Association of Nonspecific Minor ST-T Abnormalities With Cardiovascular Mortality

The Chicago Western Electric Study

Daviglus, Martha L. MD, PhD
Liao, Youlian MD
Greenland, Philip MD
Dyer, Alan R. PhD
Liu, Kiang PhD
Xie, Xiaoyuan MD
Huang, Cheng-Fang MS
Prineas, Ronald J. MD, PhD
Stamler, Jeremiah MD

Department of Preventive Medicine, Northwestern University Medical School, Chicago, Ill (Drs Daviglus, Greenland, Dyer, Liu, Xie, Stamler, and Ms Huang); Department of Preventive Medicine and Epidemiology, Loyola University Stritch School of Medicine, Maywood, Ill (Dr Liao); and Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis (Dr Prineas).

JAMA: The Journal of the American Medical Association 281(6):p 530-536, February 10, 1999.

Context

Minor electrocardiographic (ECG) ST-T abnormalities are common, but their prognostic importance has not been fully determined.

Objective

To examine associations of single (1 time only) and multiple (2 times only and >or= to 3 times) nonspecific minor ST-T abnormalities in 5 years with long-term mortality due to myocardial infarction (MI), coronary heart disease (CHD), cardiovascular disease (CVD), and all causes in middle-aged men.

Design

Prospective cohort study (29-year follow-up after 5 annual examinations).

Setting and Participants

A total of 1673 men employed at the Western Electric Company in Chicago, Ill, aged 40 to 55 years at entry, with no evidence of CHD and no major ECG abnormalities throughout the first 5-year period.

Main Outcome Measures

Minor ST-T abnormalities identified from annual resting ECGs and mortality ascertained from death certificates.

Results

Of the 1673 men, 173 had evidence of isolated nonspecific minor ST-T segment abnormalities. During the follow-up period, there were 234 deaths due to MI, 352 deaths due to CHD, 463 deaths due to CVD, and 889 deaths due to all causes. For men with 3 or more annual recordings of minor ST-T abnormalities, risk of death due to MI, CHD, CVD, and all causes was significantly greater than for those with normal ECG findings. For men with 3 or more ECGs with minor ST-T abnormalities, relative risks (and 95% confidence intervals) adjusted for cardiovascular and other risk factors were 2.28 (1.16-4.49), 2.39 (1.39-4.12), 2.30 (1.44-3.68), and 1.60 (1.06-2.42), respectively, with a graded relationship between frequency of occurrence of ST-T abnormalities and mortality risk (linear trend, P < or= to.007).

Conclusions

Persistent, minor, nonspecific ST-T abnormalities are associated with increased long-term risk of mortality due to MI, CHD, CVD, and all causes; the higher the frequency of occurrence of minor ST-T abnormalities, the greater the risk. These data underscore the potential value of including nonspecific ECG findings in the overall assessment of cardiovascular risk.

JAMA.1999;281:530-536