Serotonin is associated with coronary artery disease and cardiac events

Background-Blood platelets are related to coronary atherogenesis. Platelets secrete serotonin (5-hydroxytryptamine) which has several effects on the v ascular wall and promotes thrombogenesis, mitogenesis, and proliferation of smooth muscle cells. Serotonin may therefore be one of the factors involve d in the development of coronary artery disease (CAD). We have assessed ser otonin among conventional predictors for CAD in patients undergoing coronar y angiography for chest pain or clinically suspected angina pectoris. Methods and Results-Of 121 consecutive male patients (mean age 65, range 41 to 90 years) undergoing angiography, 96 had coronary artery stenosis and 2 5 had normal angiograms. Serotonin, blood platelet count, rind conventional biochemical risk factors for CAD were determined in the morning the day be fore the angiography. High serotonin (cut-point 1000 nmol/L) was significan tly associated with CAD with an odds ratio (OR) of 3.4 (95% confidence inte rval 1.2 to 9.8). The corresponding OR for smokers was 4.8 (1.9 to 12.2); h ypercholesterolemia (>7 mmol/L), 2.9 (1.1 to 7.6); high platelet count (cut -point 325 10(9)/L), 3.0 (1.0 to 9.5); and family history of heart disease, 2.3 (1.0 to 5.2). After adjustment with conventional risk factors, the OR for CAD was 3.8 (1.1 to 13.1), comparing high and low values of serotonin. The relation between serotonin and CAD was strengthened only when patients <70 years (n=82) were included in the analysis. In this age group, the occu rrence of cardiac events during a mean of 3.7 years of follow-up was signif icantly associated with high serotonin values. Conclusions-The study suggests that serotonin is associated with coronary a rtery disease and occurrence of cardiac events, particularly in younger age groups. This association seems to persist after adjustment for conventiona l risk factors.