Association between nonbacterial thrombotic endocarditis and hypoxigenic pulmonary diseases

Observation of patients with nonbacterial thrombotic endocarditis (NBTE) in the setting of hypoxia from various lung diseases raised the question of a possible pathogenetic relationship between hypoxia and the development of NBTE. We reviewed 50 autopsied patients with NBTE and compared them with 50 age/race/gender-matched control patients without NBTE. We noted the lung weight and graded the histopathological severity of lung involvement by disease, clinical respiratory compromise, and the extent of any cancer present. Patients with NBTE had heavier lungs (P < 0.01) and histologically and clinically more severe pulmonary disease (both P < 0.005). There was no statistically significant difference in the extent of metastatic cancer between the NBTE patients and the controls (P > 0.5). When patients with cancer were excluded from the group of NBTE cases, there was still a statistically significant preponderance in the mean lung injury and clinical compromise scores of the NBTE patients (both P < 0.05), but the difference in lung weight was no longer statistically significant (P > 0.05). The study suggests that, in some patients, hypoxia may lead to NBTE, possibly through altered coagulation states.