Fatal coronary embolism in infective endocarditis: a case of sudden circulatory collapse

A 48-year-old woman was transferred to our hospital with worsening dyspnoea and intermittent fever over the past 2 months. Transthoracic echocardiography (TTE) upon admission revealed severe mitral regurgitation and vegetations on the mitral valve, measuring up to 16 mm in diameter (Panel A). Blood cultures identified Streptococcus viridans in three separate blood samples, confirming the diagnosis of infective endocarditis (IE). Despite the presence of heart failure and vegetations ≥ 10 mm, conservative antibiotic therapy was pursued due to haemorrhagic cerebral infarction and significant abnormal uterine bleeding caused by a large fibroid. On hospital Day 13, she experienced sudden circulatory collapse followed by pulseless electrical activity. Venoarterial extracorporeal membrane oxygenation was initiated. Repeat TTE showed the disappearance of the previously observed mitral vegetation (Panel B). Contrast-enhanced computed tomography (Panel C) and coronary angiography (Panel D) identified thrombosis of the left main trunk. Revascularization was achieved through aspiration thrombectomy (Panel E); however, the patient succumbed to worsening haemorrhagic stroke 8 h after the cardiac arrest. Histopathological analysis of the aspirated thrombus revealed multiple gram-positive cocci embedded within the thrombus (Panel F). The case highlights the high mortality associated with IE, which can arise from diverse complications. Acute coronary syndrome (ACS) is a rare but potentially fatal event, with an incidence reported to be 2.2% in IE cases; 88% of the ACS cases had a coronary embolism.1 Early consideration of surgical intervention alongside antibiotic therapy may be critical in managing such complex cases. S.Y. has received grant support from Takeda Pharmaceutical, Abbott and Boston Scientific and lecture fees from Daiichi Sankyo and Bristol Myers Squibb. The other authors declare no conflicts of interest. No data were generated or analysed for or in support of this article. This work was supported by the Grants-in-Aid programs of the Japan Society for the Promotion of Sciences (23K06843 and 23KK0300 to H.S.).