Epidemiology and Prognostic Factors in Acute Lower Limb Ischaemia: A Population Based Study

The aim of this study was to evaluate the contemporary population based incidence of acute lower limb ischaemia (ALI) and factors associated with major amputation/death at one year.In this retrospective observational study, in hospital, operation, radiological, and autopsy registries were scrutinised to capture 161 citizens of Malmö, Sweden, with ALI between 2015 and 2018. Age and sex specific incidence rates were calculated in the population of Malmö between 2015 and 2018, expressed as number of patients per 100 000 person years (PY). Independent risk factors for major amputation/death at one year were identified by multivariable logistic regression analysis and expressed as odds ratios (ORs) with 95% confidence intervals (CIs).One hundred and sixty-one patients with ALI gave an overall incidence of 12.2/100 000 PY (95% CI 10.3 - 14.1), with no sex related differences. Embolism (42.2%) was the most common cause of ALI. Among 52 patients with atrial fibrillation, 38.5% were on anticoagulant medication. Endovascular or open vascular revascularisation was performed in 54.7% of patients. The total cause specific mortality ratio was 2.63 (95% CI 1.66 - 3.61)/1 000 deaths, without no sex related differences. The combined major amputation/mortality rate at one year for the whole cohort was 46.6%. Rutherford ≥ IIb ALI (OR 4.19, 95% CI 1.94 - 9.02; p < .001), age (OR 1.03/year, 95% CI 1.00 - 1.06; p = .036), female sex (OR 2.37, 95% 1.07 - 5.26; p = .034), and anaemia (OR 2.46, 95% CI 1.08 - 5.62; p = .033) were associated with an increased risk of major amputation/death at one year. The major amputation/mortality rate at one year was 100% (n = 14/14) for patients living in a nursing home on admission.The incidence of ALI appears to be unchanged, and major amputation and mortality at one year remain high. It is necessary to include the substantial proportion of patients with ALI that do not undergo revascularisation in epidemiological studies. There is room for improvement in anticoagulation therapy in patients with atrial fibrillation to prevent ALI due to embolism. Research on gender inequalities in patients with ALI is warranted.