"The end of good luck''--long-term survival without anticoagulation: a case report and review of the literature.

Long-term anticoagulation in patients with metallic prosthetic valve disease is required according to current guidelines. We describe a patient with a functioning mitral mechanical valve without anticoagulation for 27 years. A 46-year-old man admitted to the emergency department with complains of palpitation. The patient had a mitral valve replacement because of severe mitral stenosis. He discontinued warfarin treatment 1 month after surgery because of the unavailability of this drug in Turkey. Transthoracic echocardiography revealed functioning metalic mitral valve with a mean gradient of 9 mm Hg. Fluoroscopy showed normal excursions of the mechanical mitral valve. Transesophageal echocardiography was performed and revealed fresh thrombus formation in the left atrial appendix. Admission international normalized ration (INR) level was 1.79. Due to the higher INR level and long-term survival, genetic analysis of warfarin polymorphism was performed. There was a homozygous mutation in the vitamin K epoxide reductase complex 1 (VKORC1) 1173C>T and 1639G>A genotypes. The possible explanations of long-term survival and baseline higher INR level were linked to the mutation in warfarin metabolism. We also briefly review the literature.