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Comorbidity and myocardial dysfunction are the main explanations for the higher 1-year mortality in acute myocardial

Ulf Stenestrand1, Fariborz Tabrizi, Johan Lindbäck

  • 1Department of Cardiology, University Hospital of Linköping, SE 581 85 Linköping, Sweden. stenestrand@riks-hia.se.

Circulation
|September 29, 2004
PubMed

Insights

Left bundle-branch block (LBBB) in myocardial infarction (MI) patients is linked to higher mortality initially. However, after adjusting for risk factors and left ventricular ejection fraction, LBBB is not an independent predictor of 1-year mortality in MI.

Area of Science:

  • Cardiology
  • Clinical Research
  • Mortality Studies

Background:

  • Left bundle-branch block (LBBB) is a condition affecting the heart's electrical system.
  • Its independent impact on mortality following acute myocardial infarction (MI) requires clarification.

Purpose of the Study:

  • To determine the independent contribution of LBBB to 1-year mortality in a large cohort of acute MI patients.

Main Methods:

  • Prospective cohort study of 88,026 MI cases (1995-2001).
  • Cox regression analysis with propensity score adjustment for covariates.
  • Subgroup analysis including left ventricular ejection fraction.

Main Results:

  • LBBB was present in 9% of MI admissions and associated with older age and more comorbidities.
  • Unadjusted 1-year mortality risk was 2.16 for LBBB patients.
  • Adjusted 1-year mortality risk for LBBB was 1.19; this became non-significant (1.08) when left ventricular ejection fraction was included.

Conclusions:

  • MI patients with LBBB have higher unadjusted mortality and more comorbidities.
  • LBBB is not an independent predictor of 1-year mortality in MI after adjusting for baseline characteristics, comorbidities, and left ventricular ejection fraction.
Abstract

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