Characteristics of patients initiating PCSK9i mAb following myocardial infarction and comparability of treatment groups in the Netherlands

Abstract

Abstract Background The clinical benefits of lipid lowering treatment (LLT) for reducing risk of atherosclerotic cardiovascular disease (ASCVD) are well established. Recent findings support early initiation of proprotein convertase subtilisin/kexin type 9 inhibitors monoclonal antibodies (PCSK9i mAb) to maximize clinical benefit. However, when comparing treatment effects in a real-world setting, it is important to establish comparability of treatment groups and assess and adjust for confounding. Purpose To compare clinical characteristics and LLT use in patients initiating and not initiating PCSK9i mAb within 365 days following a myocardial infarction (MI). Methods MI events occurring in patients ≥18 years between 1 April 2016 and 31 December 2020 were identified in PHARMO Database Network, a population-based network of electronic healthcare databases linking data from general practitioners, out-patient and in-patient pharmacies and hospitals in the Netherlands. The database has about 3.3 million patients, representative of the Dutch population with respect to age and sex albeit with slight over-representation of those >80 years old. Characteristics of patients were presented by treatment groups: initiating PCSK9i mAb and not initiating PCSK9i mAb within 365 days post-MI. Characteristics and LLT use in the two treatment groups was evaluated. Results Of the 28,975 MI events, 157 (0.5%) initiated a PCSK9i mAb within 365 days. Patients who initiated a PCSK9i mAb within 365 days post-MI were younger than those who did not (median age of 63 versus 69 years), more likely to have a history of ASCVD prior to the MI event (56% versus 39%) and dyslipidaemia (55% versus. 28%), while non-initiators were more likely to have diabetes mellitus, chronic kidney disease and atrial fibrillation (Table). Patients who initiated PCSK9i mAb within 365 days post-MI had higher low-density lipoprotein cholesterol levels (3.7 versus 2.9 mmol/L), higher use of ezetimibe (25% versus 4%) and high-intensity statins (15% vs 11%, Figure). Conclusions In the Netherlands, despite being at very high risk of recurrent ASCVD, based on this dataset excluding Patient Support Programs, fewer than 1% of patients initiated a PCSK9i mAb within 365 days post-MI. Further analyses are needed to reveal if these treatment groups are comparable to assess differences and uncontrolled confounders in cardiovascular outcomes in the real world.