Background: The golden standard treatment in patient with acute coronary syndrome is long term administration of acetylsalicylic acid (ASA). The European Society of Cardiology guideline for management of acute myocardial infarction with ST segment elevation in 2017, recommend the introduction as soon as possible of ASA in all patients without contraindications (IB). It is well known that periprocedural double antithrombotic treatment: ASA-thienopyridines is essential for short time and long-time reduction of intrastent thrombosis, as well. Very few studies exist regarding the optimal therapeutic approach in patients with known hyper-sensitivity to ASA.
Case presentation: A 55 years old patient, smoker (40 packs/year), with known allergy to Paracetamol, So-dic Metamizole, and multiple antibiotics who was ad-mitted in our clinic in order to undergo a primary angioplasty for postero-infero-lateral STEMI associated to anaphylactic shock, after oral administration of 250 mg Aspirine and 180 mg Ticagrelor. Because of the severe hypersensitivity reaction (considered to be related to aspirin administration) the patient was endotracheal intubated and mechanicaly ventilated. Also it was necessary to administrate adrenaline, corticotherapy and antihistamines.
The echocardiography revealed a moderate LV systolic dysfunction, inferior, lateral and posterior wall akinesia, at least moderate mitral regurgitation due to ischemic restriction in movement of posterior mitral valve. The initial approach was to delay the percutaneous coronary intervention and resumed to: trombolysis with teneteplase associated with administration of enoxaparin, with following up of antihistamines and corticosteroid treatment; after acute stage, low dose of betablocker, sartan, statine and H2-receptor inhibitor gastric protection were added. The ECG changes indicated the presence of reperfusion criteria, and mitral regurgitation became moderate to mild, findings compatible to recovery of myocardium at risk for infarction. 72 hours after having resolved the hypersensitivity reaction it was decided under the supervision of an allergologist to attempt a fast aspirin desensitization and we orally administrated 325 mg of ASA diluted in 100 ml water in increasing doses (0.1ml, 0.2 ml, 0.5 ml, 1 ml, 2 ml, 5 ml, 10 ml, 25 ml, 50 ml) every 10 minutes; the procedure was successful. On the fifth day from the admission, the myocardial ischemia was proved to be effort induced, and the coronarography was performed. It revealed one critical coronary stenosis of second marginal diagonal brunch where a drug eluting stent was implanted during a rescuing angioplasty, with a favorable postprocedural evolution and with the im-provement of echocardiographic parameters.
Discussions: Although an increasing report of ASA al-lergy with atypical symptoms in patients, only 0.3-0.9% from general population have documented hypersensi-tivity to ASA. This case presents a patient with a genui-ne symptomatology suggesting type III hypersensitivity to ASA. There are several protocols for desensitization but none of them is unanimously accepted, therefore the allergologist adapted this one. After the successful finalizing of desensitization, daily administration of to-lerated dose of ASA is essential as well as reinforcing the protocol if treatment was stopped for more than 5 days. The particularity of this case is the occurrence of life threatening anaphylactic shock which jeopardized the medical approach and imposed temporization of revascularization by percutaneous coronary interven-tion (PCI) until the desensitization procedure has been completed. The most important decision was the admi-nistration of thrombolytic therapy during the anaphy-lactic shock to a patient that was treate with loading dose of tricagrelor. This therapeutic approach has not produced hemorrhage, but reperfusion (permeablity of coronary artery on angiography) and improvement of ECG and echocardiographic parameters with an im-portant regression of ischemic mitral regurgitation.
Conclusions: In the case of patients with STEMI and hypersensitivity to ASA, with recommendation for reperfusion therapy by PCI and dual antiplatelet regimen, those can be performed after successful finalizing of desensitization. We need more studies to implement the optimal therapeutic approach in these difficult ca-ses and to find the ideal time frame of desensitization.