Prinzmetal's angina in patients with antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is an acquired hypercoagulable disease that is associated with both arterial and venous thrombosis. It is known to cause a spectrum of cardiovascular manifestations including myocardial infarction, stroke, valvular abnormalities, as well as vascular and intracardiac thrombosis. The pathogenesis of myocardial infarction and angina due to APS is thought to be due to coronary thrombosis. Coronary vasospasm without thrombosis can produce myocardial ischemia and chest pain, this is known as Prinzmetal's angina. To our knowledge, Prinzmetal's angina is not known to be associated with APS. In our clinical practice, we came across two cases of APS in which the patients presented with angina and were found to have coronary vasospasm without thrombosis. The finding of these two uncommon diagnoses in multiple individuals raises the possibility that these disorders are associated.