Cardiovascular Interactions of Renin-Angiotensin-Aldosterone System Assessed by Cardiac Magnetic Resonance: The Multi-Ethnic Study of Atherosclerosis

Abstract

Background: The effects of the renin-angiotensin-aldosterone system in cardiovascular system have been described based on small studies. The aim of this study was to evaluate the relationship between aldosterone and plasma renin activity (PRA) and cardiovascular structure and function.

Methods: We studied a random sample of Multi-Ethnic Study of Atherosclerosis participants who had aldosterone and PRA blood assays at 2003-2005 and underwent cardiac magnetic resonance at 2010. Participants taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were excluded.

Results: The aldosterone group was composed by 615 participants, mean age 61.6 ± 8.9 years, while the renin group was 580 participants, mean age 61.5 ± 8.8 years and both groups had roughly 50% females. In multivariable analysis, 1 SD increment of log-transformed aldosterone level was associated with 0.07 g/m2 higher left ventricle (LV) mass index (P = 0.04) and 0.11 ml/m2 higher left atrium (LA) minimal volume index (P < 0.01). Additionally, higher log-transformed aldosterone was associated with lower LA maximum strain and LA emptying fraction (P < 0.01). Aldosterone levels were not significantly associated with aortic measures. Log-transformed PRA was associated with lower LV end diastolic volume index (β standardized = 0.08, P = 0.05). PRA levels were not significantly associated with LA and aortic structural or functional differences.

Conclusions: Higher levels of aldosterone and PRA are associated with concentric LV remodeling changes. Moreover, aldosterone was related to deleterious LA remodeling changes.

Keywords: blood pressure; cardiac magnetic resonance imaging; hypertension; left atrium dysfunction; left ventricle remodeling; renin–angiotensin–aldosterone system; vascular remodeling.