Association of isolated minor non-specific ST-segment and T-wave abnormalities with subclinical atherosclerosis in a middle-aged, biracial population: Coronary Artery Risk Development in Young Adults (CARDIA) study.
AIMS
Isolated minor non-specific ST-segment and T-wave abnormalities (NSSTTAs) are common and known to be independent electrocardiographic risk markers for future cardiovascular disease (CVD) events. The association of NSSTTA with subclinical atherosclerosis is not well defined, but has been postulated as a potential mechanism of association with future clinical events.


METHODS AND RESULTS
We studied participants from the Year 20 examination of the middle-aged, biracial CARDIA cohort. This examination included measurement of traditional risk factors, 12-lead electrocardiograms (ECGs), coronary artery calcium (CAC) measurement and common carotid intima-media thickness (CC-IMT). ECGs were coded using both Minnesota Code (MC) and Novacode (NC) criteria. Isolated minor STTA was defined by MC as presence of MC 4-3, 4-4, 5-3, or 5-4, and by NC as presence of NC 5.8. ECGs with secondary causes of STTA (i.e., LVH) were excluded. Multivariable logistic regression was used to determine the cross-sectional association of isolated minor NSSTTAs with CAC and CC-IMT. The study sample consisted of 2175 participants with an average age of 45 years (57% female and 43% Black). Isolated NSSTTAs were present in 5.1% of males and 6.3% of females. No association was observed between NSSTTA and CAC. After multivariable-adjustment for traditional CVD risk factors, the presence of isolated minor NSSTTAs remained significantly associated with the extent of CC-IMT (odds ratio 1.25 (1.06-1.48), p < 0.01). This association remained significant after further adjustment for CAC.


CONCLUSIONS
Isolated minor NSSTTAs were associated with the extent of CC-IMT, but not with CAC, in this middle-aged biracial cohort. Further study is needed to elucidate potential mechanisms for these findings.