Antibiotics in Prosthetic valve endocarditis: AIIMS Guidelines

All India Institute of Medical Sciences, Delhi has released AIIMS Antibiotics Policy which has been prepared by the Department of Medicine with Multidisciplinary collaboration. The guidance for Infections pertaining to cardiology includes Prosthetic valve endocarditis the salient features of which are hereunder.

Prosthetic valve endocarditis (PVE): Traditionally, PVE has been classified as early, intermediate or late depending on the onset of symptoms of endocarditis following valve replacement surgery.

Early-onset PVE (within 60 days of surgery)- healthcare-acquired infections - Staphylococcus aureus commonest

Intermediate-onset PVE- 60 to 365 days- mix of healthcare- and community-acquired infections- coagulase-negative Staphylococcus (CONS) commonest

Late-onset PVE- more than 1 year - resemble native valve endocarditis (NVE)-S. aureus and CoNS

Indian studies have also shown predominance of gram positive cocci infections followed by non-HACEK gram negative bacilli in IE. A study from Hyderabad showed that Staphylococcus aureus constitutes around 30% of PVE cases. In this study methicillin resistant coagulase negative Staphylococcus spp.(MRCONS) infection constituted around 36% of culture positive PVE. Remaining 30 % was caused by non-HACEK gram negative bacilli.

When to suspect: -

Prosthetic valve endocarditis should be suspected in any patient with unexplained fever, night sweats, or signs of systemic illness after valve replacement surgery.

How to confirm –

Blood cultures should be obtained before initiation of antibiotic therapy. In critically ill patients, a minimum of three cultures from different venipuncture sites should be drawn over one hour before starting empiric therapy. In non–critically ill patients in whom endocarditis is suspected, therapy may be delayed until the results of blood cultures and echocardiography are available. Obtaining more than three blood cultures typically yields only minimal additional diagnostic information.

Baseline electrocardiography should be performed in patients with infective endocarditis so that new cardiac manifestations can be recognized early (e.g., extension of valvular disease into the conduction system, ischemia secondary to emboli to the coronary circulation). Echocardiography should be performed to identify valvular abnormalities in all patients in whom there is moderate or high suspicion of endocarditis. Transthoracic echocardiography is usually the initial imaging modality but has a modest sensitivity only. However, transesophageal echocardiography may be necessary in some patients, such as those with staphylococcus bacteremia, limited transthoracic windows because of obesity or mechanical ventilation, a prosthetic valve that renders visualization difficult secondary to shadowing, a history of endocarditis, or a structural valve abnormality.

a. Empiric:

Ceftriaxone 2gm iv OD plus Gentamicin 80 mg TDS plus Vancomycin 1g BD plus Rifampicin 300mg TDS

-Total duration at least 6 weeks

-Rifampicin to be added after 3 days

-In beta lacatam allergy- Inj Vancomycin 1g IV BD instead of beta-lactams

-Carbapenem can be used in place of ceftriaxone in suspicion of Gram negative sepsis

-Vancomycin can be replaced with Teicoplanin IV 10mg/kg loading BD X 3 doses, then 10mg/kg IV OD

b. Penicillin-susceptible Streptococci:

Preferred: Ampicillin 2gm Six times daily

Alternative: Ceftriaxone 2 g IV OD

-In beta lacatam allergy- Inj Vancomycin 1g IV BD instead of beta-lactams

-Amoxicillin 100-200 mg/kg/day in four to six divided doses can be used instead of ampicillin

-Note: Minimum duration for viridians group of streptococci is 2wks (depending on clinical response)

c. Penicillin resistant Streprococci:

Preferred: Ampicillin 2gm IV Six times daily plus Gentamicin 240 mg IV OD

Alternative: Ceftriaxone 2 g IV OD Plus Gentamicin 240 mg IV OD

Note: Gentamicin to be given only for first two weeks

d. MSSA:

Preferred: Inj Cefazolin 2gm iv TDS plus Rifampicin 300mg TDS plus Gentamicin 80mg TDS

-In beta lacatam allergy- Inj Vancomycin 1g IV BD instead of beta-lactams

-Gentamicin only for 1st 2 weeks

e. MRSA:

Preferred: Vancomycin 1g IV BD plus Rifampicin 300mg TDS plus Gentamicin 80mg TDS

- Gentamicin only for 1st 2 weeks

f. Enterococcus:

Ampicillin and gentamicin susceptible:

Preferred: Ampicillin + gentamicin (80 mg IV q8h)

Alternative: Ampicillin 2gm IV six times daily plus Ceftriaxone 2 g IV BD

Penicillin susceptible and high-level gentamicin resistant (HLAR):

Preferred: Ampicillin 2gm IV six times daily plus Ceftriaxone 2 g IV BD

Resistance to penicillin but Vancomycin- and Aminoglycoside-Susceptible Penicillin-Resistant

Preferred: Vancomycin 1g BD Plus Gentamicin 80 mg TDS

Alternative: Daptomycin 10-12 mg/kg OD or Teicoplanin 10 mg/kg iv 12 hrly 3-doses f/b iv OD can be used instead of vancomycin

Resistant to Penicillin, Aminoglycosides, and Vancomycin:

Preferred: Linezolid 600 mg IV BD

Alternative: Daptomycin 10–12 mg/kg OD

g. Fungal

Preferred:

-Liposomal Amphotericin B 3-5 mg/kg IV OD with or without Flucytosine 25mg/kg QID orally

-Step down to Fluconazole 400-800 mg/day once blood culture sterile and organism sensitive to Fluconazole

Alternative: Caspofungin 150 mg IV OD or Micafungin 150 mg IV OD or Anidulafungin 200mg IV OD

Remarks:

-Surgical excision is recommended for fungal endocarditis.

-Long term suppression with fluconazole 400 to 800 mg/day.

-If fluconazole resistant, can use voriconazole or Posaconazole