Plasma Transfusion in Major Vascular Surgery

Sponsor
Naestved Hospital (Other)
Overall Status
Completed
CT.gov ID
NCT04514575
Collaborator
Statens Serum Institut (Other)
17,000
1
264
64.4

Study Details

Study Description

Brief Summary

BACKGROUND

  • Major blood loss is frequent in open repair of ruptured and intact abdominal aortic aneurysm (AAA) as well as in aorto-bifurcated prosthesis insertion due to aortoiliac occlusive disease.

  • Major blood loss is associated with death, post-operative complications and coagulopathy.

  • Data from randomized trials in trauma patients indicate that a high plasma to red blood cell (RBC) transfusion ratio reduces 30-day mortality.

  • No randomized trial data are available for the AAA population.

  • Observational data demonstrate, that a high plasma:RBC transfusion ratio associates to a lower 30 day mortality. However, the reports are based on small cohorts of 78-165 patients, short term outcomes and lack information on major adverse events such as cardiac and respiratory.

  • The Danish Vascular Registry (DVR), covering 1996-2018, contains data on approx. 4,400 ruptured and 8,200 intact (elective/symptomatic) AAA repairs, and 5,400 open aortoiliac repairs due to occlusive disease. Expected total count 1997-2018: 17,000.

  • The Danish Transfusion Database (DTDB), covering approx. 1997-2018, contains information on units of RBCs, plasma and platelets transfused. A unique patient identification number (CPR) allows merging of all data set.

OBJECTIVE

To identify whether resuscitation with a high plasma to RBC ratio associates to improves survival in open abdominal aortic surgery as compared to a low plasma to RBC-ratio.

PICO

  • Population: Open abdominal aortic surgery

  • Intervention: "High FFP": FFP to RBC unit ratio of 2:3 to 3:3 (0.7 - 1.0)

  • Comparison: "Low FFP": FFP to RBC unit ratio of 0:3 to 1:3 (0.0 - 0.3)

  • Outcome: All-cause mortality 90 days following surgery.

DATA SOURCES

CPR, Danish Civil Registration System. DNPR, Danish National Patient registry. DVR, Danish Vascular registry. DPDB, The Danish national Prescription DataBase.

Condition or Disease Intervention/Treatment Phase
  • Biological: Plasma transfusion

Detailed Description

STATISTICAL ANALYSIS PLAN

The primary analysis will be a stratified cox regression model.

STRATIFICATION:
  • type of surgery/condition (ruptured AAA vs intact AAA vs aorto-iliac occlusive disease, source: DVR)

  • sex (CPR)

  • Center (Rigshospitalet vs. Gentofte vs. Slagelse vs. Odense vs. Kolding vs. Aarhus vs. Viborg vs. Aalborg, source: DVR)

COVARIATE ADJUSTMENT:
  • calendar time (DVR)

  • age (CPR)

  • Carlsons comorbidity index score (DNPR)

  • Priority (Acute vs. Sub-acute vs. Elective, source: DVR)

  • Use of anti-thrombotic drugs (DPDB). A covariate of 4 levels (ATC code is noted in parenthesis).

  1. None vs.

  2. Anti-platelet therapy

  • acetylsalicylic acid (B01AC06) or

  • dipyridamole (B01AC07, eg. persantin or asasantin)

  1. Anti-platelet therapy "thienopyridines-like drugs"
  • clopidogrel (B01AC04) or

  • ticagrelor (B01AC24, eg. Brilique) or

  • prasugrel (B01AC22, eg. Efient) Comment: patients prescribed thienopyridines in combination with aspirin will be included in this "thienopyridine anti-platelet group 3"

  1. Anti-coagulant therapy
  • Vitamin K antagonists (B01AA, eg. warfarin or phenprocoumon)

  • Low-molecular weight heparine (B01AB01-10)

  • Direct thrombin inhibitors (B01AE, eg. Pradaxa/Dabigatran)

  • Direct factor Xa inhibitors (B01AF, eg. Rivaroxaban/Xarelto). Comment: patients prescribed both anticoagulant- and antiplatelet therapy and will be included in this "Anti-coagulant group 4".

ADDITIONAL ANALYSES:
  1. Stratify the population into 4 groups according to the total transfusion requirement

  2. patients receiving 10 units or less of any blood product < 24 hrs or 11-15 units < 48 hrs.vs.

  3. patients receiving 11-15 units of any blood product < 24 hrs. or 16-20 units < 48 hrs. vs.

  4. patients receiving 16-20 units of any blood product < 24 hrs. or 21-25 units < 48 hrs. vs.

  5. patients receiving more than 20 units of any blood product < 24 hrs. or more than 25 units < 48 hrs.

  6. Outcome predicted by a joint function (general interaction) of total plasma transfusion and total blood cell transfusion will be assessed in an exploratory way by inspection and by agnostic modelling in the mold of Multivariate Adaptive Regression Splines (MARS) and recursive partitioning, i.e. Classification And Regression Trees (CART).

  7. Redefine intervention and control group as 4th and 1st quartile of FFP:RBC ratio. Initially, the population will be divide into 4 groups according to quartiles and compared the population below 1st quartile with the population above the 4th quartile, which will define the low vs. the high FFP group, resp. However, to allow for stratification for operation type (ruptured AAA vs. intact AAA vs. occlusive disease) it may be necessary to adjust the percentile cut to retain power in the analyses. For instance, the population may be cut according to tertiles, or, if there is sufficient data, cut by quintiles (5 groups) or deciles (10 groups).

  8. Confine the population to patient with blood loss above 50 % of total blood volume (calculated by Naddler's equation accounting for sex, weight and height). If height and weight are not available, the registered blood loss must exceed 2 L in females and 2.5 L in males.

  9. Adjusting exclusively for calendar year, sex, age, Charlson's comorbidity index score, and center (ie, excluding priority and antithrombotic therapy).

MISSING DATA

Missing data will not be an issue for the number of blood transfusions because units of blood products transfused are used as an inclusion criterion. All remaining covariates are discrete, and missing data for each of those will be included as separate parameters (factor level).

STATISTICAL SIGNIFICANCE LEVEL

Bonferroni adjustment of the significance level will be applied to control for multiple testing.

With one primary and four secondary outcomes, only a P-value below 0.01 (0.05/5) will be considered statistically significant. A P-value between 0.01 and 0.05 will be considered borderline significant.

Study Design

Study Type:
Observational
Actual Enrollment :
17000 participants
Observational Model:
Cohort
Time Perspective:
Retrospective
Official Title:
Plasma Transfusion in Major Vascular Surgery: a Danish Nationwide Registry Study
Actual Study Start Date :
Jan 1, 1997
Actual Primary Completion Date :
Dec 31, 2018
Actual Study Completion Date :
Dec 31, 2018

Arms and Interventions

Arm Intervention/Treatment
High-FFP

Patients transfused with an FFP:RBC ratio of 2:3 to 3:3 (0.7 - 1.0)

Biological: Plasma transfusion
Transfusion of allogeneic fresh frozen plasma or cryoprecipitate

Low-FFP

Patients transfused with an FFP:RBC ratio at or below 1:3 (0.0 - 0.3).

Biological: Plasma transfusion
Transfusion of allogeneic fresh frozen plasma or cryoprecipitate

Outcome Measures

Primary Outcome Measures

  1. 90-day survival [First 90 days after index surgery]

    Survival data. Source: CPR

Secondary Outcome Measures

  1. 30-day survival [First 30 days after index surgery]

    Survival data. Source: CPR

  2. 1-year survival [1 year after index surgery]

    Survival data. Source: CPR

  3. Death or any major adverse events at 90-days [First 90 days after index surgery]

    Dichotomous outcome. Source: DNPR and DVR. A. Major adverse cardiovascular events "MACE" [ICD10-codes] acute myocardial infarction [DI21.0-23.9, DT817Y2] stroke [DI60-64.9, DT817Y1] non-fatal cardiac arrest [DI460] B. Major adverse respiratory events adult respiratory distress syndrome [DJ80] pulmonary edema [DJ81] pulmonary embolism [DI26, DT817D] C. Major adverse vascular event bowel ischemia [DK550C-H] vascular reoperation for deep rebleeding or thrombus or embolus [KPWE, KPWG], lower-limb fasciotomy [KNGM09, KNHM09, KNFM09] or explorative laparotomy [KJAH00] major lower limb amputation [KNE-HQ] acute limb ischemia requiring intervention D. Other renal replacement therapy [BJFD, DZ992] AB0-incompatibility reaction [DT803] Rhesus-incompatibility reaction [DT804] Hemorrhage and hematoma complicating a procedure, not elsewhere classified [T810, DT810G, DT810E]

  4. Number of days alive outside hospital within 90 days [Day 90 after index surgery]

    Count data. Source: DNPR and CPR

Eligibility Criteria

Criteria

Ages Eligible for Study:
41 Years to 99 Years
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
No
Inclusion Criteria:
  1. Open abdominal aortic repair with the insertion of prosthesis for either
  • intact (elective or symptomatic) AAA

  • ruptured AAA

  • aorto-iliac occlusive disease

  1. Requiring massive transfusion defined as 10 units or more of any blood product(*) transfused on the same date (source DTDB)

(*) = Allogeneic packed RBCs, FFP, cryoprecipitate, or platelets. Cryoprecipitate will account for 4 units of FFP in the FFP:RBC ratio.

Exclusion Criteria:
  1. Surgery time limited to < 50 minutes (DVR)

  2. No prosthesis inserted (DVR) AND operation date (DVR) equal to the death date (CPR)

Excluding patients with surgery time less than 50 minutes or cases where no prosthesis has been inserted is expected to minimize survival bias from patients exsanguinating in the operation theater before blood products can be delivered. Intentionally, it may also exclude cases where surgery was considered futile and halted.

Contacts and Locations

Locations

Site City State Country Postal Code
1 Slagelse Hospital Slagelse Region Zealand Denmark 4200

Sponsors and Collaborators

  • Naestved Hospital
  • Statens Serum Institut

Investigators

  • Study Director: Ole Pedersen, MD, PhD, Department of Clinical Immunology, Naestved Hospital, Denmark.

Study Documents (Full-Text)

More Information

Publications

Responsible Party:
Naestved Hospital
ClinicalTrials.gov Identifier:
NCT04514575
Other Study ID Numbers:
  • REG-144-2017
First Posted:
Aug 17, 2020
Last Update Posted:
Jan 28, 2021
Last Verified:
Jan 1, 2021
Individual Participant Data (IPD) Sharing Statement:
No
Plan to Share IPD:
No
Studies a U.S. FDA-regulated Drug Product:
No
Studies a U.S. FDA-regulated Device Product:
No
Additional relevant MeSH terms:

Study Results

No Results Posted as of Jan 28, 2021