Multimodality imaging assessment of mitral annular disjunction in mitral valve prolapse

Abstract

ObjectiveMitral annular disjunction (MAD) is an abnormality linked to mitral valve prolapse (MVP), possibly associated with malignant ventricular arrhythmias. We assessed the agreement among different imaging techniques for MAD identification and measurement.Methods131 patients with MVP and significant mitral regurgitation undergoing transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) were retrospectively enrolled. Transoesophageal echocardiography (TOE) was available in 106 patients. MAD was evaluated in standard long-axis views (four-chamber, two-chamber, three-chamber) by each technique.ResultsConsidering any-length MAD, MAD prevalence was 17.3%, 25.5%, 42.0% by TTE, TOE and CMR, respectively (p<0.05). The agreement on MAD identification was moderate between TTE and CMR (κ=0.54, 95% CI 0.49 to 0.59) and good between TOE and CMR (κ=0.79, 95% CI 0.74 to 0.84). Assuming CMR as reference and according to different cut-off values for MAD (≥2 mm, ≥4 mm, ≥6 mm), specificity (95% CI) of TTE and TOE was 99.6 (99.0 to 100.0)% and 98.7 (97.4 to 100.0)%; 99.3 (98.4 to 100.0)% and 97.6 (95.8 to 99.4)%; 97.8 (96.2 to 99.3)% and 93.2 (90.3 to 96.1)%, respectively; sensitivity (95% CI) was 43.1 (37.8 to 48.4)% and 74.5 (69.4 to 79.5)%; 54.0 (48.7 to 59.3)% and 88.9 (85.2 to 92.5)%; 88.0 (84.5 to 91.5)% and 100.0 (100.0 to 100.0)%, respectively. MAD length was 8.0 (7.0-10.0), 7.0 (5.0-8.0], 5.0 (4.0-7.0) mm, respectively by TTE, TOE and CMR. Agreement on MAD measurement was moderate between TTE and CMR (ρ=0.73) and strong between TOE and CMR (ρ=0.86).ConclusionsAn integrated imaging approach could be necessary for a comprehensive assessment of patients with MVP and symptoms suggestive for arrhythmias. If echocardiography is fundamental for the anatomic and haemodynamic characterisation of the MV disease, CMR may better identify small length MAD as well as myocardial fibrosis.

Arrhythmic mitral valve prolapse: Diagnostic parameters for high‐risk patients: A systematic review and meta‐analysis

“…30,31 Disjunction is usually measured through TTE (in millimeters) at end-systole in apical long-axis or parasternal view, even if cardiac magnetic resonance imaging (CMR) is the gold standard for diagnosis. 32, 33 Notably, the wider the MAD magnitude, the higher is the incidence of nonsustained ventricular tachycardia on the Holter monitor. 30 Interestingly, MAD, even in the absence of concomitant MVP, seems to be associated with complex arrhythmic events (aborted cardiac arrest and ventricular tachycardia [VT]), suggesting that MAD itself could be a marker of complex VAs.…”

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

“…Currently, its diagnosis relies on the separation greater or equal to 5 mm between the mural leaflet insertion into the left atrial wall and the base of the LV free wall, a cut-off deriving from the initial pathological description [64], later verified by TTE studies [65]. CMR is the gold standard for the diagnosis, although TTE has been shown to have good agreement with it [66]. In different works it has been shown to be a common, but not exclusive, feature of patients with MVP, independently from the diagnostic technique used: 2D TTE [65,67], 3D TTE [68], and to correlate to pathological findings [69].…”

A New Malignant MVP Phenotype?

“…Because the prevalence of concomitant MAD in patients with MVP is 42% by CMR ( 13 ), and MAD has a varying amount of normal interspersed tissue, perhaps MAD was “concealed” ( 10 ). MAD is strongly associated with myxomatous mitral valve disease ( 14 ).…”