An estimated three million people are affected by chronic obstructive pulmonary disease (COPD) in the UK, giving it a prevalence of 1.5% of the population in 2007/08. COPD accounts for approximately 30,000 deaths each year in the UK and is an important co-morbidity in those dying from other smoking related diseases, most commonly ischaemic heart disease and lung cancer. The National COPD audit showed a very high level of co-morbidity, the association with cardiovascular disease being particularly strong with 51% of patients with cardiovascular disease having been admitted for COPD within the preceding 24 months. Patients with COPD are at increased risk of myocardial infarction compared to the general population. Although this increase in cardiovascular risk exists, it is not clear is whether survival after myocardial infarction is different in patients with and without COPD and what factors contribute to this survival difference. Differences in survival may arise due to differences in prescribing certain drugs such as beta-blockers, differences in prevalence of risk factors (e.g. current smoking status) or increased COPD events such as exacerbations which themselves are associated with increased mortality.

The investigators primary aim is to investigate whether survival after first myocardial infarction is shorter in patients with COPD than those without COPD and to establish reasons for these differences in survival.

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).

Objectives:

1. To investigate survival differences after first myocardial infarction in patients with and without COPD.
2. To investigate if these survival differences exist due to a) differences in prevalence of risk factors (e.g. smoking) b) differences in management after myocardial infarction (e.g. uptake of cardiac rehabilitation, prescription of beta-blockers) and c) COPD related events (e.g. exacerbations).

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.

The study population is comprised of patients 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