Assessment and role of myocardial deformation by cardiac magnetic resonance in patients with arrhythmic mitral valve prolapse

Mitral valve prolapse (MVP) is the most common valvulopathy in the general population, affecting 2—3% of adults. Its arrhythmic phenotype is associated with an increased risk of malignant ventricular arrhythmias and sudden cardiac death, even in patients with preserved left ventricular ejection fraction (EF) and in the absence of significant mitral regurgitation. Myocardial fibrosis detected by late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR), mitral annular disjunction (MAD), and curling represent the main risk markers identified to date. Myocardial deformation analysis by CMR Feature Tracking (CMR-FT) has emerged as a potential tool for detecting subclinical systolic dysfunction in this population. The primary objective was to assess global and regional left ventricular contractility through Strain parameters (Circumferential, Longitudinal, and Radial) and Time-to-Peak (TtP), calculated by CMR-FT, in a cohort of patients with MVP with preserved left ventricular ejection fraction (LVEF) and in the absence of significant mitral regurgitation. A secondary in-depth analysis was performed to investigate whether the presence of myocardial fibrosis (LGE), curling, or ventricular arrhythmias — each considered individually within the MVP population — resulted in significant differences in myocardial deformation parameters. The study included 129 consecutive patients with an echocardiographic diagnosis of MVP, referred to the Cardiology Clinic of Padua between 2009 and 2025, with a history of cardiac arrest, syncope, or documented ventricular arrhythmias, who underwent contrast-enhanced CMR. Patients with moderate-to-severe mitral regurgitation, left systolic dysfunction, ischaemic heart disease, or cardiomyopathy were excluded. A group of 69 subjects without MVP or cardiovascular history, who underwent CMR for other indications, was used as a control group. For each patient, in addition to clinical and electrocardiographic characteristics, conventional CMRi parameters, morphological features typical of MVP and myocardial deformation parameters were recorded — global and regional (basal and mid wall) Radial, Longitudinal, and Circumferential Strain of the left ventricle, with corresponding Time-to-Peak values — by CMR Feature Tracking. Myocardial deformation analysis revealed a significant reduction in global and regional Circumferential Strain in patients with MVP compared to controls (median G-CS −17.7 vs −19.5; q < 0.001), with a concomitant increase in Circumferential Time-to-Peak values, and without alterations in EF in either group. Similar findings were also detectable in the subgroup of MVP patients without LGE. No significant differences in myocardial deformation parameters emerged from the comparison between subgroups stratified by the presence or absence of LGE, curling, or ventricular arrhythmias. Patients with MVP show significant alterations in global and regional myocardial deformation, independently of LVEF and traditional risk markers (fibrosis, curling, and ventricular arrhythmias). These alterations, detectable even in the absence of demonstrable LGE, indicate that subclinical mechanical dysfunction precedes fibrotic tissue damage and suggest a non-benign phenotype that, in the presence of arrhythmias, warrants adequate clinical and therapeutic follow-up. Also considering the evidence available for various cardiac conditions, Strain analysis by CMR-FT represents a valid strategy for early arrhythmic risk stratification in this population.