Assessment and validation of a novel angiographic scoring system for peripheral artery disease

BackgroundAngiography is used routinely in the assessment of lower-limb arteries, but there are few well validated angiographic scoring systems. The aim of this study was to develop and validate a novel angiographic scoring system for peripheral artery disease. MethodsAn angiographic scoring system (the ANGIO score) was developed and applied to a sample of patients from a single vascular surgical department who underwent CT angiography of the lower limbs. The reproducibility of the ANGIO score was compared with those of the Bollinger and Trans-Atlantic inter-Society Consensus (TASC) IIb systems in a series of randomly selected patients. Associations between the ANGIO score and lower-limb ischaemia, as measured by the ankle:brachial pressure index (ABPI), and outcome events (major lower-limb amputations and cardiovascular events-myocardial infarction, stroke and cardiovascular death) were assessed. ResultsSome 256 patients undergoing CT angiography were included. The interobserver reproducibility of the ANGIO score was better than that of the other scoring systems examined (=090, P = 0002). There was a negative correlation between the ANGIO score and ABPI (=-033, P = 0008). A higher ANGIO score was associated with an increased risk of major lower-limb amputation (hazard ratio (HR) for highest versus lowest tertile 930, 95 per cent c.i. 195 to 4438; P = 0005) and cardiovascular events (HR 273, 131 to 570; P = 0007) following adjustment for established risk factors. ConclusionThe ANGIO score provided a reproducible and valid assessment of the severity of lower-limb ischaemia and risk of major amputation and cardiovascular events in these patients with peripheral artery disease. Wider validation necessary