Mitral annular disjunction and Pickelhaube sign in children with mitral valve prolapse: A prospective cohort study

Complex Ventricular Arrhythmias in Patients with Mitral Annular Disjunction: A Systematic Review and Meta-Analysis

PURPOSE

Mitral annular disjunction (MAD) frequently co-occurs with mitral valve prolapse (MVP). It is unclear, however, whether MAD is associated with an additional risk of arrhythmogenic events in patients with MVP. We aimed to evaluate the incidence of complex ventricular arrhythmias (VA) and sudden cardiac death (SCD) in patients with MAD compared to those without MAD.

METHODS

We systematically searched PubMed, Embase, and Web of Science for studies evaluating the incidence of complex VA and the composite outcome of complex VA and SCD among patients with versus without MAD. We performed a random-effects meta-analysis to pool odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals.

RESULTS

We included 16 studies comprising 6001 patients, of whom 23% had MAD; 41% were female; the mean age was 56.5 years. MVP was significantly present in both groups, with a higher prevalence in the MAD group in 1030 patients (74.5%) with MAD and in 1942 patients (47%) without MAD. The incidence of complex VA was significantly higher in patients with MAD (OR 3.88; 95% CI 1.69-8.93; p = 0.001), compared with patients without MAD. Patients with MAD also had a higher risk of the composite outcome of complex VA and SCD (HR 2.51; 95% CI 1.94-3.24; p < 0.00001) (OR 3.13; 95% CI 1.38-7.11; p = 0.006).

CONCLUSION

In this meta-analysis, the presence of MAD was significantly associated with the development of complex VA and the composite outcome of complex VA and SCD. The outcome of SCD was not evaluated as an isolated endpoint.

Does Preliminary Chest Shape Assessment Improve the Prognostic Risk Stratification of Individuals with Mitral Annular Disjunction? A Case Report and Narrative Review

Background: Mitral annular disjunction (MAD), a mitral annular abnormality involving the whole mitral valve annulus circumference, commonly detected in individuals with mitral valve prolapse (MVP), has been recently recognized as a potential risk factor for malignant ventricular arrhythmias (VAs) and sudden cardiac death. Recent evidence indicates that a multimodality imaging assessment comprehensive of echocardiography, cardiac magnetic resonance (CMR), and cardiac computed tomography angiography (CCTA) may improve MAD detection. To date, no previous author has considered the potential influence of chest wall conformation on MAD presence. Considering the strong association between MVP and anterior chest wall deformities and the increased prevalence of MAD among MVP individuals, we have hypothesized that MAD presence might be more frequently detected among MVP individuals with a narrow anteroposterior (A-P) thoracic diameter and/or concave-shaped chest wall conformation, as noninvasively assessed by the modified Haller index (MHI). Methods: Herein, we present a case of MVP female with relevant MAD distance and moderate mitral regurgitation (MR) who underwent a diagnostic study comprehensive of transthoracic echocardiography, transesophageal echocardiography, CMR, CCTA, and exercise stress echocardiography. Results: The patient was found with a concave-shaped chest wall conformation (MHI > 2.5) and narrow A-P thoracic diameter (<13.5 cm), with a moderate and non-hemodynamically significant MR, without areas of LGE on CMR and with low arrhythmic profile. Conclusions: A preliminary chest shape assessment by the MHI might improve the prognostic risk stratification of MVP patients with MAD, potentially identifying a benign phenotype of MVP individuals, i.e., those with a narrow A-P thoracic diameter.

The Prevalence, Pathophysiological Role and Determinants of Mitral Annular Disjunction Among Patients with Mitral Valve Prolapse: A Systematic Review

Background: Over the last two decades, a number of imaging studies have evaluated the characteristics and clinical implications of mitral annular disjunction (MAD) among patients with mitral valve prolapse (MVP). The present systematic review has been primarily designed to summarize the main findings of these studies and to examine the overall impact of MAD in MVP patients. Methods: All imaging studies assessing the prevalence, pathophysiological role and determinants of MAD in MVP individuals, selected from the PubMed and EMBASE databases, were included. There was no limitation in terms of time period. The risk of bias was assessed by using the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: The full texts of 23 studies on 7718 MVP individuals were analyzed. The overall pooled prevalence of MAD in MVP individuals was 40% (range 5.4-90%). When considering the different imaging modalities for assessing MAD, the average MAD prevalence was 20% for cardiac computed tomography studies, 31.3% for transthoracic echocardiography (TTE) studies, 44.7% for transesophageal echocardiography studies and 47% for cardiac magnetic resonance studies. MAD presence was more commonly associated with female sex, young age, narrow antero-posterior thoracic diameter, symptoms of palpitations and syncope, T-wave inversion in inferolateral leads and frequent and/or complex ventricular arrhythmias (VAs) on electrocardiogram, myxomatous leaflets, bileaflet prolapse, larger mitral valve annulus and non-severe mitral regurgitation on TTE. A total of 12 studies (52.2%) provided follow-up data. Over a median follow-up time of 3.9 yrs (range 1-10.3 yrs), MVP individuals with MAD showed increased risk of clinical arrhythmic events, no difference in survival rate and good surgical outcomes. Conclusions: MAD was present in more than one-third of MVP patients, with a wide range of variability depending on the specific imaging method used for assessing MAD presence and on a nonunivocal MAD definition, with a possible overestimation due to Pseudo-MAD rather than True-MAD measurement. A multimodality imaging approach comprehensive of noninvasive chest shape assessment might improve MAD detection among MVP individuals. It appears that careful serial monitoring for VAs should be mandatory for MAD patients.

Mitral annular disjunction with atrial septal defect in children: An intriguing association

Mitral annular disjunction (MAD) is defined as a separation between the mitral annulus and the left ventricular myocardium and is most often seen in association with mitral valve prolapse (MVP). MAD has been linked to ventricular arrhythmias in adults, independent of MVP. However, it has rarely been reported in children. We, hereby, report two cases of MAD associated with a large atrial septal defect (ASD). Thus far, there are no consensus guidelines for the management of MAD. The additional association of large ASD further complicates the decision-making in these patients. To the best of our knowledge, this is the first report of the association of MAD with ASD. We further discuss the challenges in the management of this condition.

Mitral Annular Disjunction: Clinical Implications and Surgical Considerations

Mitral annular disjunction is a cardiac structural abnormality characterized by the distinct separation between the top of the left ventricular myocardium and the mitral annulus supporting the posterior mitral leaflet occurring during systole. It has recently gained wide attention due to the increasing recognition of the link between mitral annular disjunction and arrhythmogenic mitral valve prolapse, particularly, with the increased risks of ventricular arrhythmias resulting in sudden cardiac death. This review has summarized the recent progress in the diagnostic modalities, clinical implications of mitral annular disjunction, and its specific surgical considerations.