Dyspnea and reversibility of antiplatelet agents: Ticagrelor, elinogrel, cangrelor, and beyond

Context: Oral reversible platelet P2Y12 receptor inhibitors (ticagrelor and elinogrel) cause double-digit rates of dyspnea, while irreversible oral antiplatelet drugs (aspirin, ticlopidoine, clopidogrel, and prasugrel) or intravenous glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, or tirofiban) do not increase the incidence of dyspnea in randomized trials. Dyspnea after oral reversible antiplatelet agents remains unexplained. A transfusion-related acute lung injury (TRALI) hypothesis has been proposed. The dyspnea risks after cangrelor, an intravenous reversible antiplatelet agent, are not well defined but may offer a universal mechanism linking TRALI, dyspnea, and reversible platelet inhibition. Objective: We analyzed safety data from recent head-to-head randomized trials with reversible antiplatelet agents (ticagrelor, elinogrel, and cangrelor) compared to irreversible (clopidogrel/placebo) comparators. Results: All three reversible antiplatelet agents cause excess dyspnea. In contrast to the high double-digit rates after oral ticagrelor or elinogrel, the dyspnea risks after intravenous cangrelor were smaller (