Invasive Aortic Valve Endocarditis: Clinical and Tissue Findings From a Prospective Investigation.

BACKGROUND: Advanced aortic valve infective endocarditis (IE) with progression and destruction beyond the valve cusps-invasive IE-is incompletely characterized. This study aimed to characterize further the invasive disease extent, location, and stage and correlate macroscopic operative findings with microscopic disease patterns and progression. METHODS: A total of 43 patients with invasive aortic valve IE were prospectively enrolled from August 2017 to July 2018. Of these patients, 23 (53%) had prosthetic valve IE, 2 (5%) had allograft IE, and 18 (42%) had native aortic valve IE. Surgical findings and intraoperative photography were analyzed for invasion location, extent, and stage. Surgical samples were formalin fixed and analyzed histologically. The time course of disease and management were evaluated. RESULTS: Pathogens included Staphylococcus aureus in 17 patients (40%). Invasion predominantly affected the non-left coronary commissure (76%) and was circumferential in 15 patients (35%) (14 had prosthetic valves). Extraaortic cellulitis was present in 29 patients (67%), abscess in 13 (30%), abscess cavity in 29 (67%), and pseudoaneurysm in 8 (19%); 7 (16%) had fistulas. Histopathologic examination revealed acute inflammation, abscess formation, and lysis of connective tissue but not of myocardium or elastic tissue. Median time from onset of symptoms to antibiotics was 5 days, invasion confirmation 15 days, and surgery 37 days. Patients with S aureus had a 21-day shorter time course than patients non-S aureus. New or worsening heart block developed in 8 patients. CONCLUSIONS: Advanced invasive aortic valve IE demonstrates consistent gross patterns and stages correlating with histopathologic findings. Invasion results from a confluence of factors, including pathogen, time, and host immune response, and primarily affects the fibrous skeleton of the heart and expands to low-pressure regions.

Late-onset native valve endocarditis caused by Corynebacterium kroppenstedtii.

Corynebacterium kroppenstedtii is an emerging cause of granulomatous mastitis and recurrent breast abscesses in women, but data on its clinical relevance in nongynecological disease conditions are limited. Here, we report the first case of a late-onset endocarditis of a native aortic valve in a 73-year-old male patient who presented with symptomatic aortic insufficiency. Echocardiography and cardiac computed tomography revealed the perforation of the noncoronary cusp and a large perivalvular abscess cavity. Hence, the surgical replacement of the aortic valve and aortic root were performed. Intraoperatively obtained tissue specimens grew C. kroppenstedtii and the patient made a full recovery after a 6-week course of antibiotic treatment. We briefly review the literature pertaining to antimicrobial susceptibility patterns of C. kroppenstedtii and available treatment recommendations. Our report calls for further studies to assess the role of this bacterium as a causative agent of infections other than granulomatous mastitis.

Percutaneous device closure of a large complex aortic root pseudoaneurysm.

Pseudoaneurysm of the aorta is a rare and high-risk complication of native aortic valve endocarditis and can develop following cardiac surgery for aortic valve and root disease. If left untreated, there is a significant risk of aortic wall rupture and fatality. Given the high risk of mortality associated with traditional open surgical repair of aortic pseudoaneurysms, endovascular approach is a potentially favourable alternative. We describe a unique case of a young woman with a large and complex paraprosthetic pseudoaneurysm with multiple communicating fistulae which was successfully percutaneously treated with two occluder devices. In this technically challenging case, a minor but unique procedural complication is also illustrated.