The impact of discontinuing proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors on clinical outcomes

Abstract Background/Introduction Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors have demonstrated efficacy in lowering low-density lipoprotein cholesterol (LDL-C) levels and reducing the risk of cardiovascular events. Despite these advantages, some patients are unable to continue the use of PCSK9 inhibitors due to financial or other reasons. Limited clinical studies have been conducted to investigate the clinical outcomes of patients discontinuing PCSK9 inhibitors for various reasons. Purpose This study aims to specifically investigate patients who were unable to continue PCSK9 inhibitors, with a particular focus on those discontinuing due to financial or other reasons. The primary objective is to assess the impact of discontinuation on major adverse cardiovascular events (MACE). Methods This study focused on 205 Japanese patients who received PCSK9 inhibitors between July 2016 and December 2023. The clinical outcomes of patients who continued or discontinued PCSK9 inhibitors were comprehensively compared. The primary endpoint was major adverse cardiovascular events (MACE), encompassing cardiovascular death, coronary revascularization, target lesion revascularization (TLR), and fatal or non-fatal myocardial infarction (MI). Results Among 205 patients (median age: 69 years; interquartile range [IQR]: 60-76 years 68% male), the median follow-up was 413 days (IQR, 49-1148 days). At one year, the median LDL-C was 43mg/dL, and 158 patients (77%) achieved LDL-C <70 mg/dL. During the follow-up, 64% (131 patients) continued PCSK9 inhibitors, while 36% (74 patients) discontinued. Of the discontinuation group, 30% (22 patients) cited financial problems, 24% (18 patients) clinical stability, and 12% (9 patients) patient preference. Multivariate Cox regression analysis revealed that the group discontinuing PCSK9 inhibitors had a higher incidence of MACE than the group that continued (hazard ratio: 1.84; 95% confidence interval: 1.02 to 3.55; p=0.05). Conclusions This study suggests an increased risk of MACE when PCSK9 inhibitors are discontinued for financial or other reasons. This insight is vital for healthcare management and decision-making among medical practitioners.PCSK9: continuation vs discontinuation