Decreased serum PCSK9 levels after ischaemic stroke predict worse outcomes

Background: Soluble mediators have been investigated to predict the prognosis of acute ischaemic stroke (AIS). Among them, proprotein convertase subtilisin/kexin type 9 (PCSK9) might have both clinical and pathophysiological relevance. Materials and methods: All available serum samples from a cohort of patients with first AIS (n = 72) were tested for PCSK9 and included in this substudy analysis. The primary endpoint investigated the predictive value of early PCSK9 level variations (ΔPCSK9) from AIS onset to day 7 or from day 1 to day 7, towards a 90-day outcome by modified Rankin Scale (mRS). The secondary endpoint explored the association between ΔPCSK9 and the risk of major adverse cardiovascular events (MACEs). Results: Decreased serum PCSK9 levels at days 1 and 7 were associated with poor clinical outcomes at day 90. At the cut-off point identified by ROC curve analysis (−61·28 ng/mL), ΔPCSK9 day 7–day 1 predicted a poor mRS at day 90 after AIS. ΔPCSK9 day 7–day 1 ≤ −61·28 ng/mL was associated with an increased rate of MACEs. Conclusion: A decrease in PCSK9 levels was a predictor for poor outcome and increased MACEs after AIS. Additional studies targeting post-AIS PCSK9 levels and activity are required to clarify the prognostic and pathophysiological relevance of PCSK9 after AIS.