Platelet morphology in patients with mechanical circulatory support

Area of Science:

• Cardiovascular Science
• Hematology
• Biomaterials Science

Background:

• Mechanical circulatory support (MCS) devices are vital for end-stage heart failure.
• Thromboembolic events are significant complications of MCS due to device thrombogenicity.
• Activated platelets are central to the thrombotic process in MCS patients.

Purpose of the Study:

• To investigate changes in platelet morphology in patients with end-stage cardiac insufficiency undergoing MCS.
• To assess the role of platelet activation in the context of device-related thrombogenicity.

Main Methods:

• Scanning electron microscopy was used to examine platelet morphology in eight patients with Novacor left ventricular assist system (LVAS).
• Blood samples were collected preoperatively and at various time points up to 3 months post-implantation.
• Platelet activation and aggregation were quantified based on shape change, alongside evaluation of coagulation parameters.

Main Results:

• Preoperative levels of activated platelets were 15.0 ± 4.6%, increasing significantly to 32.8 ± 8.0% within the first postoperative week (P < 0.05).
• Longer support duration (> 30 days) showed a higher percentage of activated platelets (34.8 ± 3.4%) compared to shorter duration (< 30 days; 24.3 ± 3.3%, P = 0.004).
• A correlation was observed between activated clotting time and activated platelets, with unique platelet deformations noted during support.

Conclusions:

• Implanted MCS devices likely induce significant platelet morphology alterations through surface activation.
• These findings highlight the importance of considering platelet behavior in postoperative anticoagulation management.
• Understanding platelet response to MCS devices is critical for mitigating thromboembolic risks.