Pulsatile Strangulation of the Aorta　― A Rare Presentation and Etiology of Infective Endocarditis ―

A 76-year-old man presented with a fever of 2 days’ duration. He had undergone bioprosthetic aortic valve replacement for aortic regurgitation 1 year ago. Blood cultures yielded persistent Corynebacterium striatum. Prompt transthoracic echocardiography (TTE) revealed preserved function of the prosthetic valve without vegetations, but he declined transesophageal echocardiography (TEE). After 4 weeks of daptomycin, however, progressive dyspnea developed and subsequent TTE indicated a newly developed false lumen surrounding the aortic valve (Figure A; Supplementary Movie) that was dynamically compressing the aortic root, resulting in severe regurgitation. TEE showed a direct connection between the false lumen and the left ventricle. Outward flow in systole caused pulsatile compression of the aorta. Vegetations and septa were also observed (Figure B). 3D echocardiography and computed tomography confirmed the diagnosis of aortic pseudoaneurysm (Figure C,D). Unfortunately, the patient died during surgery.

Figure.

Echocardiography showing (A) false lumen (arrowheads) and (B) vegetations (arrow). Aortic pseudoaneurysm on (C) 3D echocardiography (arrows) and (D) computed tomography.

Corynebacterium striatum is rarely reported as a pathogen and usually occurs in immunocompromised patients.^1,2 Initial screening is usually negative.¹ Although most cases of early endocarditis are successfully treated medically, a daptomycin-resistant strain has been reported with potential to cause invasive disease.² Despite daptomycin susceptibility in the present case, the complicated aortic pseudoaneurysm suggested failure of medical therapy, with a major reason being the delayed diagnosis. Follow-up TTE should have been performed within 1 week of the first examination, which may have changed the outcome. In conclusion, this case sheds light on the importance of persistent screening for endocarditis even if the pathogen is regarded as atypical and minor.

Conflicts of Interest / Funding

None.

Supplementary Files

Supplementary Movie. Compression of the false lumen.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-20-0495

References

• 1.   Rasmussen M, Mohlin AW, Nilson B. From contamination to infective endocarditis: A population-based retrospective study of Corynebacterium isolated from blood cultures. Eur J Clin Microbiol Infect Dis 2020; 39: 113–119.
• 2.   Tran TT, Jaijakul S, Lewis CT, Diaz L, Panesso D, Kaplan HB, et al. Native valve endocarditis caused by Corynebacterium striatum with heterogeneous high-level daptomycin resistance: Collateral damage from daptomycin therapy? Antimicrob Agents Chemother 2012; 56: 3461–3464.