Unstable angina or MI: raised troponinT levels increased the risk of death.

Clinical bottom line (level 2b)

  1. 7% of patients with chest pain and abnormal ECGs died within a month.
  2. Patients with a raised troponin T level were more likely to die (NNF = 13 for 30 days) .
Ohman et al: New England Journal of Medicine 1996; 335 (18): 1333-1341
Expires June 2003

The study

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

Setting: 96 hospitals, NorthAmerica

855 patients (aged mean 63years, 69% male) chest discomfort for <12 hours and an abnormalECG (STelevation/depression >0.1 mV, or T wave insertion)

Excluded if
  • active bleeding
  • serum creatinine concentration >221 µ mol/l
  • stroke within last year
  • contraindications to heparin therapy



    • Factors studied:
  • mortality
  • elevated troponin T >0.1 ng/ml


    • Patients were taken from a randomised controlled trial. All patients received 160 mg aspirin at enrolment and 80 to 325 mg thereafter. Patients were randomly assigned to heparin (5000 units bolus, then 1000 units iv per hour) or desirudin (0.6 mg/kg iv bolus followed by infusion of 0.2 mg/kg per hour)

    Logistic regression analysis was performed to adjust for confounding factors.

    88% followed for 30 days
    Outcomes studied:
  • death

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    death 30 days 49/755 6.5%
    (4.7% to 8.3%)

    prognostic factor for
    death     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    elevated troponin T 30 days 3.01
    (1.77 to 5.13)     		13
    (6 to 33)

    • ECGchanges were found to be a risk factor for death as well: p=0.009.
    • 46% of patients had anMI.

    Comments

    1. No adjusted relative risks given- crude relative risks will be overestimates.
    2. CK-MB levels were not found add prognostic value beyond that of Troponin-Tlevel.

    Citation

    1. Ohman EM, Armstrong PW, Christenson RH, et al: Cardiac troponin T levels for risk stratification in acute myocardial ischemia. New England Journal of Medicine 1996; 335 (18): 1333-1341
    Contributor: Nick Shenker, Chris Ball and Clare Wotton, June 2000
    Reviewer: William Rhoton

    Clinical Question.
    Patient chest discomfort
    Intervention or Exposure troponinT
    Outcome death