Further evidence for ICD implantation in patients with lamin A/C mutations and conduction disease

Abstract

patients with AV conduction disease. 4 In this issue of HeartRhythm, Anselme et al 5 publish a follow-up of a relatively large group of patients with this rare disease between 1999 and 2009. They postulated that AV conduction delay and block is a marker for sudden tachyarrhythmic death irrespective of the left ventricular function. A high percentage of patients (52%) received appropriate ICD therapy. At the time of ICD intervention, left ventricular ejection fraction was Z45% in 9 of 11 patients with appropriate ICD therapy. Although appropriate ICD therapy depends on ICD settings and was based on studies that were available at the time of study inclusion, none of these patients died suddenly. In the whole but small group of patients (n ¼ 47) with this rare disease, randomization did not seem appropriate. The decision to implant an ICD was made on the premise that AV conduction delay is a marker for SCD, and only on ethically founded clinical grounds did patients with lamin A/C mutations and conduction disease not receive an ICD. As lamin A/C mutations form a heterogenic genetic disorder, it is important to select the patients who have even minor AV conduction delay as this group is more prone to SCD and could benefit from an ICD implantation. Heart failure is not the primary cause of death in this group of patients, and life expectancy is considerably longer than in most patients who receive an ICD for primary prevention of SCD. Whether AV block is a marker or part of the electrical disease has to be determined. So far, the results of the study of Anselme et al form a firm plea for ICD implantation in lamin A/C-deficient patients with AV conduction irrespective of the left ventricular function and contribute to the rising amount of data in the literature. 2,6 Consideration should be given to those patients with AV block where continuous ventricular stimulation is needed. In this patient group, careful echocardiographic follow-up is mandatory to detect pacing-induced deterioration of the left ventricular function in an early stage. When these patients have low ejection fractions or even heart failure before device implantation, a cardiac resynchronization therapy defibrillator should be considered according to the guidelines. These guidelines were published after the inclusion of these prospectively evaluated patients by the Anselme group.