Courtesy of Dr. Carlos Fava.
The benefits derived from transcatheter aortic valve replacement (TAVR) are clear and self-evident, and its progressively better outcomes are due to better patient selection, greater operator experience, and the development of new valves that enhance procedural safety and complexity. However, the question of durability remains a major unresolved issue, particularly now that we are progressively moving on towards younger or low-risk populations.
A new definition of structural valve deterioration (SVD) in Doppler echocardiography has been recently proposed. According to it, moderate SVD was defined as transprosthetic gradient ≥20 mmHg and <40 mmHg, and <20 mmHg change from baseline (before discharge or within 30 days) and/or moderate new leak or worsening baseline leak, while severe SVD was defined as mean gradient ≥40 mmHg and/or ≥20 mmHg change from baseline (before discharge or within 30 days) and/or severe new leak or worsening baseline leak. Valve failure (VF) was defined as repeat intervention (valve-in-valve), paravalvular leak closure, surgical aortic valve replacement, or confirmed autopsy findings of valve deterioration. VF included non-structural valve deterioration (paravalvular leak, patient-prosthesis mismatch, prosthesis malposition, late embolisation, degeneration, and/or dysfunction), thrombosis, and endocarditis.
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The study included 378 patients between 2002 and 2012, with at least over 5 years of follow-up.
Mean patient age was 83.3 years old (45.9% of subjects were male). Most patients were in New York Heart Association functional class III-IV and presented multiple comorbidities. The EuroSCORE score was 22.8.
The valve area was 0.68 cm2, the gradient was 50 mmHg, all devices used were balloon-expandable valves (SAPIENS XT 56%, SAPIENS 21.5%, and PVT/Cribier-Edwards 20.5%), and a transfemoral access approach was used in over 80% of all cases.
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After implantation, the gradient went down to 9.7 mmHg and the aortic area increased to 1.8 cm2. Moderate/severe leak was present in 5.6% of patients and severe leak was present in 0.6% of them.
The mortality rate at 30 days was 13.2%; stroke, 1.8%; vascular complications, 15.1%; major bleeding, 24.6%; need for a permanent pacemaker, 5.6%.
The survival rate at 12 months was 71.4%; at 5 and 8 years, it was 31.7% and 9.6%, respectively. At the 8-year follow-up, the incidence of SVD and VF was 3.2% (95% confidence interval [CI]: 1.45-6.11 and 95% CI: 0.15-2.75, respectively), with 9 SVD patients and 2 VF patients.
Although high-risk/inoperable patients have poor survival rates, these data do not provide cause for alarm concerning TAVR durability. Careful assessment in younger and lower-risk patients must include comparison with surgical valves for further assessment of the long-term durability of TAVR.
This analysis proves that TAVR is safe and that its hemodynamic performance is warranted at 8 years.
Survival is a limiting variable, since these are high-risk patients with many comorbidities.
These data encourage us to go further with research in lower-risk and younger populations. These must clearly be randomized, well-controlled investigations, like current ongoing studies, since surgically-implanted valves warrant durability for about 15 years or maybe more.
Original title: Assessment of Structural Valve Deterioration of Transcatheter Aortic Bioprosthetic Balloon-Expandible Valves Using the New European Consensus Definition.
Reference: Helene Eltchaninoff et al. EuroIntervention 2018:13-online publish-ahead-of-print March 2018.
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