Multimodality Cardiac Imaging Evaluation and Guidance of Management for Aortic Regurgitation

Aortic regurgitation (AR) is a valvular heart disease characterized by the pathological backflow of blood from the aorta into the left ventricle during diastole, causing left ventricular pressure and volume overload. This results in dilation and enlargement of the left ventricle, causing left ventricular hypertrophy and, ultimately, left ventricular dysfunction. AR has a wide range of causes, which include congenital, acquired, and genetic diseases. Therefore, AR may present as an acute condition causing hemodynamic compromise or as a chronic condition with a long asymptomatic phase, which could progress to heart failure (HF). The clinical profile and the disease trajectory depend on the age, sex, and the type of underlying AR pathology. Noninvasive cardiac multimodality imaging (cMMI) has been integral in the serial monitoring and management of AR. Meanwhile, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) are mainly utilized as the first-line diagnosis and monitoring options for AR. Furthermore, cardiac magnetic resonance imaging (CMR) is useful in assessing regurgitant volume and the degree of myocardial remodeling. Cardiac computed tomography (CT) is another second-line imaging modality used to evaluate anatomy, particularly for surgical planning. These modalities allow a systematic assessment of AR disease severity and therapeutic decision-making. Surgical aortic valve replacement (SAVR) is the recommended modality for treating severe symptomatic AR. Meanwhile, transcatheter aortic valve replacement (TAVR) may be a potential interventional option for patients at elevated surgical risk; however, the evidence remains limited to patients with mixed aortic valvular disease. Therefore, new research is currently being performed in artificial intelligence and four-dimensional imaging to optimize the diagnostic accuracy of imaging techniques and identify patients who would benefit from early intervention, thus improving outcomes. The primary objective of this review is to explore the different indications, advantages, and disadvantages of cMMI in the diagnosis, follow-up, and treatment of severe AR, highlighting how cMMI can be utilized in optimizing clinical decision-making and patient outcomes.