Medline ® Abstract for Reference 41

OBJECTIVES: Bioprosthetic valve thrombosis (BPVT) is a rare but potentially life-threatening complication. Current guidelines favour surgery or thrombolysis as initial treatment. We set forth to characterize timing, diagnostic criteria and treatment strategies in BPVT.

METHODS: A free-text search tool was used to identify patients diagnosed with BPVT at Mayo Clinic between 1997 and 2013. We compared patients treated initially with vitamin K antagonists (VKA group; N = 15) versus surgery/thrombolysis (non-VKA group; N = 17).

RESULTS: Peak incidence of BPVT was 13-24 months after implantation in both groups. VKA and surgery/thrombolysis decreased prosthetic mean gradients to a similar extent (VKA group: 13±5 to 6±2 mmHg in mitral position, 9±3 to 5±1 mmHg in tricuspid position and 39±3 to 24±7 mmHg in aortic/pulmonary position; non-VKA group: 16±12 to 5±1 mmHg in mitral, 10±5 to 4±1 mmHg in tricuspid and 57±9 to 18±6 mmHg in aorticposition; P = 0.59 for group effect). NYHA class improved in 11 of 15 patients in the VKA group and 10 of 17 patients in the non-VKA group (P = 0.39). There were no deaths, strokes or recognized embolic events; 1 patient in each group experienced gastrointestinal bleeding requiring transfusion. Index transthoracic echocardiogram formally identified BPVT in a minority of patients.

CONCLUSIONS: BPVT may occur late after surgical implantation. VKA therapy resulted in haemodynamic and clinical improvement with minimal risk, and should be considered the first-line therapy in haemodynamically stable patients. Echocardiographic criteria for improving BPVT diagnosis are proposed.