LAUSR

Background: Smoking exposure has a strong dose-dependent relation with cardiovascular disease (CVD). Less is known about how patterns of exposure may impact CVD. In this study, we hypothesized that patterns of high or persistent smoking for 25 years would have worse myocardial structure and function at 30 years, while patterns of quitting smoking would be similar to never smokers. Methods: Data were from 5115 black and white, men and women, aged 18-30 years at baseline (1985) in the CARDIA study. Group-based trajectory modeling (SAS proc traj ) identified smoking patterns from 1985-2010 among 3178 participants with echocardiogram at year 30 (2015). Adjusted linear regression analyses assessed associations between trajectory group with left ventricular (LV) structure (LV mass, LV diastolic dimension, left atrial volume), LV function (ejection fraction, circumferential strain, global longitudinal strain), and right ventricular function (E/A, average e’, E/e’). Interactions between smoking trajectory X sex, race, and BMI with echo measures were also assessed. Results: Seven smoking trajectory groups were identified (Figure). Trajectory group was significantly associated with cardiac structure, including LV mass ( p <.001) and LV diastolic dimension ( p =.003). For example, LV mass was greater among all smoking groups (except declining heavy smokers, n=49) compared to nonsmokers (all p s<.05); moreover, compared to heavy smokers, minimal smokers ( p =.008) and quitters ( p =.047) had smaller LV mass (Figure). Trajectory group was not associated with cardiac function (all p s>.10). None of the interactions with trajectory group was significant (all p s>.05). Conclusions: Any level of smoking during young adulthood was associated with poorer cardiac structure, but not function, compared to never smokers. Patterns of minimal and declining smoking also had significantly better structure than heavy smoking. These results suggest that quitting and reducing smoking may help preserve or restore cardiac structure over time.