVE cases. Moreover, these previous studies of PVE defined a substantially higher mortality rate associated with early vs late PVE. This prognostic difference in early vs late PVE was believed to be related to the preponderance of periannular or sewing-ring infections seen in early PVE as opposed to a higher incidence of leaflet or strut infection in late PVE . Lastly, these older investigations suggested that early PVE cases were acquired either via intraoperative (probably airborne) valve contamination7 or hematogenously secondary to postoperative extracardiac infections,5’8 while late PVE