Abstract 3123: Prolonged QRS Duration is Associated with Abnormal Left Ventricular Function, but not with Subclinical Atherosclerosis in Adults without Clinical Cardiovascular Disease - The Multi-Ethnic Study of Atherosclerosis (MESA) Study
Marker of ventricular dyssynchrony, prolonged QRS has been associated with poor prognosis in heart failure. The relation between QRS duration, subclinical atherosclerosis, ventricular function and events in adults without clinical cardiovascular disease has not been investigated. In the Multi-Ethnic Study of Atherosclerosis (MESA), we examined cross-sectional differences in coronary artery calcium (CAC), common/internal carotid intima-medial thickness (CC/IC IMT), left ventricular ejection fraction (LVEF), end-diastolic mass (LVEDM) and volume (LVEDV) across QRS duration among 4681 (mean age 62, 53% women) participants free of clinical cardiovascular disease and with LVEF > 0.5 at enrollment. Multivariable linear/logistic regressions were used to analyze the association between QRS duration, subclinical atherosclerosis and LV function. Cox proportional hazards analysis was used to examine the relation between QRS duration, heart failure and hard coronary heart disease events. Participants with prolonged QRS were older and more likely to be Caucasian men. There were no other major differences in the demographic characteristics or cardiovascular risk factors between the QRS groups. Prolonged QRS was not associated with higher CAC or CC/IC IMT, but was associated with a higher LVEDM/LVEDV and lower LVEF (Table⇓). After a mean follow-up of 4 years, 42 and 58 participants (2.2 and 3.1/1000 person-years) developed heart failure and hard coronary heart disease events, respectively. Although the number of events was low, we observed no increased risk across increasing QRS duration (p>0.2). In adults free of clinical cardiovascular disease and with preserved ventricular function, we found no relation between QRS duration and subclinical atherosclerosis. Prolonged QRS was associated with lower LVEF and higher LVEDM and LVEDV. Further studies are needed to establish the temporal relation of these associations.