Discordance between aortic valve gradient and area: do I trust the significant gradient?

Aortic stenosis is an increasingly relevant pathology not only for its high prevalence in the population (especially elderly), but also because in recent decades traditional surgery has been accompanied by transcatheter aortic valve implantation, a technique that has allowed a significant increase in effective therapeutic procedures, even in patients previously considered at high surgical risk. It has become essential to make precise diagnoses, based mainly on echo-Doppler that allows to identify the aetiology and severity of the valvular disease. A stenosis is considered severe when the area is <1 cm2, the mean gradient exceeds 40 mmHg and the peak velocity is >4 m/s. Although in many cases these cut-offs are decisive, in others a discrepancy between area (<1 cm2) and gradient (<40 mmHg) is observed, requiring the inclusion of other variables such as ejection fraction (EF > or <50%) and the systolic volume index (normal SVi >35 mL/m2 or reduced <35 mL/m2) to define the severity of the stenosis. This article describes the reasons for this discrepancy, identifies echo-Doppler parameters that further improve the classification of stenosis severity, and defines the indications for second-level examinations such as computed tomography and transoesophageal echocardiography.