Khan SZ, et al. - In peripheral arterial disease (PAD) patients with diabetes, the incidence of cardiovascular and limb-specific adverse outcomes is higher. This study was undertaken to determine the effect of metformin on outcomes after intervention for PAD. In this work, metformin proved to have no beneficial impact regarding improved patency or limb salvage rates but was independently associated with improved survival and decreased major adverse cardiac events (MACEs) in patients with PAD. In nondiabetics and patients taking metformin and other oral hypoglycemics [OHs], similar Limb salvage was observed. Insulin use seemed associated with increase limb loss.

Methods

• From June 2001 and December 2014, researchers retrospectively identified patients who underwent revascularization for chronic limb ischemia (Rutherford 3-6).
• Using Kaplan-Meier and Cox regression, they compared primary patency, secondary patency, limb salvage, major adverse cardiac events (MACEs), and survival rates of patients taking metformin with those not taking metformin.

Results

• Researchers identified 1564 limbs in 1204 patients (147 metformin, 196 other oral hypoglycemics [OHs], 216 insulin only, 645 nondiabetics).
• Compared with other subgroups, nondiabetics indicated markedly lower incidence of coronary artery disease and hypertension (P < .05).
• The metformin group indicated significantly higher statin and aspirin use (P < .05).
• A significantly greater number of patients with end-stage renal disease and critical limb ischemia were identified in the insulin group (P < .05).
• The 60-month primary patency was significantly greater in nondiabetics 62% (P = .005), with no significant difference between metformin (56%), OH (60%), and insulin (51%) groups (P = .06).
• Similar 60-month secondary patency was evident in metformin (76%), OH (85%), insulin (76%), and nondiabetic (80%) groups (P = .272).
• In the insulin group, limb salvage was significantly worse (62%; P < .001); however, there appeared no significant difference regarding limb salvage between metformin (84%), OH (83%), and nondiabetic (87%) groups (P = .451).
• Significantly improved 60-month survival was observed in metformin (60%) and nondiabetic (60%) groups compared with the OH (41%) and insulin (30%) groups (P < .001).
• Freedom from MACEs was markedly higher in the metformin (44%) and nondiabetic (52%) groups compared with the OH (37%) and insulin (25%) groups (P < .001).
• They identified metformin use (hazard ratio, 0.7 [0.5-0.9]; P = .008) as an independent factor associated with survival (Fig).