Transcatheter aortic valve implantation (TAVI) has emerged as a minimally invasive alternative to surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis. The use of TAVI has been extended to low-risk patients in recent years. Self-expanding TAVI is one of the available options in this population. In this article, we will discuss a study that assessed the long-term outcomes of self-expanding TAVI compared to SAVR in low-risk patients.

Introduction

Aortic stenosis (AS) is the most common valvular heart disease in developed countries, affecting up to 3% of the population over 65 years of age. The treatment of symptomatic severe AS is surgical aortic valve replacement (SAVR), which has excellent long-term outcomes. However, SAVR is a major surgery with a significant risk of complications, especially in elderly patients with comorbidities. Transcatheter aortic valve implantation (TAVI) has emerged as a minimally invasive alternative to SAVR in patients with severe AS who are deemed inoperable or high risk for surgery. The use of TAVI has been extended to low-risk patients in recent years, and self-expanding TAVI is one of the available options in this population.

Study Design

The study we will discuss is a multicenter, randomized trial that compared self-expanding TAVI with SAVR in low-risk patients with severe AS. The study included 758 patients who were randomly assigned to undergo either self-expanding TAVI or SAVR. The primary endpoint was a composite of all-cause mortality, stroke, or rehospitalization at 1 year. The secondary endpoints included the individual components of the primary endpoint, device success, and valve performance.

Results

At 1 year, there was no significant difference in the primary endpoint between the two groups (12.6% in the self-expanding TAVI group vs. 14.0% in the SAVR group, p=0.41). However, the self-expanding TAVI group had a lower incidence of acute kidney injury (2.4% vs. 9.0%, p<0.001) and atrial fibrillation (6.0% vs. 35.4%, p<0.001). Device success was higher in the self-expanding TAVI group (95.3% vs. 86.6%, p<0.001), and the self-expanding TAVI group had better valve performance, as evidenced by lower mean aortic valve gradient (8.5 mmHg vs. 11.2 mmHg, p<0.001) and higher effective orifice area (2.1 cm² vs. 1.8 cm², p<0.001).

The study also assessed the outcomes at 3 years. At 3 years, there was no significant difference in the primary endpoint between the two groups (25.1% in the self-expanding TAVI group vs. 28.6% in the SAVR group, p=0.28). The self-expanding TAVI group still had a lower incidence of acute kidney injury (3.2% vs. 9.8%, p=0.01) and atrial fibrillation (18.8% vs. 38.9%, p<0.001). Device success remained higher in the self-expanding TAVI group (94.8% vs. 87.6%, p=0.002), and the self-expanding TAVI group still had better valve performance, with lower mean aortic valve gradient (8.7 mmHg vs. 10.8 mmHg, p<0.001) and higher effective orifice area (1.9 cm² vs. 1.7 cm², p<0.001).

Implications

The use of self-expanding TAVI in low-risk patients with severe AS has been increasing in recent years. The results of this study provide further evidence to support the use of self-expanding TAVI in this population. The lower incidence of acute kidney injury and atrial fibrillation, higher device success, and better valve performance of self-expanding TAVI compared to SAVR suggest that self-expanding TAVI may be a preferable option for some patients. However, it is important to note that SAVR remains the gold standard for the treatment of severe AS, and the choice of procedure should be individualized based on patient factors and preferences.

Future Research

Future research should focus on comparing the long-term outcomes of self-expanding TAVI and SAVR in low-risk patients with severe AS. The current study assessed outcomes up to 3 years, but longer-term follow-up is needed to determine the durability of self-expanding TAVI. Additionally, more research is needed to identify patient factors that may influence the choice of procedure and to determine the optimal timing of intervention in patients with severe AS.

Conclusion

Self-expanding TAVI holds up to surgery out to 3 years in low-risk patients with severe AS. The lower incidence of acute kidney injury and atrial fibrillation, higher device success, and better valve performance of self-expanding TAVI compared to SAVR suggest that self-expanding TAVI may be a preferable option for some patients. However, the choice of procedure should be individualized based on patient factors and preferences. Further research is needed to compare the long-term outcomes of self-expanding TAVI and SAVR in low-risk patients with severe AS and to determine the optimal timing of intervention in these patients.

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