Antithrombogenic Regimen for Clinical Use of Pneumatic Ventricular Assist Device

Summary

Antithrombogenic regimens for pneumatic ventricular assist devices (VADs) were evaluated in 77 VADs used clinically in a total of 70 patients. Macroscopic thrombus formation in the devices was assessed in relation to potential risk factors, including hematological and hemodynamic derangements, during use of the VAD. Effects of varions antithrombogenic regimens were assessed on the basis of this risk analysis. A thrombus score was used to quatititate the grade of thrombosis. As a linear increase in the thrombus score was noted in accordance with increase in support duration, a time-adjusted thrombus score was calculated to compare scores in anticoagulant groups with different pumping duration. The scores appeared to be high in patients in those groups which received gabexate mesilate (GM, a protease inhibitor). Heparin was not demonstrated to be effective in this study. Univariate risk analysis showed that the use of GM, low-flow pumping, prolonged pumping, and semi-normal platelet count were significantly correlated with the incidence and grade of thrombosis. A multivariate regression analysis also indicated that the use of GM, low-flow, and prolonged pumping were detrimental to anti-thrombogenicity. As the use of GM was demonstrated to be predominantly detrimental, its withdrawal from use should lead to a substantial reduction in the incidence and grade of thrombosis.