PCSK9 inhibitors and incidence of arrhythmias in clinical practice: a phase IV multicentric study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: PCSK9 inhibitors (PCSK9i) are a novel drug class indicated for the treatment of dyslipidaemia. PCSK9i have been shown to remarkably reduce cardiovascular events in patients at high risk, but little data is currently available regarding the incidence of atrial fibrillation, no reports exist on ventricular events or other cardiac arrhythmias, and is not documented if this drug class is safe regarding arrhythmias as a potential side effect. PURPOSE: To study the incidence of arrhythmias in patients before and after treatment with PCSK9i. METHODS: All consecutive patients starting treatment with PCSK9 inhibitors, either evolocumab or alirocumab, were consecutively enrolled in two high-volume Italian arrhythmia centres. All patients were treated according to ESC guidelines for primary and secondary prevention. All patients failed to achieve the recommended LDL goals with standard treatment before the introduction of PCSK9i. Patients with familial hypercholesterolemia were excluded. All arrhythmic endpoints were collected in a one-year time frame before and after the first dose of PCSK9i. RESULTS: 191 patients were enrolled (mean age 63±15 years, 76.6% males) and followed up for one year. 13.2% were labelled as "statin-intolerant" and were treated only with ezetimibe, all the others had PCSK9i prescription on top of both statin and ezetimibe. The recommended LDL threshold was reached in 45.1% of patients at very high-risk and 76.7% at high-risk. 14.9% of all patients had a history of PACs and 15.6% had a history of PVCs. 7.8% had a previous diagnosis of atrial fibrillation, 2.1% of TRNAV and 6.4% of sustained ventricular arrhythmias. These 6.4% all had an ICD implanted for secondary prevention, while another 0.9% had a primary prevention indication. The total number of PACs in 24 hours decreased from 1260 to 800, although the difference was not statistically significant (p=0.058). Similar results were noted for PVCs (from 271 to 195 in 24 hours; p=0.089). The one-year incidence was 6.1% for atrial fibrillation, 2.3% for TRNAV and 3.8% for sustained ventricular arrhythmias, with no difference between the year before (all p=NS). Of all patients with an ICD and a history of appropriate ICD therapies (n=11, 5.7%) only one experienced appropriate therapies in the year after PCSK9i started. CONCLUSIONS: The treatment with PCSK9 inhibitors does not significantly modify the risk of supraventricular or ventricular arrhythmias in patients with non-familial hypercholesterolemia. Preliminary data support the safety of this class of drug also regarding arrhythmic events.