The change of serum serotonin levels between acute coronary syndrome and chronic stable angina undergoing percutaneous coronary intervention

Background Activated platelets release serotonin (5-hydroxytryptamine, 5HT) causing vasoconstriction and aggregation of platelets in patients with acute coronary syndrome (ACS). It can lead to undergo percutaneous coronary intervention (PCI). We investigated the serial changes of serotonin level in patients with ACS and chronic stable angina (CSA) treated with PCI. Methods From July 2009 to April 2010, 123 consecutive patients who have undergone PCI for either ACS (n=63) or CSA (n=60) were enrolled. After the loading dose of aspirin 300mg and clopidogrel 600mg before PCI, maintenance once daily dose of 100mg and 75mg have been given from the day after PCI in all patients. Serum serotonin level (SERO) were serially measured at baseline, pre-, post-PCI, 90 min, 6 hours, 12 hours, 24 hours and 48 hours to compare between ACS and CSA groups. All demographic, biochemical variables, and clinical events were also collected for comparison in each group. Results SERO at post-PCI (55.2±120.0 vs 20.1±24.0, p=0.03) and peak level (94.0±170.9 vs 38.8±72.3, p=0.02) were significantly higher in ACS group. SERO after 90 min (34.4±66.1 vs 28.7±38.2, p=0.8), 6 hours (23.9±38.3 vs 10.1±10.0, p=0.34), 24 hours (55.8±108.5 vs 37.2±88.2, p=0.39) and 48 hours (43.5±122.9 vs 25.2±65.5, p=0.53) tended to be higher in ACS group than CSA group without statistical significance. SERO rebounded at 24 hours post-PCI and dropped at 48 hours. Conclusions SERO was more elevated in patients with ACS than those with CSA undergoing PCI, suggesting the need for more potent and sustained platelet inhibition particularly in ACS patients. SERO might be considered as a substitute marker of platelet activation. Triple antiplatelet therapy including selective serotonin receptor antagonist on top of aspirin and clopidogrel could be as an option for ACS patients undergoing PCI Funding Acknowledgement Type of funding source: Other. Main funding source(s): Hallym University Research Fund 2017 (HURF-2017-84)