Risk of coronary obstruction and protection strategies in transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has emerged as the first-line treatment for aortic valve stenosis. Coronary obstruction is a severe complication of TAVR, with mortality rates exceeding 30%. Coronary obstruction can be classified as acute or delayed based on the timing of the onset, and as direct or indirect obstruction according to the underlying mechanism. Risk factors for predicting coronary obstruction include a small sinus of Valsalva diameter, excessively long native leaflets, low coronary height, and small sinotubular junction height and diameter. Accurate preoperative assessment of these anatomical parameters using CT is crucial for selecting the appropriate valve type, size, and implantation depth. Preventive technical strategies for coronary obstruction include intraoperative interventional treatments (such as the "Chimney" stenting technique), leaflet modification (such as the BASILICA technique), and alignment of the annulus and coronaries. These techniques have demonstrated significant efficacy in reducing the incidence of coronary obstruction and associated mortality. This paper reviews the epidemiology, classification, and mechanisms of coronary obstruction, with a particular focus on the identification, prevention, and treatment of high-risk patients. The aim is to highlight the importance of recognizing and managing coronary risks during TAVR and to provide actionable recommendations for the prevention and treatment of coronary obstruction in clinical practice.