From the Guidelines
The risk of prosthetic valve endocarditis is highest in the first 3–6 months after prosthetic valve implantation. This initial period represents the time of greatest vulnerability as the prosthetic material becomes incorporated into the surrounding tissue 1. During this time, the surgical wound is still healing, and the prosthetic valve material has not yet been fully endothelialized, leaving exposed surfaces that can serve as attachment sites for circulating bacteria. Blood-borne pathogens can more easily adhere to these non-endothelialized surfaces of the prosthetic valve, initiating infection. Additionally, any perioperative contamination may manifest during this time period.
Some key points to consider in the management of patients after heart valve surgery include:
- The risk of prosthetic valve endocarditis remains relatively constant after the initial 3-6 months 1
- There is a lifelong requirement for antibiotic prophylaxis for dental, endoscopic, and surgical procedures 1
- Vigilance for the symptoms and signs of prosthetic valve endocarditis throughout follow-up is essential 1
- Patients with annuloplasty rings are also at risk, although the risk is lower than that of prosthetic valves 1
It's also worth noting that other guidelines, such as those from the American College of Cardiology/American Heart Association, recommend prophylaxis against infective endocarditis for patients with prosthetic cardiac valve or prosthetic material used for cardiac valve repair who undergo dental procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa 1. However, the most recent and highest quality study prioritizes the first 3-6 months as the highest risk period 1.
From the Research
Risk Period for Prosthetic Valve Endocarditis
The risk period for prosthetic valve endocarditis after valve replacement can be divided into two main categories: early and late onset.
- Early onset prosthetic valve endocarditis occurs within the first year after valve replacement, with the majority of cases happening within the first 60 days 2.
- Late onset prosthetic valve endocarditis occurs after the first year, with an incidence rate of around 0.5 to 1% per year 3.
Time Frame with the Highest Risk
The time frame with the highest risk for prosthetic valve endocarditis is within the first year after valve replacement, particularly within the first 60 days 2.
- During this period, the risk of prosthetic valve endocarditis is highest due to the possibility of intraoperative contamination or postoperative infections at extracardiac sites 2.
- The mortality rate for early onset prosthetic valve endocarditis is around 60-70% 3, making it a critical period for close monitoring and prevention.
Factors Influencing the Risk Period
Several factors can influence the risk period for prosthetic valve endocarditis, including: