Silent strike: stroke in context of endocarditis - brain imaging as a catalyst for diagnosis.

Introduction: Endocarditis is a pathology which is rarely encountered in clinical practice that presents itself in various manners, thus posing a great challenge for the clinician in the process of formulating a timely diagnosis, especially given its potentially lethal evolution. The diagnosis of infective endocarditis is based on Modified Duke Criteria. A wide array of complications may accompany endocarditis, including septic or thrombotic emboli to various territories - those occluding branches of cerebral arteries result in ischemic strokes, which may be demonstrated by brain imaging and the symptoms which may range from mild mental status alteration to deep coma. Objective: Assessment of brain imaging as a diagnostic tool for bacterial endocarditis.

Materials and methods: This is a nested case-control study, in which 84 patients with ischemic stroke were enrolled, half of them having endocarditis related stroke (cases), and the other half stroke due to cardioembolism from other sources or to large-artery atherosclerosis (controls).

Results: Brain imaging revealed statistically significant differences between the two cohorts, endocarditis related stroke being more strongly associated with multiple territories involvement, multiple lesions coexistence, watershed lesions, and a greater extent of ischemia all these may serve as valuable diagnostic clues. Among these findings, the presence of multiple lesions has been the most sensitive tool (Sn = 0.786, Sp = 0.857, LR+ = 5.497, LR- = 0.25), while the involvement of multiple arterial territories had the highest specificity and positive likelihood ratio for endocarditis-related stroke (Sn = 0.738, Sp = 0.929, LR+ = 10.394, LR- = 0.282). A larger ischemic lesion as quantified by pc-ASPECTS score (more than by the ASPECTS score) also increases the likelihood of endocarditis as the cause of ischemic stroke, with an AUROC of 0.7361 (95% CI 0.629-0.843).

Conclusions: Early brain imaging could play a crucial role in endocarditis, helping the clinician to suspect this diagnosis. Further studies are needed to understand the role of early brain imaging when Modified Duke Criteria fail to establish the diagnosis.