Related Experiment Videos
Vascular antithrombin and clinical outcome in heart transplant patients
C A Labarrere1, R J Torry, D R Nelson
1Methodist Research Institute, Methodist Transplant Center, Indiana University, Riley Hospitals, Indianapolis 46202, USA. clabarrere@clarian.com
Insights
Loss of vascular antithrombin in heart transplants accelerates coronary artery disease (CAD) and graft failure. Recovery of antithrombin and capillary binding improves outcomes, reducing CAD and failure risk.
Area of Science:
- Cardiology
- Immunology
- Transplantation Science
Background:
- A procoagulant microvasculature is linked to faster coronary artery disease (CAD) development and heart transplant failure.
- Understanding natural anticoagulation's role in cardiac allografts is crucial for patient outcomes.
Purpose of the Study:
- To investigate how changes in natural anticoagulation, specifically vascular antithrombin, within cardiac allografts impact patient prognosis.
- To correlate antithrombin levels and binding patterns with the development and progression of CAD and graft failure.
Main Methods:
- Prospective study of 141 cardiac allograft recipients transplanted between 1988-1997.
- Immunohistochemical analysis of serial endomyocardial biopsy specimens to assess vascular antithrombin.
- Annual coronary angiograms to evaluate the incidence, severity, and progression of CAD.
Main Results:
- Allografts maintaining vascular antithrombin showed the best prognosis.
- Persistent early loss of vascular antithrombin was associated with earlier, more severe CAD, and increased graft failure (p < 0.001).
- Recovery of vascular antithrombin and development of capillary antithrombin binding improved outcomes, reducing CAD and graft failure (p < 0.01).
Conclusions:
- A persistent lack of thromboresistance in the microvasculature significantly increases the risk of CAD and graft failure post-transplant.
- Restoration of vascular antithrombin and altered capillary binding patterns can improve cardiac allograft survival and reduce disease progression.
Abstract:
A procoagulant microvasculature is associated with accelerated development of coronary artery disease (CAD) and failure in heart transplant patients. This study was performed to evaluate how changes in natural anticoagulation within cardiac allografts affect outcome. We prospectively studied 141 consecutive cardiac allograft recipients who underwent transplantation between 1988 and 1997. Serial endomyocardial biopsy specimens (6.5 +/- 0.1 biopsy specimens/patient) obtained during the first 3 months after transplantation were studied immunohistochemically to evaluate vascular antithrombin, and annual coronary angiograms (3.8 +/- 0.2 angiograms/patient) were studied to evaluate CAD. Antithrombin was present in arteries and veins, but not in capillaries, of all donor heart biopsy samples. Allografts that maintained vascular antithrombin had the best prognosis. Allografts with early and persistent loss of vascular antithrombin (n = 21) developed CAD earlier (p < 0.001), developed more severe disease (p < 0.001), showed more disease progression (p < 0.001), and failed more often (p = 0.003) and earlier (p < 0.001) than allografts retaining normal vascular antithrombin (n = 45). However, allografts that lost and recovered vascular antithrombin while developing unusual capillary antithrombin binding (n = 75) had less CAD, developed CAD later, had less severe disease and less disease progression (p < 0.01), and failed less often (p = 0.01) and later (p = 0.03) than allografts with persistent loss of vascular antithrombin. The persistent lack of a thromboresistant microvasculature increases risk of subsequent CAD and graft failure. However, recovery of vascular antithrombin and development of unusual capillary antithrombin binding improves allograft outcome.