P98 A CASE OF “RECURRENT” AORTIC VALVE STENOSIS

Abstract

Abstract Clinical Case A 80–year–old man underwent coronary angiography in 2006 because of stable angina. There was chronic total occlusion of middle left anterior descending artery requiring percutaneous intervention. In 2009 he underwent coronary angiography for recurrent angina: a severe stent restenosis was treated with stenting in stent (DES in BMS). The patient was subsequently asymptomatic till 2018 when he complained of exertional dyspnea and angina. Stent patency and severe aortic valve stenosis (AVA 0.85 cm2) were documented. The patient underwent successful transcatheter aortic valve implantation and discharged with dual antiplatelet therapy (DAPT) (Asa 100 mg and Clopidogrel 75 mg). Clinical and echocardiographic follow–up was unremarkable (mean prosthetic gradient 17 mmHg, DVI=0.45). In July 2021 during a cardiological check the patient complained of bruising: ASA was discontinued. In February 2022 the patient suffered from an exertional angina. A dipyridamole stress–echocardiography failed to demonstrate inducible ischemia, although the patient experienced angina at the peak load step. Transthoracic echocardiogram (TTE) revealed high mean trans–prosthetic aortic gradient (52 mmHg, DVI=0.18). A trans–esophageal echocardiogram (TEE) showed reduced mobility of the thickened left coronary and non–coronary aortic prosthetic leaflets. In the hypothesis of prosthetic valve thrombosis, warfarin (INR range 2–3) was started after stopping clopidogrel. After three months a TTE showed normalized mean trans–prosthetic gradients (17 mmHg, DVI=0.5). When a 6 month–period of anticoagulant therapy was accomplished, warfarin was stopped and DAPT administered again. In September 2022 the patient complained of worsening dyspnea and chest pain on exertion. At TTE mean trans–prosthetic gradients (46 mmHg) was increased. A new TEE showed thickening of non–coronary and right coronary leaflets, suggestive of recurrent valve thrombosis. After stopping DAPT, warfarin was started again with good result (mean prosthetic gradient 12 mmHg, DVI=0.5). Conclusion Thrombosis of aortic valve prothesis is an infrequent event usually occurring in early post–implantation period. In our case it occurred four years after implantation following DAPT interruption. The likely initial prosthetic valve degeneration together with a simplification of DAPT may have had a causative role. Since the proved efficacy of warfarin and the limited experience of DOAC in this field, the patient was given warfarin sine die.