Myocardial infarction: a high Cardiac Infarction Injury Score increased the risk of mortality.

Clinical bottom line (level 1b)

  1. Post-myocardial infarction, the use of a Cardiac Infarction Injury Score (CIIS) was not very helpful at assessing prognosis.
  2. Patients with higher CIIS scores had a trend to greater mortality at three years, but this was not marked.
van Domburg et al: European Heart Journal 1998; 19: 1034-1041
Expires March 2003

The study

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

Setting: multicentre trial of anticoagulation, The Netherlands

3395 patients (aged range 24 to 89 years; mean 61, 80% male) myocardial infarction diagnosed as chest pain with typical serum enzyme pattern and an evolving ST-T segment and/or Q waves

Excluded if
  • established indications for anticoagulant treatment
  • anticoagulant therapy within 6 months prior to index infarction
  • increased bleeding tendency
  • anticipated coronary revascularisation procedure
  • malignant disease with poor prognosis



    • Factors studied:
  • total mortality
  • Cardiac Infarction Injury Score 20-30
  • Cardiac Infarction Injury Score 30-40
  • Cardiac Infarction Injury Score > or = 40


    • Patients were originally randomised to 'active' anticoagulant therapy or matching placebo.

    Multivariate analysis was used to adjust for confounding factors.

    100% median follow up 37 months (range 6-60) with analysis made using a Kaplan-Meier model assuming patients had been followed for 3 years
    Outcomes studied:
  • total mortality

    • Cardiac Infarction Injury Score- duration of Q in lead aVL (ms)- Q absent, score 5; 10 ms, 1; 20 ms, 3; 30 ms, 9; 40 ms, 10; 50 ms, 12: amplitude of positive T in lead aVL- = 0.5 mm or > 3 mm, score 3: amplitude of negative T in lead aVL (mm), score mm x2: amplitude of negative R in lead aVR < 5 mm, score mm x-1: amplitude of negative T in lead aVR (mm)- absent, score 6; 1, score 3; 2, score 0; 3, score -2; 4, score -5; 5, score -7; 6, score -9; 7, score -11; 8, score -13: largest Q/R amplitude ratio in lead II or a VF = 1/5, score 12: duration of Q in lead III or a aVL = 40 ms, score 5: amplitude of T in lead III >1mm, score 5: amplitude of positive R lead V1 > 2mm, score 5: amplitude of negative R in lead V2 <3 or = 1/4 mm, score 5: amplitude of negative T in lead V2 = 14 mm, score 5: largest Q/R amplitude ratio in lead V3 >1/20, score 9: amplitude of S in lead V5 <2mm, score 5. A total score of <10 was considered as no myocardial infarction. A score of 10-20, possible MI. A score of 20 or more, probable MI. As all patients had sustained an MI, they were also classified into cohorts of 10, in four categories: score <20 (I); 20-30 (II); 30-40 (III) and = 40 (IV).

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    total mortality 3 years 359/3395 10.6%
    (9.54% to 11.6%)

    prognostic factor for
    total mortality     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    Cardiac Infarction Injury Score 20-30 3 years 1600/2393
    (66.9%)     		1.49
    (1.10 to 2.02)     		12
    (7 to 48)
    Cardiac Infarction Injury Score 30-40 3 years 1557/2342
    (66.5%)     		1.52
    (1.13 to 2.05)     		12
    (7 to 38)
    Cardiac Infarction Injury Score > or = 40 3 years 1994/3013
    (66.2%)     		1.68
    (1.16 to 2.42)     		10
    (6 to 31)

    Comments

    1. The complexity of this score does not seem justified given the prognostic data derived from it. No estimate is made of the additional information over 'clinical impression' or maximum CK level, for example.

    Citation

    1. van Domburg RT, Klootwijk P, Deckers JW, et al: The Cardiac Infarction Injury Score as a predictor for long-term mortality in survivors of a myocardial infarction. European Heart Journal 1998; 19: 1034-1041
    Contributor: Clare Wotton and Bob Phillips, January 2000
    Reviewer:

    Clinical Question.
    Patient myocardial infarction
    Intervention or Exposure high Cardiac Infarction Injury Score
    Comparison low Cardiac Infarction Score
    Outcome mortality