Effects of HeartWare on vWF profiles

Effects of HeartWare Ventricular Assist Device on the von Willebrand Factor: Results of an academic Belgian center

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN39517567

Enrollment

Registered

2016-07-18

Start date

2013-04-15

Completion date

Unknown

Last updated

2019-09-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heart failure Circulatory System

Interventions

15 LVAD recipients (HeartWare®, Framingham, MA, USA) were compared to 12 HF patients, matched for age and body mass index. This study contained 2 parts. For part 1, researchers evalua

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Male 2. LVAD-supported patients 3. HF patients matched for age and body mass index to LVAD-supported patients

Exclusion criteria

Exclusion criteria: Participants not fulfilling inclusion criteria

Design outcomes

Primary

Measure	Time frame
1. vWF profile - measuring vWF antigen and vWF activity via an immuno-turbidimetric assay, using a fully automated hemostasis analyser (BCS XP system, Innovance Siemens® Healthcare, USA). HMWM-vWF were studied by Western Blot analysis (GE, Healthcare, Germany), using SDS-agarose gel electrophoresis 2. ADAMTS13 activity - assessed by a chromogenic ELISA method (Technozym, Technoclone, Austria), based on its activity on a synthetic peptide of vWF 3. Factor VIII (% activity of normal plasma) and coagulant fibrinogen (mg/dL) were determined by chronometric techniques by means of fully automated hemostasis analyzers (BCS XP system, Siemens® Healthcare, USA; Multifibren U, Siemens® Healthcare, USA; respectively). Prothrombin time (PT, % time of normal plasma), international normalized ratio (INR), activated Partial Thromboplastin Time (aPTT, sec) were also assessed by chronometric techniques 4. Platelet aggregation , tested at physiological calcium condition by the Multiplate™ analyser (Dynabyte, Munich, Germany), using agonists of thrombin receptor activating peptide-6 (TRAP-6), arachidonic acid (ASPI), adenosine diphosphate (ADP), a collagen binding activity assay (COL), and ristocetin. Ristocetin-induced platelet aggregation was determined at concentrations of 1 mg/mL 5. Bleeding events: The major bleeding consisted on the spontaneous rupture of a hemangioma in the inferior pole of spleen 93 days after LVAD implantation. He received 2 packed cell units and 4 units of fresh frozen plasma (FFP). This event occurred 65 days prior participation to this study. The 4 minor bleeds consisted in 3 transient nose bleedings and 1 hemorrhoid bleeding. All blood samples were transported immediately to the hematology laboratory in order to measure the blood components.	—

Measure

Time frame

1. vWF profile - measuring vWF antigen and vWF activity via an immuno-turbidimetric assay, using a fully automated hemostasis analyser (BCS XP system, Innovance Siemens® Healthcare, USA). HMWM-vWF were studied by Western Blot analysis (GE, Healthcare, Germany), using SDS-agarose gel electrophoresis 2. ADAMTS13 activity - assessed by a chromogenic ELISA method (Technozym, Technoclone, Austria), based on its activity on a synthetic peptide of vWF 3. Factor VIII (% activity of normal plasma) and coagulant fibrinogen (mg/dL) were determined by chronometric techniques by means of fully automated hemostasis analyzers (BCS XP system, Siemens® Healthcare, USA; Multifibren U, Siemens® Healthcare, USA; respectively). Prothrombin time (PT, % time of normal plasma), international normalized ratio (INR), activated Partial Thromboplastin Time (aPTT, sec) were also assessed by chronometric techniques 4. Platelet aggregation , tested at physiological calcium condition by the Multiplate™ analyser (Dynabyte, Munich, Germany), using agonists of thrombin receptor activating peptide-6 (TRAP-6), arachidonic acid (ASPI), adenosine diphosphate (ADP), a collagen binding activity assay (COL), and ristocetin. Ristocetin-induced platelet aggregation was determined at concentrations of 1 mg/mL 5. Bleeding events: The major bleeding consisted on the spontaneous rupture of a hemangioma in the inferior pole of spleen 93 days after LVAD implantation. He received 2 packed cell units and 4 units of fresh frozen plasma (FFP). This event occurred 65 days prior participation to this study. The 4 minor bleeds consisted in 3 transient nose bleedings and 1 hemorrhoid bleeding. All blood samples were transported immediately to the hematology laboratory in order to measure the blood components.

—

Secondary

Measure	Time frame
1. Incidence of minor bleeding (blood loss without transfusion): We observed 4 minor bleeding 2. Incidence of major bleeding (need for transfusion >7 days after implantation, death after a bleeding, the need for re-operation, or any transfusion of packed red blood cells 7 days after implantation): 1 major bleeding 3. Incidence of thrombosis, defined as the formation of a blood clot within one of the VAD components, or any systemic thrombo-embolic event: 1 thrombotic event All taken from medical history, retrieved from the patients’ medical records.	—

Measure

Time frame

1. Incidence of minor bleeding (blood loss without transfusion): We observed 4 minor bleeding 2. Incidence of major bleeding (need for transfusion >7 days after implantation, death after a bleeding, the need for re-operation, or any transfusion of packed red blood cells 7 days after implantation): 1 major bleeding 3. Incidence of thrombosis, defined as the formation of a blood clot within one of the VAD components, or any systemic thrombo-embolic event: 1 thrombotic event All taken from medical history, retrieved from the patients’ medical records.

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Countries

Belgium

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Mar 12, 2026