Abstract 4141170: Impact of Serum 5-Hydroxytryptophan Levels on 15-Year Major Adverse Cardiovascular Events in ST-Elevation Myocardial Infarction Patients

Background: 5-Hydroxytryptophan (5-HTP) is a natural amino acid and precursor to serotonin, which is essential for various physiological functions. In cardiovascular research, serotonin has been implicated in modulating vascular tone, platelet aggregation, and myocardial function. Another derivative of 5-HTP, 5-methoxytryptophan (5-MTP), has been associated with reduced inflammation and cardiovascular calcification. However, the specific cardiovascular effects of 5-HTP remain less understood. This study investigates the relationship between baseline 5-HTP levels and the incidence of major adverse cardiovascular events (MACE) in patients who have experienced ST-elevation myocardial infarction (STEMI). Objective: Our goal was to determine if higher 5-HTP levels at the time of initial blood draw correlate with a lower incidence of MACE during long-term follow-up. Methods: This prospective cohort study included 453 STEMI patients (mean age 69.8 years, 53 women) followed for up to 15 years. Baseline serum 5-HTP levels were measured, with 2.42nM used as the threshold to categorize patients into high and low 5-HTP groups. The primary outcome was the incidence of MACE, including death, acute myocardial infarction, recurrent angina, congestive heart failure, coronary artery bypass grafting, stroke, planned percutaneous coronary intervention (PCI), unplanned PCI, and atrial fibrillation. Results: During the 15-year follow-up, 232 patients (51.2%) experienced MACE. Using the Cox proportional hazards model, we found that patients with higher baseline 5-HTP level (≥2.42nM) had a significantly lower risk of experiencing MACE (hazard ratio: 0.747, 95% CI: 0.561-0.996). Further analysis using a multivariable Cox proportional hazards model, adjusting for hypertension (HTN), use of Clopidogrel, use of Ticagrelor, Killip class during the initial STEMI event, age, and gender, confirmed that high 5-HTP levels were independently associated with a lower risk of MACE (hazard ratio: 0.712, 95% CI: 0.510-0.995). Conclusion: Higher 5-HTP levels are independently associated with a reduced risk of MACE in patients after STEMI. These findings suggest that 5-HTP could potentially be used as a biomarker for cardiovascular risk stratification. Additionally, supplementation with 5-HTP might be explored as a therapeutic strategy to reduce the risk of subsequent MACE in this high-risk population. Further research is warranted to confirm these findings and to understand the underlying mechanisms.