MAD is common and prognostically neutral after adjustment, but larger disjunction distances are associated with higher native T1 relaxation time values at the annulus, suggesting local subclinical myocardial remodelling.
Key Findings
Results
Mitral annular disjunction (MAD) was highly prevalent in an all-comer CMR cohort, with end-systolic MAD present in approximately one quarter of patients.
End-systolic MAD was present in 509 patients (25.9%) of 1969 total patients
End-diastolic MAD was present in 366 patients (18.6%)
MAD was defined as ≥1 mm separation between the left atrial wall at the mitral valve hinge point and the adjacent left ventricular myocardium
Data were drawn from a prospective CMR registry at the Vienna General Hospital
Results
Patients with MAD were younger and had fewer comorbidities and higher left ventricular ejection fractions compared to those without MAD.
MAD patients were younger (59.6 ± 18.5 vs. 65.2 ± 17.9 years, p < 0.001)
MAD patients had higher left ventricular ejection fractions (58.8% ± 10.4% vs. 56.8% ± 14.4%, p = 0.009)
MAD patients had fewer comorbidities
These differences suggest MAD is more common in a relatively healthier subgroup of CMR referrals
Results
After multivariable adjustment, end-diastolic MAD was not independently associated with all-cause mortality.
485 deaths occurred during a median follow-up of 63.7 months
Adjusted hazard ratio for end-diastolic MAD and mortality was 0.95 (95% CI 0.74–1.23, p = 0.712)
All-cause mortality was analyzed by Cox proportional hazards regression
The authors conclude MAD is 'prognostically neutral after adjustment'
Results
MAD distance correlated with native annular T1 relaxation time, suggesting local subclinical myocardial remodelling at the annulus.
MAD distance correlated with native annular T1 relaxation time (r = 0.24, p < 0.001)
Patients with MAD ≥5 mm showed higher annular T1 relaxation time than those with MAD <5 mm (1041 ± 148 vs. 1010 ± 72 ms, p = 0.028)
Mid-septal T1 relaxation time showed no significant difference by MAD status (r = 0.06, p = 0.252)
The localized nature of the T1 elevation (annular but not mid-septal) suggests the remodelling is confined to the region of disjunction
Results
The T1 elevation associated with larger MAD distances was anatomically specific to the annular region rather than reflecting diffuse myocardial involvement.
Native T1 relaxation times were measured at both septal and lateral positions of the mitral annulus in the 4-chamber view
Annular T1 correlated with MAD distance (r = 0.24, p < 0.001), while mid-septal T1 did not (r = 0.06, p = 0.252)
This spatial specificity supports the interpretation of local rather than global myocardial remodelling
The authors characterize this as 'local subclinical myocardial remodelling'
Methods
MAD was assessed at both end-systole and end-diastole using CMR, with end-systolic measurements identifying more cases than end-diastolic measurements.
End-systolic MAD prevalence was 25.9% (509/1969 patients)
End-diastolic MAD prevalence was 18.6% (366/1969 patients)
The phase-dependent difference in detection rates highlights that measurement timing affects prevalence estimates
Both phases were analyzed for their association with outcomes
What This Means
This research examined a structural heart finding called mitral annular disjunction (MAD), where a gap forms between the ring-like structure supporting the mitral valve and the surrounding heart muscle. Using cardiac MRI scans from nearly 2,000 patients at a major hospital, the researchers found that MAD is quite common — present in about 1 in 4 patients when measured at peak heart contraction. Patients with MAD tended to be younger and have slightly better heart function than those without it.
The study's main question was whether MAD predicts a higher risk of death over time. After accounting for other health factors, MAD was not associated with increased mortality over a median follow-up of more than five years. This suggests that, on its own, the presence of MAD does not signal a worse long-term prognosis in a general cardiology population. However, the researchers also found that patients with larger MAD gaps (5 mm or more) had elevated tissue signals specifically at the annular region of the heart — a finding that may indicate subtle, localized changes in the heart tissue around the disjunction site, without affecting the rest of the heart muscle.
This research suggests that while MAD is a frequent incidental finding on cardiac MRI and does not independently worsen survival outcomes, larger gaps may be associated with localized tissue remodelling at the annulus. This could be relevant for understanding why some patients with MAD develop complications, such as abnormal heart rhythms, and may inform how clinicians interpret and monitor this finding going forward.
Mascherbauer K, Nantschev N, Kronberger C, Donà C, Koschutnik M, Dannenberg V, et al.. (2026). Association of Mitral Annular Disjunction on Magnetic Resonance Imaging With Cardiovascular Outcomes.. European journal of clinical investigation. https://doi.org/10.1111/eci.70235