Routine Protamine Administration for Bleeding in Transcatheter Aortic Valve Implantation: The ACE-PROTAVI Randomized Clinical Trial.

Importance: Vascular complications after transfemoral transcatheter aortic valve implantation (TAVI) remain an important cause of procedure-related morbidity. Routine reversal of anticoagulation with protamine at the conclusion of transfemoral TAVI could reduce complications, but data remain scarce.

Objective: To evaluate the efficacy and safety of routine protamine administration after transfemoral TAVI.

Design, setting, and participants: The ACE-PROTAVI trial was an investigator-initiated, double-blind, placebo-controlled randomized clinical trial performed at 3 Australian hospitals between December 2021 and June 2023 with a 1-year follow-up period. All patients accepted for transfemoral TAVI by a multidisciplinary heart team were eligible for enrollment.

Interventions: Eligible patients were randomized 1:1 between routine protamine administration and placebo.

Main outcomes and measures: The coprimary outcomes were the rate of hemostasis success and time to hemostasis (TTH), presented as categorical variables and compared with a χ2 test or as continuous variables as mean (SD) or median (IQR), depending on distribution. The major secondary outcome was a composite of all-cause death, major and minor bleeding complications, and major and minor vascular complications after 30 days, reported in odds ratios (ORs) with 95% CIs and P values.

Results: The study population consisted of 410 patients: 199 patients in the protamine group and 211 in the placebo group. The median (IQR) patient age in the protamine group was 82 (77-85) years, and 68 of 199 patients receiving protamine (34.2%) were female. The median (IQR) patient age in the placebo group was 80 (75-85) years, and 89 of 211 patients receiving the placebo (42.2%) were female. Patients receiving up-front protamine administration had a higher rate of hemostasis success (188 of 192 patients [97.9%]) than patients in the placebo group (186 of 203 patients [91.6%]; absolute risk difference, 6.3%; 95% CI, 2.0%-10.6%; P = .006); in addition, patients receiving up-front protamine had a shorter median (IQR) TTH (181 [120-420] seconds vs 279 [122-600] seconds; P = .002). Routine protamine administration resulted in a reduced risk of the composite outcome in the protamine group (10 of 192 [5.2%]) vs the placebo group (26 of 203 [12.8%]; OR, 0.37; 95% CI, 0.1-0.8; P = .01). This difference was predominantly driven by the difference in the prevalence of minor vascular complications. There were no adverse events associated with protamine use.

Conclusions and relevance: In the ACE-PROTAVI randomized clinical trial, routine administration of protamine increased the rate of hemostasis success and decreased TTH. The beneficial effect of protamine was reflected in a reduction in minor vascular complications, procedural time, and postprocedural hospital stay duration in patients receiving routine protamine compared with patients receiving placebo.

Trial registration: anzctr.org.au Identifier: ACTRN12621001261808.