Abstract Body (Do not enter title and authors here): Background:
Folic acid, a B vitamin, is essential for DNA synthesis and repair, and its role in reducing homocysteine levels has been linked to cardiovascular health. Elevated homocysteine is a risk factor for cardiovascular diseases, including acute myocardial infarction (MI) and coronary artery disease (CAD). Despite evidence suggesting that folic acid supplementation may lower homocysteine levels, its clinical benefits in reducing cardiovascular events remain unclear.

Methods:
A comprehensive literature search was conducted in PubMed/Medline, Google Scholar, and Cochrane Library databases for studies published from 2000 to 2024 using MeSH terms related to “folic acid,” “B vitamin,” “acute myocardial infarction,” “cardiac arrest,” “heart attack,” and “coronary heart disease.” Only randomized controlled trials (RCTs) and observational studies in English involving adult patients with acute MI or CAD were included. Exclusion criteria were applied to poor-quality studies, irrelevant outcomes, overlapping populations, and non-English texts. Data on study characteristics and patient demographics were extracted, and study quality was assessed using the RoB2 tool. Outcomes were pooled using RevMan 5.3.4 software.

Results:
Fourteen studies on all-cause mortality showed a risk ratio (RR) of 0.99 [95% CI: 0.94-1.04], indicating no significant difference between folic acid and control groups. Eight studies on cardiovascular mortality yielded a RR of 0.90 [95% CI: 0.82-0.99], suggesting a significant reduction in cardiovascular deaths with folic acid supplementation. Analyses of sudden death, coronary artery bypass graft (CABG) events, revascularization procedures, stroke, and recurrent MI found no significant associations with folic acid supplementation.

Conclusions:
High-dose folic acid supplementation appears to reduce cardiovascular mortality in post-MI patients but shows no significant impact on other clinical outcomes. This meta-analysis’s limitations include potential publication bias, heterogeneity among included studies, and variability in folic acid dosages and treatment durations. Furthermore, the lack of comprehensive homocysteine level data constrained the analysis. Future large-scale RCTs are needed to fully ascertain the therapeutic potential of folic acid supplementation in secondary prevention of cardiovascular events.