Myocardial infarction: primary ventricular fibrillation increases in-hospital mortality.

Clinical bottom line (level 2b)

  1. Three percent of patients with acute myocardial infarction will have primary ventricular fibrillation as a complication, about 10% of these will die immediately, but those who survive the initial event are no more likely to die in hospital or in the year after discharge than are patients with uncomplicated acute MI.
  2. Patients with a primary ventricular fibrillation complication may be more likely to die in-hospital than those without.
Behar et al: American Journal of Cardiology 1990; 66: 1208-1211
Expires March 2003

The study

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

Setting: 14 coronary care units, Israel

5839 patients (aged mean 61 years, 76% male) acute myocardial infarction

Factors studied:
  • primary ventricular fibrillation, in-hospital mortality with primary VF, in-hospital mortality without primary VF
  • primary ventricular fibrillation




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

    100% followed for until hospital discharge
    Outcomes studied:
  • primary ventricular fibrillation
  • in-hospital mortality

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    primary ventricular fibrillation until hospital discharge 122/5839 2.95%
    (2.51% to 3.38%)
    in-hospital mortality until hospital discharge 338/3829 8.83%
    (7.93% to 9.73%)

    prognostic factor for
    in-hospital mortality     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    primary ventricular fibrillation ? 338/3829
    (8.83%)     		2.52
    (1.42 to 4.46)     		9
    (5 to 31)

    Comments

    1. The number needed to follow is overestimated as the overall control rate for in-hospital mortality was used.
    2. Data on prognostic value of a primary ventricular fibrillation complication is based on in-hospital death, but does not indicate whether it is a factor for immediate ventricular fibrillation death, or death after resuscitation.
    3. Data was taken from a randomised controlled trial of nifedipine versus placebo.

    Citation

    1. Behar S, Goldbourt U, Reicher-Reiss H, et al: Prognosis of acute myocardial infarction complicated by primary ventricular fibrillation. American Journal of Cardiology 1990; 66: 1208-1211
    Contributor: Clare Wotton and Chris Ball, October 1999
    Reviewer: Roy M. Poses

    Clinical Question.
    Patient myocardial infarction
    Intervention or Exposure primary ventricular fibrillation
    Comparison no ventricular fibrillation
    Outcome in-hospital mortality