Echocardiographic features of bioprosthetic valve endocarditis

Clinical problems in patients with prosthetic heart valves

Information from the UK Heart Valve Registry, which was established in 1986 and receives data from all centres in the National Health Service, shows that more than 5,000 artificial heart valves are implanted each year in Britain and that almost two-thirds of these are mechanical. This article is intended as a practical outline of the clinical problems and complications which may occur.

Prosthetic valve endocarditis 1976-1987. Antibiotics, anticoagulation, and stroke

We retrospectively reviewed the clinical characteristics and outcomes of 61 patients with 62 episodes of prosthetic valve endocarditis, paying particular attention to neurologic complications (stroke). Atypical features of the group included a benign outcome of early postoperative infection (18% mortality) and a high stroke morbidity and mortality rate with Staphylococcus epidermidis infections. Eleven patients (18%) suffered an embolic stroke, most less than or equal to 3 days after diagnosis and before the initiation of antimicrobial therapy; the rate of embolic stroke recurrence was low (9%). The risk of embolic stroke was lower with bioprosthetic than with mechanical valves. No protective effect of anticoagulation therapy with warfarin was observed. Six patients (8%) suffered brain hemorrhage due to septic arteritis, brain infarction, or undetermined causes; no specific risk of hemorrhagic stroke was evident with anticoagulation therapy. Antibiotic treatment appears to be more important than anticoagulation to prevent neurologic complications in patients with prosthetic valve endocarditis.

[Bacterial endocarditis on prosthetic valves]

Bacterial endocarditis is a rare, but often lethal, complication of cardiac valve replacement. The endocarditis is called "early" when it occurs within 2 months of the operation, and "late" when it develops after that period. Contamination of the prosthesis with bacteria may occur intra-operatively or post-operatively. The clinical diagnosis is often difficult in early endocarditis when another focus of infection is present and in late endocarditis in the absence of fever and positive blood cultures. Isolation of the pathogen from blood cultures is essential to the diagnosis and treatment. Therapeutic surgery now has wider indications than formerly. The incidence of this dangerous complication can only be reduced by well-planned and well executed prophylactic measures.