Background: Cardiovascular diseases are the leading cause of death worldwide. According to the WHO, about 32% of the world's population died by cardiovascular diseases in 2019. We examined the association of amino acids with mortality in the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study.

Methods: The LURIC study includes 3316 patients who were admitted to a hospital in a tertiary care centre in southwest Germany for coronary angiography. The patients were followed for a median of 9.9 years. Blood samples from 1845 participants in the LURIC study were analysed for amino acid profiles. The association between serum amino acids and morbidity and mortality was analysed using logistic regression and Cox proportional hazards regression, respectively. A primary prevention group and a secondary prevention group were defined and ROC analyses were performed in the LURIC subgroups to investigate whether the addition of amino acids to the ESC guideline SCORE 2 for primary prevention and the SMART Score for secondary prevention could improve risk prediction.

Results: For a number of different amino acids significant associations with mortality were identified. For example in primary prevention, the addition of non-essential amino acids improved the Harrell´s C of the ESC SCORE2 from 0.766 to 0.792, while for secondary prevention, the addition of branched-chain amino acids improved the Harrell´s C of the Smart Score from 0.722 to 0.730.

Conclusion:The measurement of amino acid profiles has the potential to improve risk prediction in primary prevention as well as secondary prevention. However, further comparative studies are needed to assess the individual risk of patients with a medium to high cardiometabolic risk and to use nutritional parameters to target preventive measures in clinical practice.

Keywords: Amino acids, All-cause mortality, Cardiovascular mortality, , SCORE2, SMART