Myocardial infarction: prior angina carried a worse prognosis.

Clinical bottom line (level 1b)

  1. In patients with first myocardial infarction, a history of angina was associated with a worse outcome in hospital (NNF = 33 for unknown) and at 5.5 years (NNF = 24 for 5.5 years) .
Behar et al: American Heart Journal 1992; 123 (6): 1481-1485
Expires March 2003

The study

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

Setting: university medical centre in Israel

4166 patients (aged mean 61 y, 73% male) acute myocardial infarction (defined by symptoms, ECG changes and/or enzyme criteria)

Factors studied:
  • age; site of infarct; diabetes; heart failure on admission
  • angina pectoris >1 month prior to MI
  • angina pectoris >1m prior to MI


    • given standard care for 1981-83, without thrombolysis, and randomised to nifedipine or placebo

    Multivariate logistic regression analysis was used to adjust for confounding factors.

    ?100% followed for 12 months
    Outcomes studied:
  • in hospital mortality
  • 5.5 year mortality

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    in hospital mortality 12 months 560/4166 13.4%
    (12.4% to 14.5%)
    5.5 year mortality 12 months 808/4166 19.4%
    (18.2% to 20.6%)

    prognostic factor for
    in hospital mortality     		time to outcome control rate (%) adjusted OR
    (90% CI)    		 NNF+
    (95% CI)
    angina pectoris >1 month prior to MI ? 276/2365
    (12%)     		1.30
    (1.10 to 1.53)     		33
    (19 to 96)

    prognostic factor for
    5.5 year mortality     		time to outcome control rate (%) adjusted OR
    (90% CI)    		 NNF+
    (95% CI)
    angina pectoris >1m prior to MI ? 407/2365
    (19%)     		1.29
    (1.16 to 1.44)     		24
    (16 to 42)

    Comments

    1. Total infarct registry studied - not just those included in the RCT (SPRINT).
    2. As sex is a weak negative prognostic indicator in AMI, and there was an increased proportion of female patients in the 'angina' group, failure to control for this variable may account for part of the increased risk.

    Citation

    1. Behar S, Reicher-Reiss H, Abinader E, et al: The prognostic significance of angina pectoris preceding the occurrence of a first acute myocardial infarction in 4166 consecutive hospitalized patients. American Heart Journal 1992; 123 (6): 1481-1485
    Contributor: Bob Philips and Clare Wotton, November 1999
    Reviewer:

    Clinical Question.
    Patient patients with first myocardial infarction
    Intervention or Exposure prior angina for >1 month
    Outcome mortality