Researchers found that patients with left ventricular assist devices (LVADs) showed a high rate of clinically relevant bleeding complications following device implantation, according to a new study published in the Journal of Thrombosis and Haemostasis.

For patients undergoing continuous-flow LVAD implantation, bleeding complications had previously been reported to be the most common adverse event, according to the study investigators. Many aspects of the coagulation system appear to be involved, and LVAD surface characteristics and nonphysiological shear stress associated with these devices may be linked to coagulation changes.

In this prospective study conducted by researchers at the University of Leipzig in Germany, patients with heart failure who were undergoing continuous-flow LVAD implantation were evaluated. Patients were included in either a bleeder group (19 patients) or a nonbleeder group (20 patients); the latter group consisted of patients who did not experience postoperative or nonsurgical bleeding (NSB) after implantation.


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The study investigators analyzed multiple patient characteristics and laboratory parameters with regard to bleeding outcomes. Flow cytometry was used for estimating the abundance of platelet receptors, and platelet aggregation capacity was measured using aggregometry.

The investigators found that patients in the bleeder group showed reduced surface expression levels of the platelet receptors P-selectin and GPIba in comparison with levels of these receptors in nonbleeders (P <.01 and P =.04, respectively) in unstimulated platelets.

Results of a fluorescence-based assay indicated that bleeders showed lower levels of platelets expressing adenosine diphosphate (ADP)-stimulated P-selectin and platelet endothelial cell adhesion molecule-1 (PECAM-1) in comparison with nonbleeders (P =.04 and P =.03, respectively). A possible trend of greater abundance of reactive oxygen species was suggested with platelets of bleeders versus nonbleeders (P =.05).

The investigators considered the evidence of oxidative stress and the lower levels of GPIba, P-selectin, and ADP-stimulated P-selectin and PECAM-1 in the bleeder group to represent possible biomarkers for risk of NSB after LVAD implantation.

“Taken together, it should be considered that understanding the complex molecular mechanisms of platelet integrity is crucial for prevention and management of NSB after LVAD implantation,” the investigators wrote in their report. They concluded that changes in platelet receptors, in addition to oxidative damage, may be linked to the rate of spontaneous hemorrhage associated with LVAD support.

Reference

Klaeske K, Dieterlen MT, Eifert S et al. Device-induced platelet dysfunction in patients after left ventricular assist device implantation. J Thromb Haemost. Published online February 26, 2021. doi:10.1111/jth.15279