Elsevier

American Heart Journal

Volume 150, Issue 3, September 2005, Pages 402-410
American Heart Journal

Clinical Investigation
Acute Ischemic Heart Disease
Performance of the Thrombolysis in Myocardial Infarction (TIMI) ST-elevation myocardial infarction risk score in a national cohort of elderly patients

https://doi.org/10.1016/j.ahj.2005.03.069Get rights and content

Background

The TIMI ST-elevation myocardial infarction (STEMI) score was developed and validated in a randomized controlled trial population. We sought to assess its accuracy in a community-based cohort of elderly patients hospitalized with STEMI.

Methods

We evaluated the TIMI STEMI score in 47 882 patients aged ≥65 years hospitalized with STEMI in US hospitals from 1994 to 1996. We assessed TIMI STEMI score discrimination and calibration for 30-day mortality and compared observed and published TIMI mortality rates.

Results

The cohort's median TIMI score was 6 (25th-75th percentile 4, 8). Thirty-day mortality rates were higher among patients with higher TIMI scores (TIMI score 2: 4.4% vs TIMI score >8: 35.6%, P < .0001 for trend). However, the TIMI score provided only modest discrimination (c = 0.67) and calibration (goodness-of-fit P < .0001). Mortality rates for TIMI scores differed between patients who did and did not receive reperfusion therapy (P < .0001 for TIMI score × reperfusion therapy interaction). Thirty-day mortality rates in the cohort were higher than published TIMI estimates (P = .001; eg, TIMI score 2: 4.4% cohort vs 2.2% published rate).

Conclusions

The TIMI score provided modest prognostic discrimination and calibration among elderly patients with STEMI. Our findings highlight the difficulties in applying risk scores developed in randomized controlled trial cohorts to elderly patients.

Section snippets

Cooperative Cardiovascular Project

The CCP included fee-for-service Medicare beneficiaries discharged from an acute care nongovernmental hospital in the United States with a primary discharge diagnosis of acute MI (International Classification of Diseases, Ninth Revision, Clinical Modification code 410) between January 1994 and February 1996, with the exception of readmissions (code 410. × 2).15 These patients' records were centrally abstracted for detailed clinical data including medical history, presentation, inhospital

Patient characteristics

Patients in the study cohort were predominantly white, 76 years of age on average, and slightly less than half were female. Reperfusion therapy was provided to 17 579 patients (36.7%), with 14 858 patients (84.5% of patients receiving reperfusion therapy) receiving fibrinolytic therapy and 2721 patients receiving a primary percutaneous transluminal coronary angioplasty. Patients who received reperfusion therapy were younger and a greater proportion were male, white, and had fewer comorbid

Discussion

Our evaluation of the TIMI score in a national, community-based population of elderly patients hospitalized with STEMI found the TIMI score provided only modest prognostic discrimination and calibration. Furthermore, published estimates of the 30-day mortality rates for TIMI scores were lower than those observed in the CCP cohort. Together, these data indicate the TIMI score may not accurately predict prognosis among elderly patients with STEMI.

Our evaluation of the TIMI score highlights how a

References (32)

  • The InTIME II Investigators

    Intravenous NPA for the treatment of infarcting myocardium early; InTIME-II, a double-blind comparison of single-bolus lanoteplase vs accelerated alteplase for the treatment of patients with acute myocardial infarction

    Eur Heart J

    (2000)
  • P.Y. Lee et al.

    Representation of elderly persons and women in published randomized trials of acute coronary syndromes

    JAMA

    (2001)
  • B.J. McNeil

    Shattuck Lecture: hidden barriers to improvement in the quality of care

    N Engl J Med

    (2001)
  • S.S. Rathore et al.

    Validity of a simple ST-elevation acute myocardial infarction risk index: are randomized trial prognostic estimates generalizable to elderly patients?

    Circulation

    (2003)
  • M. Singh et al.

    Scores for post-myocardial infarction risk stratification in the community

    Circulation

    (2002)
  • D.A. Morrow et al.

    Application of the TIMI risk score for ST-elevation MI in the National Registry of Myocardial Infarction 3

    JAMA

    (2001)
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    Saif Rathore was supported by NIH/National Institute of General Medical Sciences Medical Scientist Training Grant GM07205.

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