Cardiac and Neuromuscular Features of Patients WithLMNA-Related Cardiomyopathy

Background Mutations in the LMNA (lamin A/C) gene have been associated with neuromuscular and cardiac manifestations, but the clinical implications of these signs are not well understood. Objective To learn more about the natural history of LMNA-related disease. Design Observational study. Setting 13 clinical centers in Italy from 2000 through 2018. Patients 164 carriers of an LMNA mutation. Measurements Detailed cardiologic and neurologic evaluation at study enrollment and for a median of 10 years of follow-up. Results The median age at enrollment was 38 years, and 51% of participants were female. Neuromuscular manifestations preceded cardiac signs by a median of 11 years, but by the end of follow-up, 90% of the patients had electrical heart disease followed by structural heart disease. Overall, 10 patients (6%) died, 14 (9%) received a heart transplant, and 32 (20%) had malignant ventricular arrhythmias. Fifteen patients had gait loss, and 6 had respiratory failure. Atrial fibrillation and second- and third-degree atrioventricular block were observed, respectively, in 56% and 51% of patients with combined cardiac and neuromuscular manifestations and 37% and 33% of those with heart disease only. Limitations Some of the data were collected retrospectively. Neuromuscular manifestations were more frequent in this analysis than in previous studies. Conclusion Many patients with an LMNA mutation have neurologic symptoms by their 30s and develop progressive cardiac manifestations during the next decade. A substantial proportion of these patients will have life-threatening neurologic or cardiologic conditions. Primary funding source None.