Dattani A; Department of Cardiovascular Sciences, University of Leicester UK.
Yeo JL;Brady EM; Cowley A; Marsh AM; Sian M; Bilak JM; Graham-Brown MPM; Singh A; Arnold JR; Adlam D;Yates T; McCann GP; Gulsin GS;
Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance [J Cardiovasc Magn Reson] 2024 Oct 28, pp. 101120.
Date of Electronic Publication: 2024 Oct 28.
Background: Type 2 Diabetes (T2D) leads to cardiovascular remodeling, and heart failure has emerged as a major complication of T2D. There is a limited understanding of the impact of T2D on the right heart. This study aimed to assess subclinical right heart alterations and their contribution to aerobic exercise capacity (peak VO 2 ) in adults with T2D.
Methods: Single center, prospective, case-control comparison of adults with and without T2D, and no prevalent cardiac disease. Comprehensive evaluation of the left and right heart was performed using transthoracic echocardiography and stress cardiovascular magnetic resonance. Cardiopulmonary exercise testing on a bicycle ergometer with expired gas analysis was performed to determine peak VO 2 . Between group comparison was adjusted for age, sex, race and body mass index using ANCOVA. Multivariable linear regression including key clinical and left heart variables, was undertaken in people with T2D to identify independent associations between measures of right ventricular (RV) structure and function with peak VO 2 .
Results: 340 people with T2D (median age 64 years, 62% male, mean HbA1c 7.3%) and 66 controls (median age 58 years, 58% male, mean HbA1c 5.5%) were included. T2D participants had markedly lower peak VO 2 (adjusted mean 20.3(95% CI: 19.8-20.9) vs. 23.3(22.2-24.5) mL/kg/min, P<0.001) than controls and had smaller left ventricular (LV) volumes and LV concentric remodeling. Those with T2D had smaller RV volumes (indexed RV end-diastolic volume: 84(82-86) vs. 100(96-104) mL/m, P<0.001) with evidence of hyperdynamic RV systolic function (global longitudinal strain: 26.3(25.8-26.8) vs. 23.5(22.5-24.5) %, P<0.001) and impaired RV relaxation (longitudinal peak early diastolic strain rate: 0.77(0.74-0.80) vs. 0.92(0.85-1.00) s -1 , P<0.001). Multivariable linear regression demonstrated that RV end-diastolic volume (β=-0.342, P=0.004) and RV cardiac output (β=0.296, P=0.001), but not LV parameters, were independent determinants of peak VO 2 .
Conclusions: In T2D, markers of RV remodeling are associated with aerobic exercise capacity, independent of left heart alterations.