Actuarial analysis of the risk of prosthetic valve endocarditis in 1,598 patients with mechanical and bioprosthetic valves
R. Rutledge, B. J. Kim and R. E. Applebaum
We reviewed the charts of 1,598 patients undergoing valve replacement at
the National Institutes of Health, Bethesda, Md, from 1956 through 1981.
Retrospective analysis disclosed that 43 patients had prosthetic valve
endocarditis (PVE). Twelve patients had early (less than 60 days after
operation) and 31 patients had late (greater than 60 days after operation)
endocarditis. The cumulative risk was 3% at five years and 5% at ten years.
We also calculated the interval risk of PVE. The high risk of early PVE
development peaked 15 days after operation. The peak risk was 45 episodes
per 100,000 patient days. The risk then declined rapidly and from 150 days
to 20 years remained stable at approximately one episode per 100,000
patient days. Nine hundred fifty-two patients had valve replacement with a
Starr-Edwards prosthesis and 363 patients had valve replacement with a
bioprosthetic valve; there was no significant difference in the risk of PVE
in either group. Neither the valve make, position, model, nor the number of
valves implanted affected the frequency of PVE or the mortality. Actuarial
techniques disclosed the high early risk of PVE, the prolonged risk of PVE
up to 150 days after operation, and the low but persistent risk late after
operation. There was no significant difference in the risk of PVE in
patients with bioprosthetic v mechanical valves.
