The Cardioprotective Effects of Metformin in Myocardial Infarction Patients Without Diabetes: Current Status and Future Prospects

Abstract

Metformin is a first-line drug in type 2 diabetes mellitus (T2DM) treatment. Evidence is mounting that metformin can improve the long-term prognosis of myocardial infarction (MI) patients with diabetes. However, the therapeutic effect of metformin in MI patients without diabetes is a controversial subject. Some studies have revealed that metformin plays a nonsignificant role in determining the prognosis of these patients. In contrast, other clinical trials have noted that metformin plays a protective role and may have direct beneficial effects on the heart. In this review, we focus on therapeutic targets of metformin in non-diabetic MI patients. Different key mechanisms and signalling pathways that may be responsible for the cardioprotective effects of metformin are summarized. We conclude that metformin use is associated with limited MI size, preserved left ventricular (LV) function, and improved prognosis in experimental studies, including in non-diabetic MI animal models; furthermore, metformin treatment can reduce mortality and lead to improvements in some cardiovascular risk factors in non-diabetic MI patients. However, more clinical trials will be needed to clarify its effects on MI size, progression of atherosclerosis and cardiac function in these patients.