All contemporary guidelines for secondary prevention in acute coronary syndromes recommend a combination of aspirin, beta-blockers, ACE-inhibitors and statins. Yet underutilisation of these drugs is common. We do not know in detail what drives underutilisation, nor what its long term consequences are for survival after discharge from hospital. Also unknown is whether potential adverse effects of underutilisation are the same for individual secondary prevention drugs.

This study will assess the impact of secondary prevention underutilisation on survival.

Using information from an England and Wales audit of acute coronary syndromes (the Myocardial Ischaemia National Audit Project (MINAP)) we aim to assess:

(i) Survival from first time MINAP-registered event to death as a function of secondary prevention medications: To what degree do the effects of medications (assumed equal, independent and additive) relate to patient survival? Is there evidence of a differential effect of discharge medications? (ii) (a) Survival from first time MINAP-registered event to death or second time MINAP-registered event as a function of secondary prevention medications: To what degree do the effects of medications (assumed equal, independent and additive) relate to competing risks? Is there evidence of a differential effect of discharge medications? (b) Survival from first time MINAP-registered event to death or second time MINAP-registered phenotyped as STEMI, NSTEMI or Unstable Angina. To what degree do the effects of medications (assumed equal, independent and additive) relate to competing risks? Is there evidence of a differential effect of discharge medications? (iii) What impact would ensuring all medication is taken have on event free 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).

Inclusion Criteria:

• Individuals with Acute Coronary Syndrome who have been registered with the MINAP database.

Exclusion Criteria:

• None

Individuals with data entered into the Myocardial Ischaemia National Audit Project (MINAP) database in England and Wales.