This Article Figures Only Full Text Full Text (PDF) 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shlipak, M. G. Search for Related Content PubMed PubMed Citation Articles by Shlipak, M. G.

CLINICAL STUDY

Treatment and outcomes of left bundle-branch block patients with myocardial infarction who present without chest pain

Michael G. Shlipak, MD, MPH^* , Alan S. Go, MD , Paul D. Frederick, MPH, MBA, Judith Malmgren, PhD, Hal V. Barron, MD, FACC ^||, John G. Canto, MD, MSPH, FACC^¶ for the National Registry of Myocardial Infarction 2 Investigators

^* San Francisco VA Medical Center, San Francisco, California, USA
University of California, San Francisco, California, USA
the Northern California Kaiser Division of Research, Oakland, CaliforniaUSA
the University of Washington Clinical Research Coordinating Center, Seattle, Washington, USA
^|| the Division of Medical Affairs, Genentech, San Francisco, California, USA
^¶ the University of Alabama Medical Center, Birmingham, Alabama, USA

Manuscript received September 13, 1999; revised manuscript received March 16, 2000, accepted April 19, 2000.

Reprint requests and correspondence: Dr. Michael G. Shlipak, General Internal Medicine Section, VA Medical Center (111A1), San Francisco, California 94121
shlip{at}itsa.ucsf.edu

OBJECTIVES

We sought to determine the importance of chest pain on presentation as a predictor of in-hospital treatment and mortality in myocardial infarction (MI) patients with left bundle-branch block (LBBB).

BACKGROUND

Left bundle-branch block patients have a high mortality after MI but are unlikely to receive reperfusion therapy despite evidence from clinical trials demonstrating the efficacy of thrombolytic therapy. Nearly half of MI patients with LBBB present without chest pain.

METHODS

We studied the clinical features, treatment and in-hospital survival of 29,585 patients with LBBB enrolled in the National Registry of MI 2 (June 1994 through March 1998). Multivariate logistic regression was used to assess the independent effect of chest pain on reperfusion decisions and in-hospital mortality.

RESULTS

Left bundle-branch block patients with chest pain were greater than five-fold more likely to receive reperfusion therapy (13.6% vs. 2.6%) than LBBB patients without chest pain; they were also more likely to receive aspirin, beta-adrenergic blocking agents, heparin and nitrates (all p < 0.0001). Unadjusted in-hospital mortality was 18% in patients with chest pain and 27% in patients without chest pain. Adjusting for patient characteristics reduced the odds ratio associated with the absence of chest pain from 1.47 (95% confidence interval: 1.41 to 1.54) to 1.21 (95% confidence interval: 1.12 to 1.30). The remainder of the mortality difference was caused by the undertreatment of patients without chest pain, particularly the low utilization of aspirin and beta-blockers.

CONCLUSIONS

Left bundle-branch block patients with MI who present without chest pain are less likely to receive optimal therapy and are at increased risk of death. Prompt recognition and treatment of this high-risk subgroup should improve survival.

Abbreviations and Acronyms   ACE = angiotensin-converting enzyme   CABG = coronary artery bypass graft surgery   CI = confidence interval   ECG = electrocardiogram   LBBB = left bundle-branch block   MI = myocardial infarction   NRMI-2 = National Registry of Myocardial Infarction 2   OR = odds ratio   PTCA = percutaneous transluminal coronary angioplasty

This article has been cited by other articles:

				B. Olshansky Wide QRS, Narrow QRS: What's the Difference? J. Am. Coll. Cardiol., July 19, 2005; 46(2): 317 - 319. [Full Text] [PDF]

				F. Mauri, M. G. Franzosi, A. P. Maggioni, E. Santoro, and L. Santoro Clinical value of 12-lead electrocardiography to predict the long-term prognosis of gissi-1 patients J. Am. Coll. Cardiol., May 15, 2002; 39(10): 1594 - 1600. [Abstract] [Full Text] [PDF]

				LBBB in Patients with MI Is Undertreated Journal Watch Emergency Medicine, November 15, 2000; 2000(1115): 4 - 4. [Full Text]

				G. C. Friesinger II and R. F. Smith Old age, left bundle branch block and acute myocardial infarction: a vexing and lethal combination J. Am. Coll. Cardiol., September 1, 2000; 36(3): 713 - 716. [Full Text] [PDF]