Related Experiment Video
Updated: Aug 9, 2026
Standardized Model of Ventricular Fibrillation and Advanced Cardiac Life Support in Swine
Published on: January 30, 2020
Evaluation of the fibrinolytic system in calves implanted with an artificial heart and ventricular assist device
H al-Mondhiry1, W E Pae, W S Pierce
1Department of Medicine, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey 17033.
Insights
Total artificial hearts (TAH) and ventricular assist devices can cause thromboembolism. Some TAH calves showed enhanced fibrinolytic system activity, potentially offering protection against blood clots.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Hematology
Background:
- Thromboembolism is a significant risk with long-term use of intracirculatory devices like total artificial hearts (TAH) and ventricular assist devices (VADs).
- Understanding the hemostatic system's alterations is crucial for mitigating complications associated with these devices.
Purpose of the Study:
- To prospectively evaluate changes in the fibrinolytic system during long-term implantation of TAH and VADs.
- To assess the potential protective role of fibrinolysis against thrombosis in animals with these devices.
Main Methods:
- Four calves were implanted with TAH and four with VADs.
- Blood fibrinolytic activity, plasma plasminogen, and plasminogen activator activity were measured.
- Hypofibrinogenemia and fibrinogen survival were assessed; autopsy evaluated for thrombotic lesions.
Main Results:
- Elevated blood fibrinolytic activity and increased plasma plasminogen were observed in some TAH calves.
- VAD-implanted calves generally showed normal fibrinolytic and hemostatic parameters.
- No significant thrombotic lesions were found in any of the animals post-mortem.
Conclusions:
- Some calves with TAH exhibited enhanced activation of the fibrinolytic system.
- This heightened fibrinolytic activity may provide a degree of protection against thrombosis.
- Further research is needed to elucidate the mechanisms and clinical implications.
Abstract:
Thromboembolism is a serious complication of prolonged use of intracirculatory devices such as total artificial hearts (TAH) and ventricular assist devices. The authors have evaluated alteration in the hemostatic system associated with long-term use of TAH and ventricular assist devices. This article reports results of a prospective evaluation of the fibrinolytic system in four calves implanted with TAHs and four with ventricular assist devices. Blood fibrinolytic activity measured with a solid phase radiometric assay was elevated in two of four TAH calves; plasma plasminogen activity was increased in three. Plasma plasminogen activator activity was undetectable (normal) in all animals. Slight to moderate hypofibrinogenemia was noted in all TAH calves. Calves implanted with a left ventricular assist device had mostly normal blood fibrinolytic activity, fibrinogen, and plasminogen levels. Fibrinogen survival was measured in two calves with ventricular assist devices and three with TAH and was in the normal range in all of these animals. No significant thrombotic lesions were noted at autopsy in five calves that died or were electively killed. These observations suggest enhanced activation of the fibrinolytic system in some calves implanted with a TAH. This may offer a measure of protection against thrombosis in some animals.
