Abstract
BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) and chronic aortic regurgitation (AR) increases with age and may also increase cardiac morbidity and mortality; however, their comprehensive effects based on cardiac strain remain unexplored. This study aimed to use cardiac magnetic resonance (CMR) feature tracking to investigate the additive effects of T2DM and AR on the left heart and left-atrioventricular interaction in patients with T2DM and AR. METHODS: A total of 286 patients with T2DM (203 without AR and 83 with AR) and 105 controls were retrospectively included from January 2015 to October 2022. The patients with T2DM and AR were divided according to echocardiographic findings into three AR groups: mild (n=39), moderate (n=25), and severe (n=19). The left-atrial (LA) phasic function and left-ventricular (LV) function parameters were compared to determine the additive effects of T2DM and AR and their interaction. Multivariate analysis was performed to identify the independent indicators of LA longitudinal strain. RESULTS: Compared with controls, the patients with T2DM without AR had a lower total LA emptying fraction (LAEF) and passive LAEF (all P values <0.05). The patients with T2DM and mild AR showed decreased LA reservoir strain (ε(s)) and passive strain (ε(e)) (P<0.001), whereas those with moderate and severe AR showed significant increases in LA volume and LV volume but a decrease in LAEF, LA strain, and LV ejection fraction (all P values <0.05) compared with controls. In the patients with T2DM and AR, the ε(s) was independently correlated with LV end-diastolic volume (LVEDV) (β=-0.304), regurgitation degree (β=-0.43), and LV mass index (LVMI) (β=-0.312). The active strain (ε(a)) was independently correlated with regurgitation degree (β=-0.478) and LVMI (β=-0.364), whereas the ε(e) was independently correlated with age (β=-0.226) and diabetes duration (β=-0.256; all P values <0.05). CONCLUSIONS: AR may aggravate LA and LV dysfunction in patients with T2DM. Regurgitation degree was an independent factor contributing to ε(s) and ε(a). Both LVEDV and LVMI were independent determinants affecting ε(s), and LVMI was an independent determinant of ε(a) in patients with T2DM and AR.