Chronic disease burden, not admission laboratory results, marks limb-threatening severity in acute lower-limb arterial thrombosis: a registry study of 288 patients from Kazakhstan

Acute lower-limb arterial thrombosis is a vascular emergency that often reaches internists and emergency physicians before a vascular specialist, and data from Central Asia are scarce. We asked which patient-level factors mark limb-threatening severity at first presentation, and whether routine admission laboratory tests add to that judgement. We studied a registry of 288 consecutive patients hospitalised with acute lower-limb arterial thrombosis between 2017 and 2022 at a tertiary centre in Karaganda, Kazakhstan. Severity was graded with the Savelyev classification, with grades IIB-IIIA defined as limb-threatening. Associations were tested by logistic regression with Firth-penalised and bootstrap sensitivity analyses, and predictors of tissue loss were modelled separately. Patients were mostly elderly men (median age 67 years, 72.2% male) with a heavy atherosclerotic burden (hypertension 74.0%, coronary disease 54.9%, diabetes 19.1%, prior revascularisation 35.8%). At presentation 142 (49.3%) had limb-threatening ischaemia and 31 (10.8%) tissue loss. Independent markers of limb-threatening severity were diabetes (adjusted odds ratio 2.15, 95% CI 1.02-4.55), hypertension (2.14, 1.05-4.37), tissue loss (2.55, 1.01-6.45) and lower body-mass index (0.71 per 5 kg/m2, 0.52-0.97). Admission haematology, coagulation and metabolic values did not differ between severity groups (all p>0.10), and the chronic-disease model discriminated modestly (area under the curve 0.68). Low body-mass index (0.49 per 5 kg/m2, p=0.005) and prior amputation (7.08, p=0.04) independently predicted tissue loss. Limb-threatening severity tracked the chronic vascular-metabolic phenotype rather than the admission laboratory profile, which did not discriminate. Low body weight was a consistent danger signal. Bedside assessment, not routine bloods, should anchor early triage.