Plasma tissue factor, tissue factor pathway inhibitor and restenosis following femoropopliteal percutaneous transluminal angioplasty in claudicants
Thesis or dissertation
- © 2011 Biswajit Ray. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.
Introduction: The primary goal in the management of intermittent claudication is to decrease cardiovascular morbidity and mortality by disease modifying therapy. However percutaneous transluminal angioplasty (PTA) is often performed to improve limb related symptoms. Claudicants may have variation in symptomatology and disease progression while awaiting PTA Moreover restenosis following PTA is a major therapeutic problem despite high initial success rate, limiting the long-term efficacy of the procedure. There is growing evidence that the tissue factor-tissue factor pathway inhibitor (TF-TFPI) interaction, a major regulator of haemostasis, plays an important role in the healing response of arteries following PTA.
In this study, 1) we reassessed claudicants awaiting femoropopliteal PTA for more than 3 months to determine changes in patient symptomatology and disease distribution during the wait period and 2) we investigated any association between plasma TF and TFPI concentration and the development of restenosis following PTA.Patients and methods: In the first part of study, 47 claudicants with a median waiting period of 9.6 (interquartile range 4-21) months for femoro-popliteal PTA were assessed. Assessment included symptom and co-morbidity appraisal. Arterial duplex was performed on the symptomatic limb and compared with previous duplex study forassessment of disease progression.
In the second part, 52 unilateral claudicants undergoing femoropopliteal PTA and 10 healthy controls were studied for association of plasma TF and TFPI level with peripheral arterial disease and restenosis. Baseline (Pre PTA) plasma samples were collected from healthy controls and claudicants before PTA. Claudicants underwent arterial Duplex prior to and at 24 hours, one month, three month and six months following PTA to identify restenosis. Plasma TF and TFPI levels were measured using standard enzyme linked immunosorbent assay (ELISA). Results: On reassessment of claudicants awaiting PTA, 30(64%) patients were stable whilst 10 (21%) and 7 (15%) had symptomatically improved or deteriorated respectively. 9 (19%) patients demonstrated disease progression on arterial duplex. As a result of reassessment, 21 patients (45%) were removed from the PTA waiting list.Plasma TF and TFPI concentrations were significantly higher in claudicants compared to healthy controls. The baseline plasma TF and TFPI concentrations were significantly higher in claudicants who developed restenosis following PTA than those who did not. Following PTA, claudicants who developed restenosis showed higher concentrations of plasma TF at 24 hour, 1 month, 3 month and 6 month follow-up intervals. Conversely, the TFPI levels were significantly lower in the restenosis group at month 1 and 6 following PTA. The group differences did not reach statistical significance at day 1 and month 3 following PTA. The ratio of baseline plasma TF and TFPI was found to be raised significantly in claudicants who developed restenosis than those whose angioplasty siteremained patent.
Conclusions: 1.Claudicants awaiting PTA may experience a change in symptomatology with time which might alter management decisions. In units with a long waiting list, patients should be reassessed in the clinic to review symptom and evidence of disease progression or regression.2. Increased baseline plasma TF and TFPI levels are associated with restenosis following PTA; however it is more likely that an altered TF/TFPI balance could be involved in the occurrence of restenosis.
- Postgraduate Medical School, The University of Hull
- McCollum, Peter T.; Ettelaie, Camille; Chetter, Ian
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