Prosthetic valve endocarditis – Indications for surgery

Prosthetic valve endocarditis – Indications for surgery

Prosthetic valve endocarditis is a life threatening situation and often can be refractory to medical therapy, requiring surgical intervention. Indications for surgery in prosthetic valve endocarditis (PVE) include:

1. Persistent bacteremia after 7-10 days
2. Heart failure
3. Early prosthetic valve endocarditis
4. Fungal endocarditis
5. Paravalvular leak
6. Annular or aortic abscess
7. True or false aneurysm
8. Fistula formation
9. New onset conduction disturbance
10. Recurrent peripheral embolization despite therapy

A best evidence topic review suggested that unless patient is a poor surgical candidate, surgery is the treatment of choice in prosthetic valve endocarditis [1]. They recommended early surgery if there is hemodynamic instability, heart failure, valvular dysfunction, dehiscence or annular abscess. In addition they recommended early surgery for prosthetic valve endocarditis due to Staphylococcus aureus.

PALSUSE score has been developed by Spanish Collaboration on Endocarditis to predict in hospital prognosis for valve surgery in endocarditis [2]. PALSUSE score parameters are prosthetic valve, age 70 years or more, large intracardiac destruction, Staphylococcus, urgent surgery, female gender and a EuroSCORE of 10 or more. They noted a mortality rate of 45.4% in patients with PALSUSE score above 3.

Even though heart failure is an important reason for urgent surgery in prosthetic valve endocarditis, it need not indicate a bad prognosis. Large vegetations and uncontrolled infection are considered the main factors associated with high in hospital mortality in those undergoing urgent surgery [3]. In hospital mortality was forty one percent in this series with 46 patients having left sided infective endocarditis. Thirty five percent in hospital mortality for surgery in prosthetic valve endocarditis has been reported by Rekik S and colleagues [4].

The concept of biofilm and role of surgery

Most organisms causing infective endocarditis are capable of producing a nearly impenetrable barrier around them called a biofilm [5]. Biofilm is an extra cellular polysaccharide slime like matrix which can protect the organisms from the host immune mechanisms. It also impedes the efficacy of antimicrobial agents due to poor penetration [6]. Surgery for prosthetic valve endocarditis mechanically disrupts the biofilm and exposes the viable microorganisms to antibiotics and the host immune system. In addition to this surgery also removes infected tissue and foreign material. A full course intravenous antimicrobial therapy is needed after surgery for the complete clearance of the organisms.

References

1. Attaran S, Chukwuemeka A, Punjabi PP, Anderson J. Do all patients with prosthetic valve endocarditis need surgery? Interact Cardiovasc Thorac Surg. 2012 Dec;15(6):1057-61.
2. Martínez-Sellés M, Muñoz P, Arnáiz A, Moreno M, Gálvez J, Rodríguez-Roda J, de Alarcón A, García Cabrera E, Fariñas MC, Miró JM, Montejo M, Moreno A, Ruiz-Morales J, Goenaga MA, Bouza E; Spanish Collaboration on Endocarditis -Grupo de Apoyo al Manejo de la Endocarditis infecciosa en ESpaña (GAMES). Valve surgery in active infective endocarditis: a simple score to predict in-hospital prognosis. Int J Cardiol. 2014 Jul 15;175(1):133-7.
3. Revilla A, López J, Sevilla T, Villacorta E, Sarriá C, Manzano Mdel C, Fulquet E, Pozo E, Mota P, Gómez I, Vilacosta I, San Román JA. In-hospital prognosis of prosthetic valve endocarditis after urgent surgery. Rev Esp Cardiol. 2009 Dec;62(12):1388-94.
4. Rekik S, Trabelsi I, Znazen A, Maaloul I, Hentati M, Frikha I, Ben Jemaa M, Hammami A, Kammoun S. Prosthetic valve endocarditis: management strategies and prognosis: A ten-year analysis in a tertiary care centre in Tunisia. Neth Heart J. 2009 Feb;17(2):56-60.
5. Elgharably H, Hussain ST, Shrestha NK, Blackstone EH, Pettersson GB. Current Hypotheses in Cardiac Surgery: Biofilm in Infective Endocarditis. Semin Thorac Cardiovasc Surg. 2016 Spring;28(1):56-9.
6. Pettersson GB, Hussain ST. Current AATS guidelines on surgical treatment of infective endocarditis. Ann Cardiothorac Surg. 2019 Nov;8(6):630-644.