Does Metformin Have an Effect on Stent Patency Rates

Abstract

Background: Metformin is the most commonly used drug for type 2 diabetes. Research has shown that metformin also has a protective effect on endothelium by decreasing endothelial vascular reactivity. We hypothesize that metformin will decrease restenosis/reintervention rates in patients receiving lower extremity non-drug-eluting stents (nDESs) in the superficial femoral artery(SFA) and/or popliteal artery.

Materials/methods: Retrospective study was performed on 187 patients from October 2012 to December 2015 who received an nDES in the SFA and/or popliteal artery. Patients were divided into 3 groups (Table 1) and compared against for duplex based restenosis (>60%) rates, limb loss rates, and reintervention rates. Each patient's Trans-Atlantic-Inter-Society-Consensus II (TASC-II) class was collected. Postoperative duplex was performed 1 week after the procedure, then every 3 months for the first year, then, every 6 months to check for patency. IBM-SPSS-22 was used for all analyses.

Results: Average age of the patients was 64.65 ± 73.4 years. 101 patients had 101 procedures performed on the left lower extremity; 86 patients had 86 procedures performed on the right lower extremity; 123 patients were male and 64 were female. Average length of follow-up was 13.1±9.7 months. Most common indication for intervention was claudication, followed by critical limb threatening ischemia. Restenosis and reintervention by groups can be seen in Table 1. No patients experienced limb loss. There were no statistically significant differences between any of the 3 groups and their limb loss, restenosis, or reintervention rates.

Conclusions: Despite having multiple proven effects in improving certain clinical outcomes and a proven protective effect on endothelium by decreasing endothelial vascular reactivity, metformin does not appear to reduce restenosis or reintervention rates in patients receiving lower extremity nDESs in the SFA and/or popliteal artery.

Keywords: lower extremity stenting; metformin; peripheral arterial disease.