Myocardial infarction: recurrent infarction was associated with high death rates.

Clinical bottom line (level 2b)

  1. In patients with acute myocardial infarction (MI), admission data predicted the risk of a recurrent MI.
  2. In patients with acute myocardial infarction, recurrent MI in the first year was a strong predictor of poor prognosis (40% mortality rate).
Kornowski et al: American Journal of Cardiology 1993; 72: 883-888
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

3695 patients (aged mean 61 y, 74% male) acute myocardial infarction (defined by symptoms, ECG changes and/or enzyme criteria)

Factors studied:
  • sex, age (10y increments), peripheral vascular disease, anterior Q-wave infarction vs not, preexisting angina, heart failure on admission, diabetes, hypertension, post-MI angina
  • recurrent MI
  • age (10 year increments)
  • past stroke
  • heart failure on admission
  • previous angina
  • female
  • 0 or 1 risk factor
  • 2 risk factors
  • 3 risk factors
  • 4 risk factors
  • 5 or 6 risk factors
Patients were given standard care for 1981-83, i.e without thrombolysis, and randomised to nifedipine or placebo

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

?100% followed for 12 months
Outcomes studied:
  • all cause mortality
  • risk of recurrent myocardial infarction in first year after MI (risk factors; history of angina, hypertension, diabetes, peripheral vascular disease, anterior first-MI)

The evidence

outcome time to outcome number of patients/total number %
(95% CI)
all cause mortality 12 months 148/730 20%
(17% to 23%)
risk of recurrent myocardial infarction in first year after MI 12 months 220/3675 6%
(5.2% to 7.8%)

prognostic factor for
all cause mortality 		time to outcome adjusted RR
(95% CI)
recurrent MI 12 months 4.76
(4.06 to 5.57)
age 12 months 1.72
(1.62 to 1.83)
past stroke 12 months 1.93
(1.56 to 2.38)
heart failure on admission 12 months 1.60
(1.43 to 1.80)
previous angina 12 months 1.24
(1.11 to 1.38)
female 12 months 1.21
(1.07 to 1.36)

prognostic factor for
risk of recurrent myocardial infarction in first year after MI 		time to outcome control rate (%) NNF
(95% CI)
0 or 1 risk factor 12 months 66/1663
(3.9%) 		26
(23 to 33)
2 risk factors 12 months 64/1166
(5.5%) 		18
(15 to 24)
3 risk factors 12 months 52/619
(8.4%) 		12
(9 to 16)
4 risk factors 12 months 31/210
(15%) 		7
(5 to 10)
5 or 6 risk factors 12 months 7/30
(23%) 		4
(3 to 12)

Comments

  1. Patient population is of all first MI patients who were eligible for admission into a trial of nifedipine; may represent a distinct sub-group.
  2. Risk factors for recurrent MI were not validated; may be data specific.

Citation

  1. Kornowski R, Goldbourt U, Zion M, et al: Predictors and long-term prognostic significance of recurrent infarction in the year after a first myocardial infarction. American Journal of Cardiology 1993; 72: 883-888
Contributor: Bob Phillips and Clare Wotton, November 1999
Reviewer:

Clinical Question.
Patient myocardial infarction
Intervention or Exposure recurrent infarction
Outcome mortality, or risk of recurrent infarction