Misconceptions, diagnostic challenges and treatment opportunities in bioprosthetic valve thrombosis: lessons from a case series.
OBJECTIVE
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 aortic position; 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.
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA sorin.pislaru@mayo.edu.
Sorin V
SV
Pislaru
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA.
Imad
I
Hussain
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA.
Patricia A
PA
Pellikka
Anatomic Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA.
Joseph J
JJ
Maleszewski
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA.
Richard D
RD
Hanna
Cardiovascular Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA.
Hartzell V
HV
Schaff
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA.
Heidi M
HM
Connolly
D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001705:Bioprosthesis / Q000009:adverse effects*; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013927:Thrombosis / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D014812:Vitamin K / Q000037:antagonists & inhibitors
D000925:Anticoagulants; D014812:Vitamin K
Anticoagulant therapy; Bioprosthetic valves; Prosthetic valve thrombosis