Neurological effects of proprotein convertase subtilisin/kexin type 9 inhibitors: direct comparisons

Aims Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors considerably alter the lipid profile. We sought to examine the rates of ischaemic stroke and neurocognitive deficits in patients treated with and without PCSK9 inhibitors. Methods and results Randomized controlled trials (RCTs) reporting rates of ischaemic stroke and neurocognitive deficits in patients using PCSK9 inhibitors were identified. Standard meta-analysis techniques were used to compare these outcomes among patients treated with and without PCSK9 inhibitors and the two US Food and Drug Administration-approved PCSK9 inhibitors, evolocumab and alirocumab. The results were presented in terms of risk ratio (RR) with 95% confidence intervals (CIs). Sixteen RCTs with 39 104 patients were included. Evolocumab was used in six RCTs with 33 450 patients, whereas alirocumab was used in 10 RCTs with 5654 patients. We observed a significantly lower risk of ischaemic stroke among those treated with PCSK9 inhibitors (RR 0.77, 95% CI 0.64-0.93) when compared with those without. We did not observe any difference in the risk of neurocognitive deficits between the aforementioned groups (RR 1.11, 95% CI 0.93-1.32). The lower stroke risk in the PCSK9 inhibitors group was driven by evolocumab studies. We observed no difference in the risk of neurocognitive deficits among evolocumab and alirocumab when compared with no PCSK9 inhibitors group. Conclusion Treatment with PCSK9 inhibitors significantly lowers the risk of ischaemic stroke, without any increased risk of neurocognitive deficits. PCSK9 inhibitors are neuroprotective due to the decrease in ischaemic-mediated neurovascular events and should be considered cognitively innocuous medications.