Myocardial infarction: premature ventricular beats affected prognosis.

Clinical bottom line (level 2b)

  1. Patients with myocardial infarction who have more than 10 premature ventricular beats per hour, were more likely to die than those with no premature beats (NNF = 54 for 6 months) .
  2. Thoose who had complex ventricular arrythmias were also at increased risk (NNF = 52 for 6 months)
Maggioni et al: Circulation 1993; 87: 312-322
Expires March 2003

The study

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

Setting: multicentre, Italy

8676 patients (aged ?, 82% male) acute myocardial infarction- chest pain with ST segment elevation of > or = 1 mm in any limb lead of the ECG and/or > or = 2 mm in any precordial lead

Excluded if
  • not admitted within 6 hours of the onset of symptoms
  • contraindication to fibrinolytic treatment and/or to heparin



    • Factors studied:
  • >10 premature ventricular beats per hour
  • complex ventricular arrhythmias more than 10 premature ventricular beats per hour and/or any number of couplets and/or nonsustained ventricular tachycardia)


    • Patients randomly assigned to streptokinase or tissue-type plasminogen activator

    Multivariate analysis performed using Cox proportional hazard model to adjust for confounding factors.

    98.5% followed for 6 months
    Outcomes studied:
  • death

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    death 6 months 256/8552 3.0%
    (2.6% to 3.4%)

    prognostic factor for
    death     		time to outcome adjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    >10 premature ventricular beats per hour 6 months 1.62
    (1.16 to 2.26)     		54
    (26 to 208)
    complex ventricular arrhythmias 6 months 1.64
    (1.27 to 2.12)     		52
    (30 to 123)

    Comments

    1. The study is too small to show any difference in mortality between those with 1 to 10 premature ventricular beats and those with none.
    2. Trial data with antiarrythmics (class I) suggests suppressing the arrythmias does not affect mortality.

    Citation

    1. Maggioni AP, Zuanetti G, Franzosi MG, et al: Prevalence and prognostic significance of ventricular arrythmias after acute myocardial infarction in the fibrinolytic era: GISSI-2 results. Circulation 1993; 87: 312-322
    Contributor: Clare Wotton and Bob Phillips, October 1999
    Reviewer:

    Clinical Question.
    Patient acute myocardial infarction
    Intervention or Exposure ventricular arrhythmias
    Comparison no ventricular arrhythmias
    Outcome mortality