Myocardial Infarction as the First Manifestation of Coronary Heart Disease: Rates of Heralded and Unheralded Myocardial Infarction

Sponsor

London School of Hygiene and Tropical Medicine (Other)

Overall Status

Completed

CT.gov ID

NCT01168869

Collaborator

British Medical Research Council (Other), University College, London (Other)

9,000

Enrollment

Location

Duration (Months)

176.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Some myocardial infarctions (MI) occur as the first manifestation of coronary artery disease. These are termed 'unheralded' events as they have not been preceded by other forms of coronary artery disease. Unheralded MIs are important because of the high likelihood of missed opportunities for prevention. The proportion of MIs that are 'unheralded' is unknown.

This study aims to quantify the proportion of MIs that occur 'unheralded' and also give an estimate of the incidence of 'unheralded' MI in the UK, compared to 'heralded' MI and those with angina of recent onset (MIs with premonitory symptoms).

Condition or Disease	Intervention/Treatment	Phase
Myocardial Infarction

Detailed Description

This study is part of the CALIBER (Cardiovascular disease research using linked bespoke studies and electronic records) programme funded over 5 years from the NIHR and Wellcome Trust. The central theme of the CALIBER research is linkage of the Myocardial Ischaemia National Audit Project (MINAP) with primary care (GPRD) and other resources. The overarching aim of CALIBER is to better understand the aetiology and prognosis of specific coronary phenotypes across a range of causal domains, particularly where electronic records provide a contribution beyond traditional studies. CALIBER has received both Ethics approval (ref 09/H0810/16) and ECC approval (ref ECC 2-06(b)/2009 CALIBER dataset).

Using data from MINAP and GPRD, patients experiencing their first myocardial infarction (MI) will be separated into three categories:

'Heralded MI': patients who have been diagnosed or treated for cardiovascular disease for more than 90 days before MI.
'MI with premonitory symptoms': patients who have been diagnosed or treated for cardiovascular disease within the 90 days prior to MI.
'Unheralded MI': patients without a cardiovascular disease diagnosis or treatment at any time before MI.

Patients with MI will be identified in the linked GPRD-MINAP record. Using GPRD population denominators, this study will establish the absolute incidence rates of first 'unheralded' MI by calendar year, age, sex, season, MI subtype (ST-elevation MI and non ST-elevation MI) and region and compare these to the rates of first 'heralded' MIs and first 'MI with premonitory symptoms'.

Study Design

Study Type:

Observational

Actual Enrollment :

9000 participants

Time Perspective:

Retrospective

Official Title:

Myocardial Infarction as the First Manifestation of Coronary Heart Disease: Rates of Heralded and Unheralded Myocardial Infarction. A CALIBER Study

Study Start Date :

Sep 1, 2009

Actual Primary Completion Date :

Dec 1, 2013

Actual Study Completion Date :

Dec 1, 2013

Arms and Interventions

Arm	Intervention/Treatment
GPRD patients All patients included in "up to standard" GPRD practices that agreed to the linkage with the MINAP database are included in this cohort.

Outcome Measures

Primary Outcome Measures

First myocardial infarction (MI) [Average time frame: patients in the GPRD are followed from registration until they experience the outcome, leave the practice, die, or 31st December 2009, whichever occurs first.]
First MIs will be divided into three groups: (i) Those with previous manifestations of cardiovascular disease, diagnosed or treated more than 90 days before the MI. These are the 'Heralded MIs'. (ii) Those with a diagnosis or treatment of cardiovascular disease occurring only within 90 days before MI. These are the 'MIs with premonitory symptoms'. (iii) Those without any previous manifestation of cardiovascular disease at any time before MI. These are the 'Unheralded MIs'.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Patients in GPRD practices which are deemed "up to standard" by GPRD criteria will be included if their practice agreed to be linked to the MINAP dataset.
Age over 18.

Exclusion Criteria:

Patients will be excluded after experiencing their first MI.
Patients will be excluded if they do not fulfil one of the inclusion criteria.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	London School of Hygiene and Tropical Medicine	London		United Kingdom	WC1E 7HT

Sponsors and Collaborators

London School of Hygiene and Tropical Medicine
British Medical Research Council
University College, London

Investigators

Principal Investigator: Emily Herrett, MSc, London School of Hygiene and Tropical Medicine
Study Director: Harry Hemingway, FRCP, University College, London