Trends in aortic root enlargement with bioprosthetic valves

Purpose: Aortic root enlargement (ARE) during aortic valve replacement (AVR) mitigates patient-prosthesis mismatch, but adoption has been low. Transcatheter aortic valve-in-valve (aVIV) was approved in 2015 for high-risk patients, renewing interest in ARE during index AVR. This study demonstrates the trends and outcomes of ARE after the introduction of aVIV.

Methods: We identified 2,183 patients undergoing elective or urgent AVR with a bioprosthetic valve from 08/2007 to 12/2022 at a single-center. Patients with endocarditis, aortic dissection, or concomitant root replacement or ventricular assist device placement were excluded. Of those, 74 (3.4%) underwent ARE. Trends in ARE utilization and valve size and types were compared over the study period. Outcome measures included 30-day mortality, valve size, and gradients; and were compared between patients with AVR alone and ARE group.

Results: Overall, the ARE group was younger (64 vs 68, p=.001), had more females (59 (80%) vs 743 (35%), p<.0001), had smaller BSA (1.9 vs. 2.0, p=.02), and had more reoperations (27 (36%) vs 312 (15%), p<.0001). ARE group had similar co-morbidities and predicted risk of operative mortality (PROM) compared to the AVR group (median Society of Thoracic Surgery PROM 1.7%). Utilization of ARE has increased since 2015 (Figure 1A) and the implantation of 19mm and 21mm valves has decreased (Figure 1B). Almost all patients now receive stented bovine pericardial valves with expandable frames (Figure 1C). ARE had longer bypass time (140 min vs 102 min, p<.0001), longer cross-clamp times (114 min vs 86 min, p<.0001), smaller median implanted valve size (23mm vs 25mm, p< 0.0001), and comparable postoperative mean gradients (11 vs. 11 mmHg, p=.11). Both groups had similar ICU time, length of stay (5-6 days), post-operative complications, and 30-day readmissions. ARE had higher rates of 30-day mortality (5 (7%) vs 48 (2%), p=.014); however, elective ARE had similar 30-day mortality compared to elective AVR (2/65 [3%] vs 39/1899 [2%], p=.57).

Conclusion: Utilization of ARE has increased since aVIV approval. The implantation of larger sized valves did not affect early safety in elective cases and was associated with similar postoperative gradients to patients not requiring ARE. Further studies need to be performed to determine strategies to optimize aVIV after ARE.

Identify the source of the funding for this research project: N/A