Evolution from mitral annular dysfunction to severe mitral regurgitation in Barlow’s disease

Abstract

OBJECTIVES Barlow’s disease (BD) is characterized by thick, redundant mitral valve (MV) leaflets, which can lead to prolapse and significant mitral regurgitation (MR). MV annular abnormalities are also commonly observed and increasingly recognized as possible primary pathology, with leaflet thickening being secondary to increased stress on the MV apparatus. To provide more insights into this hypothesis, the evolution of MV abnormalities over time in patients with BD was assessed. METHODS A total of 64 patients (54 ± 12 years, 72% male) with BD who underwent MV surgery and had multiple transthoracic echocardiograms (TTE) before surgery were included. In total, 186 TTE were analysed (median time interval 4.2, interquartile range 2.2–6.5 years) including specific MV characteristics. RESULTS At baseline, MV leaflet length, thickness, billowing height and annular diameter were larger in patients with BD compared to 59 healthy subjects. Systolic outward motion (curling) of the annulus was observed in 77% and severe mitral annular disjunction (≥5 mm) in 38% of patients with BD. Forty (63%) patients had MR grade I–II and 24 (37%) MR grade III–IV; at baseline, the 2 groups only differed in left atrial volume and in thickness and billowing height of the posterior leaflet, showing comparable MV annular abnormalities and dilatation despite different grades of MR. Over time, MV annulus diameter, leaflet length and billowing height increased significantly along with MR grade. CONCLUSIONS In patients with BD, MV annulus abnormalities are present at an early stage and precede the development of significant MR, suggesting their substantial role in the pathophysiology of this disease and as an important target for surgical treatment.

Definition, prevalence, and clinical significance of mitral annular disjunction in different patient cohorts: A systematic review

“…Our search yielded 80 potentially relevant studies. After screening of titles, abstracts, and full manuscripts of potentially relevant studies, a total of twelve studies 1,8,[11][12][13][14][15][16][17][18][19][20] met the inclusion criteria and were included in the review (Figure 4). 1.…”

“…In total, nine studies investigated MAD in MVP and/or Barlow's disease. 1,[11][12][13][15][16][17]19,20 The most commonly reported dimension of MAD was ≥5 mm. From these studies the pooled rate of MVP / Barlow's disease and MAD was 30.1%.…”

Arrhythmic Mitral Valve Prolapse: Introducing an Era of Multimodality Imaging-Based Diagnosis and Risk Stratification

“…In patents with MAD and MVP both the annular height and annular height-to-commissural width ratio (Figure 1) decreased, resulting in paradoxical annular flattening during systole [68], while the systolic annular diameter increased [67]. Although annular alterations have not been investigated as a risk factor for SCD, both in vivo [5] and advanced computational [72] evidence demonstrate the significance of the physiological saddle-shaped annulus in maintenance of normal MV leaflet stress, suggesting that MAD might be one of the precursor mechanisms leading to MR in MVP [63] but also for the occurrence of VA.…”

“…Different alterations involving the MA itself have been extensively studied, but have been only indirectly implicated as risk factors for SCD: As precursors [63] for the development of MR and as risk factors for non-sustained VA.…”

Commentary: The Barlow valve: Understanding disease and symmetry

“… 5 Modern echocardiography has helped to better understand the sequence of events until mitral regurgitation becomes significant. 12 , 13 Surgical experiences with follow-up outcomes allowed us to confirm these valves are amenable for repair. 3 …”