Clinical trial NCT01604486: Natural Ischaemic Preconditioning Before First Myocardial Infarction
Official title: Natural Ischaemic Preconditioning Before First Myocardial Infarction: an Analysis of Prospectively Collected UK Electronic Primary Care Records Linked to the National Registry of Acute Coronary Syndromes
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Myocardial Infarction
Angina Pectoris
Coronary Heart Disease
Peripheral Arterial Disease
Cerebrovascular Disease
Keywords: Myocardial infarction
Ischaemic preconditioning
Myocardial Ischaemia National Audit Project
General Practice Research Database
Hospital Episode Statistics
Office for National Statistics
Lead sponsor: London School of Hygiene and Tropical Medicine
Sponsor class: OTHER
Collaborators: name: University College, London
First posted: 2012-05-23
Enrollment: 16000
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study population is comprised of patients with a first myocardial infarction who are registered at those GPRD practices that agreed to the linkage with the MINAP database, and whose practices are "up to standard" according to GPRD criteria. Practices taking part in the GPRD are chosen to be representative of all UK practices, and 98% of people in the UK are registered with a GP. Therefore the GPRD should be a representative sample of the UK population.

Brief summary: There is a sharp rise in the rate of coronary heart disease diagnoses and chest pain consultations in the 90 days before a first heart attack. There is some evidence that chest pain and angina symptoms in this period have a beneficial effect on heart attack outcomes in hospital and shortly after discharge. However, the available evidence is lacking in three key areas. First it is based on a retrospective patient report of symptoms after the heart attack has occurred; this means that patients are required to survive their heart attack and may make errors when reporting prior symptoms. Second, evidence for an effect on longer term outcomes, and coronary outcomes in particular (e.g. coronary death, further heart attacks) are unknown. Third, there is conflicting evidence that these effects might differ by age, in men and women, and according to treatment in hospital.

The investigators hope to address the limitations in the evidence by performing a large, prospective study of the occurrence, timing and effect of different types of symptoms and disease diagnoses occurring before heart attack.

The investigators hypothesise that prospectively collected, clinical measures of chest pain symptoms and cardiovascular diagnoses in primary care will have a beneficial effect on short term coronary mortality and may have a beneficial effect on longer term coronary outcomes.


Eligibility criteria: 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, HES and ONS datasets.
* Patients must have at least one year of GPRD "up to standard" registration before the date of first MI.
* Age over 18.
* First myocardial infarction occurring between 1st January 2003 and 31st December 2008, as recorded in the Hospital Episode Statistics data or the Myocardial Ischaemia National Audit Project.

Exclusion Criteria:

* Patients will be excluded if they do not fulfil one of the inclusion criteria.

Primary outcomes:
measure: Recurrent myocardial infarction
timeFrame: Up to seven years
Secondary outcomes:
measure: Coronary mortality
timeFrame: Up to seven years
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: London School of Hygiene and Tropical Medicine
Study officials:
affiliation: London School of Hygiene and Tropical Medicine
name: Emily Herrett, MSc
role: PRINCIPAL_INVESTIGATOR
affiliation: University College, London
name: Harry Hemingway, FRCP
role: STUDY_DIRECTOR
References:
citation: Herrett E, Bhaskaran K, Timmis A, Denaxas S, Hemingway H, Smeeth L. Association between clinical presentations before myocardial infarction and coronary mortality: a prospective population-based study using linked electronic records. Eur Heart J. 2014 Sep 14;35(35):2363-71. doi: 10.1093/eurheartj/ehu286. Epub 2014 Jul 19.