Overcoming prosthesis-patient mismatch with transcatheter aortic valve replacement

For decades, surgeons have recognized the risk of prosthesis-patient mismatch (PPM) when treating aortic stenosis (AS) with surgical aortic valve replacement (SAVR). The concept of PPM—or placing a valve that is too small for the cardiac output requirements of the patient—has been associated with worse patient outcomes, including increased risk of death. Transcatheter aortic valve replacement (TAVR) has become the standard treatment for most patients with severe symptomatic AS and is associated with improved hemodynamics and lower risks of PPM. Larger surgical valves, stentless, and sutureless technology, and surgical aortic annulus enlargement (AAE) have been employed to avoid severe PPM. However, especially in the small aortic annulus (SAA), TAVR may provide a benefit. Understanding who is at risk for PPM requires preplanning, and cardiac-gated computed tomography (CT) imaging is the standard of care when considering TAVR. It should be standard for all patients with AS. Once SAA is identified, the risk of PPM can be calculated, and an informed decision made on whether to proceed with SAVR or TAVR. In the current TAVR era, younger patients are treated with TAVR driven by patient preference, but with little long-term data to support the practice. Selecting the best valve for the patient is a multifactorial decision often nuanced by anatomical considerations, hemodynamic and durability expectations, and decisions regarding lifetime management that may include placing a second valve. Although PPM may be only one of the factors to consider, the association with elevated mean gradients and worse outcomes certainly makes TAVR a good solution for many patients.