The impact of anaemia on the clinical outcomes of infra-inguinal bypass for critical limb ischaemia

ABSTRACT NUMBER: NESS_8

 

Authors
Nandhra.S, Boylan.L, Prentis. J, Nesbitt. C and the Northern Vascular Centre

Introduction
Anaemia in elective cardio-vascular surgery has been shown to have a detrimental impact on clinical outcomes and survival. Non-elective caseload is high in vascular surgery and the timely revascularisation in critical limb-ischaemia (CLI) significantly contributes towards this workload. The outcomes are hugely significant to the patient. Equally a 2017 Delphi consensus identified that improving outcomes in CLI are a top ten research priority. As such, this tertiary centre cohort studies evaluates the impact of anaemia on CLI revascularisation outcomes.

Methods
All infra-inguinal bypass operations for CLI between 2016 and 2018 were identified from a prospectively maintained database. Anaemia was defined as a pre-operative haemoglobin (Hb) of less than 120g/dL. Pre-, intra- and post-operative metrics were analysed to understand if anaemia impacted on clinical outcome. Comparative statistics and regression analyses were performed.

Results
124 bypasses for CLI were included. 45 were anaemic with an average Hb of 105 (9.5) vs. the non-anaemic 141.7 (14.7) group. 
Baseline comparisons were equivalent for age, gender, co-morbidity and medications, as were the duration of surgery and intra-operative blood loss. 
Post-operatively there was a greater rate of wound infection (p=0.036) and myocardial infarction (p=0.02) in the anaemic group. Regression analysis demonstrated that anaemic patients were 9(OR) times more likely to have an MI.
The mean length of stay was longer in the anaemic group (26.8 (22.6) vs. 14(15.9) days (P=0.001). 
1-year mortality was also higher in the anaemic group(P=0.037) and OR of 3.6(1.02 – 12.8)(P=0.046). Anaemia and length of stay significantly correlated with 1-year mortality.
There was no difference in 30-day mortality or limb loss.

Conclusion
Pre-operative anaemia significantly increases the rate of complications and length of hospital stay following surgical revascularisation for CLI. It is also associated with higher 1-year mortality. Consequently, optimisation of baseline Hb may improve these outcomes in this high risk non-elective group of patients.
Disclosure: Nothing to disclose