Expected eligibility for PCSK9i therapy in secondary prevention, ESC/EAS guidelines vs Irish reimbursement criteria in post PCI patients
Authors: Waters M , Coughlan J J , Pollock A , O'connor C , Arnous A , Kiernan T J 
Published: November 2023

Abstract

Introduction
Reimbursement of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) in Ireland is determined by the national center for pharmacoeconomics (NCPE) managed access protocol. To be eligible for a PCSK9i, patients must have had a myocardial infarction or CABG, LDL of &gt;3.5mmol/L, be treated with a high dose statin and ezetimibe. In contrast, the 2019 ESC/EAS dyslipidemias guidelines recommend that patients at ‘very high risk’ with an LDL-C of &gt;1.4mmol/L on a maximally tolerated dose of a statin and ezetimibe, be considered for PCSK9i. In this study, we aimed to define the proportion of patients who are potentially suitable for a PCSK9i at follow-up outpatient post-percutaneous coronary intervention (PCI).

Method
We retrospectively analysed data on patients who had PCI in University Hospital Limerick (UHL) between January 2016 to December 2019, with follow-up complete lipid profiles at baseline and at 6 - 8 weeks during outpatient review. We sought to compare the potential PCSK9i eligible population in our cohort based on guideline recommendations vs Irish reimbursement criteria. We performed a hierarchal analysis of patients on high dose statin therapy with an LDL-C &gt;1.4mmol/L at follow-up, who could potentially be eligible for a PCSK9i based on expected LDL-C. Expected LDL-C in these patients was calculated based on a 25% reduction in LDL-C with the addition of ezetimibe.

Results
Our analysis includes 1817 patients, with baseline characteristics; mean age 63.65years, 78.26% male, 40.01% smokers, 20.09% Diabetes Mellitus.
844 (46.45%) patients had a history of MI making them eligible for a PCSK9i based on NCPE clinical criteria. 12 patients (0.66%) in this group were on a high dose statin, and would have an expected LDL-C of &gt;3.5mmol/L with the addition of ezetimibe, therefore making them eligible for a PCSK9i as per NCPE MAP criteria.
In contrast to the NCPE MAP criteria all 1817 patients were deemed eligible for a PCSK9i based on ESC/EAS clinical criteria of "very high risk". 1275 patients (70.17%) had an LDL-C level &gt;1.4mmol/L, 6 - 8 weeks post PCI despite high dose statin therapy. Only a minority of patients in this cohort were on ezetimibe, 57/1817 (3.14%). The addition of ezetimibe to patients with an LDL-C &gt;1.4mmol/L, would result in 784 (43.14%) potentially being eligible for a PCSK9i based on current ESC guidelines, results are summarized in figure 1.

Discussion
Our data highlights the discrepancy between current ESC/EAS guidelines and reimbursement criteria for PCSK9i in Ireland. Based on expected attainable LDL-C minimal patients with coronary artery disease are eligible for reimbursement of a PCSK9i in Ireland for secondary prevention. Our findings also highlight that the majority of patients with established coronary disease do not meet their LDL-C goal at early follow-up. The addition of ezetimibe, would still result in over 40% of our cohort still having a significant lipid burden.