Non-ST-elevation myocardial infarction

Last reviewed: 5 Jan 2023
Last updated: 13 Jan 2023



History and exam

Key diagnostic factors

  • chest pain
  • risk factors for cardiovascular disease
  • marked sweating
  • cardiogenic shock
  • acute heart failure
Full details

Other diagnostic factors

  • nausea and vomiting
  • arrhythmias
  • heart murmur
  • epigastric pain
  • dyspnoea
  • syncope
  • back pain
Full details

Risk factors

  • atherosclerosis (history of angina, myocardial infarction, stroke, transient ischaemic attack, peripheral vascular disease)
  • diabetes
  • smoking
  • dyslipidaemia
  • family history of premature coronary artery disease (CAD)
  • age >65 years
  • hypertension
  • obesity and metabolic syndrome phenotype
  • physical inactivity
  • cocaine use
  • depression
  • stent thrombosis or restenosis
  • chronic kidney disease
  • surgical procedures (including intra-operative and postoperative periods)
  • sleep apnoea
Full details

Diagnostic investigations

1st investigations to order

  • ECG
  • high-sensitivity troponin
  • chest x-ray
  • full blood count
  • urea, electrolytes, and creatinine
  • liver function tests
  • blood glucose
  • C-reactive protein
Full details

Investigations to consider

  • echocardiography
  • invasive coronary angiography (ICA)
Full details

Treatment algorithm


clinically unstable (suspected or confirmed NSTEMI)

clinically stable (suspected or confirmed NSTEMI)




Expert advisers

Resham Baruah, MBBS, BSc MRCP, PhD

Consultant Cardiologist

Chelsea and Westminster Hospital NHS Foundation Trust

Royal Brompton & Harefield NHS Foundation Trust




RB is specialist advisor to the 2018 NICE guideline on chronic heart failure in adults and is a member of the European Heart Failure Association Task Force on palliative care in heart failure.


RB has received honoraria/speakers’ fees from Novartis and Boehringer Ingelheim.

Adam Hartley, MBBS, BSc, MRCP

Wellcome Trust Clinical Research Fellow

Imperial College London

Specialist Registrar in Cardiology

Imperial College Healthcare NHS Trust




AH declares that he has no competing interests.


BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:

Cody S Deen, MD

Assistant Professor of Medicine

Director of Cardiology

Hillsborough Hospital

University of North Carolina




CSD was previously the Director of Cardiac Rehab for Chatham Hospital, which was financially set up as a consultancy relationship, until 2017. CSD has spoken (unpaid) at the Update in Cardiology and Update in Internal Medicine Conferences at UNC for the last 5 years. CSD has served as the PI for the Dal-GeneE (site now closed) and the ACCELERATE Trials at the University of North Carolina (trial now completed). Each trial required paid travel to an investigator meeting.

Peer reviewers

Gavin Galasko, BM, BCh, MA, DM (Oxon), FRCP

Consultant Interventional Cardiologist

Director of Research, Development and Innovation

Blackpool Teaching Hospitals NHS Foundation Trust




GG declares that he has no competing interests.


Annabel Sidwell

Section Editor, BMJ Best Practice


AS declares that she has no competing interests.

Susan Mayor

Lead Section Editor, BMJ Best Practice


SM works as a freelance medical journalist and editor, video editorial director and presenter, and communications trainer. In this capacity, she has been paid, and continues to be paid, by a wide range of organisations for providing these skills on a professional basis. These include: NHS organisations, including the National Institute for Health and Care Excellence, NHS Choices, NHS Kidney Care, and others; publishers and medical education companies, including the BMJ Group, the Lancet group, Medscape, and others; professional organisations, including the British Thoracic Oncology Group, the European Society for Medical Oncology, the National Confidential Enquiry into Patient Outcome and Death, and others; charities and patients’ organisations, including the Roy Castle Lung Cancer Foundation and others; pharmaceutical companies, including Bayer, Boehringer Ingelheim, Novartis, and others; and communications agencies, including Publicis, Red Healthcare and others. She has no stock options or shares in any pharmaceutical or healthcare companies; however, she invests in a personal pension, which may invest in these types of companies. She is managing director of Susan Mayor Limited, the company name under which she provides medical writing and communications services.

Rachel Wheeler

Lead Section Editor, BMJ Best Practice


RW declares that she has no competing interests.

Julie Costello

Comorbidities Editor, BMJ Best Practice


JC declares that she has no competing interests.

Adam Mitchell

Drug Editor, BMJ Best Practice


AM declares that he has no competing interests.

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