Evolution of Small Balloon-Expandable Valves

Small aortic rings (20 mm) have posed a significant challenge for both surgery and transcatheter aortic valve implantation (TAVI) due to their association with an increased risk of prosthesis-patient mismatch (PPM), which correlates with a higher incidence of heart failure and mortality. However, there are no medium- or long-term follow-up studies on this topic.

Researchers conducted an analysis on 316,091 patients in the TVT Registry who received SAPIEN 3, SAPIEN 3 Ultra, or SAPIEN 3 Ultra RESILIA balloon-expandable valves, comparing those who received 20-mm valves with those who received 23-, 26-, or 29-mm valves.

Due to group heterogeneity, propensity score matching was performed. As a result, each group included 8100 patients.

After implantation, patients with small ring showed a higher incidence of gradient ≥20 mmHg (26.4% vs. 6.9%; p <0.0001), a lower indexed effective aortic area (0.8±0.3 vs. 1±0.3; p <0.0001), higher severe PPM (20% vs. 8.2%; p <0.0001), and a greater risk of moderate or severe paravalvular leak (1.8% vs. 0.5%; p <0.0001). Ring rupture was less frequent in patients with small ring, with no differences regarding major vascular complications or life-threatening bleeding.

At the 30-day and one-year follow-up, there were no differences in all-cause mortality, stroke, bleeding, or readmission. The need for pacemaker was lower in patients with small ring at both 30 days and one year (4.8% vs. 8.5%; p <0.0001 and 5.8% vs. 9.8%; p <0.0001, respectively). However, researchers observed a trend toward a higher reintervention rate in this group (0.6% vs. 0.2%; p = 0.0005).

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At 3 years of follow-up, there were no differences in the composite outcome of all-cause mortality or stroke. However, severe PPM was associated with higher mortality compared to patients with moderate or no PPM.

Patients with mean gradient <10 mmHg and ejection fraction <50%, as well as those with mean gradient >30 mmHg, showed higher mortality at 3 years of follow-up.

In a multivariate analysis, mortality was associated with moderate or severe paravalvular leak, as well as with mean gradient <10 mmHg or >30 mmHg at follow-up.

Conclusion

Patients who received a small (20 mm) balloon-expandable valve had comparable three-year survival rates to those who received 23-mm valves or larger. However, severe PPM and gradient <10 mmHg, associated with a low ejection fraction, were linked to higher mortality, suggesting that low ejection fraction may be the determining factor in unfavorable outcomes.

Original Title: 3-Year Outcomes of Balloon-Expandable Valves 20-mm vs Larger Valves (>23 mm).

Reference: Marvin H. Eng, et al. JACC Cardiovasc Interv. 2024;17:2041–2051.