Association of Type 2 Diabetes with Left Atrioventricular Coupling and Myocardial Deformation in Hypertension: A 3.0 T Cardiac Magnetic Resonance Study

Abstract

Background: Hypertension (HTN) and type 2 diabetes mellitus (T2DM) frequently coexist, synergistically increasing heart failure risk. The specific incremental impairment of T2DM on left atrioventricular mechanics in hypertensive patients remains poorly characterised. This study aimed to assess whether the presence of T2DM is associated with further alterations in cardiac deformation and atrioventricular coupling beyond hypertension alone. Methods: We performed a retrospective analysis including 130 hypertensive patients (74 HTN-only, 56 HTN-T2DM) and 42 age-and sex-matched controls, all undergoing 3.0 T cardiac magnetic resonance. Intergroup comparisons of atrioventricular function and deformation were adjusted for age, sex, BMI, heart rate and SBP using ANCOVA. Multivariable regression was applied to identify independent determinants of left atrioventricular deformation and coupling, and the independent effect of T2DM. Results: Key cardiac parameters demonstrated graded impairment from controls to HTN-only and HTN-T2DM groups (all P < 0.05). This progressive decline was evident in LV systolic function (peak global longitudinal strain: -19.99% [-21.16, -19.13] vs. -17.15% [-19.18, -15.58] vs. -16.03% [-17.86, -13.94]) and LA phasic function (reservoir strain/εs: 48 ± 10% vs. 40 ± 14% vs. 33 ± 15%; conduit strain/εe: 33% [27, 36] vs. 21% [16, 31] vs. 16% [10, 24]). Consequently, the left atrioventricular coupling index (LACI) was significantly elevated in the HTN-T2DM group (24% [23, 30]) compared to both the HTN-only (22% [18, 28]) and control groups (17% [16, 20]). Multivariable linear regression analysis indicated that in the overall population, hypertensive patients with and without T2DM independently reduced left atrial εs, εe and left ventricular GLS, and significantly increased LACI; the detrimental effects were more marked in the HTN-T2DM group (all P<0.05). In the hypertensive subgroup, after adjusting for confounding factors, comorbid T2DM remained an independent risk factor for reduced LA reservoir function (εs: β = -6.09, P = 0.018), impaired LA conduit function (εe: β = -5.58, P = 0.002), and worsened LV systolic function (GLS: β= -1.37, P = 0.010). Conclusion: Hypertensive patients with T2DM demonstrate more significant impairment of myocardial deformation, and worse left atrioventricular uncoupling compared with those with HTN alone, underscoring the need for integrated cardiometabolic management in this high-risk population.