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Facilitating future access to the coronary arteries in patients who need transcatheter aortic valve replacement: A significant step in the right direction

In 2019, the number of transcatheter aortic valve replacements (TAVRs) performed in the United States exceeded the number of surgical aortic valve replacements for the first time. Given evidence supporting its safety and feasibility, TAVR is now an approved therapy for all patients with severe aortic stenosis, without regard to estimated risk for surgical complications. This expanded indication is expected to result in continued increase in TAVR volume. Because TAVR is being performed in increasingly younger individuals who might require future coronary intervention, concern is growing about the feasibility and ease of coronary access in patients with a transcatheter valve. Depending on prosthesis design and patient anatomy, the valve frame could impede catheter manipulation and coronary cannulation. This is of special relevance in patients undergoing valve implantation with the self‐expanding Evolut TAVR system, as it has a supra‐annular leaflet location and a taller frame that extends past the coronary ostia. Importantly, the valve has commissural posts—a higher point to which the leaflets are attached —that, if placed in front of the coronary ostium, can make coronary access difficult or even impossible. In this issue of Catheterization and Cardiovascular Interventions, Tang et al. report their experience comparing the conventional advancement and positioning of the Evolut delivery system against a modified approach that aims to align the valve's commissural posts away from the coronary ostia. The modified technique places the flush port located at the proximal end of the device at the 3‐o'clock position instead of the conventional 12‐o'clock position. The effect of the valve's “hat marker” orientation in achieving adequate commissural alignment also was analyzed. The authors established the prosthetic valve's position in relationship to the coronary ostia by using computed tomography, which was obtained before and after TAVR in the 220 patients who underwent conventional insertion as part of the Evolut Low‐Risk Trial, and before TAVR in 240 patients who underwent modified insertion at their center. For the latter group, fluoroscopy co‐registration with the previously acquired computed tomography images was performed to estimate commissural tab position. Severe overlap was defined as the post being within 20 degrees of the coronary ostium. The authors confirmed that orienting the hat marker to the outer curvature (OC) of the aorta or to the center front (CF) position resulted in significantly better commissural alignment than orienting the hat marker to the inner curvature or center back position. Advancing the delivery system with the flush port at the 3‐o'clock position oriented the hat marker favorably in 93.3% of the patients, compared with 69.5% of patients who underwent conventional insertion, resulting in a statistically significant reduction in severe commissural overlap with the coronary ostia. In a few patients in the modified insertion group, the hat marker was not in a favorable orientation when assessed in the descending aorta; however, in most of these cases, the delivery system was successfully rotated and adequate positioning was achieved during deployment. These findings are relevant, supporting the growing practice of using the modified delivery technique when implanting this self‐expanding valve platform, and the authors should be lauded for this meaningful contribution to the existing body of literature supporting this strategy. However, it is worth noting that 20.8% of patients who underwent the modified insertion technique still were labeled as having severe overlap, with the valve commissure facing one or both coronary artery ostia. Available evidence suggests that the rate of successful coronary engagement is much lower in patients with poor commissure alignment than patients with favorable positioning. Moreover, even when the self‐expanding Evolut valve is adequately aligned, the rate of successful engagement appears to be markedly lower than that achievable with the balloon‐expandable Sapien 3. Ease of coronary access after TAVR will remain a topic of significant interest going forward, as additional long‐term valve durability data become available and the use of these prostheses in younger patients increases. If an Evolut valve is used, inserting it with the flush port at the 3‐o'clock position and then verifying that the hat marker orientation is in the OC/CF position is currently the best and easiest way to achieve commissural alignment and facilitate future coronary engagement. It remains to be determined whether more precise positioning of the hat marker, beyond quadrant‐based OC/CF positioning, can produce even better commissural alignment rates. In future iterations of this valve, having frames with wider cells could facilitate further coronary intervention in patients who need TAVR and would be a welcome improvement.