Left Ventricular Assist Device–Induced Coagulation and Platelet Activation and Effect of the Current Anticoagulant Therapy Regimen

Abstract

Left ventricular assist devices (LVADs) are mechanical pumps that enhance cardiac function in patients with heart failure. In all, 7 patients with an LVADs (1.8 international normalized ratio warfarin, 81 mg aspirin) were evaluated monthly for 3 months for platelet and coagulation activation (controls: 5 healthy adults and 5 patients having warfarin). Platelet works revealed greater inhibition of collagen (31.8% vs 7.9%; P = .004), arachidonate- (30.9% vs 8.2%; P = .001), and adenosine diphosphate- (10.9% vs 6.1%; P = .004)-induced platelet aggregation for LVADs. Thrombelastography (recalcified whole blood) showed inhibition of clot initiation time (R; 8.81 vs 6.02 min; P = .001) and stronger clot formation (maximum amplitude; 69.1 vs 64.9 mm; P = .016). Platelet function determined by plateletMapping and flow cytometry was within the normal range. The LVADs had increased ratio of von Willebrand Factor (vWF) antigen and vWF propeptide, indicating increased degradation of vWF (2.04 vs 1.44; P = .144). Coagulation and platelet activation caused by LVAD is suppressed by pharmacotherapy, yielding a profile similar to that of patients on warfarin alone.