The role of early CRT-D implantation in dilated cardiomyopathy (DCM) patients with narrow QRS carrying LMNA mutation

Background: DCM caused by lamin A/C gene (LMNA) mutation is complicated with atrioventricular conduction disturbances, malignant ventricular arrhythmias and progressive severe heart failure. Due to the possibility of permanent ventricular pacing and ventricular arrhythmia with relatively preserved EF, we evaluated a strategy of CRT-D implantation in LMNA patients with established indication for pacemaker or ICD.

Methods: Between 2011-2019 in 3/34 families (8.8%) with familial DCM likely pathogenic mutation in LMNA gene was identified. Among the 14 LMNA DCM patients five have been implanted (4 pacemaker and 1 ICD) before the genetic diagnosis (non CRT-D group). Additional five DCM LMNA patients who had an indication for device implantation (3 for pacemaker due to symptomatic AV block, 2 for ICD due to sustained VT and primary prevention, underwent CRT-D implantation (CRT-D group). We compared ECG, holter, echocardiography and the clinical course of LMNA DCM patients in CRT-D group versus non CRT-D device group during the follow up.

Results: Five LMNA DCM patients with indication for pacemaker or ICD underwent CRT-D implantation in addition to ACE inhibitors , age 53.2± 12 years, maximal PR 268± 50 msec, QRS 92± 16 msec, EF 61±2%, LVEDD 5.3±0.3 cm. After 6.4± 4 years of follow up LMNA DCM patients in the early CRT-D group had significantly higher EF (61±4% vs 32± 15%, p=0.004) and lower VPC amount in holter (452± 450 vs 2520± 167, p=0.006) compared to LMNA DCM with non CRT-D device. In addition, no patient in early CRT-D group died or underwent cardiac transplantation as compared to two patients in non CRT-D device group. One patient in the CRT-D group (indication pacemaker) experienced appropriated ICD shock.

Conclusion: LMNA DCM is one of the leading causes of heart failure, heart transplantation and SCD. Early CRT-D implantation in addition to ACE inhibitors have a beneficial effect.