ALETHEIA: An observational study on treatment patterns and clinical outcomes of patients experiencing a myocardial infarction in clinical practice

Study type
Protocol
Date of Approval
Study reference ID
20_114
Lay Summary

In 2011, 3.7% of men and 1.6% of women in England (approximately 965,000 men and 430,000 women) experienced a heart attack. Those who experience such an event have an increased long-term risk of a future attack. According to the National Institute for Health and Care Excellence (NICE), better preventive treatment could prevent more than 30,000 deaths per year in England and Wales. Though clinical guidelines now recommend an extension of dual antiplatelet therapy (DAPT) beyond 12 months following a heart attack, real-world data are scarce on the characteristics of patients receiving this treatment, as well as their patterns of use.
This study aims to describe the characteristics of patients receiving antiplatelet therapy for prevention of heart attack beyond 12 months. The medications of interests are ticagrelor 60 mg and other recommended antiplatelets (clopidogrel, prasugrel, or ticlopidine). As ticagrelor 60 mg was recently added to clinical guidelines in 2019, treatment persistence, bleeding complications, and cardiovascular events among patients receiving this treatment will also be investigated. This study would inform healthcare professionals and health authorities on how closely clinical practice in England follows current NICE guidelines, which in turn can lead to improved treatment in patients with MI. It will also offer insight into risks and benefits of ticagrelor 60 mg, providing clinical practice with evidence of the benefits and safety of the new therapy, and guiding physicians to better evidence-based treatment decisions. This knowledge can improve the overall treatment pathway and protect vulnerable patient populations from avoidable risks.

Technical Summary

According to the British Heart Foundation, the prevalence of myocardial infarction (MI) in England in 2011 was 3.7% in men and 1.6% in women. It is estimated that better secondary prevention after MI could prevent more than 30,000 deaths per year in England and Wales. Most guidelines recommend 12-month DAPT with aspirin (ASA) and an oral P2Y12 inhibitor, a group of antiplatelets that inhibits the platelet P2Y12 receptor, as the mainstay of antithrombotic therapy after MI, and clinical guidelines have recently recommended extending DAPT beyond 12 months. However, there is a lack of real-world data on patient characteristics and antiplatelet treatment beyond 12 months of MI.
This is an observational cohort study aiming to describe the characteristics of patients initiating ticagrelor 60 mg and other P2Y12 inhibitors 12 months after MI in England, using data from Hospital Episode Statistics (HES) linked to the Clinical Practice Research Datalink (CPRD) Gold and Aurum. Additionally, we will investigate the treatment persistence, incidence and event rates of bleeding requiring hospitalisations, CV events in patients receiving ticagrelor 60 mg. Patient characteristics will be summarised for each treatment group using descriptive statistics. Median treatment duration of ticagrelor 60 mg and cumulative incidence of clinical outcomes will be calculated using the Kaplan-Meier method. Incidence rates and event rates will be calculated per 100 person-years.
This study would inform healthcare professionals and health authorities on how closely clinical practice in England follows current NICE guidelines, which in turn can lead to improved treatment in patients with MI. It will also offer insight into risks and benefits of ticagrelor 60 mg, providing clinical practice with evidence of the benefits and safety of the new therapy, and guiding physicians to better evidence-based treatment decisions. This knowledge can improve the overall treatment pathway and protect vulnerable patient populations from avoidable risks.

Health Outcomes to be Measured

This is a descriptive study, so patient characteristics will be summarised for patients initiating ticagrelor 60 mg or other P2Y12 inhibitors (clopidogrel, prasugrel, or ticlopidine) 12 months after MI in the UK.
Additionally, as NICE has recently recommended ticagrelor 60 mg for the prevention of atherothrombotic events in adults with MI at high risk of a future event,1 we will also investigate treatment persistence, bleeding complications requiring hospitalisation, and CV events among these patients. The following outcomes are of interest:
• Persistence to treatment: measured as time to discontinuation (see more details in section N)
• Bleeding requiring hospitalisation: hospitalisation for intracranial haemorrhage, gastrointestinal bleeding, or other bleeding.
• Bleeding events (code lists attached in appendices)
o Intracranial haemorrhage
o Gastrointestinal bleeding requiring hospitalisation
o Bleeding other than intracranial haemorrhage or gastrointestinal bleeding requiring hospitalisation
o Fatal bleeding (overall, intracranial, gastrointestinal, other)
o Bleeding not requiring hospitalisation, here denoted minor bleeding
• CV events (code lists attached in appendices)
o Composite of hospitalisation for MI or stroke, and all-cause mortality
o Composite of hospitalisation for MI or stroke, and CV death (three-point major adverse CV events [MACE])
o Hospitalisation for MI, hospitalisation for ischaemic stroke, CV death, coronary heart disease (CHD) death, all-cause mortality, coronary revascularization (composite of percutaneous coronary intervention [PCI], coronary artery bypass graft [CABG]) assessed individually
• Dyspnoea
• Lower-limb amputation

Collaborators

Eva Lesen - Chief Investigator - AstraZeneca AB (Sweden)
Mai Duong - Corresponding Applicant - Evidera Ltd - UK
Chris Hewitt - Collaborator - AstraZeneca Ltd - UK Headquarters
Dimitra Lambrelli - Collaborator - Evidera, Inc
Jason Simeone - Collaborator - Evidera, Inc
Sharon MacLachlan - Collaborator - Evidera, Inc

Linkages

HES Admitted Patient Care;ONS Death Registration Data;Practice Level Index of Multiple Deprivation