From the Guidelines
Yes, an echocardiogram should be performed in all patients with Staphylococcus aureus bacteremia (SAB), even when it's only suspected but not yet confirmed. This recommendation is based on the most recent and highest quality study, which emphasizes the importance of early detection of infective endocarditis in patients with SAB 1. The study recommends that transthoracic echocardiography (TTE) should be performed initially, with consideration for transesophageal echocardiography (TEE) if TTE is negative but clinical suspicion for endocarditis remains high. Some key points to consider include:
- The high propensity of S. aureus to cause infective endocarditis, occurring in approximately 25-30% of patients with SAB
- The importance of early detection of endocarditis in management decisions, including the duration of antibiotic therapy and the potential need for surgical intervention
- The potential for serious complications, including heart failure, embolic events, and increased mortality, if endocarditis is not identified and treated appropriately
- The recommendation for echocardiography in all adult patients with bacteremia, with TEE preferred over TTE 1 The echocardiogram should be obtained as soon as possible after blood cultures become positive, ideally within 5-7 days, and repeated within 5-7 days if the initial examination is negative but clinical suspicion remains high 1. Overall, the evidence suggests that echocardiography is a crucial diagnostic tool in the management of patients with SAB, and its use can significantly impact patient outcomes in terms of morbidity, mortality, and quality of life.
From the Research
Echocardiogram in Patients with Possible Blood Culture of Staph Aureus
- The decision to perform an echocardiogram in patients with possible blood culture of Staph aureus should be based on individual patient risk factors and clinical presentation 2, 3, 4, 5, 6.
- Patients with prosthetic heart valves or cardiac rhythm management (CRM) devices should receive early cardiological input and transoesophageal echocardiography due to their high risk of developing infective endocarditis (IE) 2, 3, 5.
- In patients with a clearly defined line-related bacteraemia who do not have a prosthetic valve or CRM device or clinical features of IE, response to treatment could be closely monitored and imaging deferred 2.
- A normal transthoracic echocardiogram (TTE) may be adequate to rule out IE in patients without community-acquired SAB, high-risk cardiac conditions, and intravenous drug use 4.
- The use of echocardiography has increased over time, with a significant association between echocardiography use and lower in-hospital mortality 5.
- A simplified algorithm to guide the use of transesophageal echocardiography (TEE) in SAB cases has been proposed, taking into account individual patient risk factors, mode of acquisition of SAB, and clinical presentation 6.
Risk Factors for Infective Endocarditis
- Presence of prosthetic heart valves or CRM devices 2, 3, 5
- Intravenous drug use 3, 4
- Community-acquired bacteremia 4
- High-risk cardiac conditions 4
- Prolonged bacteremia 3
- Cardiac devices 3