Timing of pacemaker and ICD implantation in mutation carriers.

Aims: cardiomyopathy is often associated with pathology in the cardiac conduction system necessitating device implantations. The aim was to study the timing and types of device implantations and need for re-implantations in mutation carriers.

Methods: We studied the hospital records of 60 mutation carriers concerning device implantations and re-implantations and their indications. Data were collected until April 2019.

Results: The median follow-up time from the first ECG recording to the last clinical follow-up, transplantation, or death was 7.7 (IQR=9.1) years. Altogether 61.7% (n=37) of the mutation carriers received a pacemaker or an implantable cardioverter defibrillator (ICD), and of them 27.0% (n=10) needed a device upgrade. Notably, in some patients the upgrade took place very soon after the first implantation. The first device was implanted at an average age of 47.9 years (SD=9.5), whereas the upgrade took place at an average age of 50.3 years (SD=8.1). Most upgrades were ICD implantations. Male patients underwent device upgrade more often and at a younger age than women. By the end of follow-up, 35.0% (n=21) of the patients fulfilled echocardiographic criteria for dilated cardiomyopathy, and 90.5% of them (n=19) needed pacemaker implantation.

Conclusion: Most mutation carriers underwent pacemaker implantation in this study. Due to the progressive nature of -cardiomyopathy, device upgrades are quite common. An ICD should be considered when the initial device implantation is planned in an mutation carrier.