People with an acute coronary syndrome where no ST elevation is demonstrated (non-ST elevation ACS or NSTEACS) are treated with aspirin. Clopidogrel is added in many cases, particularly if the risk of cardiovascular events is felt to be high and early PCI is being considered. Depending on whether early PCI is planned, a factor Xa inhibitor or a potentiator of antithrombin (fondaparinux or low molecular weight heparin respectively) may be added. In very high-risk scenarios, inhibitors of the platelet glycoprotein αIIbβ3a receptor such as eptifibatide or tirofiban may be used.