Mojca Stegnar

By Mojca Božič-Mijovski, Vinko Boc, Vladka Salapura, Aleš Blinc and Mojca Stegnar

Percutaneous transluminal angioplasty (PTA) is an established method for treatment of peripheral artery disease (PAD) of the femoropopliteal artery. However, in up to 50% of patients restenosis and/or reocclusion remain a frequent complication occurring in the first year after the procedure. In this study, we focused on the influence of compromised postprocedural infrapopliteal runoff of the affected limb, on the hypercoagulability as detected by a global hemostasis assay and on genetic predisposition to hypercoagulability and on the regulation of the inflammation through the nuclear receptor related 1 protein (NuRR1). Consecutive PAD patients treated by femoropopliteal PTA because of disabling claudication or critical limb ischemia were followed up by vascular ultrasound imaging at 1, 6, and 12 months after the procedure. Venous blood samples for hemostasis, inflammation, and gene analysis were obtained before and 24 h after PTA. One month after femoropopliteal PTA, 23% of patients with compromised runoff developed the combined end point restenosis/reocclusion in comparison to 11% with good runoff (p = 0.03). After 6 months, the differences were no longer significant. It was concluded that compromised postprocedural infrapopliteal runoff predisposes to early restenosis/reocclusion after femoropopliteal PTA and that the deterioration of infrapopliteal runoff in the year after femoropopliteal PTA is accompanied by worsening of long-term femoropopliteal patency. Patients were genotyped for the prothrombotic gene polymorphisms: platelet receptor glycoprotein IIIa T1565C, coagulation factor V G1691A, coagulation factor II G20210A, coagulation factor XII C(-4)T, and plasminogen activator inhibitor-1 4G5G. We were not able to show any association between these polymorphisms and the restenosis/reocclusion rate in patients treated with femoropopliteal PTA. Furthermore, no association between thrombin generation and restenosis/reocclusion rate was established. NuRR1 haplotypes significantly increased the restenosis/reocclusion rate after PTA (adjusted relative risks were 1.6, 95% CI 1.1–2.3 for haplotype 2 and 2.0, 95% CI 1.3–2.8 for haplotype 3). To conclude, this study suggested a significantly higher restenosis/reocclusion rate in patients with compromised runoff compared to patients with a good runoff 1 month after the procedure. Hypercoagulability was not associated with the restenosis/reocclusion rate, and the prothrombotic polymorphisms were equally distributed among patient with and without restenosis/reocclusion, suggesting minor or no role in restenosis/reocclusion. Haplotypes 2 and 3 in the NuRR1 gene significantly increased the restenosis/reocclusion rate, suggesting significant role of inflammation. In this ongoing study, further analysis on a larger group of patients is warranted.

Part of the book: Thrombosis, Atherosclerosis and Atherothrombosis