One of the limitations of aortic bioprostheses is their durability. When these devices fail, percutaneous valve implantation is a valid strategy. However, it has been shown that there may be high gradients involved.
This gradient increase has been associated with worse outcomes and higher mortality rates, as observed in the PARTNER 2 study at 12 months. This, however, was not the case at the 5-year follow-up, highlighting the lack of conclusive evidence in this scenario.
An analysis was conducted on 12,122 patients who underwent transcatheter aortic valve implantation (TAVI) in surgically bioprosthetic aortic valves with severe structural deterioration. The primary endpoint at 12 months included all-cause death, stroke, myocardial infarction, or valve reintervention.
Patients were divided into four groups according to mean gradient: <10 mmHg (2272 patients), between 10 and <20 mmHg (5803 patients), between 20 and <30 mmHg (2889 patients), and >30 mmHg (1158 patients).
The mean age was 76 years, and 61% of patients were men. While groups were similar in many aspects, those with a post-procedural high gradient tended to have a higher initial gradient and a higher body mass index. They more frequently had a history of smoking, more aortic insufficiency, and an aortic valve area <1 cm2.
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On the other hand, patients with a low gradient had higher rates of atrial fibrillation, lower ejection fraction, larger valve rings, elevated hemoglobin levels, and more urgent or emergent procedures.
The primary endpoint at 12 months was 11.1%, with a mortality rate of 7.6%, a myocardial infarction rate of 1%, and a valve reintervention rate of 1.2%.
A gradient ≥20 mmHg was associated with increased mortality at 12 months (adjusted hazard ratio [HR], 1.017 [95% confidence interval, 1.005–1.030] per mmHg; P=0.007).
An adjusted analysis according to gradient (<10 mmHg, between 10 and >20 mmHg, between 20 and <30 mmHg, and ≥30 mmHg) showed increased mortality when the gradient was <10 mmHg or ≥30 mmHg.
Conclusion
In conclusion, there is a complex and nonlinear relationship between post-TAVI mean gradient in surgically deteriorated bioprosthetic aortic valves and clinical outcomes. There is a relative increase in adverse events in patients with low or extremely high gradients. Further studies are needed to better understand the factors influencing this relationship, especially in patients with low gradients.
Dr. Carlos Fava.
Member of the Editorial Board of SOLACI.org.
Original Title: Impact of Elevated Gradients After Transcatheter Aortic Valve Implantation for Degenerated Surgical Aortic Valve Bioprostheses.
Reference: Riyad Yazan Kherallah, et al. Circ Cardiovasc Interv. 2024;17:e013558. DOI: 10.1161/CIRCINTERVENTIONS.123.013558.
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