Article Text

Download PDFPDF
Original research article
Incidence and outcomes of unstable angina compared with non-ST-elevation myocardial infarction
  1. Christian Puelacher1,2,
  2. Mathias Gugala2,
  3. Philip D Adamson3,
  4. Anoop Shah4,
  5. Andrew R Chapman5,
  6. Atul Anand3,
  7. Zaid Sabti2,
  8. Jasper Boeddinghaus2,
  9. Thomas Nestelberger2,
  10. Raphael Twerenbold2,
  11. Karin Wildi2,
  12. Patrick Badertscher2,
  13. Maria Rubini Gimenez2,6,
  14. Samyut Shrestha1,2,
  15. Lorraine Sazgary1,2,
  16. Deborah Mueller2,
  17. Lukas Schumacher2,
  18. Nikola Kozhuharov2,
  19. Dayana Flores2,
  20. Jeanne du Fay de Lavallaz2,
  21. Oscar Miro7,
  22. Francisco Javier Martín-Sánchez8,
  23. Beata Morawiec9,
  24. Gregor Fahrni10,
  25. Stefan Osswald10,
  26. Tobias Reichlin10,11,
  27. Nicholas L Mills12,
  28. Christian Mueller2
  1. 1 Department of Internal Medicine, University Hospital Basel, Basel, Switzerland
  2. 2 Cardiovascular Research Institute Basel, Department of Cardiology, University Hospital Basel, University Basel, Basel, Switzerland
  3. 3 Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
  4. 4 BHF/University Centre for Cardiovascular Science, Royal Infirmary of Edinburgh, Edinburgh, UK
  5. 5 BHF/University Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
  6. 6 Parc de Salut Mar-IMIM-UPF, Parc de Salut, Spain
  7. 7 Emergency Department, Hospital Clinic, Barcelona, Spain
  8. 8 Emergency Department, Hospital San Carlos de Madrid, Madrid, Spain
  9. 9 2nd Department of Cardiology, Medical University of Silesia, Zabrze, Poland
  10. 10 Department of Cardiology, University Hospital Basel, Basel, Switzerland
  11. 11 Department of Cardiology, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland
  12. 12 BHF Centre for Cardiovascular Sciences, The University of Edinburgh, Edinburgh, UK
  1. Correspondence to Professor Christian Mueller, Department of Cardiology, University Hospital Basel, Basel 4031, Switzerland; Christian.Mueller{at}


Objective Assess the relative incidence and compare characteristics and outcome of unstable angina (UA) and non-ST-elevation myocardial infarction (NSTEMI).

Design Two independent prospective multicentre diagnostic studies (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] and High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome [High-STEACS]) enrolling patients with acute chest discomfort presenting to the emergency department. Central adjudication of the final diagnosis was done by two independent cardiologists using all clinical information including serial measurements of high-sensitivity cardiac troponin (hs-cTn). All-cause death and future non-fatal MI were assessed at 30 days and 1 year.

Results 8992 patients were enrolled at 11 centres. UA was adjudicated in 8.9%(95% CI 8.0 to 9.7) and 2.8% (95% CI 2.3 to 3.3) patients in APACE and High-STEACS, respectively, and NSTEMI in 15.1% (95% CI 14.0 to 16.2) and 13.4% (95% CI 12.4 to 14.3). Coronary artery disease was pre-existing in 73% and 76% of patients with UA. At 30 days, all-cause mortality in UA was substantially lower as compared with NSTEMI (0.5% vs 3.7%, p=0.002 in APACE, 0.7% vs 7.4%, p=0.004 in High-STEACS). Similarly, at 1 year in UA all-cause mortality was 3.3% (95% CI 1.2 to 5.3) vs 10.4% (95% CI 7.9 to 12.9) in APACE, and 5.1% (95% CI 0.7 to 9.5) vs 22.9% (95% CI 19.3 to 26.4) in High-STEACS, and similar to non-cardiac chest pain (NCCP). In contrast, future non-fatal MI in APACE was comparable in UA and NSTEMI (11.2%, 95% CI 7.8 to 14.6 and 7.9%, 95% CI 5.7 to 10.2), and higher than in NCCP (0.6%, 95% CI 0.2 to 1.0).

Conclusions The relative incidence and mortality of UA is substantially lower than that of NSTEMI, while the rate of future non-fatal MI is similar.

  • unstable angina pectoris
  • acute coronary syndrome
  • mortality
  • myocardial infarction

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • NLM and CM contributed equally.

  • CP, MG and PDA contributed equally.

  • Contributors The authors designed the study, gathered and analysed the data, vouch for the data and analysis, wrote the paper and decided to publish. CP, MG, PDA, NLM and CM had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. All authors have read and approved the manuscript.

  • Funding Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, British Heart Foundation Project Grants, Butler Senior Clinical Research Fellowship, New Zealand Heart Foundation Overseas Research Fellowship, Chest Heart and Stroke Scotland.

  • Disclaimer The sponsors had no role in the design or conduct of the study, the gathering or analysing of the data, writing the manuscript or the decision to publish.

  • Competing interests Dr CP reports a personal grant from the PhD Educational Platform Health Sciences, outside this study. Dr MG report no conflicts of interest. Dr PDA reports grants from New Zealand Heart Foundation, during the conduct of the study, and grants from AstraZeneca, outside the submitted work. Dr AS reports other from Abbott Diagnostics, during the conduct of the study. Dr AA reports personal fees from Abbott Diagnostics, outside the submitted work. Dr MRG received speaker honoraria from Abbott, outside the submitted work. Dr RT reports grants from Swiss National Science Foundation (grant number P300PB-167803), personal fees from Roche Diagnostics, personal fees from Abbott, personal fees from Siemens, outside the submitted work. Dr TR has received research grants from the Goldschmidt-Jacobson Foundation, the Swiss National Science Foundation (PASMP3-136995), the Swiss Heart Foundation, the Professor Max Cloëtta Foundation, the University of Basel and the University Hospital Basel as well as speaker honoraria from Brahms and Roche, outside the submitted work. Dr NLM reports grants and personal fees from Abbott Diagnostics, Roche Diagnostics and Singulex outside the submitted work. Dr CM has received research support from the Swiss National Science Foundation, the Swiss Heart Foundation, the KTI, the Stiftung für kardiovaskuläre Forschung Basel; Abbott, Alere, AstraZeneca, Beckman Coulter, Biomerieux, Brahms, Roche, Siemens, Singulex, Sphingotec and the Department of Internal Medicine, University Hospital Basel, as well as speaker honoraria/consulting honoraria from Abbott, Alere, AstraZeneca, Biomerieux, Boehringer Ingelheim, BMS, Brahms, Cardiorentis, Novartis, Roche, Siemens and Singulex, during conduct of this study. All other authors report no conflicts of interest with this study.

  • Ethics approval This study was approved by the local ethics committees.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.