Effect of Different Oral Anticoagulant Intensities on Prothrombin Fragment 1+2 in Thai Patients with Mechanical Heart Valve Prosthesest
PANUTSAY A TIENTADAKUL, M.D.*, NISARAT OPARTKIATTIKUL, M.D., Ph.D. (Medical Sciences)*, WANIDA SANGTAWESIN, M.D., M.Sc. (Medical Science)*, PRINY A SAKIY ALAK, M.D., M.Sc., F.A.C.S. **
Affiliation : * Department of Clinical Pathology, ** Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. t Present at Siriraj Scientific Congress of the 50th Anniversary (Golden Jubilee) Celebrations of His Majesty's Accession to the Throne, March 4-8, 1996, Bangkok, Thailand.
Abstract
The minimal intensity of oral anticoagulant required for antithrombotic protection in
patients with a mechanical heart valve is still debatable, and that of the Westerner may not be
directly applied to Thai patients. Our preliminary clinical review suggested that International Nor-
malized Ratio (INR) 2-3 might be enough but it needs further supporting evidence. Therefore, we
studied the effect of different anticoagulant intensities, expressed as INR, on the in vivo coagula-
tion activation by measuring prothrombin fragment 1 +2 (F1 +2) in 116 patients with mechanical
heart valve replacements. The patients had received warfarin for not less than one month with dif-
ferent intensities. The mean ± S.D. of F1+2 level in 30 normal controls was 0.7±0.17 nmol/L.
After excluding two outliers, the maximum linear correlation between INR and Fl +2 was -0.658
(p Keywords :
