Plasminogen Activator Inhibitor-1 Levels and Activity Decrease After Intervention in Patients with Critical Limb Ischaemia

Abstract

Patients with peripheral arterial occlusive disease (PAOD), in particular critical limb ischaemia (CLI), carry a high risk of thrombotic events. We hypothesised that patients undergoing conservative, endovascular, or open surgical treatment for CLI have increased levels of plasminogen activator inhibitor-1 (PAI-1), leading to a prothrombotic state. The objective was to determine levels of PAI-1 in patients with acute or chronic PAOD/CLI. Thirty-two patients with a median age of 74 (49-90) years were included. Three underwent thrombolysis for acute limb-threatening ischaemia. Twenty-six patients with chronic ischaemia received endovascular (n = 20) or open (n = 6) surgical treatment. Three were treated conservatively. Biomarkers and ankle brachial index (ABI) were measured before and up to 1 month after intervention. Patency was studied with repeated duplex ultrasound. Ankle pressure and ABI improved after intervention (p < .001). C-reactive protein (CRP) increased from a median of 7.90 mg/L at baseline to 31.5 on day 1 (p < .001), 28.0 on day 6 (p < .001), and returned to baseline levels on day 30. PAI-1 antigen and activity decreased from day 6 and onwards post-intervention compared with baseline (p < .05). A great individual variability in PAI-1 antigen and activity was observed. Although most actively treated patients had normal PAI-1 activity, 11/29 (38%) were above that level of normality at baseline, 10/24 (42%) on day 1, 3/23 (13%) on day 6, and 5/27 (19%) on day 30 after intervention. Endovascular and open surgical treatment resulted in improved ankle pressure and ABI. The intervention was followed by a transient increase in CRP and a sustained reduction in PAI-1 levels and activity.