Cardiovascular disease (CVD) is an important public health problem that affects millions of people worldwide. Associations between risk factors, such as smoking, dyslipidaemia or hypertension, and prevalent CVD are well documented. However, few studies have investigated associations with onset of disease. The initial manifestation of CVD, for example an episode of unstable angina, is important because it influences the prognosis, the quality of life and the management of disease. Furthermore, the extent to which social deprivation, alcohol consumption or atrial fibrillation affects presentation of CVD is poorly understood and deserves further consideration.

Most previous studies have considered CVD as a single entity. However, differences in aetiology between coronary phenotypes suggest that risk factors may not be shared across specific coronary phenotypes and their relative importance is likely to differ for each phenotype. Gaining knowledge of these differences could provide insights into the pathophysiology of specific forms of CVD and could eventually lead to modification of recommendations for patient management and disease prevention.

We propose to use the linkage of the national registry of coronary events to general practice records in the Clinical Practice Research Database (CPRD), to investigate whether demographic, behavioral, and clinico-metabolic risk factors differentially influence the onset of specific types of CVD.

Inclusion Criteria:

• Aged ≥30yrs old
• Registered in CPRD practices in England consenting to data linkage
• ≥1 year of up-to-standard pre-study follow-up

Exclusion Criteria:

• History of any of the CVD endpoints considered before study follow-up initiation.

The study population will include all patients aged ≥30yrs old, registered in CPRD practices in England consenting to data linkage, with at least 1 year of up-to-standard pre-study follow-up and no history of any of the CVD endpoints considered. Follow-up for endpoints will commence on the earliest date on which a patient fulfils the criteria, within the period between 1st January 1997 and 25th March 2010.