Incremental Risk of Annular Enlargement: A Multi-Institutional Cohort Study

Annular enlargement (AE) is a critical technique to avoid patient-prosthesis mismatch and may help facilitate future valve-in-valve (ViV) transcatheter replacement. We hypothesized that the addition of annular enlargement would increase risk of morbidity and mortality and that the number of annular enlargement procedures is increasing to accommodate future ViV procedures.

Patients undergoing aortic valve replacement ± coronary surgery (2012 to 2017) were extracted from a regional Society of Thoracic Surgeons database. Patients were stratified by annular enlargement and era, pre-ViV (2012 to 2014) vs ViV (2015 to 2017) for univariate analysis. Risk-adjusted outcomes were assessed by hierarchical regression modeling adjusting for predicted risk of mortality.

Of 6045 patients, the 300 (5.0%) who received an annular enlargement were younger and more commonly female. Patients receiving an annular enlargement had higher complication rates including operative mortality (4.7% vs 2.5%, P = .024). After risk adjustment, AE was independently associated with increased mortality (odds ratio, 2.06, P = .016) and major morbidity (odds ratio, 1.41, P = .042). The rate of enlargement increased from 3.9% pre-ViV to 6.3% ViV (P < .001). The use of ViV capable valves (bioprosthetic ≥23 mm) from 61% to 67% (P = .001), and more in AE patients (30% vs 11% non-AE). Alternatively, the rate of patient prosthesis mismatch declined from 23% to 16%.

Increasing utilization of AE coincides with a decline in patient prosthesis mismatch and may facilitate future ViV transcatheter aortic valve replacement. However, AE was independently associated with increased morbidity and mortality. High variability in AE volume may be increasing risk and deserves further investigation.