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In Vitro Thrombosis Test for Ventricular Assist Devices
Published on: March 21, 2025
PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management: The PREVENT multi-center study
Simon Maltais1, Ahmet Kilic2, Sriram Nathan3
1Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota.
Insights
Structured clinical practices significantly reduce HeartMate II pump thrombosis risk. Adhering to PREVENT recommendations for implant technique, anticoagulation, and pump speed lowers early pump thrombosis rates.
Area of Science:
- Cardiovascular Surgery
- Medical Devices
- Biomedical Engineering
Background:
- HeartMate II (HMII) left ventricular assist device (LVAD) is associated with pump thrombosis (PT).
- PREVENT recommendations were developed to mitigate early PT risk.
- This study assessed HMII PT rates with adherence to PREVENT guidelines.
Purpose of the Study:
- To prospectively evaluate the HeartMate II pump thrombosis rate.
- To determine the impact of adherence to PREVENT recommendations on PT.
- To assess PT and composite adverse event rates at 3 and 6 months post-implantation.
Main Methods:
- Prospective, multi-center, single-arm study of 300 HMII patients.
- Evaluation of confirmed PT at 3 and 6 months post-implantation.
- Assessment of adherence to PREVENT recommendations: implant technique, heparin bridging, and pump speed management.
Main Results:
- Confirmed PT rates were 2.9% at 3 months and 4.8% at 6 months.
- High adherence to PREVENT recommendations (e.g., 95% for heparin bridging) was observed.
- Full adherence to PREVENT guidelines significantly reduced PT risk (1.9% vs. 8.9%) and composite adverse events.
Conclusions:
- Adherence to structured surgical implant technique and clinical management (PREVENT recommendations) is linked to low PT rates.
- Implementing PREVENT recommendations is crucial for reducing HeartMate II pump thrombosis.
- Structured management strategies are effective in improving LVAD safety and outcomes.
Background:
Recommended structured clinical practices including implant technique, anti-coagulation strategy, and pump speed management (PREVENT [PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management] recommendations) were developed to address risk of early (<3 months) pump thrombosis (PT) risk with HeartMate II (HMII; St. Jude Medical, Inc. [Thoratec Corporation], Pleasanton, CA). We prospectively assessed the HMII PT rate in the current era when participating centers adhered to the PREVENT recommendations.
Methods:
PREVENT was a prospective, multi-center, single-arm, non-randomized study of 300 patients implanted with HMII at 24 participating sites. Confirmed PT (any suspected PT confirmed visually and/or adjudicated by an independent assessor) was evaluated at 3 months (primary end-point) and at 6 months after implantation.
Results:
The population included 83% men (age 57 years ± 13), 78% destination therapy, and 83% Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Profile 1-3. Primary end-point analysis showed a confirmed PT of 2.9% at 3 months and 4.8% at 6 months. Adherence to key recommendations included 78% to surgical recommendations, 95% to heparin bridging, and 79% to pump speeds ≥9,000 RPMs (92% >8,600 RPMs). Full adherence to implant techniques, heparin bridging, and pump speeds ≥9,000 RPMs resulted in a significantly lower risk of PT (1.9% vs 8.9%; p < 0.01) and lower composite risk of suspected thrombosis, hemolysis, and ischemic stroke (5.7% vs 17.7%; p < 0.01) at 6 months.
Conclusions:
Adoption of all components of a structured surgical implant technique and clinical management strategy (PREVENT recommendations) is associated with low rates of confirmed PT.
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