In recent years, the indications for transcatheter aortic valve implantation (TAVI) have been expanded from patients who are ineligible or at high risk for surgical aortic valve replacement to patients who have a lower risk profile.1,2

Despite advances in technology and improvements in valve devices, several factors can affect the mid- to long-term durability of the prosthesis such as the degree of expansion, the geometry of the stent frame, calcifications, and left ventricular outflow tract protrusion.3,4 Another critical point is commissural alignment (CA) between native and prosthesis commissures. Recent research demonstrates that preprocedural planning is key to achieve CA, demonstrating feasibility, safety and advantages in reducing coronary artery overlap.5–7 CA feasibility and benefits are better defined for self-expandable devices.6,7 However, there is no evidence on the feasibility of CA with the novel balloon-expanding Myval (Meril Life Sciences Pvt. Ltd, India), and in general, the chances of achieving adequate CA with balloon-expandable devices are limited according to current evidence.6

The relationship among native aortic commissures and transcatheter heart valve (THV) commissures was analyzed in 10 patients undergoing TAVI with the Myval device. All patients were included in the accurate CA project approved by the local ethics committee and provided informed consent. Computed tomography (CT) based models were analyzed leading to: a) in silico model for TAVI simulation preprocedurally; and b) in vivo determination of the degree of CA and coronary overlap. Pre- and postprocedural CT was available in all patients.

In vivo demonstration

Myval devices were crimped as the in silico model orientation predicted to avoid CMA as shown in figure 1. CT scans from 10 consecutive patients who received Myval were performed 1 to 3 months after the procedure to obtain a precise comparison with the simulated model and CA was studied.

Figure 1.

A: in silico simulation of a Myval device implantation in patient-specific aortic biomodel illustrating the effect of a 60° rotation in the final implant position. B: detailed view of the aortic root with a commissural alignment implant of a Myval device, see how the neo-commissures (red asterisks) match the native commissures and how the left coronary ostium (yellow asterisk) is centered between the adjacent neo-commissures. C: valve crimping with the commissures oriented as previously calculated. D: in vitro accurate commissural alignment implant of a Myval device in a patient-specific 3-dimensional printed phantom. E: trimmed view of the previous 3-dimensional printed phantom (the aortic arch has been removed), a Judkins left catheter is engaging the left coronary artery, highlighting the absence of coronary overlap of the neo-commissures (red asterisks). F: valve implantation without significant commissural misalignment (commissural post marked by red asterisks and native commissures represented as green peaks).

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A patient-specific clockwise or counter-clockwise rotation was performed to match the commissural posts of the prosthesis with the native commissures in the aortic root biomodel. Then, the TAVI procedure was performed as standard of care, after crimping the valve into the delivery system, as previously described, to achieve the predicted angle (figure 1).

As shown in table 1, in silico simulation suggested correct alignment in all patients and in vivo procedures demonstrated correct alignment in 6 of the 10 patients and mild misalignment in the remaining 4 patients. There were no cases of moderate or severe CMA. The mean degree of misalignment was 16.7±8°. The concordance of the commissural post orientation in the in silico THV implants to the final commissural post orientation was high, with a Lin's concordance correlation coefficient of 0.983 (95% confidence interval [95%CI], 0.966-0.992), P <.001 (figure 2).

Figure 2.

Correlation of commissural post orientation among in silico and in vivo results according to post-TAVI computed tomography scan. 95%CI, 95% confidence interval; CCC, concordance correlation coefficient; LCSNCS, commissural post between left coronary sinus and noncoronary sinus; LCSRCS, commissural post between left coronary sinus and right coronary sinus; RCA, right coronary artery; RCSNCS, commissural post between right coronary sinus and noncoronary sinus.

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Regarding the degree of coronary overlap, patient-specific details are presented in figure 3. Out of 10 patients, 3 of them (patients 2, 3 and 10 in figure 3) showed significant overlap of the ostium of the right coronary artery and the commissural post. In contrast, none of the patients showed severe coronary overlap of the left coronary artery ostium. The main findings are summarized in figure 4.

Figure 3.

Degrees from the commissural post of the prosthesis to the coronary ostia detailed by patient. An angle lower than 20° reflects a high risk of coronary overlap (post in front of the ostium) and also, lower efficacy of eventual BASILICA technique if required in the future before valve-in-valve procedure. Patients 2, 3 and 10 had significant overlap of the ostium of right coronary artery and the commissural post; none of the patients showed severe coronary overlap of the left coronary artery ostium. LCA, Left coronary artery; RCA, right coronary artery.

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Figure 4.

Central illustration. The strategy for rotation of the prosthesis and the expected results are reflected on the left side of the figure. On the right side, the main findings are summarized including: a) the degree of counter-clockwise (red) or clockwise rotation (blue) when crimping; b) the degree of commissural alignment of the prosthesis (green) with the native commissures (blue) and numerical range of degrees for patients with good commissural alignment (from 7° to 18°) and in those with mild commissural misalignment (from 22° to 30°); c) the degree of coronary overlap for both right (blue) and left (red) coronary ostia with the commissural posts of the prosthesis (cases with severe coronary overlap are pointed out with a pink asterisk).

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The mean transaortic gradient was 6.1±3.3mmHg and there was no moderate-severe paravalvular leak.

CA is crucial for 2 reasons: a) commissural misalignment might be related to more difficult coronary reaccess if eventually needed and could be related to higher rates of central aortic regurgitation, greater residual gradients, and increased blood stagnation in the leaflets/sinuses of Valsalva, potentially linked to faster prosthesis degeneration5; b) coronary overlap occurring when coronary ostia are too close to the prosthesis commissural posts, is relevant if there is an eventual need for repeated valve intervention (TAVI-in-TAVI), since it is associated with a well-known and life-threatening risk of coronary obstruction; although it can be prevented by the BASILICA technique (bioprosthetic scallop intentional laceration to prevent iatrogenic coronary obstruction),6 if the coronary ostia are not in the center of the neo-sinuses but close to the commissural posts of the first prosthesis, the coronary ostia can be occluded even after leaflet laceration.

Several strategies have been developed for CA during self-expandable TAVI procedures but none of them have been demonstrated to be feasible for balloon-expandable devices. Indeed, prior techniques tried to achieve adequate alignment of balloon-expandable devices by orienting the delivery system during the deployment, which resulted in a highly unpredictable final position of the prosthesis when implanted due to difficult identification of neocommissures in the crimped devices. The proposed patient-specific technique in our research suggest that: a) CA of native and prosthetic valves can be achieved with no need to manipulate the delivery system within the patient but by CT-based planning, avoiding moderate and severe misalignment in all cases; b) coronary overlap with the commissural posts could be avoided in all patients for the left coronary artery and in 70% of patients for the right coronary artery, which still showed 3 cases of coronary overlap likely due to the greater eccentricity of the right coronary ostia in the native sinuses of Valsalva.

These findings might have important prognostic relevance in the long-term and are particularly relevant for low-risk patients undergoing TAVI. In addition, the findings for the Myval device are likely reproducible with the Sapien-3 device (Edwards Lifesciences, United States), although future research is needed to confirm these findings.

CA of the balloon-expandable Myval TAVI device can be achieved based on the analysis of the CT allowing a patient-specific orientation of the valve when crimped. As a result, moderate and severe CMA and the risk of coronary overlap of the left main can be successfully avoided. Cross validation of this technique in larger series is ongoing (NCT05097183).

This investigation received funding resources from the Sociedad Española de Cardiología (SEC) with the grant number: SEC/FEC-INV-CLI 21/023. Alfredo Redondo Diéguez is a beneficiary of a Contrato Rio Hortega grant from the Instituto Carlos III: CM20/00068. I.J. Amat-Santos is principal investigator of a FIS (Fondo de Investigación en Salud) grant No. PI21/01188 (Instituto de Salud Carlos III, Madrid, Spain).

A. Redondo, C. Baladrón, and I.J. Amat-Santos conceived the original idea. S. Santos-Martínez, A. Redondo, E. Gonzalez-Bartol, A. Barrero, P. Sánchez-Luna, A. Revilla-Orodea, C. Baladrón, A. Serrador, J.A. San Román, and I.J Amat-Santos conducted the research. All authors approved the final version of the manuscript.

I.J Amat-Santos is proctor for Meril Life, Medtronic, and Boston Scientific.