Author + information
- Giuseppe Ciconte, MD, PhD∗ (, )
- Gabriele Vicedomini, MD,
- Daniele Giacopelli, MSc,
- Zarko Calovic, MD,
- Manuel Conti, MD,
- Bernardo Spinelli, MSc,
- Massimo Saviano, MD,
- Vincenzo Santinelli, MD and
- Carlo Pappone, MD, PhD
- ↵∗Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, 20097 San Donato Milanese, Milan, Italy
The Remote Monitoring (RM) technology has recently become available in insertable cardiac monitors (ICM) (1). The purpose of this analysis was to assess feasibility, clinical reactions, and arrhythmic alerts burden of remote management for patients implanted with the novel long-dipole ICM (Biotronik, Berlin, Germany). It is a leadless device with a solid housing part and a silicone flexible part and a total 8.8-cm length of the sensing dipole. The ICM is equipped with the Home Monitoring system (HM) (Biotronik), which provides daily remote transmissions including up to 6 subcutaneous electrocardiogram (subECG) recordings.
Our model workflow for the HM management is based on a cooperative interaction among a responsible physician and 2 expert allied professionals. Their main responsibilities are patient’s training, HM activation, daily reviewing of transmissions, and patient contact for transmission resuming or assessing compliance to drug therapy and symptoms. Thereafter, any alert requiring physician’s competence is referred to the responsible professional for further evaluations. The study, approved by the institutional Ethics Committee, enrolled all consecutive patients receiving an ICM between September 25, 2015 and May 19, 2016 and it was divided into 2 phases. In the first 3-month period, all the transmitted subcutaneous electrocardiograms (subECGs) were analyzed by an expert physician and classified according to presence of erroneous R-wave ICM detections. The second phase consisted of a 9-month follow-up aiming to report the clinical interventions triggered by RM alerts.
A total of 100 patients (70% men, median age 63 years) were enrolled. Indications for ICM were atrial fibrillation (AF) management after ablation (51%), undocumented palpitations (23%), AF management (18%), unexplained syncope (5%), and cryptogenic stroke (3%). The majority of patients enrolled underwent ICM for AF-related issue because our center is a national referral for AF treatment. During the initial 3-month study phase, out of the expected 9,000, 8,476 transmissions were successfully received with a 94.2% (95% confidence interval [CI]: 92.1% to 96.2%) daily transmission rate. The median HM compliance per patient was 98.8% (95% CI: 95.5 to 100) without differences according to patients’ age (younger and older than 65 years; 98.9% vs. 98.8%; p = 0.668).
A total of 5,851 arrhythmic alerts were received and analyzed. The majority of alerts were AF, 4,764 (81.4%); high ventricular rate, 537 (9.2%); bradycardia, 506 (8.6%); and asystole episodes, 44 (0.8%), respectively. The highest incidence of subECG with QRS misdetection was found in the asystole episodes (39 of 44; 89%) all occurring in 1 patient, followed by high ventricular rate (138 of 537; 26%), bradycardia (105 of 506; 21%) and AF (368 of 4,764; 8%). Reasons for QRS misdetection were oversensing of noise (n = 365; 56%), QRS undersensing (n = 221; 34%) and P-wave oversensing (n = 64; 10%), as shown in Figure 1 (left panel). Fifteen patients (15%; 95% CI: 9% to 23%) were free from HM alerts. The remaining 85 subjects (85%; 95% CI: 76% to 91%) had at least 1 type of alert: 69 AF; 49 high ventricular rate; 17 bradycardia; and 5 asystole (Figure 1, right panel). The median number of arrhythmic alerts per patient during the first phase was 14 (interquartile range: 1 to 74).
During the 9-month period following ICM implantation, there were 261 reactions triggered by HM alerts. The most frequent was a patient phone contact (217 of 261; 83%), resulting in 24.1 contacts per 100 patient-months (95% CI: 21.0 to 27.5). Among the remaining 44 (17%) medical interventions, there were 25 pharmacological therapy optimizations, 11 AF ablations, 3 electrical cardioversions, and 4 pacemaker implantations.
The main findings of the present study are the following: 1) the HM system associated to the ICM device ensured very high HM transmission success rates; 2) the majority of patients (85%) had alerts, with a median number of 14 episodes per patient in a 3-month period; and 3) there were 261 actions triggered by HM alerts, and 17% of them had relevant medical impact.
The HM system has been intensively investigated in patients implanted with pacemakers and implantable cardioverter-defibrillators (2,3). In this study, a very high HM compliance was also reported for ICM recipients with a 98.8% per-patient daily successful transmission rate. There are 2 main advantages related to the RM: it shortens the time to relevant clinical information, allowing appropriate therapeutic actions and reduces the risk of data loss due to device memory overflow. However, ICM are designed to be highly sensitive and may generate an excessive number of transmitted recordings, determining a potentially higher workload for the hospital staff (4,5). In the present study, we quantified a median number of 14 arrhythmic alerts per patient during the 3-month follow-up, with 15% of subjects free from any alerts. As compared to other cardiac implantable devices, we observed a higher number, not only of alerts, but also of patients’ contacts, with a total of 24 contacts per 100 patient-months corresponding to 2.9 per patient-year. Therefore, in a certain subset of patients, an intense level of monitoring might be unnecessary and perhaps excessive, determining an increase in health care utilization. Future studies are needed to evaluate the appropriate level of monitoring, particularly after AF ablation.
In conclusion, ICM-associated RM system is feasible showing high rate compliance. It is characterized by a consistent arrhythmic alerts burden, which highlights the need of an organizational model for episodes reviewing.
Please note: Daniele Giacopelli and Bernardo Spinelli are employees of Biotronik Italia. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- 2018 American College of Cardiology Foundation