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Page 2 of 7 Rostagno. Vessel Plus 2020;4:7 I http://dx.doi.org/10.20517/2574-1209.2019.29

studies have shown a continuous increasing trend [1-3] . This is associated with a significant increase in
[4]
economic costs, above $120,000 per patient . Both native and prosthetic valve endocarditis epidemiology
are affected by the increasing number of health care-associated infections, contributing for not less than
25% of overall cases. Hemodialysis, implantable cardiac devices, venous catheters, immunosuppression,
[5,6]
and intravenous drug use are main risk factors for infective endocarditis (IE) . Patients are older and
frail, often affected by serious comorbidities. Infections due to staphylococci are continuously increasing
in comparison to oral streptococci. Staphylococci at present are the most frequent etiologic organism.
A Danish study showed that between 1957 and 1990, Staphylococcus aureus bacteremia increased from
3 to 20 per 100,000 person-years, paralleling the increase of hospital admissions and invasive medical
[7]
procedures . Hand-hygiene, barrier precautions, and antisepsis are effective measures in reducing the
rate of bacteremia. Microbial eradication is the goal of treatment in IE. Broad spectrum empiric antibiotic
treatment should be started as soon as possible, immediately after collection of samples for blood-culture.
Identification of etiologic microorganism allows tailored therapy to be administered, even if antibiotic
[2,8]
resistance is a growing worrying phenomenon . Overview of medical management of IE is beyond the
aim of present review. It must be emphasized that in patients in medical treatment, a close reassessment of
clinical, laboratory and echocardiographic findings is mandatory since infective endocarditis may rapidly
progress even under antibiotic treatment. Moreover, in patients without indication to urgent surgery,
hemodynamic changes related to residual valve damage are associated with a decreased life expectancy.
A large study conducted in France showed that surgical treatment was the only independent predictor of
[9]
long-term survival in patients admitted to hospital for infective endocarditis .

Indications to surgery
The indications for surgery in patients with IE have been defined by American Association for Thoracic
Surgery, American Heart/American College of Cardiology and European Heart Society (ESC) [10-12] .
According to guidelines, surgery is defined as urgent, usually within index hospitalization before completion
of a full course of antibiotics. The ESC guidelines distinguish emergency surgery (within 24 h) from urgent
surgery (within a few days), or elective surgery (after 1 to 2 weeks) of antibiotic therapy. More than 50% of
patients with native valve endocarditis needs surgery, more frequently on an urgent basis.

Hemodynamic impairment due to severe valve regurgitation, characterized by severe left ventricular
dysfunction, refractory pulmonary edema and/or cardiogenic shock, is the more frequent indication for
urgent surgery (class I level of evidence B). Early surgery is also indicated in the case of extension of the
infection beyond the valve annulus, with perivalvular abscess, fistula, or pseudoaneurysm formation or
with involvement of heart conduction system (AV block).

In native valve endocarditis, extra valvular spreading occurs in about 30% of cases. Urgent surgery may
be needed to prevent potential catastrophic embolism in the presence of large (> 10 mm) and/or mobile
vegetations. A randomized study showed that in native valve endocarditis characterized by large vegetations
(> 10 mm) and/or severe valve regurgitation, surgery was associated with a significant decreased risk of
[13]
death and embolic events in comparison with medical care .

Neurologic involvement, not rarely asymptomatic, may be demonstrated in about 50% of patients with
infective endocarditis. Staphylococcus aureus is the more frequent etiologic agent. The timing of surgery in
patients after embolic stroke is challenging and controlled studies are not available. Delay in surgery may
be associated with risk of recurrent embolism, however patients undergoing early surgery are at the risk of
hemorrhagic transformation of the stroke since full anticoagulation is needed for cardiopulmonary by-pass.
Moreover, hypoperfusion during surgery may be associated to an extension of ischemic area. A careful
multidisciplinary evaluation weighing the relative role of severity of hemodynamic impairment against that
of neurologic damage may help in scheduling surgery. Results from observational studies suggest that the