Abstract 10860: Limb and Cardiovascular Event Risk in Type 1 and 2 Diabetic Patients With Peripheral Artery Disease

Introduction: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that often coexists with type 1 (T1) and type 2 (T2) diabetes mellitus (DM), which differ mechanistically. There is a paucity of data on comparative risk of LE and CVE in T1DM and T2DM patients with PAD. Methods: We queried our database of 40,144 patients ≥18y old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated patients with T1DM or T2DM and with PAD diagnosed by ABI (low [<1.0] or elevated [>1.4]). We retrieved demographics including hemoglobin A1c (A1c). Primary outcomes were LE (critical limb ischemia or vascular amputation) and CVE (myocardial infarction or ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, A1c, hypertension, hyperlipidemia, coronary artery disease (CAD), chronic kidney disease (CKD), and tobacco use. Results: Our study found 9,271 patients with PAD and DM (36% T1DM, 64% T2DM) with median follow-up time 34 mo (interquartile range [IQR] 85 mo). T1DM patients were younger than T2DM (mean age 67 vs 70y), with higher median A1c (7.7 [IQR 1.9] vs 6.7% [IQR 1.6]), and higher prevalence of hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use did not differ. Elevated ABI was more common in T1DM (47 vs 27%). LE occurred in 23% and CVE in 12% of patients. LE risk was higher in T1DM patients than T2DM (HR 1.59[95% CI 1.45,1.74], p<0.0001), but CVE and all-cause mortality did not differ significantly. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for A1c and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed to minimize limb morbidity.