Background: Medial arterial calcification (MAC) of the tibial and pedal arteries has been associated with an increased risk of amputation among people with diabetes. Endovascular interventions on infrageniculate vessels are frequently performed with the intent of treating peripheral artery disease (PAD) and decreasing the risk of amputation in those with diabetes. This study aimed to investigate how the extent of MAC impacts outcomes of endovascular procedures in people with diabetic foot ulcers (DFU).
Methods: We identified all patients who had undergone infrageniculate angioplasty in the setting of DFU at our institution between 2009 and 2019. Subjects were assigned a MAC score based on the severity of MAC in each vessel visualized on plain radiographs of the ankle and foot. We evaluated the relationship between MAC and the primary outcome, major adverse limb event (MALE), using stratified Cox proportional modeling.
Results: Among 99 subjects with DFU who had undergone infrageniculate angioplasty, MALE occurred in 50% (95% confidence interval [CI] 38%-61%) of patients within 1 year of intervention. On univariate Cox regression analysis, each 1 point increment in MAC score (hazard ratio [HR], 1.09; 95% CI 1.01-1.18), the third tertile of MAC score (HR, 2.27; 95% CI 1.01-5.11), age (HR 0.96; 95% CI 0.93-0.99), and wound grade (HR, 5.34; 95% CI 2.17-13.14), were significantly associated with increased risk of MALE. On adjusted analysis stratified by wound grade, MAC score was found to be associated with MALE only in patients with a low wound grade.
Conclusion: Increased severity of MAC is associated with increased risk of MALE for subjects undergoing infrageniculate angioplasty with a low wound grade. Further research is needed to better understand the complex relationships of MAC, PAD, DFU, and interventions aimed at promoting healing of DFU.
Keywords: angioplasty; calcification; diabetic foot ulceration; endovascular; limb salvage.