SMART 2-year TAVR hemodynamic data: Medtronic Evolut is better compared to Edwards Sapien in small annulus patients

The latest two-year, late-breaking findings from the SMART trial reinforce the superior hemodynamic performance of the Medtronic Evolut valve compared to the Edwards Lifesciences Sapien 3 in patients with small aortic annuli undergoing transcatheter aortic valve replacement (TAVR).

Howard C. Herrmann, MD, MSCAI, section chief of interventional cardiology at the Hospital of the University of Pennsylvania and lead investigator of the SMART trial, presented the new data at a late-breaking session during the Cardiovascular Research Technologies (CRT) 2025 conference in Washington, D.C., in early March. He spoke with Cardiovascular Business in a video interview at CRT about the data and key takeaways.

He notes those differences remained or increased in the year-two data. "There was still a 36% difference in the bioprosthetic valve dysfunction endpoint, with 20% of the Sapien patients, one in five, had a mean gradient greater than 20 mmHg compared to 1% of the Evolut population,” he says. “And the mean gradients were about 50% lower." 

Remaining consistent between years one and two were the primary trial endpoints for death, disabling stroke, and heart failure rehospitalization. Both valves performed well, with no statistically significant differences. 

Concerns raised about increasing rates of HALT and TIA

The other interesting findings include a higher instance of transient ischemic stroke (TIA) in the Sapien group, 4% versus 1%. There also was a difference in prosthetic valve leaflet thrombosis, also known as hypoattenuated leaflet thickening (HALT) based on its appearance in cardiac CT used to evaluate the condition. Sapien 3 valves had a HALT rate of 4.2%, and Evolut 1%. 

While most of these HALT events were subclinical, Herrmann says they did have an effect on patient management. All of the patients who had subclinical leaflet thrombosis, most of whom were found by evaluating their gradients, resulted in either hospitalization, office visits, or more testing such as CT scans. Most of the time there was a change to anticoagulation medication, which he says can have its own set of issues, including increased bleeding risks. 

A meta-analysis has showed HALT is more common in the Sapien 3 balloon expandable bovine leaflets than in the self-expanding Evolut super annular porcine leaflets, he notes.

While significance of HALT is not fully understood, Herrmann says, it is often benign and can resolve on its own. But, there is often concern that thrombus can embolize from the valve leaflets and cause strokes.

Clinical implications of the SMART trial data

Herrmann emphasized that while adverse hemodynamics can impact long-term durability, it often takes three to five years for clinical consequences to emerge. The SMART trial’s five-year follow-up will provide further insight into whether these hemodynamic advantages translate into longer valve durability and better patient outcomes.

"We know that adverse hemodynamics do affect clinical outcomes, but it takes several years. We have data from the National Australian Echo Registry, we have meta-analysis after TAVR. We have some analysis from the Evolut database, all of which have shown that adverse hemodynamics affect clinical outcomes. But it takes three to five years to see those effects, so it wasn't really a surprise in the SMART trial that we didn't see clinical differences at two years, but that's why we're following patients for five years,” Herrmann said. 

Panelists at the late-breaking CRT session noted the issues seen in surgical valves over time once hemodynamic issues are seen. Another panelist said the choice of valve for small annuli patients appears to be evident from this trial. 

"I think the SMART trial shows that there is no disadvantage to using the self-expanding super annular valve, the results are equivalent at two years. But, there are some signals of disadvantage to the balloon expandable valve," Herrmann said. 

Here is an interview with Herrmann on the one-year SMART trial results at ACC 2024.

References:

1. Herrmann H. Two-Year Outcomes of the Five-Year SMART Trial, presented at CRT 2025.

2. Garcia S., Fukui M., Dworak M., et al. Clinical Impact of Hypoattenuating Leaflet Thickening after Transcatheter Aortic Valve Replacement. Circ Cardiovasc Interv. March 2022;15:e011480.Doi:10.1161/circinterventions.121.011480.

3. Playford D, Stewart S, Celermajer D, Prior D, Scalia GM, Marwick T, Ilton M, Codde J, Strange G; NEDA Contributing Sites. Poor Survival with Impaired Valvular Hemodynamics After Aortic Valve Replacement: The National Echo Database Australia Study. J Am Soc Echocardiogr. 2020 Sep;33(9):1077-1086.e1. doi: 10.1016/j.echo.2020.04.024. Epub 2020 Jun 24. PMID: 32593505.

4. Sá, M, Jacquemyn, X, Van den Eynde, J. et al. Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement: Meta-Analysis of Kaplan-Meier–Derived Individual Patient Data. J Am Coll Cardiol Img. 2023 Mar, 16 (3) 298–310.https://doi.org/10.1016/j.jcmg.2022.07.013

5. Iribarren AC, AlBadri A, Wei J, et al. Sex differences in aortic stenosis: Identification of knowledge gaps for sex specific personalized medicine. Am Heart J Plus. September 2022;21:100197.

6. Tribouilloy C, Bohbot Y, Rusinaru D, Belkhir K, et al. Excess Mortality and Undertreatment of Women with Severe Aortic Stenosis. J Am Heart Assoc. 2021 Jan 5;10(1):e018816.

7. Williams M, Kodali SK, Hahn RT, et al. Sex-related differences in outcomes after transcatheter or surgical aortic valve replacement in patients with severe aortic stenosis: Insights from the PARTNER Trial (Placement of Aortic Transcatheter Valve). J Am Coll Cardiol. April 22, 2014;63(15):1522–1528.

Click here for indications, safety and warnings. Like any other procedure, TAVR risks can include death, stroke, bleeding.

Third-party brands are trademarks of their respective owners. All other brands are trademarks of a Medtronic company.

Dr. Herrmann did not receive compensation for this piece; however, he has received compensation from the medical device industry, including Medtronic.

Valve performance as defined as freedom from BVD through 24 months. BVD is a composite including any of the following: hemodynamic structural valve dysfunction (mean gradient ≥ 20 mmHg), non-structural valve dysfunction (severe prosthesis patient mismatch or ≥ moderate aortic regurgitation), thrombosis, endocarditis, and aortic valve reintervention.