Published Online
on September 27, 2004

A more recent version of this article appeared on October 5, 2004

This Article Full Text (PDF) All Versions of this Article: 110/14/1896    most recent 01.CIR.0000143136.51424.38v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Stenestrand, U. Articles by Wallentin, L. Search for Related Content PubMed PubMed Citation Articles by Stenestrand, U. Articles by Wallentin, L. Pubmed/NCBI databases Substance via MeSH Medline Plus Health Information Heart Attack Related Collections Ablation/ICD/surgery Acute myocardial infarction

Submitted on March 23, 2004
Revised on June 15, 2004
Accepted on June 21, 2004

Comorbidity and Myocardial Dysfunction Are the Main Explanations for the Higher 1-Year Mortality in Acute Myocardial Infarction With Left Bundle-Branch Block

Ulf Stenestrand MD, PhD^*, Fariborz Tabrizi MD, Johan Lindbäck MSc, Anders Englund MD, PhD, Mårten Rosenqvist MD, PhD, and Lars Wallentin MD, PhD

From the Department of Cardiology, University Hospital of Linköping, Linköping (U.S.); Department of Cardiology, South Hospital, Stockholm (F.T., M.R.); Uppsala Clinical Research Center, Uppsala University, Uppsala (J.L., L.W.); and Department of Cardiology, Örebro University Hospital, Örebro (A.E.), Sweden.

^* To whom correspondence should be addressed. E-mail: stenestrand{at}riks-hia.se.

Background--The purpose of this study was to assess the independent contribution of left bundle-branch block (LBBB) on cause-specific 1-year mortality in a large cohort with acute myocardial infarction (MI).

Methods and Results--We studied a prospective cohort of 88 026 cases of MI from the Register of Information and Knowledge about Swedish Heart Intensive care Admissions in 72 hospitals in 1995 to 2001. Long-term mortality was calculated by Cox regression analysis, adjusted for multiple covariates that affect mortality by calculation of a propensity score. LBBB was present in 9% (8041 of 88 026) of the MI admissions. Patients with LBBB were older and had a higher prevalence of comorbid conditions than patients with no LBBB. The unadjusted relative risk of death within 1 year was 2.16 (95% CI, 2.08 to 2.24; P<0.001) for LBBB (42%, 3350 of 8041) compared with those with no LBBB (22%, 17 044 of 79 011). After adjustment for a propensity score that takes into account differences in risk factors and acute intervention, LBBB was associated with a relative risk of death of 1.19 (95% CI, 1.14 to 1.24; P<0.001). In a subgroup of 11 812 patients for whom left ventricular ejection fraction was available and could be added to the analysis, the contributing relative risk of LBBB for death was only 1.08 (95% CI, 0.93 to 1.25; P=0.33). The most common cause of death in both groups was ischemic heart disease.

Conclusions--MI patients with LBBB have more comorbid conditions and an increased unadjusted 1-year mortality. When adjusted for age, baseline characteristics, concomitant diseases, and left ventricular ejection fraction, LBBB does not appear to be an important independent predictor of 1-year mortality in MI.

Key words: bundle-branch block • mortality • myocardial infarction • patients • prognosis

This article has been cited by other articles:

				Y.-F. Lin, V.-C. Wu, W.-J. Ko, Y.-S. Chen, Y.-M. Chen, W.-Y. Li, N.-K. Chou, A. Chao, T.-M. Huang, F.-C. Chang, et al. Residual Urine Output and Postoperative Mortality in Maintenance Hemodialysis Patients Am. J. Crit. Care., September 1, 2009; 18(5): 446 - 455. [Abstract] [Full Text] [PDF]

				M. O. Sweeney and F. W. Prinzen Ventricular Pump Function and Pacing: Physiological and Clinical Integration Circ Arrhythm Electrophysiol, June 1, 2008; 1(2): 127 - 139. [Full Text] [PDF]

				F. Tabrizi, A. Englund, M. Rosenqvist, L. Wallentin, and U. Stenestrand Influence of left bundle branch block on long-term mortality in a population with heart failure Eur. Heart J., October 2, 2007; 28(20): 2449 - 2455. [Abstract] [Full Text] [PDF]

				E. L. Fosbol, M. Seibaek, B. Brendorp, D. V. Moller, M. Ersboll, C. Torp-Pedersen, L. Kober, and for the Danish Investigations and Arrhythmia ON Do Differential prognostic importance of QRS duration in heart failure and acute myocardial infarction associated with left ventricular dysfunction Eur J Heart Fail, August 1, 2007; 9(8): 814 - 819. [Abstract] [Full Text] [PDF]

				F. Zannad, E. Huvelle, K. Dickstein, D. J. van Veldhuisen, C. Stellbrink, L. Kober, S. Cazeau, P. Ritter, A. P. Maggioni, R. Ferrari, et al. Left bundle branch block as a risk factor for progression to heart failure Eur J Heart Fail, January 1, 2007; 9(1): 7 - 14. [Abstract] [Full Text] [PDF]

				A. Di Chiara Right bundle branch block during the acute phase of myocardial infarction: modern redefinitions of old concepts Eur. Heart J., January 1, 2006; 27(1): 1 - 2. [Full Text] [PDF]