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Heart 99:35-40 doi:10.1136/heartjnl-2012-302632
  • Original articles
    • Acute coronary syndromes

Evaluation of the NICE mini-GRACE risk scores for acute myocardial infarction using the Myocardial Ischaemia National Audit Project (MINAP) 2003–2009: National Institute for Cardiovascular Outcomes Research (NICOR)

  1. Christopher P Gale1,3
  1. 1Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK
  2. 2York and Hull Medical School, University of York, York, UK
  3. 3Department of Cardiology, York Teaching Hospital NHS Foundation Trust, York, UK
  4. 4Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, USA
  5. 5Department of Cardiology, Pinderfields General Hospital, Wakefield, UK
  6. 6National Institute for Cardiovascular Outcomes Research, University College London, London, UK
  7. 7Leeds Institute of Health Sciences, University of Leeds, Leeds, UK
  8. 8Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
  9. 9Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK
  1. Correspondence to Dr A D Simms, Centre for Epidemiology and Biostatistics, Level 8, Worsley Building, University of Leeds, Clarendon Way, West Yorkshire, Leeds LS2 9JT, UK; simmsy{at}doctors.org.uk
  • Received 26 July 2012
  • Revised 16 August 2012
  • Accepted 17 August 2012
  • Published Online First 22 September 2012

Abstract

Objective To evaluate the performance of the National Institute for Health and Clinical Excellence (NICE) mini-Global Registry of Acute Coronary Events (GRACE) (MG) and adjusted mini-GRACE (AMG) risk scores.

Design Retrospective observational study.

Setting 215 acute hospitals in England and Wales.

Patients 137 084 patients discharged from hospital with a diagnosis of acute myocardial infarction (AMI) between 2003 and 2009, as recorded in the Myocardial Ischaemia National Audit Project (MINAP).

Main outcome measures Model performance indices of calibration accuracy, discriminative and explanatory performance, including net reclassification index (NRI) and integrated discrimination improvement.

Results Of 495 263 index patients hospitalised with AMI, there were 53 196 ST elevation myocardial infarction and 83 888 non-ST elevation myocardial infarction (NSTEMI) (27.7%) cases with complete data for all AMG variables. For AMI, AMG calibration was better than MG calibration (Hosmer–Lemeshow goodness of fit test: p=0.33 vs p<0.05). MG and AMG predictive accuracy and discriminative ability were good (Brier score: 0.10 vs 0.09; C statistic: 0.82 and 0.84, respectively). The NRI of AMG over MG was 8.1% (p<0.05). Model performance was reduced in patients with NSTEMI, chronic heart failure, chronic renal failure and in patients aged ≥85 years.

Conclusions The AMG and MG risk scores, utilised by NICE, demonstrated good performance across a range of indices using MINAP data, but performed less well in higher risk subgroups. Although indices were better for AMG, its application may be constrained by missing predictors.