High Hemoglobin A1c Associated with Increased Adverse Limb Events in Peripheral Arterial Disease Patients Undergoing Revascularization

• Type of Material: Article
• Authors: Shipra Arya, Emory University; Zachary Binney, Emory University; Anjali Khakharia, Emory University; Chandler A Long, Duke University; Luke Brewster, Emory University; Peter Wilson, Emory University; William Jordan Jr, Emory University; Yazan Duwayri, Emory University
• Language: English
• Date: 2017-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2017 Published by Elsevier Inc. on behalf of the Society for Vascular Surgery.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jvs.2016.10.028
• Title of Journal or Parent Work: Journal of Vascular Surgery
• ISSN: 0741-5214
• Volume: 65
• Issue: 1
• Start Page: e10
• End Page: e11
• Grant/Funding Information: Arya: American Heart Association Mentored Clinical and Population Research Award (15MCPRP25580005); NIH-NIA 1R03AG050930; American Geriatric Society/Society for Vascular Surgery (SVS) Foundation Jahnigen Career Development Award.; Wilson: Veteran Affairs Merit Grant I01-CX001025; This material is the result of work supported with resources and the use of facilities at the Atlanta VA Medical Center, Decatur GA.; Brewster: NIH- NHLBI, 1KO8HL119592; SVS Foundation/American College of Surgeons Mentored Clinical Scientist Research Career Development Award; Department of Defense, CDMRP/OPORP; OP140015
• Keywords: peripheral artery disease; vascular surgery; cardiology; genomic medicine; Hemoglobin; adverse limb events; revascularization; endovascular therapy; epidemiology; A1c
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Medicine and Surgery

Abstract

Objective—Diabetes mellitus (DM) and peripheral arterial disease (PAD) are independently associated with increased risk of amputation. However, the effect of poor glycemic control on adverse limb events has not been studied. We examined the effects of poor glycemic control (high hemoglobin A1c) on the risk of amputation and modified major adverse limb events (mMALE) after lower extremity revascularization. Methods—Patients undergoing PAD revascularization who had HbA1c levels available within 6 months were identified in the VA database 2003– 2014 (N=26799). The diagnosis of preoperative DM (PreopDM) was defined using DM diagnosis codes and evidence of treatment. Amputation and modified MALE (mMALE) risk was compared for HbA1c levels using Kaplan Meier analysis. Cox proportional hazards models were created to assess the effect of high HbA1c on amputation/mMALE (adjusted for age, gender, race, SES, comorbidities, cholesterol levels, creatinine, supra/infrainguinal procedure, open/endovascular procedure, severity of PAD, year of cohort entry and medications) for all patients and stratified on PreopDM. Results—High HbA1c levels were present in 33.2% of the cohort while 59.9% had PreopDM. Amputations occurred in 4,359 (16.3%) patients and 10,580 (39.5%) had mMALE. Kaplan Meier curves showed worst outcomes in patient with PreopDM and high HbA1c. In the Cox model, incremental HbA1c levels of 6.1–7.0%, 7.1–8.0% and >8% were associated with 26% (HR 1.26, 95% CI 1.15– 1.39), 53% (HR 1.53, 95%CI 1.37–1.7) and 105% (HR 2.05, 95% CI 1.87–2.26) higher risk of amputation respectively. Similarly, the risk of mMALE also increased by 5% (HR 1.05, 95%CI 0.99–1.11), 21% (HR 1.21, 95%CI 1.13–1.29) and 33% (HR 1.33, 95%CI 1.25–1.42) with worsening HbA1c levels of 6.1–7.0%, 7.1–8.0% and >8% respectively (versus HbA1c ≤6.0%). In stratified analysis by established by PreopDM, the relative risk of amputation/mMALE was much higher with poor glycemic control (HbA1c >7.0%) in patients without PreopDM. Conclusion—PAD patients with worse perioperative glycemic control have a significantly higher risk of amputation and mMALE. Incremental increases in HbA1c levels are associated with higher hazards of adverse limb outcomes independent of PreopDM status. Poor glycemic control (HbA1c> 7.0%) in patients without a preoperative diagnosis of DM carries twice the relative risk of amputation and mMALE than those with good glycemic control. These results suggest that screening of diabetic status and better management of glycemic control could be a target for improvement of perioperative and long term outcomes in PAD patients.