The cost-effectiveness of intensive low-density lipoprotein cholesterol lowering in people with peripheral artery disease

Background: People with peripheral artery disease are at a high risk of major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Randomized controlled trials suggest that intensive lowering of low-density lipoprotein cholesterol (LDL-C) with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors is an effective strategy to prevent these events. This study estimated the potential benefit and cost-effectiveness of administrating PCSK9 inhibitors to a cohort of participants with peripheral artery disease. Methods: A total of 783 participants with intermittent claudication (IC; n = 582) or chronic limb-threatening ischemia (CLTI; n = 201) were prospectively recruited from three hospitals in Australia. Serum LDL-C was measured at recruitment, and the occurrence of MACE and MALE was recorded over a median (interquartile range) follow-up of 2.2 years (0.3-5.7 years). The potential benefit of administering a PCSK9 inhibitor was estimated by calculating the absolute risk reduction and numbers needed to treat (NNT) based on relative risk reductions reported in published randomized trials. The incremental cost-effectiveness ratio per quality-adjusted life year gained was estimated. Results: Intensive LDL-C lowering was estimated to lead to an absolute risk reduction in MACE of 6.1% (95% confidence interval [CI], 2.0-9.3; NNT, 16) and MALE of 13.7% (95% CI, 4.3-21.5; NNT, 7) in people with CLTI compared with 3.2% (95% CI, 1.1-4.8; NNT, 32) and 5.3% (95% CI, 1.7-8.3; NNT, 19) in people with IC. The estimated incremental cost-effectiveness ratios over a 10-year period were $55,270 USD and $32,800 USD for participants with IC and CLTI, respectively. Conclusions: This analysis suggests that treatment with a PCSK9 inhibitor is likely to be cost-effective in people with CLTI.