The following is a summary of “Implications of the Mitral Leaflet Coaptation Pattern on Clinical Outcomes in Patients With Functional Mitral Regurgitation,” published in the July 2023 issue of the Cardiovascular Disease by Kim et al.

The categorization of secondary mitral regurgitation (MR) relies on atrial functional MR (AFMR) or ventricular functional MR (VFMR) and alterations in volume; however, the MR mechanism is also influenced by the mitral leaflet coaptation angle. The medical significance of the coaptation angle on cardiovascular (CV) outcomes has to be thoroughly assessed. A cohort of 469 consecutive patients (265 with atrial fibrillation mitral regurgitation [AFMR] and 204 with ventricular fibrillation mitral regurgitation [VFMR]) presenting with moderate or more significant mitral regurgitation (MR) were assessed for the incidence of heart failure, mitral valve surgeries, and cardiovascular mortality. The coaptation angle was evaluated by quantifying the internal angle between the two leaflets during mid-systole using the apical 3-chamber view. A coaptation angle of 130° or greater was categorized as leaflet flattening, while an angle less than 130° was categorized as leaflet tethering. 

Atrial fibrillation with mitral regurgitation (AFMR) and ventricular fibrillation with mitral regurgitation (VFMR) were correlated with increased occurrences of leaflet flattening and tethering, respectively. Atrial fibrillation with rapid ventricular response (AFMR) demonstrated a higher likelihood of being connected with advanced age, the presence of atrial fibrillation, and preserved ejection fraction, all exhibiting a significant association with leaflet flattening. During a subsequent evaluation spanning 2.3 years, 83 individuals experienced heart failure, accounting for 17.7% of the patient population. Additionally, 21 patients required mitral valve operations, representing 4.5% of the cohort. Furthermore, 34 patients, unfortunately, succumbed to their medical conditions, resulting in a mortality rate of 7%. Compared to leaflet tethering, leaflet flattening demonstrated a stronger correlation with cardiovascular (CV) events. 

In contrast, the rates of CV events were not as distinctly varied in atrioventricular functional mitral regurgitation (A/VFMR). Regardless of the presence of A/VFMR, the flattening of the leaflet and the occurrence of atrial fibrillation were correlated with an increased incidence of cardiovascular events. The adjusted analysis revealed that leaflet flattening was a significant predictor of cardiovascular events (hazard ratio 3.5, 95% confidence interval 1.11 to 4.88, P = 0.003). At the same time, atrioventricular functional mitral regurgitation (A/VFMR) did not exhibit the same predictive value. In summary, the leaflet coaptation angle in patients with functional mitral regurgitation (MR) may offer risk stratification surpassing atrioventricular functional MR (A/VFMR). Leaflet flattening is observed to be correlated with adverse clinical outcomes.

Source: sciencedirect.com/science/article/abs/pii/S0002914923002655