The utility of non-contrast enhanced MRA (4D- phase contrast angiography (4D-PCA)) compared with contrast enhanced MRA on patients with congenital heart disease (RF_FR_426)

Mitral annular disjunction (MAD) refers to the separation of the mitral valve annulus from the left ventricular (LV) myocardium. MAD has recently gained interest in research and clinical practice; however, its prevalence in Marfan syndrome (MFS) based on cardiovascular magnetic resonance (CMR) imaging data is unknown. The purpose of this study was to evaluate the prevalence of MAD in MFS patients using CMR and to examine its association with other CMR findings.



Methods:

This retrospective multicenter study included baseline CMR studies of patients treated for MFS at four tertiary care medical centers with diagnosis based on the revised Ghent criteria and a confirmed (likely) pathogenic FBN1 gene variant. The authors evaluated the datasets for MAD (at the attachment of the mitral valve to the anterior, anterolateral, inferolateral, and inferior segments; ≥1 mm), mitral valve prolapse (MVP; ≥2 mm), aortic root z-score, LV ejection fraction (LVEF), LV end-diastolic diameter (LVEDD), and left atrial (LA) size.



Results:

Among 91 patients (28.9±14.0 years, 43 (47.3%) female, body surface area (BSA) 1.9±0.4), 74 (81.3%) had MAD (6.1±2.6 mm), most commonly at the inferior ventricular wall (66 (72.5%), 6.9±3.2 mm). The remaining sites showed a similar prevalence (anterior: 56 (61.5%), 6.0±2.5 mm; anterolateral: 55 (60.4%), 6.1±3.1 mm; inferolateral: 54 (59.3%), 7.0±3.6 mm). There were no significant differences (all p >0.05) between MAD and no MAD groups in aortic root z-score (5.3±3.1 vs. 5.5±3.1), LVEF (62.3±8.0 vs. 57.7±14.7 %), LVEDD/BSA (29.7±7.7 vs. 30.0±8.6 mm/m²), and LA size (11.2±3.1 vs. 11.4±2.7 cm/m²). Decreased LVEF was associated with anterolateral (r=-0.46) and inferolateral (r=-0.39) MAD, whereas increased LVEDD/BSA was mainly observed in anterior (r=0.63) and anterolateral (r=0.46) MAD. Thirty-five patients (38.5%) had MVP, predominantly in patients with MAD (33 (36.3%) vs. 2 (2.2%), p=0.017), especially in anterior MAD (r=0.69).



Conclusion:

MAD is highly prevalent in MFS and mostly located at the inferior site. While aortic dimensions, LV parameters, and LA size in patients with MAD were not different in patients without MAD, certain locations showed an association with decreased LV function and increased diameter. MVP was almost exclusively found in MAD and was mostly associated with anterior MAD.


Figure legend: Cardiovascular magnetic resonance (2-chamber view (A), 4-chamber view (B), 3-chamber view (C and D)) in a 29-year-old male with Marfan syndrome depicting mitral annular disjunction at all four sites (blue arrow: anterior, green arrow: inferior, red arrow: anterolateral, yellow arrow: inferolateral; A-C). Note the concomitant bileaflet mitral valve prolapse (green line: anterior mitral leaflet, black line: posterior mitral leaflet, black interrupted line: virtual annular plane, D).
Figure Mitral Annular Disjunction SCMR.pdf