Protamine Sulfate During Transcatheter Aortic Valve Implantation

Overview

Transcatheter aortic valve implantation (TAVI) is a new, rapidly emerging standard of care in inoperable and high-risk patients with severe, symptomatic aortic stenosis. Information regarding reversal of unfractionated heparin with protamine sulfate in order to facilitate access site closure is scarce and based on expert consensus. Clinical practice varies between centers. Protamine sulphate may decrease the amount of bleeding complications related to the access-site. The impact on possible thromboembolic complications is unknown. Both bleeding and thromboembolic complications increase mortality after TAVI. A randomized trial is required in order to assess impact of protamine sulfate on prevalence and extent of bleeding and thromboembolic complications.

Information regarding reversal of unfractionated heparin (UFH) with protamine sulfate (PS) is based on expert consensus from 2012, which recommends use of UFH in order to achieve activated clotting time (ACT) \> 300 seconds as well as UFH reversal with PS in case of TAVI via transapical access as well as transfemoral access with the exception of cases with minimal bleeding risk. However, the clinical practice varies between centers - some use PS routinely, others - only in selected cases. The actual impact of PS on bleeding complications reduction is unknown. Furthermore, a pro-thromboembolic effect of the PS cannot be excluded. Both bleeding (major and life-threatening according to Valve Academic Research Consortium \[VARC\] criteria) and thromboembolic complications increase mortality after TAVI. The occurrence of these complications in international TAVI registries in 30-day observation ranges from 9.7% in case of major bleeding, 4.7% in case of life-threatening bleeds and 5% in case of strokes. There are no randomized studies assessing impact of PS on frequency of bleeding and thromboembolic complications after TAVI, its side-effects and influence on mortality. Randomized trial is required in order to assess impact of protamine sulfate on prevalence of bleeding and thromboembolic complications.