The article reviews the role of FNDC5/Irisin in cardiovascular diseases, focusing on its impact on cardiomyocyte metabolism, mitochondrial function, and various signaling pathways. Irisin, a myokine secreted primarily by skeletal muscles, is also found in high concentrations in cardiomyocytes and other tissues. It plays a crucial role in converting white adipose tissue (WAT) to brown adipose tissue (BAT) and affects mitochondrial biogenesis. The levels of FNDC5/Ir in blood and myocardium are significant in cardiovascular disease. Irisin protects against cardiac damage, reduces oxidative stress, and enhances angiogenesis. It also influences bone remodeling and vascular smooth muscle cell (VSMC) phenotype modulation. Studies show that Irisin levels correlate with the severity of atherosclerosis and cardiovascular events. Its therapeutic potential in treating cardiovascular diseases, particularly in inhibiting cardiomyocyte apoptosis and promoting regeneration, is highlighted. However, further research is needed to fully understand the mechanisms and clinical applications of Irisin.The article reviews the role of FNDC5/Irisin in cardiovascular diseases, focusing on its impact on cardiomyocyte metabolism, mitochondrial function, and various signaling pathways. Irisin, a myokine secreted primarily by skeletal muscles, is also found in high concentrations in cardiomyocytes and other tissues. It plays a crucial role in converting white adipose tissue (WAT) to brown adipose tissue (BAT) and affects mitochondrial biogenesis. The levels of FNDC5/Ir in blood and myocardium are significant in cardiovascular disease. Irisin protects against cardiac damage, reduces oxidative stress, and enhances angiogenesis. It also influences bone remodeling and vascular smooth muscle cell (VSMC) phenotype modulation. Studies show that Irisin levels correlate with the severity of atherosclerosis and cardiovascular events. Its therapeutic potential in treating cardiovascular diseases, particularly in inhibiting cardiomyocyte apoptosis and promoting regeneration, is highlighted. However, further research is needed to fully understand the mechanisms and clinical applications of Irisin.