From the Guidelines
MRI is not recommended over echo for diagnosing vegetation on prosthetic heart valves, as the provided evidence does not support the use of MRI for this specific indication, and TEE is considered the most reliable noninvasive test for defining this disease. The evidence suggests that TEE is superior to TTE in the visualization of both vegetations and perivalvular complications, with a sensitivity range of 90% to 100% in native valve endocarditis and slightly lower in prosthetic valve endocarditis 1. While MRI may provide superior soft tissue characterization, the provided evidence does not support its use as a first-line diagnostic test for prosthetic valve endocarditis.
Some key points to consider when evaluating prosthetic valve endocarditis include:
- TEE is recommended in all patients with known or suspected infective endocarditis (IE) when TTE is nondiagnostic, when complications have developed or are clinically suspected, or when intracardiac device leads are present 1
- The sensitivity of TEE in native valve endocarditis ranges from 90% to 100%, with sensitivity ranges slightly lower in prosthetic valve endocarditis 1
- TEE is superior to TTE in the visualization of both vegetations and perivalvular complications, which can be anatomic or hemodynamic in nature 1
- The positive predictive value for TEE in both native valve endocarditis and prosthetic valve endocarditis is 90% 1
In terms of limitations, TEE may not differentiate between active and healed vegetations and may not discriminate between thickened valves or valvular nodules and vegetations 1. However, TEE is considered the most reliable noninvasive test for defining this disease, and its use is recommended in conjunction with TTE for the comprehensive evaluation of hemodynamics and anatomy in patients with IE.
It's worth noting that the provided evidence does not mention the use of MRI as a diagnostic test for prosthetic valve endocarditis, and therefore, it's not possible to recommend its use based on the available evidence. The optimal approach often involves using both TTE and TEE, starting with TTE and proceeding to TEE when results are inconclusive or more detailed tissue characterization is needed 1.
From the Research
Comparison of MRI and Echo for Diagnosing Vegetation on Prosthetic Heart Valve
- There are no direct studies comparing MRI and echo for diagnosing vegetation on prosthetic heart valve in the provided evidence.
- However, the studies compare the effectiveness of different echocardiography techniques (transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and intracardiac echocardiography (ICE)) and cardiac computed tomography (CT) in diagnosing prosthetic valve endocarditis 2, 3, 4, 5, 6.
Effectiveness of Echocardiography Techniques
- TEE is superior to TTE in detecting vegetations and other complications in prosthetic valve endocarditis, with a sensitivity of 92% compared to 26% for TTE 2.
- TEE is also more effective in detecting abscesses, paravalvular leakage, and inflammatory infiltration compared to TTE 3, 4.
- ICE can be useful in patients with suspected prosthetic valve endocarditis and inconclusive findings on TTE and TEE, with a low frequency of relapse among patients in whom endocarditis could not be confirmed by ICE 5.
Role of Cardiac Computed Tomography
- Cardiac CT can be useful in diagnosing prosthetic valve endocarditis, with a sensitivity of 96% for detecting vegetations and 89% for detecting abscesses 3.
- CT is superior to echocardiography in diagnosing paravalvular abscesses, vegetations, and inflammatory infiltration, but echocardiography has a higher diagnostic value for paravalvular leakage 3.