Peripheral arterial disease is a common condition whose prevalence increases significantly with advancing age, for both men and women 1-4. With the upward trend in population aging, it is expected that increasing numbers of elderly patients will require treatment for symptomatic peripheral arterial disease 1,5. We have recently shown that AKI is a common and serious complication in patients undergoing endovascular treatment for femoro-popliteal arterial disease, and that increasing age is an independent risk factor in its development 6. The aim of this study was to investigate the incidence of AKI, as well as the short- to medium- term changes in renal function in elderly patients undergoing peripheral endovascular intervention of the femoro-popliteal segment.

All octogenarians and nonagenarians with symptomatic PAD (Rutherford stages III - VI) undergoing peripheral endovascular intervention in the femoro-popliteal segment from January 2014 to May 2019 in three vascular centres. All patients had cross-sectional lower limb imaging within two of the index procedure, as well as baseline full blood count, liver and renal biochemistry and clotting assays. All patients underwent standardised post-operative follow-up for a minimum of 90 days. A venous blood sample was obtained at 48 hours, 7 days, 30 days and 90 days post-operatively to measure Serum Creatinine (SCr).

A total of 505 patients (270 men, 53.3%) were included, corresponding to 505 treated limbs (femoropopliteal segment). The mean(s.d.) age at baseline was 85.1(4.0) years. CKD (stages II-V: 458 patients, 90.6 %), hypertension (365 patients, 72.3%), diabetes mellitus (188 patients, 37.2%), and ischaemic heart disease (104 patients, 20.6 %) were the commonest co-morbidities. Acute kidney injury was observed in 84 patients (16.63%) patients, with seven requiring renal replacement therapy or being dialysis dependent for 90 days after the index procedure. Specifically, of the 84 patients who developed acute kidney injury, 58 patients had no change in their CKD category at 48h, whilst 26 deteriorated by one CKD stage, at the 48h point. At 90 days after the procedure however, 47 patients had no change in their CKD stage, whilst 34 patients had an upstaging by 1 category, and 3 patients by 2 CKD categories respectively (Image 1,2) Short-term mortality was observed in 24 patients (4.8%), with the commonest causes being cardiovascular (15 patients, 62.5%), infective (4 patients, 16.6%), whilst a cause of death could not be ascertained in the remaining 5 patients. The composite MAKE90 endpoint was seen in 43 patients in the AKI group ( 51.2%) and 82 patients (19.5%) of those who did not develop AKI (p<10-4). No statistically significant differences were observed in the rate of major amputations between the two groups (p = 0.388). (Table)

The reported incidence of AKI in this elderly population was 16.6%, consistent with the published data about AKI in endovascular interventions 6,7. It is important to highlight the high prevalence of CKD in this elderly population (90%), which is known to be a risk factor for both developing AKI after the procedure and incidence of cardiovascular complications and mortality 6 . AKI at the first 48 hrs after the procedure was a significant factor for the level of sCr at 90 days. Another important point highlight in this study is that in the group of AKI the average level of glomerular filtration rate was still low at 90 days 35.9 (± 21.1) compared with the basal one 43.7 (± 19.5); this suggest that we need a longer renal function follow-up for patients undergoing endovascular intervention. We must make further and longer follow-ups in elderly patients undergoing endovascular procedures for CLTI; not only for the risk of decrease in renal function, but also the association between complications and mortality related to the cofounding of frailty and AKI.

1 Conte MS, Bradbury AW, Kolh P, White JV, Dick F, Fitridge R, et al. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg 2019;69(6S):3S-125S.e40. Doi: 10.1016/j.jvs.2019.02.016. 2 Diehm C, Schuster A, Allenberg JR, Darius H, Haberl R, Lange S, et al. High prevalence of peripheral arterial disease and co-morbidity in 6880 primary care patients: cross-sectional study. Atherosclerosis 2004;172(1):95-105. Doi: 10.1016/s0021-9150(03)00204-1. 3 Fowkes FGR, Rudan D, Rudan I, Aboyans V, Denenberg JO, McDermott MM, et al. Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis. Lancet 2013;382(9901):1329-40. Doi: 10.1016/S0140-6736(13)61249-0. 4 Fowkes FGR, Aboyans V, Fowkes FJI, McDermott MM, Sampson UKA, Criqui MH. Peripheral artery disease: epidemiology and global perspectives. Nat Rev Cardiol 2017;14(3):156-70. Doi: 10.1038/nrcardio.2016.179. 5 Wübbeke LF, Naves CCLM, Daemen J-WHC, Jacobs MJ, Mees BME. Editor's Choice - Mortality and Major Amputation after Revascularisation in Octogenarians Versus Non-Octogenarians with Chronic Limb Threatening Ischaemia: A Systematic Review and Meta-Analysis. Eur J Vasc Endovasc Surg 2020;60(2):231-41. Doi: 10.1016/j.ejvs.2020.04.027. 6. Katsogridakis E, Lea T, Yap T, Batchelder A, Saha P, Diamantopoulos A, et al. Acute kidney injury following endovascular intervention for peripheral artery disease. Br J Surg. 2021 Mar 12;108(2):152-9. 7 Arora P, Davari-Farid S, Pourafkari L, Gupta A, Dosluoglu HH, Nader ND. The effect of acute kidney injury after revascularization on the development of chronic kidney disease and mortality in patients with chronic limb ischemia. J Vasc Surg. 2015 Mar;61(3):720-7.