Heparin Anticoagulation in Septic Shock (HALO)

Heparin AnticoaguLation to Improve Outcomes in Septic Shock: The HALO International Phase II RCT

This study is a pragmatic open-label international randomized trial comparing therapeutic dose intravenous unfractionated heparin (UFH) to standard care venous thromboprophylaxis in patients diagnosed with septic shock.

Study Overview

• Status: Terminated
• Conditions: Septic Shock; Vasodilatory Shock
• Intervention / Treatment: Drug: Unfractionated heparin; Other: Venous thromboprophylaxis (VTE)

Detailed Description

Background and significance: Sepsis and septic shock account for 10% of admissions to the intensive care unit and constitute the second most frequent cause of death among admitted patients. The mortality rate associated with septic shock ranges from 30% to 50% and death is often due to multiple organ dysfunction coupled with systemic inflammation. Given the pathobiological relationship between coagulation and inflammation in sepsis, treatment with anticoagulants has been investigated in this population. Multiple lines of evidence suggest that heparin, a widely available, inexpensive anticoagulant, may improve clinical outcomes in sepsis, but high quality evidence to guide practice is lacking.

Hypothesis: Intravenous (IV) unfractionated heparin (UFH) reduces mortality and morbidity when administered to patients with suspected septic shock.

Study Design: A pragmatic open-label international randomized trial comparing therapeutic dose intravenous unfractionated heparin (UFH) to standard care venous thromboprophylaxis in patients diagnosed with septic shock.

Setting: To increase the external validity/generalizability of the trial results, 20 sites in 4 countries will participate.

Study Population: Patients with systemic inflammation, vasopressor dependent shock, and signs of organ dysfunction.

Interventions: IV infusion of UFH at 18 IU/kg/hr, dosed according to total body weight and pragmatically adjusted according to usual care to achieve an activated partial thromboplastin time (aPTT) of 1.5-2.5x that of the reference aPTT value (approximately 59-99 seconds). Alternately, therapeutic anti-Xa values (ie. values typically targeted for the treatment of venous thromboembolism) can be targeted based on local practice. Duration of heparin infusion is for a maximum of 5 days (120 hours) or until death, ICU discharge or discontinuation of vasopressors. The dose of UFH has been informed by our observational study and meta-analysis that showed a benefit of UFH in patients receiving therapeutic doses.

Control group: Local standard care for venous thromboprophylaxis (i.e. not therapeutic) which may include SC LMWH, SC UFH, sequential compression devices or graduated compression stockings.

Outcomes: At the end of the HALO international phase II trial, an international DSMB will be presented with by-group efficacy (vasopressor-free days) data in the context of 90-day mortality, and safety (bleeding and transfusion). With these data the DSMB will suggest: a) terminating enrollment for futility (lack of efficacy) or harm, or b) continuing to the phase III trial along with a recommended sample size to detect a clinically relevant difference in 90-day mortality. Patients will be analyzed according to the treatment group to which they are allocated. By-group data will remain blinded to study investigators so that these patients may be included in the HALO international phase III RCT. Our analytic approach provides a rationale to either stop, or to justify further investment in a large international phase III trial.

• Study Type: Interventional
• Enrollment (Actual): 178
• Phase: Phase 2

Contacts and Locations

Study Locations

• Brazil
  • Altamira, Brazil
    • Hospital Sao Jose
  • Atibaia, Brazil
    • Hospital Novo Atibaia
  • Barretos, Brazil
    • Hospital de Amor (Barretos)
  • Belo Horizonte, Brazil
    • Santa Casa de Misericórdia de Belo Horizonte
  • Bento Gonçalves, Brazil
    • Hospital Tacchini
  • Brasilia, Brazil
    • Hospital de Brasília
  • Brasília, Brazil
    • Hospital Ortopedico e Medicina Especializada ltda. - HOME
  • Brasília, Brazil
    • Instituto de Cardiologia do Distrito Federal
  • Colatina, Brazil
    • Hospital Maternidade São José
  • Florianópolis, Brazil
    • Hospital Baia Sul
  • Florianópolis, Brazil
    • Hospital Nereu Ramos
  • Jales, Brazil
    • Hospital de Amor Jales
  • Juazeiro Do Norte, Brazil
    • Unimed Cariri Hospital
  • Porto Alegre, Brazil
    • Irmandade da Santa Casa de Misericórdia de Porto Alegre
  • Porto Alegre, Brazil
    • Hospital de Clinicas de Porto Alegre
  • Ribeirão Preto, Brazil
    • Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto
  • Rio Grande, Brazil
    • Hospital Bruno Born
  • Salvador, Brazil
    • Hospital da Cidade
  • São João Del Rei, Brazil
    • Santa Casa de São João Del Rei
  • São Paulo, Brazil
    • Hospital Santa Paula
  • São Paulo, Brazil
    • Hospital Beneficencia Portuguesa
  • São Paulo, Brazil
    • Hospital AC Camargo
  • São Paulo, Brazil
    • Hospital da Luz
  • São Paulo, Brazil
    • Hospital das Clinicas da faculdade de Medicina de Universidade de São Paulo
  • São Paulo, Brazil
    • Hospital e Maternidade Sao Vicente
  • São Paulo, Brazil
    • Hospital SEPACO
  • São Paulo, Brazil
    • Instituto de Assistência Médica ao Servidor Público Estadual de Sao Paulo
  • São Paulo, Brazil
    • Universidade Federal de São Paulo - UNIFESP
  • Taguatinga, Brazil
    • Hospital Ana Nery
• Canada
  • Quebec, Canada, G1J 1Z4
    • Hôpital de L'Enfant-Jésus
  • Alberta
    • Calgary, Alberta, Canada, T2N 2T9
      • Foothills Medical Centre
  • British Columbia
    • Victoria, British Columbia, Canada, V8R 1J8
      • Vancouver Island Health Authority
  • Manitoba
    • Winnipeg, Manitoba, Canada, R3A 1R9
      • Health Sciences Centre Winnipeg
    • Winnipeg, Manitoba, Canada, R2H 2A6
      • St Boniface General Hospital
  • Ontario
    • Ottawa, Ontario, Canada, K1H 8L6
      • The Ottawa Hospital - General Campus
    • Ottawa, Ontario, Canada, K1Y 4E9
      • The Ottawa Hospital - Civic Campus
    • St. Catherines, Ontario, Canada, L2S 0A9
      • Niagara Health System - St Catharines Site
    • Toronto, Ontario, Canada, M5B 1W8
      • St Michael's Hospital
  • Quebec
    • Montréal, Quebec, Canada, H2X 0A9
      • Centre Hospitalier de l'Universite de Montreal (CHUM)
    • Québec, Quebec, Canada, G1V 4G5
      • Institut Universitaire de Cardiologie et de Pneumologie de Quebec - Université Laval
• Greece
  • Athens, Greece
    • Attikon University Hospital
  • Athens, Greece
    • Korgialeneion Benakeion Hospital
• India
  • Kolkata, India
    • AMRI Hospital Kolkata
• Pakistan
  • Karachi, Pakistan
    • Dr Ruth K.M. PFAU Civil Hospital
  • Karachi, Pakistan
    • Shaheed Mohtarma Benazir Bhutto Trauma Center
  • Karachi, Pakistan
    • The Indus Hospital
  • Lahore, Pakistan
    • Mayo Hospital Lahore
• Philippines
  • Manila, Philippines
    • The Asian Hospital
  • Manila, Philippines
    • The Medical City
  • Manila, Philippines
    • The Philippines General Hospital
• United States
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Froedtert Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• ≥ 18 years of age
• Refractory hypotension documented within 18 hours prior to enrolment that requires the institution and ongoing use of vasopressor agents, (phenylephrine, norepinephrine, vasopressin, epinephrine, midodrine or dopamine >5 mcg/kg/min) at the time of enrolment. Refractory hypotension is defined as a systolic blood pressure (SBP) less than 90 mm Hg, or a systolic blood pressure more than 30 mm Hg below baseline, or a mean arterial pressure (MAP) less than 65 mm Hg and receipt of ≥ 2 litres of intravenous fluid for the treatment of hypotension (≥ 1 litre if dialysis dependent end-stage renal disease or if the patient is felt to be in congestive heart failure).

• At least 1 other new organ dysfunction (in addition to refractory hypotension), defined by the following:

  1. Creatinine ≥1.5x the known baseline creatinine, or ≥ 26.5 µmol/L increase or <0.5 mL/kg of urine output for 6-12 hours according to the KDIGO [Kidney Disease improving Global Outcomes (KDiGO)] guideline definition of acute kidney injury.
  2. Need for invasive mechanical ventilation or a P/F ratio <250
  3. Platelets <100 x109/L, or a drop of 50 x109/L in the 3 days prior to enrolment
  4. Arterial pH < 7.30 or base deficit > 5 mmol/L in association with a lactate > 4.0 mmol/L

Exclusion Criteria:

• Other forms of shock including cardiogenic, hemorrhagic, hypovolemic, neurogenic, or obstructive shock.
• Clinical suspicion or confirmation of a viral hemorrhagic shock syndrome including, but not limited to, dengue fever
• Rapid clinical improvement; vasopressors likely to be discontinued in the next 6 hours
• Received vasopressor therapy for greater than 18 hours prior to enrolment

• Bleeding Risk:

  1. Clinical: Active bleeding; head trauma; intracranial surgery or stroke within 3 months; history of intracerebral arteriovenous malformation, cerebral aneurysm or mass lesions of the central nervous system; history of a bleeding diatheses; gastrointestinal bleeding within 6 weeks; presence of an epidural or spinal catheter; selected cases of recent surgery where IV therapeutic UFH is considered contraindicated
  2. Laboratory: Platelet count <50 x109/L, INR >2.0, or baseline aPTT >50 seconds prior to enrolment
• Known or suspected adverse reaction to UFH including heparin induced thrombocytopenia (HIT).
• Use of any of the following treatments: UFH to treat a thrombotic event within 12 hours before enrolment; LMWH at a higher dose than recommended for prophylactic use within 12 hours before the infusion; warfarin (if used within 7 days before study entry AND if the INR exceeds 2.0 at enrolment); thrombolytic therapy within 3 previous days; use of IIb/IIIa inhibitors within the previous 7 days.
• Need for therapeutic anticoagulation
• Terminal illness with a life expectancy of less than 3 months, or no commitment to aggressive care.
• Consent declined from patient or authorized 3rd party
• Physician refusal

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Unfractionated Heparin (UFH); UFH initiated at 18 IU/kg/hr	Drug: Unfractionated heparin; UFH initiated at 18 IU/kg/hr, dosed according to total body weight and pragmatically adjusted according to local institutional policy to achieve an activated partial thromboplastin (aPTT) of 1.5 to 2.5 times that of the reference aPTT value or anti-Xa values targeted to local practice levels. Duration of study intervention will be a maximum of 5 days (120 hours) or until vasopressors have been discontinued for 24 continuous hours. All participants will then receive venous thromboprophylaxis according to local practice.; Other Names: Heparin
Other: Venous thromboprophylaxis (VTE); as per local standard	Other: Venous thromboprophylaxis (VTE); May include subcutaneous heparin or dalteparin, sequential compression device or graduated compression stockings

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vasopressor-free days.	The goal of phase II trial is to provide the international Data Safety Monitoring Committee (DSMC) with a sensible estimate to justify continued enrollment in an adaptive (sample size) trial. Vasopressor use, reflecting cardiovascular collapse due to overwhelming systematic inflammation, is a key inclusion criterion for the trial and durable discontinuation of such drugs and meaningful clinical improvement. Vasopressor-free days has been recommended as a preferred clinical outcome in phase II trials in critical illness.	30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Outcome #1 - ICU mortality	Survival	From date of randomization until the first documentation of death from any cause or ICU discharge date or 90 days, whichever came first
Clinical Outcome #2 - Hospital mortality	Survival	From date of randomization to the first documentation of death from any cause or hospital discharge date or 90 days, whichever came first.
Clinical Outcome #3 - 90-day mortality	Survival	Up to day 90
Clinical Outcome # 4 - ∆SOFA score (Sequential Organ Failure Assessment)	Organ failure assessment using the SOFA scoring tool	Daily from randomization to ICU discharge or hospital discharge or time of death or to study day 9 if still in ICU or hospital.
Clinical Outcome # 5 - Hospital-free days to day 90	Hospital admission duration in the context of survival	from hospital admission to hospital discharge or time of death to day 90
Clinical Outcome #6 - Renal replacement therapy-free days to day 28	Renal replacement therapy duration in the context of survival	from start of renal replacement therapy to study day 28
Safety Outcome #1 - Major Bleeding	Rates of major bleeding using a validated bleeding assessment tool	Assessed daily to day 8
Safety Outcome #2 - Minor Bleeding	Rates of minor bleeding using a validated bleeding assessment tool	Assessed daily to day 8
Safety Outcome #3 - Suspected HIT (Heparin induced thrombocytopenia)	Incidence of any laboratory testing for HIT including screening or confirmatory tests	Assessed daily to day 8
Safety Outcome #4 - Confirmed HIT (Heparin induced thrombocytopenia)	Postive confirmatory HIT test (one of Serotonin release assay (SRA) or Heparin induced platelet aggregation (HIPA))	Assessed daily to day 8
Rate of enrolment	average number of patients enrolled per site per month	Monthly starting at individual site initiation through to end of enrollment, estimated two years

Collaborators and Investigators

• Sponsor: University of Manitoba
• Collaborators: Canadian Institutes of Health Research (CIHR); CancerCare Manitoba
• Investigators: Principal Investigator: Ryan Zarychanski, MD MSc, University of Manitoba; Principal Investigator: Anand Kumar, MD, University of Manitoba; Principal Investigator: Dean A Fergusson, PhD MHA, University of Ottawa

Study record dates

Study Major Dates

• Study Start (Actual): March 12, 2018
• Primary Completion (Actual): December 31, 2021
• Study Completion (Actual): December 31, 2021

Study Registration Dates

• First Submitted: November 9, 2017
• First Submitted That Met QC Criteria: December 18, 2017
• First Posted (Actual): December 19, 2017

Study Record Updates

• Last Update Posted (Actual): May 24, 2022
• Last Update Submitted That Met QC Criteria: May 17, 2022
• Last Verified: January 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Systemic Inflammatory Response Syndrome; Inflammation; Sepsis; Shock, Septic; Shock; Molecular Mechanisms of Pharmacological Action; Fibrinolytic Agents; Fibrin Modulating Agents; Anticoagulants; Heparin; Calcium heparin
• Other Study ID Numbers: HCA2017

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No