Metformin is an anti-diabetic drug that is known improve insulin sensitivity and reduce insulin resistance. A published meta-analysis of randomized controlled trials (RCTs) reported a reduction of weight and insulin resistance in metformin users. Animal models also showed that metformin reduces cardiac hypertrophy. Observational studies showed a beneficial effect for metformin in patients with type 2 diabetes mellitus (T2DM) and heart failure. A recent study found that metformin reduced oxidative stress in non-diabetic patients with CAD.~Metformin has multiple modes of actions involving both AMP-activated protein kinase (AMPK) dependent and AMPK-independent mechanisms that may be implicated in cardiac hypertrophy. At the systemic level, a review of clinical and experimental data showed that metformin improves endothelial function, protects from oxidative stress and inflammation, as well as the negative effects of angiotensin II. Observational studies also reported cardiovascular benefits in metformin users especially in patients with type 2 diabetes mellitus (T2DM) and heart failure. Metformin has also been shown to exert a cardio protective effect and it has been shown to reduce oxidative stress which is a common finding in heart failure patients. For these reasons, there is an increasing interest in the use of metformin in CV diseases and there is an increasing interest in studying its potential new roles in this aspect. We hypothesized that metformin might improve morbidity, mortality, cardiac function, and HR-QoL in non-diabetic patients with HFrEF.
There is an increasing interest in the use of metformin in CV diseases and there is an increasing interest in studying its potential new roles in heart failure patients. There were some concerns related to the safety of metformin in such diabetic patients due to the risk of lactic acidosis. However, recent studies showed that metformin was safe or even beneficial in HF patients. We hypothesized that metformin might improve morbidity, mortality, cardiac function, and HR-QoL in non-diabetic patients with HFrEF.