CLINICAL STUDY: ACUTE CORONARY SYNDROMES
Validated risk stratification model accurately predicts low risk in patients with unstable angina
James E. Calvin, MD, FRCPC, FACCa,
Lloyd W. Klein, MD, FACPa,
Elizabeth J. VandenBerg, MSa,
Peter Meyer, PhDa and
Joseph E. Parrillo, MD, FACPa
a Section of Critical Care Medicine, Section of Cardiology, Rush-Presbyterian-St. Lukes Medical Center, Chicago, Illinois, USA
Manuscript received March 16, 1999;
revised manuscript received June 15, 2000,
accepted July 31, 2000.
Reprint requests and correspondence: Dr. James E. Calvin, Rush-Presbyterian-St. Lukes Medical Center, Chicago, Illinois 60612 jcalvin{at}rpslmc.edu
BACKGROUND
In the mid 1990s, two unstable angina risk prediction models were proposed but neither has been validated on separate population or compared.
OBJECTIVES
The purpose of this study was to compare patient outcome among high, medium and low risk unstable angina patients defined by the Agency for Health Care Policy and Research (AHCPR) guideline to similar risk groups defined by a validated model from our institution (RUSH).
METHODS
Four hundred sixteen patients consecutively admitted to the hospital with unstable angina between January 1, 1995, and December 31, 1997, were prospectively evaluated for risk factors. The presence of major adverse events such as myocardial infarction (MI), death and heart failure was assessed for each patient by chart review.
RESULTS
The composite end point of heart failure, MI or death occurred in 3% and 5% of the RUSH and AHCPR low risk categories, respectively, and in 8% and 10% of AHCPR and RUSH high risk categories, respectively. Recurrent ischemic events were best predicted by the RUSH model (high: 24% vs medium: 12% and low: 10%, p = 0.029), but not by the AHCPR model (high: 14% vs medium: 13% and low: 9%, p = 0.876). The RUSH model identified five times more low risk patients than the AHCPR model.
CONCLUSIONS
Both models identify patients with low and high event rates of MI, death or heart failure. However, the RUSH model allowed for five times more patients to be candidates for outpatient evaluation (low risk) with a similar observed event rate to the AHCPR model; also, the RUSH model more successfully predicted ischemic complications. We conclude that the RUSH model can be used clinically to identify patients for early noninvasive evaluation, thereby improving cost effectiveness of care.
|
Abbreviations and Acronyms
| | AHCPR | = Agency for Health Care Policy and Research | | CK | = creatinine kinase | | MI | = myocardial infarction | | PTCA | = percutaneous transluminal angioplasty |
|
This article has been cited by other articles:

|
 |

|
 |
 
D Brieger, K A A Fox, G FitzGerald, K A Eagle, A Budaj, A Avezum, C B Granger, B Costa, F A Anderson Jr, P. G Steg, et al.
Predicting freedom from clinical events in non-ST-elevation acute coronary syndromes: the Global Registry of Acute Coronary Events
Heart,
June 1, 2009;
95(11):
888 - 894.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. P. Giugliano and E. Braunwald
The Year in Non--ST-Segment Elevation Acute Coronary Syndromes
J. Am. Coll. Cardiol.,
September 6, 2005;
46(5):
906 - 919.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Goldman and A. J. Kirtane
Triage of Patients with Acute Chest Pain and Possible Cardiac Ischemia: The Elusive Search for Diagnostic Perfection
Ann Intern Med,
December 16, 2003;
139(12):
987 - 995.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J Trevelyan, E W A Needham, S C H Smith, and R K Mattu
Sources of diagnostic inaccuracy of conventional versus new diagnostic criteria for myocardial infarction in an unselected UK population with suspected cardiac chest pain, and investigation of independent prognostic variables
Heart,
December 1, 2003;
89(12):
1406 - 1410.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. G. Kussmaul III
Should we catheterize all patients with unstable angina? No--only the ones with coronary artery disease
J. Am. Coll. Cardiol.,
October 1, 2001;
38(4):
977 - 978.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
ED Risk Prediction for Acute Coronary Syndromes Not Useful
Journal Watch Emergency Medicine,
January 17, 2001;
2001(117):
7 - 7.
[Full Text]
|
 |
|

|
 |

|
 |
 
D. A. Katz
Risk stratification in unstable angina: the role of clinical prediction models
J. Am. Coll. Cardiol.,
November 15, 2000;
36(6):
1809 - 1811.
[Full Text]
[PDF]
|
 |
|
|