Long-term favorable cardiovascular risk profile and 39-year development of major and minor electrocardiographic abnormalities - The Chicago Healthy Aging Study (CHAS).

BACKGROUND

Data are limited on long-term associations of favorable cardiovascular risk profile (i.e., low-risk) and changes in risk profile with ECG abnormality development.

METHODS

The Chicago Healthy Aging Study (CHAS) involved re-examination of 1395 participants, ages 65-84 years in 2007-10, free of baseline major ECG abnormalities or MI in 1967-1973. Stratified sampling method was used to recruit participants based on their baseline risk profile (low-risk and not low-risk). Low-risk status was defined as untreated SBP/DBP ≤ 120/≤80 mm Hg, untreated total cholesterol <200 mg/dl, not smoking, BMI <25 kg/m, and no diabetes. ECG abnormalities were defined by Minnesota code criteria. Multinomial logistic regression was used.

RESULTS

There were 28% women, 9% blacks, and 20% with baseline low-risk status. At follow-up, 21% developed ≥1 major ECG abnormalities, and 58% developed ≥1 minor ECG abnormalities. With multivariable adjustment, compared to those with 2 + high-risk factors, odds for developing from normal to any major ECG abnormalities were lower by 57%, 49%, and 35%, respectively, in persons with low-risk, any moderate-risk, and 1 high-risk factor (P-trend = 0.002). Findings were similar for some common specific subtypes of major and minor abnormalities. Associations were mainly due to baseline smoking and BMI. Remaining free of high-risk factors, or improving risk profile over time was also associated with lower major ECG abnormality development by 70% vs. always having any high-risk factor.

CONCLUSIONS

Favorable CVD risk profile earlier in life and maintenance or improvement in risk profile over time are associated with lower risk of ECG abnormality development at older age.