European Heart Journal Advance Access originally published online on August 3, 2007
European Heart Journal 2007 28(17):2175-2176; doi:10.1093/eurheartj/ehm279
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Are acute coronary syndromes risk models too complex?
Leeds Institute of Genetics Health and Therapeutics
Clarendon Way
University of Leeds
Leeds LS2 9JT
UK
Biostatistics unit
Centre for Epidemiology and Biostatistics
University of Leeds
West Yorkshire
Leeds LS7 9LN
UK
Academic Unit of Cardiovascular Medicine
G Floor, Jubilee Wing
The Yorkshire Heart Centre
The General Infirmary at Leeds
Great George Street
West Yorkshire
Leeds LS1 3EX
UK
Tel: +44 0113 343 7721 Fax: +44 0113 343 7738 E-mail address: c.p.gale{at}leeds.ac.uk
The article by Yan et al.1 measured the discriminatory performances of the TIMI, PURSUIT, and GRACE risk scores (RS) and suggested that they offered better prediction of in-hospital and 1-year mortality than that of global risk assessment by physicians.1 Moreover, the study revealed an inverse relationship between estimated risk and early invasive management when patients were stratified by RS, an important finding recently highlighted by Fox et al.2 In the study by Yan et al.,1 revascularization was more frequently based on physicians' global assessment, signifying that RS are not being used appropriately for estimating risk. Perhaps, this is because they are too complex?
The Evaluation of the Methods and Management of Acute Coronary Events (EMMACE) risk model is a community-derived risk model for patients presenting with ST-elevation myocardial infarction.3 It is a simple model that uses patient age, admission heart rate, and systolic blood pressure to predict 30-day mortality [C-index = 0.76 (95% CI 0.72–0.79)]. The EMMACE model has good discriminatory performance because it relies on age and haemodynamic predictors. In the article by Yan et al.,1 RS which included these variables (GRACE and PUSRUIT rather than TIMI) also offered improved discriminatory capacity. We have corroborated this using 100 686 patients from the Myocardial Infarction National Audit Project database (MINAP), an extensive community-based cohort of patients hospitalized in UK and Wales with ACS:4,5 C-index (95% CI): TIMI RS for 14-day mortality = 0.58 (0.57–0.59, P < 0.001), GRACE RS for in-hospital mortality =0.80 (0.80–0.81, P < 0.001), GRACE RS for 6-month mortality = 0.80 (0.79–0.80, P < 0.001), and PUSRUIT for 30-day mortality = 0.81 (0.78–0.81, P < 0.001).6
A concern with the GRACE and PURSUIT RS is that they rely on the collection of multiple variables when it is known that secondary abstraction of difficult-to-obtain key clinical findings adds little to the predictive power of RS.7 In the article, Yan et al.1 have inclined that RS complexity may also be prohibitive to their use. Perhaps, RS that rely on a few easily recordable variables may be used more frequently by physicians and also allow as good a risk prediction as more complex scores?
Although the findings by Yan et al.1 are important, a more appropriate external validation of the RS would have considered their performance over their original risk prediction periods (TIMI, 14 days;8 PURSUIT, 30 days;9 and GRACE, in-hospital10 and 6 months11) and outcomes (TIMI—composite of death, revascularization, and re-infarction at 14 days). Secondly, while the authors identified a significant correlation between the three RS, one would expect this because the authors have compared similar methods (i.e. RS designed to evaluate ACS mortality) over a range of values. The resultant tests of significance are therefore not relevant since it would be unusual that the RS were not related.
References
- Yan AT, Yan RT, Tan M, Casanova A, Labinaz M, Sridhar K, Fitchett DH, Langer A, Goodman SG. Risk scores for risk stratification in acute coronary syndromes: useful but simpler is not necessarily better. Eur Heart J (2007) 28:1072–1078.
[Abstract/Free Full Text] - Fox KAA, Anderson FA Jr, Dabbous OH, Steg PG, Lopez-Sendon J, Van de Werf F, Budaj A, Gurfinkel EP, Goodman SG, Brieger D, on behalf of the GRACE Investigators. Intervention in acute coronary syndromes: do patients undergo intervention on the basis of their risk characteristics? The Global Registry of Acute Coronary Events (GRACE). Heart (2007) 93:177–182.
[Abstract/Free Full Text] - Dorsch MF, Lawrance RA, Sapsford RJ, Oldham J, Greenwood DC, Jackson BM, Morrell C, Ball SG, Robinson MB, Hall AS. A simple benchmark for evaluating quality of care of patients following acute myocardial infarction. Heart (2001) 86:150–154.
[Abstract/Free Full Text] - http://www.rcplondon.ac.uk/college/ceeu/ceeu_ami_home.htm (accessed June 2007).
- Birkhead J, Pearson M, Norris RM. The national audit of myocardial infarction: a new development in the audit process. J Clin Excellence (2002) 4:379–385.
- Gale CP, Manda SOM, Batin PD, Birkhead J, Hall AS. Acute coronary syndrome risk models: Validation using the Myocardial Infarction National Audit Project Database World Congress of Cardiology. (2006.).
- Pine M, Jordan HS, Elixhauser A, Fry DE, Hoaglin DC, Jones B, Meimban R, Warner D, Gonzales J. Enhancement of claims data to improve risk adjustment of hospital mortality. JAMA (2007) 297:71–76.
[Abstract/Free Full Text] - Antman EM, Cohen M, Bernink PJ, McCabe CH, Horacek T, Papuchis G, Mautner B, Corbalan R, Radley D, Braunwald E. The TIMI risk score for unstable angina/non-ST elevation MI: a method for prognostication and therapeutic decision making. JAMA (2000) 284:835–842.
[Abstract/Free Full Text] - Boersma E, Pieper KS, Steyerberg EW, Wilcox RG, Chang WC, Lee KL, Akkerhuis KM, Harrington RA, Deckers JW, Armstrong PW, Lincoff AM, Califf RM, Topol EJ, Simoons ML. Predictors of outcome in patients with acute coronary syndromes without persistent ST-segment elevation. Results from an international trial of 9461 patients. The PURSUIT Investigators. Circulation (2000) 101:2557–2567.
[Abstract/Free Full Text] - Granger CB, Goldberg RJ, Dabbous O, Pieper KS, Eagle KA, Cannon CP, Van de Werf F, Avezum A, Goodman SG, Flather MD, Fox KA. Predictors of hospital mortality in the global registry of acute coronary events. Arch Intern Med (2003) 163:2345–2353.
[Abstract/Free Full Text] - Fox Keith AA, Dabbous Omar H, Goldberg Robert J, Pieper Karen S, Eagle Kim A, Van de Werf F, Avezum A, Goodman Shaun G, Flather MD, Anderson FA Jr, Granger CB. Prediction of risk of death and myocardial infarction in the six months after presentation with acute coronary syndrome: prospective multinational observational study (GRACE). BMJ (2006) 333:1091.
[Abstract/Free Full Text]
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C P Gale, S O M Manda, B A Cattle, C F Weston, J S Birkhead, P D Batin, A S Hall, and R M West The authors' reply: Heart, June 15, 2009; 95(12): 1019 - 1020. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||