EVALUATION OF INTRAVASCULAR HEMOLYSIS BY HAPTOGLOBIN ADMINISTRATION AFTER PROSTHETIC VALVE-REPLACEMENT

Although the measurement of serum haptoglobin (S-Hp) is of great use f or evaluation of intravascular hemolysis, it is not applicable in pati ents with mechanical prosthetic valves because S-Hp is virtually absen t. We administered haptoglobin preparation to 10 patients with Bjork-S hiley mitral prosthetic valves and 10 patients with the same aortic pr osthetic valves. Serum haptoglobin levels were measured periodically a fterwards. The maximum haptoglobin levels (Hp (max)), serum, haptoglob in reducing rate ((Hp - DELTA Hp)/ DELTA t) and expected haptoglobin d isappering time (hours) were obtained from the subsequent samples. The screening studies which were performed at the same time were not pred ictors of difference in the 2 groups. On the other hand, serum haptogl obin reducing rate and expected haptoglobin disappearing time indicate d that hemolysis is higher in patients with an aortic prosthetic valve than with a mitral prosthetic valve. This haptoglobin administration test seems to be useful for the comparative examination of the intrava scular hemolysis caused by the difference in the position of the prost hetic valve.