Prosthetic-valve and device infection

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Prosthetic-valve endocarditis involves microbial growth on a surgical or transcatheter valve, sewing ring or adjacent tissue. Cardiac implantable electronic device infection may remain in the generator pocket or extend along leads into the bloodstream, tricuspid valve and pulmonary circulation.

Foreign material supports biofilm, in which organisms adhere to surfaces, become metabolically less active and resist immune clearance. Coagulase-negative staphylococci, Staphylococcus aureus, enterococci, Gram-negative organisms and fungi vary with timing and healthcare exposure.

Clinical features may be muted: fever can be absent, inflammatory markers modest and echocardiography initially negative. Mechanical dysfunction, unexplained bacteraemia, pocket change or embolic complications may be the decisive clue.

Antibiotics cannot reliably sterilise infected non-essential hardware. Successful care combines high-quality cultures, multimodality imaging, complete device removal or valve surgery where indicated, and organism-specific treatment planned by a multidisciplinary endocarditis team.

Key points

Establish exactly what was implanted, when, why and whether any revision, haematoma, wound problem or recent bloodstream infection occurred.
In a stable adult obtain three peripheral blood-culture sets before antibiotics; in shock collect rapidly without delaying resuscitation.
Start with TTE but use TOE early because prosthetic shadowing and lead position reduce transthoracic sensitivity.
Cardiac CT and FDG PET-CT can clarify peri-prosthetic extension or metabolically active hardware when specialist interpretation is available.
Pocket erosion, exposed hardware or purulent drainage needs complete system extraction rather than antibiotics or superficial wound care alone.
Definite lead infection generally requires removal of generator and all leads, with reimplantation delayed and moved to a clean site if still needed.
Prosthetic-valve infection frequently needs early surgery for heart failure, dehiscence, abscess, uncontrolled infection or difficult organisms.
Empirical and directed combinations differ by organism, implant age, resistance, renal function and operative plan; use an endocarditis service protocol.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Peri-procedural inoculation

Skin organisms enter during implantation, revision or generator replacement and later present as pocket, lead or prosthetic infection.

Haematogenous seeding

Remote Staphylococcus aureus, enterococcal or other bacteraemia adheres to previously sterile intracardiac material and forms biofilm.

Wound and pocket breakdown

Haematoma, poor healing, repeated manipulation and erosion permit progressive contamination from skin to generator and leads.

Healthcare-associated organisms

Recent surgery, vascular access and antimicrobial exposure increase coagulase-negative staphylococci, resistant bacteria and fungal infection risk.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Surface adhesion
Microbial adhesins bind protein coating on artificial material, establishing colonies that are poorly accessible to phagocytes.
2
Biofilm maturation
Extracellular matrix and slow bacterial metabolism reduce antimicrobial killing and allow relapse when infected material remains.
3
Peri-annular invasion
Prosthetic-valve infection spreads along the sewing ring into annulus, causing abscess, dehiscence, fistula and conduction injury.
4
Lead propagation
Pocket infection tracks intravascularly along leads, producing bacteraemia, tricuspid involvement and septic pulmonary emboli. during active invasive disease.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Prosthetic valve syndromeRed flag

Fever, malaise, new regurgitant murmur, heart failure or embolus in anyone with a replacement valve should trigger endocarditis assessment.

Pocket inflammationRed flag

Pain, warmth, erythema, swelling, fluctuance, discharge, threatened skin or generator exposure indicates local device infection; manipulation risks deeper spread.

Occult bloodstream infectionRed flag

Persistent or recurrent staphylococcal, enterococcal or unexplained bacteraemia may be the only evidence of colonised valve or lead material.

Lead-related emboliRed flag

Fever with cough, pleuritic pain, haemoptysis or peripheral pulmonary nodules suggests right-sided lead vegetation and septic pulmonary embolisation.

Mechanical complicationRed flag

New paravalvular leak, prosthetic rocking, conduction delay or haemolysis suggests sewing-ring disruption, abscess or fistula.

Implant history

Recent implantation, revision, generator change, pocket haematoma, temporary pacing or wound breakdown increases probability and helps classify acquisition.

Red flags requiring action

New prosthetic-valve regurgitation, rocking or dehiscence with heart failure requires emergency cardiac-surgical assessment.
An exposed generator, draining sinus or pocket erosion constitutes cardiac-device infection even when fever and blood cultures are absent.
Staphylococcus aureus bacteraemia in a patient with intracardiac material requires urgent evaluation for lead or valve infection.
Persistent positive cultures despite active therapy suggest retained infected material, abscess or another uncontrolled metastatic focus.
New PR prolongation or atrioventricular block can signal peri-annular extension around an aortic prosthesis.
Haemoptysis, pleuritic pain or hypoxaemia with an infected right-sided lead may reflect septic pulmonary embolisation.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Three peripheral blood-culture setsFirst step
Why
Identify bloodstream organisms before antimicrobial exposure and distinguish sustained infection from contamination.
Interpretation and limitations
Use separate venepunctures and adequate bottle volume. Avoid drawing only through device-associated lines; repeat cultures until clearance after treatment begins.
02
Pocket assessment without aspiration
Why
Identify erosion, sinus, purulence and threatened skin while avoiding inoculation of an uninfected pocket.
Interpretation and limitations
Photograph and document the site. Do not needle-aspirate a closed pocket; send deep tissue and extracted hardware at removal.
03
TTE followed by TOE
Why
Assess prosthetic function, vegetations, lead masses, regurgitation and peri-annular extension.
Interpretation and limitations
TTE is the initial haemodynamic study, but TOE is usually required. Repeat imaging when suspicion remains despite a negative early examination.
04
Cardiac CT
Why
Define abscess, pseudoaneurysm, fistula, dehiscence and operative anatomy around prosthetic material.
Interpretation and limitations
Use as an adjunct when echocardiography is limited or extension is suspected; interpret with the surgical and imaging team.
05
FDG PET-CT or labelled-leucocyte imaging
Why
Detect metabolically active prosthetic infection and extracardiac septic foci in selected patients.
Interpretation and limitations
Recent implantation and postoperative inflammation can cause false-positive uptake; preparation and specialist reporting are essential.
06
ECG and rhythm monitoring
Why
Detect new conduction disturbance from peri-annular infection and manage pacing dependence before extraction.
Interpretation and limitations
New PR prolongation or heart block escalates surgical urgency; document underlying rhythm and extraction pacing plan.
07
Extraction or operative specimens
Why
Recover organisms from deep pocket tissue, leads, valve and abscess when source control occurs.
Interpretation and limitations
Send several separate specimens for culture and histology, plus molecular testing if cultures are negative after prior antibiotics.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Postoperative inflammation

Early sterile wound change or postoperative FDG uptake can mimic infection but should improve and lacks progressive erosion or matching microbiology.

Contact dermatitis

Adhesive or antiseptic reaction causes pruritic superficial erythema without pocket tenderness, fluctuance, systemic features or hardware exposure.

Sterile lead thrombus

Fibrinous lead masses occur without infection; repeated cultures, inflammatory context and embolic pattern guide interpretation. on focused clinical assessment.

Prosthetic thrombosis

Obstruction and heart failure may result from thrombus, distinguished through valve imaging, anticoagulation history and absent infective evidence.

Pannus degeneration

Fibrous ingrowth or structural valve failure causes mechanical dysfunction without bloodstream infection or peri-annular inflammatory extension.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01STABILISEManage destructive prosthetic infectionFirst stepThere is shock, pulmonary oedema, severe prosthetic dysfunction, dehiscence or conduction deterioration.

1Use ABCDE, obtain several blood-culture sets rapidly, measure lactate and support oxygenation and circulation without excessive fluid in valve failure.
2Start the locally approved empirical prosthetic-endocarditis regimen after cultures, adjusted for implant timing, allergy, renal function and healthcare resistance.
3DefinitiveArrange urgent TTE and TOE, ECG surveillance and cardiac CT where it will not delay definitive intervention.
4Activate cardiac surgery and critical care immediately because antimicrobial improvement does not remove a mechanical indication.

02POCKETControl generator-pocket infectionErosion, exposed generator, sinus, purulence or convincing pocket inflammation is present.

1Do not aspirate, squeeze or perform a limited superficial debridement; obtain peripheral cultures and define systemic features.
2Refer promptly to the extraction service for removal of generator and every lead, with deep cultures taken during the procedure.
3Give directed antimicrobial therapy according to bloodstream, lead and valve involvement rather than prescribing for skin erythema alone.
4Reassess whether pacing or defibrillation remains indicated and reimplant only after infection control at a clean site using the specialist timing plan.

03BLOODEvaluate unexplained bacteraemia with hardwareA patient with prosthetic valve or intracardiac leads has Staphylococcus aureus, persistent coagulase-negative staphylococci, enterococci or recurrent bacteraemia.

1Repeat peripheral cultures, examine every pocket and vascular access site and search for metastatic back, joint, neurological or abdominal symptoms.
2Perform TTE and TOE even if the device site looks normal; use adjunct CT or PET imaging when standard imaging is inconclusive.
3Remove infected cardiac electronic material completely where definite infection is established, rather than attempting indefinite cure with retained leads.
4Narrow antimicrobials to susceptibility and count duration from effective source control and blood-culture clearance as defined by the specialist team.

04OPERATETreat prosthetic-valve endocarditisHeart failure, abscess, dehiscence, persistent infection, resistant or fungal disease, or major embolic risk is identified.

1Convene the endocarditis team early and determine whether surgery is emergency, urgent or can follow stabilisation and neurological imaging.
2Map coronary, valve, annular and extracardiac anatomy and correct reversible renal, haematological and haemodynamic risks without delaying indicated surgery.
3At operation remove infected material and send multiple labelled valve, sewing-ring and abscess samples before they contact preservative.
4Continue organism-specific postoperative therapy with toxicity surveillance and a documented imaging, anticoagulation and reimplantation plan.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

Covers likely staphylococci, enterococci and other relevant organisms until microbiology permits a safer directed regimen.

Empirical prosthetic-valve regimen

Use the exact local intravenous endocarditis combination immediately after cultures in instability, selected for early versus late implant, healthcare exposure, allergy, body weight and renal function.

There is no single safe universal combination; obtain infection-specialist advice, use serum-level protocols for glycopeptides or aminoglycosides and narrow promptly.

Provides high-exposure bactericidal beta-lactam therapy for susceptible staphylococcal valve or device bloodstream infection.

Flucloxacillin for susceptible staphylococci

Give 2 g intravenously every four hours when methicillin-susceptible Staphylococcus aureus is confirmed, with duration and any combination component set by the endocarditis team.

Clarify immediate penicillin allergy; monitor liver, kidney, blood count and sodium exposure; persistent cultures require source-control review, not simple dose extension.

Treats resistant Gram-positive prosthetic or lead infection while definitive microbiology and source control are arranged.

Vancomycin

Use the local intravenous loading and maintenance protocol based on actual body weight, renal function and measured serum exposure for MRSA or defined beta-lactam constraints.

Monitor concentrations and kidney function, reduce concurrent nephrotoxins and switch to an active beta-lactam for susceptible disease when safely possible.

May add biofilm activity in selected staphylococcal prosthetic infections but never substitutes for extraction or surgery.

Rifampicin as a specialist adjunct

Use only in the organism-specific prosthetic-material combination and specialist-selected timing after bloodstream burden falls and source control is secured.

Never use monotherapy; resistance emerges rapidly. Check hepatic function, pregnancy status and major interactions including anticoagulants, antiretrovirals and anticonvulsants.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Prosthetic dehiscence

Sewing-ring destruction produces paravalvular regurgitation, rocking valve, haemolysis, pulmonary oedema and cardiogenic shock. without timely definitive management.

Abscess and fistula

Peri-annular infection penetrates neighbouring chambers or conduction tissue, causing persistent sepsis and heart block. without timely definitive management.

Septic embolisation

Valve fragments travel systemically, while infected right-sided leads seed pulmonary arteries and cause cavitating nodules. without timely definitive management.

Persistent biofilm infection

Retained generator, lead or prosthesis sustains bacteraemia and relapse despite apparently susceptible antimicrobial therapy. without timely definitive management.

Extraction injury

Lead removal can cause venous tear, tamponade or embolisation, requiring an experienced service with surgical rescue capability.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Repeat peripheral cultures every 24 to 48 hours until clearance and investigate any renewed positivity.
Review pocket appearance, wound healing, temperature, haemodynamics, heart failure, embolic symptoms and focal pain each day.
Monitor ECG for PR change or heart block and maintain a safe temporary pacing strategy when extraction removes essential support.
Track renal, hepatic and haematological toxicity and all serum antimicrobial concentrations required by the regimen.
Repeat echocardiography for clinical deterioration, persistent bacteraemia, new murmur or before and after relevant intervention.
After extraction inspect for retained fragments and document the indication, site and timing of any replacement system.
At discharge record antimicrobial end date, access care, anticoagulation plan, dental and skin prevention and emergency return features.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Exposure defines infection

Generator or lead erosion communicates foreign material with skin flora and is infection even without purulence, fever or positive blood cultures.

Lead masses are contextual

A lead-associated echodensity can be thrombus or fibrin; microbiology, pocket findings and embolic features determine whether it represents infection.

Biofilm changes source control

Surface-adherent organisms evade host defence and antibiotics, explaining why retained infected hardware produces relapse after apparently active courses.

Negative imaging can evolve

Small vegetations and prosthetic artefact reduce early sensitivity, so repeat TOE or adjunct imaging is justified when probability remains high.

Reimplantation is a new decision

After extraction, reassess the original device indication; some patients no longer require hardware and avoid a second infection risk.

Mechanical disease outruns antibiotics

Severe dehiscence, regurgitation or fistula needs operative correction even when fever and inflammatory markers begin to improve.

11Common pitfallsFrequent interpretation and management errors.

01
Do not dismiss pocket erosion because the patient is afebrile.
02
Do not aspirate a closed generator pocket to obtain a culture.
03
Do not leave apparently uninvolved leads behind during extraction for definite system infection.
04
Do not rely on a single negative TTE to exclude prosthetic or lead infection.
05
Do not add rifampicin empirically or use it alone before specialist source-control planning.
06
Do not defer cardiac surgery when destructive anatomy causes heart failure or uncontrolled infection.