Background
People with type 2 diabetes mellitus(T2DM) are susceptible to diabetic cardiomyopathy.1,2 While left ventricular(LV) ejection fraction(LVEF) is preserved early on, myocardial dysfunction is detectable using more sensitive techniques such as echocardiographic strain imaging.1,3 Better LV systolic function is indicated by more negative global longitudinal strain (GLS) values3, while left atrial (LA) peak reservoir strain is a marker of LA compliance.4,5
Sodium glucose cotransporter 2 inhibitors (SGLT2i) in T2DM and established cardiovascular disease(CVD) have been shown to decrease cardiovascular mortality and heart failure hospitalisation rates.6,7 However, the cardioprotective effect nor mechanism of SGLT2i in T2DM without active cardiac disease is unknown.
Objective
The effect of 12-months therapy with dapagliflozin on cardiac function in T2DM without CVD is being examined. Clinical and baseline echocardiographic findings are reported.
Methods
Subjects with suboptimally controlled T2DM (HbA1c>7%), without CVD, are commenced on 10mg dapagliflozin and followed up over 12-months. LVEF, LV GLS, diastolic function grade, LA volumes and reservoir strain will be measured by transthoracic echocardiogram before and 12-months following dapagliflozin.
Results
Baseline data from 18 subjects is presented: mean age 53.9±11.2years, T2DM duration 10.3±6.4 years and BMI 33.5±7.1kg/m2. HbA1c was elevated (8.4±1.6%, 73±22mmol/mol), 39% had ≥1 microvascular complication, none had macrovascular complications. LVEF, LV mass indexed and LA maximum volume were within range (59%, normal>55%; 83.2g/m2; 26.5ml/m2, normal<32ml/m2; respectively).8,9 However, GLS reflecting LV systolic function was impaired (-15.9%, normal≤-19.7%).8 72% of patients had LV diastolic dysfunction (median grade 1). LV filling pressures were elevated (septal E/e’ 10.3±2.4, normal<8),9 LA peak reservoir strain was reduced (29.11%, normal>42.2%).10
Conclusions
Subclinical LV systolic and diastolic dysfunction is evident in patients with suboptimally controlled T2DM without active cardiac disease being treated with dapagliflozin. These findings are consistent with previously described prevalence of diabetic cardiomyopathy. The 12-month follow-up echocardiographic assessment will demonstrate SGLT2i's impact on LV function.