Purpose: We aimed to establish a definition for MM, evaluated the incidence of MM using the CoreValve Evolut RTM, investigated potential risk factors for MM and the associated clinical outcomes.
Methods: MM was defined as movement of the prosthesis of at least 1.5 mm from its position directly before release compared to its final position. Patients were grouped according to the occurrence (+MM) or absence (-MM) of MM. Baseline characteristics, imaging data and outcome parameters in accordance with the updated valve academic research consortium (VARC-2) criteria were retrospectively analyzed.
Results:We identified 258 eligible patients. MM occurred in 31.8% (n=82) of cases with a mean magnitude of 2.8 ± 2.2 mm in relation to the left coronary cusp and 3.0 ± 2.1 mm to the non-coronary cusp. Clinical and hemodynamic outcomes were similar in both groups. The mean pressure gradient was effectively reduced after TAVI (-MM vs. +MM: 7 ± 3.4 mmHg vs. 8 ± 3.9 mmHg, p=0.326) with consistency over a follow-up period of at least three months (-MM vs. +MM: 6.7 ±3.7 mmHg vs. 7.9 ±8.4 mmHg, p=0.168). At three months follow-up most of the patients presented with no aortic regurgitation (-MM vs. +MM: 64% vs. 67.9%, p=0.569). Mild aortic regurgitation was observed in 34.2% of the -MM group and in 29.5% of the +MD group (p=0.414). Moderate aortic regurgitation occurred in 1.9% of all patients with no differences between groups (-MM vs. +MM: 1.9% vs. 2.6%, p=0.662). Patients with MM presented with a more symmetric calcification pattern (-MM vs. +MM: 27.3% vs. 40.2%; p=0.037) and a larger aortic valve area (-MM vs. +MM: 0.6 cm² ± 0.3 vs. 0.7 cm² ± 0.2; p=0.014), which was found to be a potential risk factor for the occurrence of MM in a multivariate regression analysis (OR 3.5; 95%CI: 1.1-10.9; p=0.032)
Conclusion: MM occurred in nearly one third of patients and did not affect clinical and hemodynamic outcome. A larger aortic valve area was the only independent risk factor for the occurrence of MM.