Natural history and classification of occlusive thromboaortopathy (Takayasu's disease).

Fifty-four Japanese patients with occlusive thromboaortopathy (OTAP), including four males, were classified according to evidence of complications attributed to OTAP at the time when the diagnosis was established: Group I, uncomplicated OTAP with or without the involvement of the pulmonary artery. Group II, mono-complicated OTAP: presence of a single complication together with uncomplicated OTAP. Group II was subdivided according to severity into group IIa - mild or moderate form, and group IIb - severe form. Group III, multi-complicated OTAP with two or more complications as well as uncomplicated OTAP. The five-year survival rate after established diagnosis was 83.1%. Seven patients died of OTAP within five years, but all had belonged to group IIb or III.