An ST-elevation myocardial infarction is life-threatening and requires urgent management. Before coronary intervention, preoperative loading with a P2Y12 receptor antagonist is warranted. We present a case in which urgent coronary angiography was performed after a loading dose of Aspirin and ticagrelor was given. Two and a half hours after loading Ticagrelor, patient developed hypotension with a swollen face and diffuse rash on the trunk. Considering anaphylactic shock, a steroid bolus and an inotropic infusion were administered, and the patient became hemodynamically stable. The allergic manifestations disappeared a few hours later. Ticagrelor was changed to Clopidogrel to avoid a severe allergic reaction.

Dr. Lam Man Tat graduated from Southern Medical University in China in 2014 with a bachelor's degree. Since 2018, he has been training as a cardiologist at the Conde de São Januário Hospital in Macau and has obtained his cardiologist qualification. He is also an academician of the Department of Cardiology at the Macau Academy of Medical Sciences. He has also received training in interventional therapy at Queen Mary Hospital, Hong Kong, and in critical care management at Guangdong Provincial People's Hospital. He will focus on treating coronary artery disease and structural heart disease.