Objective: Major adverse limb events (MALEs) are frequent in patients with lower extremity peripheral arterial disease (PAD). However, routine care MALE rate estimations after revascularisation are scarce. This study aimed to determine post-procedural MALE rates in revascularised patients with PAD and identify predictors of post-procedural MALEs.
Methods: This was a population based observational study on merged national registry data. Patients with PAD undergoing lower limb revascularisation between 2008 and 2016 were retrieved from the Swedish National Registry for Vascular Surgery. Information on comorbidities, medications, and post-procedural MALE endpoints were identified in national healthcare registries. Primary outcomes of interest were categorised as 2 - 4 point MALE composites that included limb amputation, acute lower limb ischaemia, progression to or relapse of chronic limb threatening ischaemia (CLTI), and ipsilateral re-interventions regardless of indication. Patients with intermittent claudication (IC) and CLTI were analysed separately using Kaplan-Meier estimates. Stepwise Cox proportional hazard models were used for predictor candidate analysis.
Results: Overall, 28 021 revascularised patients with PAD were analysed (IC, n = 10 506, 37.5%; CLTI, n = 17 515, 62.5%). During a mean follow up ± standard deviation of 3.2 ± 2.4 years, 5 226 (18.7%), 9 423 (33.6%), and 12 696 (45.3%) patients experienced a 2, 3, and 4 point MALE, respectively. The estimated one year 4 point MALE rates were 21.4% (95% confidence interval [CI] 20.6 - 22.2%) in IC and 46.9% (95% CI 46.1 - 47.7%) in CLTI. Adjusted predictors for experiencing a 4 point MALE in IC were chronic kidney disease (CKD) (hazard ratio [HR] 1.33, 95% CI 1.12 - 1.59) and previous lower limb revascularisation (HR 1.29, 95% CI 1.19 - 1.40). In CLTI, previous contralateral lower limb amputation (HR 1.60, 95% CI 1.47 - 1.73) and CKD (HR 1.25, 95% CI 1.17 - 1.34) were adjusted predictors.
Conclusion: This study emphasises the very high MALE rates in revascularised patients with lower limb PAD, especially in CLTI. Prior lower limb revascularisation correlated with increased MALE rates in IC patients, while prior lower limb amputation was linked to subsequent MALEs in CLTI. In both IC and CLTI, CKD was associated with poorer outcomes, regardless of applied MALE definition.
Keywords: Chronic limb threatening ischaemia; Incidence study; Intermittent claudication; MALE; Major adverse limb event; Peripheral arterial disease.
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