Sarpogrelate, a specific 5HT2-receptor antagonist, improves the coronary microcirculation in coronary artery disease.

Background: Serotonin (5-hydroxytryptamine: 5-HT) reduces the coronary blood flow (CBF) as a product of aggregating platelets. Sarpogrelate, a specific 5HT2-receptor antagonist, has been reported to increase the coronary collateral flow in humans; however, its effect on the microcirculation is still not fully understood. Hypothesis: This study was undertaken to determine whether sarpogrelate might improve the microcirculation in coronary artery disease (CAD). Methods: To investigate the effect of sarpogrelate on the microcirculation in CAD, we measured CBF in 15 patients with CAD but no significant stenosis in the left anterior descending artery (LAD). The patients were randomly allocated to two groups, including those receiving oral administration of 200 mg of sarpogrelate (SPG, 8 patients, age 61 ± 6 years) and those receiving no medication (controls, 7 patients, age 57 ± 8 years). Prior to and 1 h after the administration of sarpogrelate, or in controls at 1-h intervals, the average peak velocity (APV) at baseline and hyperemia was measured by an intracoronary Doppler guidewire. Systemic blood pressure (SBP) and cardiac output (CO) were also measured. Results: In the patients receiving SPG, the medication significantly increased the baseline (18 ± 9 to 19 ± 10 cm/s, p < 0.05) and maximal APV (55 ± 9 to 64 ± 31 cm/s, p < 0.05). However, no significant changes were observed in SBP and CO after the administration of SPG. In the control group, there were no significant differences in baseline and hyperemic APV. Conclusion: Sarpogrelate increased both baseline and maximal CBF without changing the systemic hemodynamics. These findings thus support that SPG improves the microcirculation by antagonizing the vasoconstrictive products of the aggregating platelets in CAD.