Decision-Making Approach to Treat Young and Low-Risk AS Patients: Key Points
The following are key points to remember from a state-of-the-art review on a decision-making approach to the treatment of young and low-risk patients with aortic stenosis (AS):
- For patients with severe symptomatic AS, current clinical practice guidelines support either transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) in low-risk patients >65 years of age in the United States and >75 years of age in Europe. Use of TAVR has been growing in all age groups, most steeply in patients aged <65 years, for whom life expectancy usually exceeds predicted index valve durability. This document provides clinicians with a pragmatic, patient-centered decision-making approach to the lifetime management of AS in young and low-risk patients.
- For patients undergoing SAVR, mechanical valves are more durable than bioprosthetic valves (15-year reintervention rate 6.9% vs. 12.1% for bioprosthetic valves). Moreover, bioprosthetic valve durability is inversely related to patient age (i.e., valve dysfunction tends to occur earlier in younger patients). On the other hand, bioprosthetic valves are associated with a lower risk of major bleeding, given the requirement for warfarin anticoagulation with mechanical valves.
- Minimally invasive SAVR techniques have gained acceptance and provide improved cosmetic results and similar clinical outcomes as compared with full sternotomy SAVR.
- The Ross procedure (SAVR with pulmonary autograft, and pulmonic valve replacement with allograft) has favorable outcomes in centers of excellence.
- Factors favoring SAVR over TAVR include: a) high-risk TAVR anatomy (such as severe peripheral arterial disease or severe left ventricular outflow tract calcification); b) bicuspid aortic stenosis (often with large annulus and asymmetrical cusp calcification); c) concomitant disease that can be best addressed surgically (e.g., severe coronary artery disease, aortic root/ascending aortic aneurysm, severe mitral regurgitation, atrial fibrillation); and d) low technical feasibility of redo TAVR. The relative ease of accessing the coronary arteries following SAVR as compared with TAVR is also a potential benefit.
- Factors favoring TAVR over SAVR include: a) high-risk SAVR anatomy (such as prior coronary artery bypass grafting with exposed patent grafts, porcelain aorta, prior mediastinal radiation); b) feasibility of redo TAVR (predictable based in part on multidetector computed tomography [MDCT] with postprocessing techniques); c) frailty; and d) socioeconomic factors (lack of family support for rehabilitation from surgery, need to return to work quickly after intervention).
- Patient-prosthesis mismatch (PPM) is associated with adverse clinical outcomes, particularly in younger patients and in patients with left ventricular dysfunction. For patients with small aortic roots, self-expanding TAVR or SAVR with aortic root enlargement reduces the risk of PPM. Preprocedural sizing based on MDCT, rather than traditional intraoperative sizing, predicts PPM risk and identifies patients who can benefit from root enlargement.
- TAVR explantation is more technically challenging and carries higher morbidity and mortality risks than redo SAVR. Therefore, in a younger patient who wishes to avoid a mechanical prosthesis, a bioprosthetic SAVR-first approach is preferable to a TAVR-first approach.
