Minor Isolated Q Waves and Cardiovascular Events in the MESA Study - 12/04/13

Doi : 10.1016/j.amjmed.2012.10.030

Yabing Li, MD ^a,^{^{1
These authors contributed equally to the article.}}, Farah Z. Dawood, MD ^b,^{^{1
These authors contributed equally to the article.}}, Haiying Chen, MD, PhD ^c, Aditya Jain, MD, MPH ^d, Joseph A. Walsh, MD ^e, Alvaro Alonso, MD, PhD ^f, Donald M. Lloyd-Jones, MD, ScM ^e, Elsayed Z. Soliman, MD, MSc, MS ^a,^b,^⁎
^a Epidemiological Cardiology Research Center (EPICARE), Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC
^b Department of Internal Medicine (Cardiology), Wake Forest School of Medicine, Winston-Salem, NC
^c Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC
^d Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Md
^e Department of Preventive Medicine and Bluhm Cardiovascular Institute, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill
^f Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis

Requests for reprints should be addressed to Elsayed Z. Soliman, MD, MSc, MS, Epidemiological Cardiology Research Center (EPICARE), Wake Forest School of Medicine, Medical Center Blvd., Winston Salem, NC 27157

Abstract

Background

The significance of minor isolated Q waves in the resting electrocardiograms (ECGs) of apparently healthy individuals is unknown.

Objective

To examine the association between minor isolated Q waves and incident cardiovascular disease events in the Multi-Ethnic Study of Atherosclerosis (MESA).

Design

This analysis included 6551 MESA participants (38% white, 28% black, 22% Hispanic, 12% Chinese) who were free of cardiovascular disease at enrollment. Cox proportional hazards models were used to examine the association between minor isolated Q waves defined by the Minnesota ECG Classification with adjudicated incident cardiovascular events.

Results

During up to 7.8 years of follow-up, 423 events occurred, with a rate of 10.7 events per 1000 person-years. A significant interaction between minor isolated Q waves and race/ethnicity was observed (P=.030). In models stratified by race/ethnicity and adjusted for demographics, socioeconomic status, common cardiovascular risk factors, and other ECG abnormalities, presence of isolated minor Q waves was significantly associated with incident cardiovascular events in Hispanics (hazard ratio [HR] 2.62; 95% confidence interval [CI], 1.42-4.82), but not in whites (HR 0.65; 95% CI, 0.32-1.33) or blacks (HR 1.46; 95% CI, 0.74-2.89). Despite the statistically significant association in the Chinese population, the small number of events precluded solid conclusions in this race/ethnicity.

Conclusion

The prognostic significance of minor isolated Q waves varies across races/ethnicities; they carry a high risk for future cardiovascular events in apparently healthy Hispanics, but not in whites or blacks.

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Keywords : Electrocardiography, MESA, Minor isolated Q waves, Race/ethnicity

Plan

Methods

Study Population and Data Collection

Electrocardiography

Ascertainment of Cardiovascular Events

	Funding: The Multi-Ethnic Study of Atherosclerosis (MESA) study was supported by contracts N01-HC-95159 through N01-HC-95169 from the National Heart, Lung and Blood Institute.
	Conflict of Interest: None.
	Authorship: All authors had role in writing the manuscript and access to the data.