Effects of New Antiplatelet Agents and Aldosterone Receptor Antagonists on Mortality in Patients with Myocardial Infarction

Dear Editor,

I have read the article by Abualsuod et al. [1] with great interest, recently published online in your journal. The authors reported that the usage of metformin is associated with lower 30-day all-cause mortality and tendency for a lower 12-month all-cause mortality in patients with acute coronary syndrome (ACS) and diabetes. In the present study of Abualsuod et al. the authors reported the incidence of patients treated with aspirin, beta-blockers, statins and renin-angiotensin-aldosterone system blockers. However, there are no data about some other significant medications which can affect the mortality rates in this study population. I want to make some criticism on methodology and results of the present study.

First, according to guidelines, it is recommended to use dual antiplatelet therapy (DAT) at least for 12 months in ACS patients to reduce mortality [2, 3]. Additionally, DAT with ticagrelor or prasugrel reduce mortality significantly than DAT with clopidogrel in ACS patients [4, 5]. Secondly, the present study of Abualsuod et al. includes patients with impaired left ventricle functions. Aldosterone receptor antagonists reduce mortality significantly in post myocardial infarction patients with left ventricle dysfunction (ejection fraction <40 %) [6]. Authors should comment on incidence of patients treated with aldosterone receptor antagonists and duration and type of DAT for all groups. Therefore, higher incidence of treatment with aldosterone receptor antagonists and DAT with ticagrelor or prasugrel may be another significant reason for lower mortality rates in metformin group.

In conclusion, metformin usage may be associated with mortality benefit in ACS patients. To define its exact role, we should be sure that all patient groups are similarly treated with medications which are known to reduce mortality rates in patients with ACS.