Risk stratification in myotonic dystrophy type 1 using cardiac magnetic resonance feature tracking: a prospective cohort study
T Pinho, M Santos, E Figueiredo, A J Madureira, C Sousa, T Proenca, C Costa, A F Amador, N Bettencourt, A Teixeira, E MartinsAbstract
Background
Myotonic dystrophy type 1 (MD1) is the most common adult-onset muscular dystrophy and is associated with a high burden of cardiac morbidity and mortality. Cardiovascular magnetic resonance (CMR) is increasingly recommended for cardiac assessment in MD1; however, the prognostic relevance of CMR-derived myocardial deformation parameters remains poorly defined. We aimed to evaluate the prognostic value of CMR feature-tracking–derived strain parameters for predicting major adverse cardiovascular events (MACE) and atrial arrhythmias in patients with MD1, and to assess their incremental value over clinical, electrocardiographic, and conventional CMR variables.
Methods
In this prospective cohort study, adult patients with neuromuscular diseases referred for cardiovascular evaluation between 2012 and 2018 underwent standardized clinical assessment and CMR. Among 53 patients, 25 had MD1. CMR included biventricular volumes and function, late gadolinium enhancement (LGE), and left ventricular myocardial deformation analysis using feature tracking. The primary endpoint was MACE, defined as all-cause mortality, cardiac hospitalization, malignant arrhythmias, conduction disorders requiring device implantation, or appropriate defibrillator therapy. Atrial fibrillation or flutter during follow-up was assessed as a secondary outcome. Cox proportional hazards models were used to evaluate predictors of MACE and their incremental prognostic value.
Results
Over a median follow-up of 8.8 years, 12 patients experienced MACE, predominantly among those with MD1. In univariable analyses, several clinical, electrocardiographic, and CMR parameters were associated with outcomes. In multivariable Cox regression, left ventricular global longitudinal peak systolic strain rate remained independently associated with MACE (hazard ratio 1.50, 95% CI 1.05–2.15; p=0.025), providing incremental prognostic value beyond clinical variables, ECG findings, left ventricular ejection fraction, and indexed ventricular volumes. Neither the presence nor the extent of LGE was associated with adverse events. Regarding atrial arrhythmias, prolonged PR interval and impaired CMR-derived strain parameters were associated with arrhythmia occurrence. Global longitudinal peak systolic strain rate demonstrated the strongest predictive performance, with a high negative predictive value (87%).
Conclusions
In patients with myotonic dystrophy type 1, myocardial deformation parameters derived from CMR feature tracking—particularly global longitudinal peak systolic strain rate—are independently associated with major adverse cardiovascular events and atrial arrhythmias, providing incremental prognostic information beyond conventional CMR, clinical, and electrocardiographic data. These findings support the use of CMR feature tracking to enhance risk stratification and guide individualized follow-up strategies in this high-risk population.