Neurological Complication of Infective Endocarditis: A Prospective Multi-site Cohort Study

The main objective of this study is to better estimate the rate of infectious intracranial aneurysms (IIA) in proved infective endocarditis (IE). It also aims to identify MRI markers capable of accurately predicting (or excluding) IIA; to assess the impact of the different MRI abnormalities on the outcome; to capture the real-world management of EI with neurological complications in comprehensive IE centers in France

Rationale:

The incidence of Infective endocarditis (IE) in developed countries is approximately 3-15 per 100,000 pers-years. Discharge mortality remains 15-30% and therapeutic management suffers in many ways from the paucity of randomized studies.(1) Symptomatic neurological complications, which occur in 15 to 30% of patients, are the most frequent extra-cardiac complication of IE and are deemed to worsen the outcome of EI.(2,3) Among this overall neurological complications, Infectious Intracranial Aneurysms (IIA) are a relatively rare, yet probably underestimate, vessel wall injury caused by septic emboli, with potentially intracranial bleeding for the patients.

Neuroimaging in the context of IE has gained wide acceptance and is encouraged in the current guidelines.(4,5) Nevertheless the benefit of early neuroimaging to optimize the initial therapeutic management remains debated.(6,7) While the appearance and the frequency of the various neurologic complications of EI are well known thanks to prospective cohort studies with systematic pre-therapeutic MRI(8-10), several clinically relevant questions are still unknow or approximate, including: 1/ What is the rate of IIA in proved EI. The current gold standard for the detection of these small and distally located aneurysms remains Digital Subtraction Angiography (DSA) and to our knowledge, there is no prospective unbiased cohort of IE with systematic DSA available in the literature. 2/ Are there MRI signs correlated with the presence of IIA on DSA? Several MRI markers such as sulcal SWI lesion or cerebral microbleeds (CMBs) with contrast enhancement look promising (10), but validation in unbiased prospective studies with systematic MRI and DSA is needed. 3/ What is the impact on the outcome of the different MRI abnormalities and of unruptured and ruptured IIA? As previously mentioned, the value of both MRI and DSA remain unclear to guide the acute therapeutic management of EI. A recent French survey highlighted differences between university Hospital in France in the management of IIA. Thus, the analysis of the current management of EI with neurological complications could also help at informing the design of future randomized trials.

Questions:

1. Better estimate the rate of IIA in proved EI.
2. Identify MRI markers able to accurately predict (or exclude) IIA.
3. What is the impact of different MRI abnormalities on the outcome?
4. Capture the real-world management of EI with neurological complications in comprehensive EI centers in France

Design and setting:

Multi-site, prospective cohort study, with standardized imaging protocol, in academic centers where MRI and DSA are performed routinely in patients with EI.

Ethics:

As for all non-interventional studies of de-identified data, written informed consent will be waived and a commitment to compliance (Reference Methodology CPMR-4) will be filed to the French data protection authority (CNIL) prior to data centralization, in respect to the General Data Protection Regulation. Patients and proxies will be informed they could oppose the use of their data for research purposes.

Eligibility Criteria:
Inclusion Criteria:

* patients with left-sided active infective endocarditis (IE) satisfying modified Duke Criteria,
* patients who underwent both digital subtraction angiography (DSA) and brainMRI (as part of routine care)
* DSA protocol with 3D rotational for both carotids and one vertebral artery
* MRI/MRA standardized protocol including at least: Diffusion, FLAIR, 3D SWI, 3DT1SE and post gadolinium 3DT1SE and 3D TOF (large field: from the vertex to the magnum foramen).

Exclusion Criteria:

* uncertain diagnosis of IE by infectious disease consultants
* patients with chronic IE
* MRI performed after the completion of Infectious intracranial aneurysms (IIA) treatment
* MRI performed without contrast injection or complete protocol
* More than 48-hours delay between performing MRI and DSA