Incremental Value of an Insertable Cardiac Monitor in Patients with Hypertrophic Cardiomyopathy with Low or Intermediate Risk for Sudden Cardiac Death

Abstract

<b><i>Aims:</i></b> The aim of the present study was to compare the rate of actionable arrhythmic events between patients with hypertrophic cardiomyopathy (HCM) who are monitored with an insertable cardiac monitor (ICM) or Holter monitoring. <b><i>Methods:</i></b> We studied 50 patients (mean age 52 years, 72% men) with HCM at low or intermediate risk for sudden cardiac death (SCD), of whom 25 patients received an ICM between November 2014 and February 2019. We retrospectively identified a control group of 25 patients who were matched on age, sex, and HCM Risk-SCD score category. The mean HCM Risk-SCD score was 3.41 ± 1.31 and 3.31 ± 1.43 for the ICM and Holter groups, respectively. The primary endpoint was an actionable event which was defined as an arrhythmic event resulting in a change in patient management. The secondary endpoint was the occurrence of ventricular tachycardia (VT). <b><i>Results:</i></b> The cumulative actionable event rate at 30 months was higher in the ICM group (51 vs. 27%, log-rank <i>p</i> value <0.01). De novo atrial fibrillation requiring oral anticoagulation occurred only in the ICM group (<i>n</i> = 3). Overall, 4 implantable cardioverter-defibrillators were implanted for primary prevention (<i>n</i> = 2 in each group). The cumulative rate of VT episodes at 30 months was similar between groups (23% [ICM group] vs. 42% [Holter group], log-rank <i>p</i> value = 0.71). Furthermore, the characteristics of VT were similar between groups with regard to the number of beats and rate. <b><i>Conclusions:</i></b> In adults with HCM, an ICM will detect more arrhythmic events requiring an intervention than a conventional Holter strategy. In contrast, the diagnostic yield of detecting VT seems similar for both groups.

Bluetooth-Enabled Implantable Cardiac Monitors and Two-Way Smartphone Communication for Patients With Hypertrophic Cardiomyopathy

“…Previous studies published using ICMs in HCM patients predominantly have involved either a low- or moderate-risk population, 15 , 16 or patients who are post–alcohol septal ablation. 17 Magnusson and Mörner 15 studied a low-risk HCM population (mean HCM-SCD risk score of 2.3%) and found the rates of AF and NSVT to be 30.0% and 23.3%, respectively.…”

“…Sakhi et al. 16 designed a prospective observational study in low- and moderate-risk HCM patients (mean HCM-SCD risk score < 6%). The rate of NSVT in the ICM group was 23%, vs 47% in the Holter monitor group, with similar characteristics of NSVT runs between groups.…”

“…Magnusson and Morner 15 studied a low-risk HCM population (mean HCM-SCD risk score of 2.3%), and found rates of AF and NSVT to be 30.0% and 23.3%, respectively. Sakhi et al 16 designed a prospective observational study in low and moderate risk HCM patients (mean HCM-SCD risk score <6%). The rate of NSVT in the ICM group was 23% compared to 47% in the Holter group, with similar characteristics of NSVT runs between groups.…”

Implantable loop recorders in patients with heart disease: comparison between patients with and without syncope

“…2 15 Furthermore, the detection of subclinical AF may necessitate the use of oral anticoagulation in patients with hypertrophic cardiomyopathy. 12 The current European Society of Cardiology guidelines recommend an ILR for patients with inherited cardiomyopathies or channelopathies who present with recurrent episodes of unexplained syncope and who are at low risk of SCD (class IIa indication). 8 Furthermore, an ILR is also recommended in patients with infrequent, suspected arrhythmia-related symptoms, if conventional methods fail to provide a symptom-rhythm correlation.…”

“…ILRs in different study populations, including those with structural and electrical heart disease. [9][10][11][12] However, there is limited data on the yield of an ILR based on the presence or absence of a history of syncope. 13 14 Furthermore, limited studies have focused on patients with structural or electrical heart disease.…”