ETD

• atrial fibrillation
• leaflet adaptation
• mitral valve remodeling
• three-dimensional echocardiography

Background: There is a key pathophysiological link between left atrial remodeling, atrial fibrillation (AF), and mitral annular adaptation without left ventricular (LV) dysfunction. However, it remains unclear whether AF directly drives annular dilatation and mitral valve (MV) remodeling. By systematically assessing annular size, leaflet morphology, and leaflet-to-annulus adaptation, we aimed to determine whether prolonged exposure to arrhythmia-induced hemodynamic stress leads to maladaptive valve changes.
Methods: In this prospective, non-randomized, single-center cohort, 44 patients with AF were enrolled and stratified as paroxysmal (n = 15) or persistent (n = 29). Patients with LV dilatation, LV dysfunction, or primary MV disease were excluded. All participants underwent comprehensive two-dimensional (2D) transthoracic echocardiographic evaluation performed according to the current guidelines, followed by three-dimensional (3D) transesophageal echocardiography. Image datasets were analyzed offline using multiplanar reconstruction (MPR) and MV Navigation (MVN, Philips Medical Systems) software, enabling detailed morphometric assessment of the mitral apparatus. Quantified indices included anteroposterior (AP) and intercommissural (IC) diameters, annular area (AA), circumferential length (CL), anterior and posterior leaflet lengths and areas, total leaflet area (TLA), total leaflet-to-annulus area ratio (TLA/AA), anterior-to-posterior leaflet length ratio (ALL/PLL), and total leaflet length-to-AP ratio (TLL/AP). Additional 3D-derived parameters—tenting height, ellipticity, and sphericity index (IC/AP)—were obtained. Statistical analyses included t-tests, χ² tests, and Pearson’s correlation coefficient (r), with p < 0.05 considered significant.
Results: Baseline characteristics were comparable between groups. Persistent AF was associated with lower but preserved LV ejection fraction (57.5 ± 4.8% vs 61.5 ± 6.4%; p = 0.035) and greater left atrial remodeling ( 49.96 ± 21.54 vs 35.13 ± 12.66 mL/m²; p = 0.006). 3D analysis revealed significantly larger AP diameter (17.61 ± 3.54 vs 15.93 ± 1.90 mm/m²; p = 0.046), annular area (578.43 ± 155.62 vs 460.92 ± 150.41 mm²/m²; p = 0.021), and anterior leaflet area (375.80 ± 146.59 vs 276.26 ± 94.09 mm²/m²; p = 0.009) in the persistent AF group. Total leaflet area was also increased (630.36 ± 178.12 vs 497.28 ± 161.75 mm²/m²; p = 0.018), while posterior leaflet area showed a non-significant trend (p = 0.143). The coaptation reserve (TLL/AP) was reduced in persistent AF (0.98 ± 0.11 vs 1.05 ± 0.79; p = 0.02), and asymmetric remodeling was evident with a higher ALL/PLL ratio (2.30 ± 0.70 vs 1.79 ± 0.30; p = 0.002). Tenting height, and sphericity index were comparable across groups. A strong positive correlation was found between annular area and anterior leaflet area (Pearson’s r = 0.993; p < 0.01)
Conclusions: Persistent AF is associated with a more pronounced degree of mitral apparatus remodeling compared with paroxysmal AF, characterized by annular dilatation, anterior leaflet enlargement, and a reduction in coaptation reserve, even in the presence of preserved LV function. The combined use of three-dimensional echocardiography enabled accurate quantification of these geometric alterations, revealing asymmetric anterior–posterior leaflet adaptation as a potential early marker of maladaptive remodeling. Advanced 3D imaging may therefore represent a sensitive tool for identifying AF patients at risk of developing atrial functional mitral regurgitation and for guiding timely rhythm-control or upstream therapeutic strategies.