Metformin Treatment in Patients With T2DM at Risk for Heart Failure

Patients with type 2 diabetes mellitus (T2DM) at risk for heart failure treated with metformin may have reduced deterioration of left ventricular (LV) filling pressures and myocardial relaxation, according to a study published in the Journal for the American College of Cardiologists: Cardiovascular Imaging.

Individuals (N=982; n=431 with T2DM) ages ≥65 years with ≥1 heart failure (HF) risk factor were recruited from the Tasmania (n=630) and Victoria (n=352) regions in Australia through radio, local press, community groups, or primary care offices. All participants underwent echocardiography at baseline and follow-up (median, 19 months; interquartile range [IQR], 17-26 months) during which global longitudinal strain (GLS) and diastolic function were assessed. Participants with T2DM were randomly assigned to receive metformin (n=290) or not (n=141).

Participants with and without T2DM differed significantly at baseline for gender (P <.001), body mass index (P =.023), systolic (P =.023) and diastolic (P =.006) blood pressures, and several comorbidities and medications. Propensity matching was used to correct for these differences. After propensity matching (n=395 in both groups), patients with vs without T2DM had lower rates of dyslipidemia (P =.035), obstructive sleep apnea (P =.020), and higher rates of myocardial infarction (P =.020).

At follow-up, participants with vs without T2DM cohort exhibited improved GLS (0.58±2.73 vs -0.70±2.12, respectively; P <.001). T2DM was positively correlated with GLS (b, 1.11; 95% CI, 0.56-1.67; P <.001) and E/e’ (b, 0.47; 95% CI, 0.004-0.94; P =.048). LV filling pressure increased from baseline both in patients with (0.49±2.33; P =.001) and without T2DM (0.33±2.42; P =.04).

Participants with T2DM who received vs did not receive metformin had greater estimated glomerular filtration rate (P =.012) and lower rates of myocardial infarction (P =.027).

At follow-up, participants receiving vs not receiving metformin had reduced LV filling pressures (b, -0.96; 95% CI, -1.66 to -0.26; P =.007) and increased myocardial relaxation (b, 0.58; 95% CI, 0.13-1.03; P =.01).

Study limitations include possible selection bias associated with recruitment protocols (eg, newspaper advertisement and invitation letters).

These data indicate that asymptomatic patients at risk for heart failure with T2DMhad improved LV filling pressures and myocardial relaxation after metformin treatment. Although improvements were observed, they were not at the level for clinical significance. Longer-term studies are needed to assess whether sustained exposure to metformin is associated with clinical benefits.

Reference

Halabi A, Yang H, Wright L, et al. Evolution of myocardial dysfunction in asymptomatic patients at risk of heart failure. JACC Cardiovasc Imaging. 2020;S1936-878X(20)30922-0. doi:10.1016/j.jcmg.2020.09.032