United States National Prevalence of Electrocardiographic Abnormalities in Black and White Middle-Age (45- to 64-Year) and Older (≥65-Year) Adults (from the Reasons for Geographic and Racial Differences in Stroke Study)

Abstract

A US national sample of 20,962 participants (57% women, 44% blacks) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study provided general population estimates for ECG abnormalities among black and white men and women. Participants were recruited during 2003–2007 by random selection from a commercially available nationwide list, with oversampling of blacks and persons from the stroke belt for a cooperation rate of 49%. Measurement of risk factors and 12-lead ECGs (centrally coded using Minnesota Code criteria) showed 28% had at least one major ECG abnormality. Prevalence of abnormalities was higher (35%+) for those 65 years and older with no differences between blacks and whites. However, among men less than 65 years, blacks had more major abnormalities than whites, most notably for atrial fibrillation, major Q waves and left ventricular hypertrophy (LVH). Men generally had more ECG abnormalities than women. The most common ECG abnormalities were T-wave abnormalities. Average heart rate corrected QT interval was longer in women than men, similar in whites and blacks and increased with age, whereas the average heart rate was higher in women than men and in blacks than whites and decreased with age. The prevalence of ECG abnormalities was related to hypertension, diabetes, blood pressure level and age. In conclusion, black men and women in the US have a significantly higher prevalence of ECG abnormalities than whites at ages 45–64 but these proportions, although larger, tend to equalize or reverse after age 65.

Prevalence of electrocardiographic abnormalities based on hypertension severity and blood pressure levels: the Reasons for Geographic and Racial Differences in Stroke study

“…In our study, prehypertension was not associated with major or minor ECG abnormalities. Using the REGARDS study cohort, Prineas et al reported a weak association of SBP (including normotension and prehypertension range) with prevalent major ECG abnormalities (OR 1.05); 17 however, in contrast to the current study, they did not adjust for a history of CHD, CV and lifestyle risk factors and HTN duration. One of the explanations for our current findings may be that the association of SBP with ECG abnormalities may only manifest at SBP levels above the prehypertension range.…”

“…8,16-20 The association of both major and minor ECG abnormalities with traditional CV risk factors, including hypertension (HTN), has been previously reported. 17,21,24 …”

Racial differences in sudden cardiac death

“…Two more recent cohort studies attempted to address this major confounder by drawing from a geographically diverse population. Prineas et al (30) analyzed ECGs obtained from participants in the Reasons for Geographic and Racial Difference in Stroke Study (REGARDS) cohort. Subjects were randomly recruited from across the United States.…”

Prevalence of electrocardiographic abnormalities in primary care patients according to sex and age group. A retrospective observational study

“…This is consistent with the previously mentioned American study that evaluated electrocardiographic disorders in 20,962 people according to sex and age. 5 These abnormalities have been correlated with significantly higher risk of fatal coronary heart disease, 27 for which primary arrhythmia is the main mechanism. 28 This ECG disorder was more prevalent among women, and this might be explained by the significant influence of sex hormones on the QT interval in women: whereas this component is only shortened through the influence of testosterone in men, significant estrogen activity in women prolongs this interval while their progesterone acts similarly to testosterone.…”