Nonbacterial thrombotic versus infective endocarditis: A necropsy study of 320 cases

The precise relationship between nonbacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE) remains to be clearly established, some believing that IE might develop from NBTE once the latter becomes secondarily infected during bacteremia. To compare the features of the two lesions, 175 cases of NBTE and 145 cases of IE encountered in more than 25,000 autopsies performed over a period of 24 years (1970–1993) were reviewed, and the relevant clinical, pathological, and bacteriological findings assessed. The results show that IE is a genuine suppurative infection of cardiac valves ab initio, whereas, in NBTE, inflammation is lacking and the lesion is a result of a usually paraneoplastic disturbance of thrombosis/thrombolysis.