Development of Non-bacterial Thrombotic Endocarditis after Percutaneous Transvenous Mitral Commissurotomy for Severely Calcified Mitral Stenosis.

Abstract

SUMMARYWe encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC. ( 1-3) With increasing performance of PTMC, the therapeutic effectiveness of this procedure has come to be widely accepted despite its risk.2, 3) Furthermore, an indication of PTMC has been extended to include even relatively complicated cases. To date, there have been no reports of the occurrence of non-bacterial thrombotic endocarditis (NBTE) [4][5][6][7][8][9][10] at the dilated site after this procedure. We report a case of thrombus formation that occurred insidiously as a rare complication of PTMC.