The role of endocarditis in sudden cardiac death: highlighting the value of the autopsy, pathological features and cardiac complications.

ABSTRACT Objective Endocarditis is increasing in incidence due to growing numbers of cardiac interventions, valve replacements and immunosuppressants. It can be difficult to diagnose clinically, has high mortality and can present as sudden cardiac death (SCD) with few/subtle preceding symptoms. True incidence of SCD related to endocarditis is unknown. Methods Retrospective analysis of UK national database of 6000 cases of SCD, 1994-2020, for “endocarditis” as cause of death. Results Of 30 cases (0.50%), 19(63%) were male and mean age was 36.2 ± 20.1 years. Post-mortem examination showed the aortic valve (AV) was solely affected in 13(43%), mitral in 9(30%), tricuspid in 2(6.7%) and pulmonary in 1(3.3%). Three cases (10%) had more than one valve affected and 2(6.7%) were non-valvular affecting the ascending aorta. Vegetations ranged from small easily-missed irregularities to large fungating masses. Ten (33%) patients developed aortic abscesses, 2 of which had aneurysms, 13 (43%) had coronary artery septic emboli with micro-abscesses and myocardial microinfarction, and 2 (6.7%) were healed endocarditis with perforation and regurgitation with ventricular remodelling. Thirteen (43%) had an identifiable underlying valve abnormality or replacement, most common being a bicuspid aortic valve (7;54%). Conclusions This study highlights that although rare, endocarditis is an important cause of SCD in those with normal valves, valvular disease and valve replacement surgery. Absence of a pre-mortem diagnosis in 70% of our cohort highlights the need for detailed analysis of the heart and cardiac valves at autopsy. Gross appearance of vegetations varies widely and can be missed. Awareness of associated cardiac complications is required for elucidation of the cause of death and will provide valuable lessons for clinicians.