Unstable angina: a raised troponin T within 48 hours indicates a worse prognosis.

Clinical bottom line (level 1b)

  1. Patients with unstable angina are at high risk of dying or having coronary revascularisation in the next three years.
  2. Patients with a raised troponin T level within 12 to 24 hours of admission are at increased risk of dying or needing revascularisation (NNF = 3 for 2 years) .
Stubbs et al: British Medical Journal 1996; 313: 262-264
Expires July 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: coronary care unit, acute hospital, UK

183 patients (aged mean 61 years, 72% male) admitted with chest pain, who had a final diagnosis of unstable angina, defined as chest pain, cardiac enzymes below two times upper limit of normal and evidence of ischaemic heart disease:
  • cardiac event during follow-up
  • angiogram showing 50% stenosis or more of a major coronary segment
  • positive exercise test
  • detection of ischaemia on thallium scintigraphy



Multiple regression analysis was performed on risk factors.

100% followed for 0 to 5 years (mean 3)
Outcomes studied:
  • cardiac death or revascularisation
  • cardiac death
  • coronary revascularisation

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    cardiac death or revascularisation 0 to 5 years (mean 3) 74/183 40.4%
    (33.3% to 47.6%)
    cardiac death 0 to 5 years (mean 3) 26/183 14.2%
    (9.15% to 19.3%)
    coronary revascularisation 0 to 5 years (mean 3) 48/183 26.2%
    (19.9% to 32.6%)

    prognostic factor for
    cardiac death or revascularisation     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    troponin T 0.2 µ g/ml or more, 12 to 24 hours after admission 3 years 40/121
    (33.1%)     		2.55
    (1.28 to 5.08)     		4
    (3 to 18)

    prognostic factor for
    cardiac death     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    troponin T 0.2 µ g/ml or more 3 years /
    (%)     		1.50
    (0.43 to 5.41)     		21
    (-16 to 3)

    prognostic factor for
    coronary revascularisation     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    troponin T 0.2 µ /ml or more 3 years 26/121
    (21.5%)     		3.18
    (1.37 to 7.37)     		4
    (2 to 17)

    Comments

    1. No details given about medical therapy during hospital admission.
    2. Can other clinical features predict a poor prognosis as well as troponin T?
    3. Data based on Kaplan-Meier curves

    Citation

    1. Stubbs P, Collinson P, Moseley D, et al: Prospective study of the role of cardiac troponin T in patients admitted with unstable angina. British Medical Journal 1996; 313: 262-264
    Contributor: Nick Shenker and Chris Ball, July 2000
    Reviewer: Donald Stanley

    Clinical Question.
    Patient unstable angina
    Intervention or Exposure troponin T
    Outcome death, myocardial infarction