Role of home monitoring in children with implantable cardioverter defibrillators for Brugada syndrome

Transcription

1 Europace (2013) 15, i17 i25 doi: /europace/eut112 Role of home monitoring in children with implantable cardioverter defibrillators for Brugada syndrome Carlo de Asmundis*, Danilo Ricciardi, Mehdi Namdar, Gian-Battista Chierchia, Andrea Sarkozy, and Pedro Brugada Heart Rhythm Management Centre, Cardiovascular Division, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium Received 20 March 2013; accepted after revision 29 March 2013 Aims Implementation of remote home monitoring systems (HM) in clinical practice has become undoubtedly an added value forall patientswith implantable cardiacdevices. The aim of this study wasto investigate the impact of HM in a population of children with Brugada syndrome (BS) who received an implantable cardioverter defibrillator (ICD).... Methods Eleven children (age between 6 months and 18 years) implanted with an ICD were followed either by means of HM and and results with conventional in-hospital visits in our centre. Alerts and/or device-related clinical events were recorded, analysed, and subsequent clinical decisions were made if needed. During an average observation time of 26 months a total of 16 relevant alerts (13 pre-emptive alerts) were recorded in seven patients of our population. One patient experienced appropriate therapies for life-threatening ventricular arrhythmias. Three patients experienced inappropriate therapies due to supraventricular tachycardia and lead dislodgement. By means of HM two patients were discovered to have lead problems because of dislodgement or lead fracture. Mean anticipation of treatment based on the alerts was days.... Conclusion Remote monitoring systems substantially improve the proper management of children with BS Keywords ICD Brugada syndrome Home monitoring Telemedicine Introduction Implant-based telecardiology, e.g. by modern devices with home monitoring (HM) capability, offers the opportunity to observe a number of different parameters which may be potentially useful for detecting device failure or tachyarrhythmias, on a daily basis. Data transmission is performed automatically and independent of the patient, thus increasing compliance. The transmitted parameters include but are not restricted to heart rhythm parameters like mean heart rate, mean heart rate at night, ventricular extrasystoles per hour, heart rate variability, atrial fibrillation burden, and the occurrence of atrial or ventricular tachyarrhythmias, heart failure-associated parameters like patient activity, and technical parameters like the percentage of pacing or lead integrity. All measured values are transmitted every day at a programmable time (default 01:00 am). Additionally, specific event messages can be sent after the occurrence of tachyarrhythmias and for deviations from preset technical parameters, such as lead impedances. For further diagnostics, high-resolution intracardiac electrograms are transmitted after tachyarrhythmias event messages. This unique system allows the attending physician to monitor each patient very closely and to react in time to prevent potential cardiovascular events at an early stage. Brugada syndrome (BS) is a primary cardiac electrical disorder, which manifests as coved-type ST-segment elevation, either spontaneously or after the administration of intravenous class I antiarrhythmic drugs. The syndrome predisposes to ventricular arrhythmias eventually leading to sudden cardiac death (SCD). According to current knowledge, the implantation of an implantable cardioverter defibrillator (ICD) is the only proven lifesaving therapy. The decision to implant an ICD in a child is always a delicate one because implantation of an ICD is not without potential problems. This holds particularly true for patients diagnosed with BS, who are otherwise healthy, do not develop any overt structural cardiac * Corresponding author. Tel: ; fax: , carlodeasmundis@me.com; carlo.deasmundis@uzbrussel.be The first two authors have equally contributed to the study. Published on behalf of the European Society of Cardiology. All rights reserved. & The Author For permissions please journals.permissions@oup.com.

2 i18 C. de Asmundis et al. disease and do not feel the physical limitations like it is the case in patients with, for instance, heart failure or congenital structural cardiac disease. Lead and device problems can give rise to inappropriate therapies due to either over- or under-sensing with significant impact on the quality of life of patients and relatives. Automatic remote monitoring systems, nowadays widely available for ICD and pacemaker recipients, were first introduced by Biotronik HM. It checks the device, either manually using a telemetry wand, or automatically, using wireless technology, and transmits the data to a central HM service and subsequently to the physician. In the last years, these systems have also helped in improving the clinical management in ICD patients giving the opportunity for early recognition of lead and device failures. 1,2 There are few data about the long-term follow-up of children with BS implanted with ICD, and also no literature showing the role of HM in managing these patients. Therefore, the aim of this study was to investigate the impact of HM in clinical management of this particular patient population. Methods All children with BS who received an ICD and a Home Remote Monitoring Device (HM BIOTRONIK SE & Co.) at the Universitair Ziekenhuis Brussel, Free University of Brussels, between April 2006 and December 2011 were included in this study. Home monitoring devices were implanted either de novo or at battery change in cases of prior implantations. The diagnosis of BS was based on the following electrocardiogram (ECG) findings: coved-type ST-segment elevation, either spontaneously or after the administration of intravenous ajmaline and a high risk based on medical history (i.e. sudden cardiac arrest or syncope), family history of BS or SCD, and inducibility of ventricular tachyarrhythmia s according to the latest consensus statements. 3 The class I pharmacological test was performed in all patient using the ajmaline with a dosage up to 1 mg/kg of body weight in 5 min and an anaesthesiologist was always present during the procedure. Because of the automatic HM concept, which does not demand any patient action, the vast majority of our children were implanted with a Biotronik HM device and only results from these patients were evaluated in this study. The HM systems use the Table 1 Baseline characteristics Baseline characteristics and follow-up N (%) data Total patients n Mean age at implant + SD Male sex 7 (64) Syncope 9 (81) Previous resuscitated SCD 3 (27) EPS performed/inducible 5 (45)/1 SCN5A 2 (18) Total HM follow-up time (days) 6967 Mean HM follow-up time (days) SD, standard deviation; SCD, sudden cardiac death; HM, home monitoring; EPS, electrophysiological study. Table 2 Device characteristics Devices characteristics N (%)... Single chamber 7 (64) Dual chamber 4 (36) Abdominal implantation 8 (72) Epicardial implantation 4 (36) Single VF zone ( ms) 7 (64) VF zone + VT monitor 3 (27) VT, ventricular tachycardia; VF, ventricular fibrillation. global system for mobile communications net to transmit the data to the HM data centre. Briefly, the devices communicate every night with the HM base sending a complete interrogation including alerts if present. The HM service centres process the data and make the alerts as well as the routine follow-up (FU) messages available for the referring physician via and/or dedicated websites notifications (Tables 1 and 2). Results All patients received a third-generation single-chamber or dual-chamber ICD (Lumax 340 or 540 VR-T or DR-T Biotronik GmbH), able to record and store all electrocardiographic data at the time of episodes. The decision to perform an epicardial or endocardial implantation or to place the ICD in a thoracic or in a subcostal pocketwastaken according to the age and the anthropometrics of the patients (e.g. abdominal implantation for very young children) and in accordance to the aesthetical preferences and the level of activity of the patient. Programming of the tachycardia settings was left to the physician s choice. Especially in young patients without any structural heart disease, the most frequently used setting comprised a single ventricular fibrillation (VF) detection zone.200 b.p.m., and occasionally, if needed, in adjunction with a ventricular tachycardia (VT) monitoring zone without any therapy. However, these settings were adjusted on an individual basis to avoid inappropriate therapies during the FU. The pacing mode was left to the physicians preference (DDI, DDD, or VVI mode). The choice between single- and dual-chamber device was made according to the clinical evidence of supraventricular arrhythmias (SVT) or sinus node dysfunction. Following our clinical management strategies, each patient was assigned to a remote HM device for communicating with the ICD and transmitting the data when scheduled. The only responsibility of the patient or the relatives was to keep the HM device close-by to allow proper transmission of data. Accordingly, parents were requested to keep the device in the bedroom of the children as the transmission of data was systematically scheduled during night times. Follow-up All patients receiving the HM system at the time of implantation or change of battery underwent a FU hospital visit at 1 and 3 months and thereafter every 6 months, or more often if clinically indicated (need for reprogramming, clinical event alert, or significant device alert). A dedicated research nurse reviews the HM messages, which are sent to a specific mailbox and, in case of alerts, contacts the responsible physician, who, if necessary, calls the patient for further device interrogation and/or treatment within 24/48 h, depending on the alert. The messages are reviewed only on weekdays. The alerts were programmed on an individual basis according to the patient and device type. Thirty-four different parameters could be

3 Home monitoring in children with Brugada syndrome i19 chosen out of eight different alert groups (general device settings, lead abnormalities, amount of biventricular pacing in resynchronization therapy, atrial and ventricular arrhythmia, heart rate monitor, other arrhythmia episodes, and HM message settings). However, the following were set by default: high-/low-ventricular pacing impedance (,250 or.1500 V); shock impedance,25 or.110 V; elective replacement index; VF detected; ineffective ventricular maximal energy shock(s); deactivated therapy. In absence of significant alerts, the physician or the nurse systematically review the routine daily transmission to check any early signs of device dysfunction, heart rate histograms, and changing in electrical parameters such as threshold, sensing, or impedance values to assess early signs of lead dysfunction. Statistical analysis The statistical analysis was performed using the SPSS software version 19 (SPSS Inc.). Continuous variables are presented as mean + standard deviation. Results Baseline characteristics, implantable cardioverter defibrillator implantation, and follow-up In the reference centre database a total of 17 children with BS have been followed up since One patient died 11 years after the diagnosis and 3 years afterthe ICD implantation due to an electrical storm not recognized by the device as the patient experienced slow VTs (the patient was under Quinidine VF zone 200 b.p.m.), unfortunately the patient was in 1 day holiday without the HM system. Since 2006, 11 children with BS are being followed with HM devices at our centre and represent our study population. (The remaining patients are followed in other centres.) Baseline characteristics are given in Table 1. Mean age at implant was years Figure 1 Abdominal-epicardial ICD implantation in a 6-month-old patient. Table 3 Relevant episodes occurring in our population Patient Age at implant Alerts Modification Average D time (years) (days) a... #3 8 Two alerts because of NSVT and one alert for VT (atrial Therapy adjustment and ICD 63 tachycardia) where inappropriate shock was delivered reprogramming #6 16 Multiple episodes of SVT detected and one episode of VT ICD reprogramming 35 inappropriate ATP for atrial tachycardia #7 18 Two episodes of VT with one inappropriate ATP (ayrial and evidence of lead dislodgement b #8 9 Four episodes of VF with appropriate therapy No action #9 7 VF of 12 s, shock aborted, evidence of noise on ventricular channel #10 6 months RV threshold below safety limit and several episodes of SVT appropriately recognized ICD reprogramming and reoperation 13 Further strict HM follow-up and 85 clinical evaluation ICD reprogramming 130 NSVT, non-sustained ventricular tachycardia; SVT, supraventricular arrhythmias; VT, ventricular tachycardia; VF, ventricular fibrillation; ICD, implantable cardioverter defibrillator; HM, home monitoring. a Mean time between the alert and the next scheduled follow-up. b See text for details.

4 i20 C. de Asmundis et al. Figure 2 Alert for an episode of non-sustained VF was received in a 7-year-old patient that turned out to be electrical noise on the ventricular channel lasting 12 s fortunately without any inappropriate therapy. (range 6 months to18 years, 64% male). The majority of the population was implanted due to syncope (9 patients) and either a spontaneous (1 patient) or pharmacologically provoked (10 patients) type 1 Brugada ECG pattern. Of note, one patient presented a sustained VF during the ajmaline test necessitating cardiopulmonary resuscitation (Patient #4); three experienced a resuscitated SCD (Patients #4, #5, and #7). Four patients of our population had a familial history of SCD. The electrophysiological study was performed in five patients and was positive for sustained VT in one patient. Genetic assessment was performed in all patients, two revealed a SCN5A mutation. Eight patients (72%) underwent an abdominal implantation and four of them had an epicardial lead implantation (Figure 1) while the rest had an endocardial lead placement with left subclavian or cephalic vein cannulation and tunnelling to the abdomen. The majority of the individuals received a single-chamber device (64%) programmed with a single zone for detection of VF (VF zone ms). The average follow-up of the entire population was months (range months), because two patients received the HM system later during their follow-up. By means of HM a total of 6967 days were analysed ( 232 months) and the mean individual FU

5 Home monitoring in children with Brugada syndrome i21 Figure 2 (continued). was days ( months; range months) (Table 2). Alerts analysis Seven patients of our population (64%) presented alerts during the FU: a total of 16 relevant alerts were received. Importantly, repetitive alerts due to same reasons as SVT, were excluded from recounting (Patients #5, #6, and #9), means of episodes per week. All the alerts were received far from the scheduled FU visits and often required an additional visit to modify the settings or start drug therapy. Table 3 shows all the relevant episodes occurring in our population: one patient (#7) experienced four episodes of appropriate therapies for life-threatening arrhythmias (27% of alerts received). The remaining 11 alerts were mainly due to supraventricular tachyarrhythmias (seven alerts 47% of the total). Three patients experienced inappropriate therapies for mis-diagnosis of supraventricular tachycardia, in particular Patient #6 presented several messages for SVT 5 months after the implantation and two anti-tachycardia pacing (ATP) based on a VT (at that time the ICD was programmed with two zones with a VT zone with only ATP therapy between 180 and 200 b.p.m.), which turned out to be a dislocation of atrial lead (no sensing) and retraction of the ventricular lead (double counting because of a sub-tricuspid position, with the second signal in the ventricular blanking period) due to an ongoing SVT. Interestingly these problems were asymptomatic. The patient, of course, was

6 i22 C. de Asmundis et al. Figure 3 Episode of atrial tachycardia with inappropriate shock. re-operated for lead repositioning. The two other patients (Patients #2, #6) presented one inappropriate shock and one inappropriate ATP, respectively, for SVT, all the two were not recognized by the child or the relatives whom were recalled by the physicians, the electrophysiological study was performed in Patient #5 because of.200 SVT alerts, and an atypical AV node re-entry tachycardia was induced and ablated. One lead failure was recognized due to the HM system because of a sudden modification in the sensing and threshold values (Patient #4) and the patient underwent to a lead replacement and device allocation changing (in the same patient another lead failure was found 1 month earlier at the time of battery changing that required an epicardial sensing/pacing lead positioning not counted because prior of HM starting). One other alert for an episode of non-sustained VF was received in a 7-year-old patient (#8) that turned out to be electrical noise on the ventricular channel lasting 12 s fortunately without any inappropriate therapy (Figure 2). The patient was recalled and a strict FU was recommended because of the sole episode, the negativity of provocative tests, and the stability of the electrical pacing measurements; at present no more episodes received. The remaining relevant alerts (Patient #9) were due to a chronic increase of ventricular threshold values (alert because of pacing output below safety margin). Here again, the patient was recalled adjustment of the ICD settings. In the same patient several episodes of SVT were found in the HM, correctly diagnosed by the device. As already mentioned, in all patients the alerts were far from the conventional programmed FU and the

7 Home monitoring in children with Brugada syndrome i23 Figure 4 Episode of VF with appropriate shock. average putative rate of the anticipation of the recalling and the treatment was days. Figures 3 5 briefly summarizes all the episodes occurred during our follow-up: the appropriate and inappropriate therapies, the lead and devices dysfunction. Home monitoring challenges Interestingly, in one family, three members (%; mother and two sons) had been implanted with ICD due to diagnosed BS. All abovementioned individuals were followed by two HM systems in the same home: one in the mother s room and the other in the children room. Obviously, avoiding competition during data transmission was of utmost importance. Therefore, we decided to programme the ICD devices to send the routine information at different times during the night to overcome this challenge. Discussion To the authors knowledge, this study is the first analysing a children population with BS implanted with a single- or dual-chamber ICDs. The infant population with an ICD has already been demonstrated to be more difficult in managing not only because of the high incidence of inappropriate therapies, 4 but also due to the long lifeexpectancy of the ICD recipient as compared with the conventional ICD patient population, where lead failure rates have been reported

8 i24 C. de Asmundis et al. Appropriate Therapies 1 pt/ 4 Alerts Episodes 7 pts Inappropriate Therapies 3 pts/ 4 Alerts Supraventricular Tachycardia 2 alerts Lead Failure Supraventricular Tachycardia 2 alerts Impedance and threshold 1 alert Lead and Device Disfunction 3 pts/ 3 Alerts External electrical noises 1 alert Increase threshold 1 alert Figure 5 Briefly summarizes all the episodes occurred during our follow-up. to be in the range of 15 and 40% after 5 and 8 years, respectively. 5 However, limited paediatric case series have also demonstrated a high incidence of lead failure and infection in young patients and investigators have hypothesized that increased complications occur in children because they are more active and possibly less diligent with wound care than adults. 6,7 Of note, no significant differences in inappropriate therapies were found in patients implanted with dual-chamber devices as compared with those with single-chamber devices. 8 The decision to implant an ICD in children or young patients is a delicate undertaking for all involved parties, all the more as the indications for primary prevention in asymptomatic children with increased risk for SCD are still a matter of debate. 9 The fact that the vast majority of these patients is physically active and has a very long life-expectancy represents one of the major challenges. Complications can occur related to the implantation-procedure as such (haematoma and pocket infections) and/or to the ICD systems (generator- and/or lead-specific). 10 However, the most commonly encountered complication is the occurrence of inappropriate ICD therapy, which can range between 11 and 50% in a young patient population. 4,6,10 12 In addition, this favourable outcome, encompassing a long-term follow-up and thus physical development and growth of these children is somehow challenging the popular belief, that younger and smaller patients may have a higher risk of lead complications due to anthropometrics. 10,11 To date, different novel less and less invasive strategies for an appropriate device and lead placement are being used to keep the complication rate as low and the efficacy as high as possible in children. Nevertheless, the decision for the one or the other strategy (e.g. nonthoracic vs. thoracic device implantation/epicardial vs. endocardial lead placement) is always taken on an individual basis depending on the patients age, body shape, and size as well as aesthetical considerations. One of the first reports introducing the use a single defibrillation electrode with an abdominal placement of the device showed satisfactory results in terms of feasibility, defibrillation threshold, and cosmetical acceptance. 13 However, the lead was placed transvenously and the approach suggested the avoidance of a thoracotomy only in children over 20 kg. Accordingly, our population shows a very high percentage of device malfunction without any significant difference between single- and dual-chamber devices, even if implanted in an abdominal site and a considerable percentage of inappropriate therapies delivered, equally distributed among the age. By means of HM systems all the problems were identified as soon as they presented and most importantly, much earlier than the time of the scheduled FU, demonstrating one of the major advantages when using these modalities. Half of the alerts were due to SVTs such as atrial or sinus tachycardia, representing the most frequent causes of inappropriately delivered therapies. The inappropriate ATPs in two patients of our group were only recognized by means of HM and the subsequent reprogramming impeded unnecessary and eventually harmful therapies, which holds also true for the cases where lead failures represented the main concern. The management of children is totally different as compared with older ICD recipients, not least due to the high psychological impact on the patients as well as their relatives. Accordingly, the HM ensures a better safety for the patients and reinsures the relatives, who in certain cases are also carriers of ICDs. Children with an

9 Home monitoring in children with Brugada syndrome i25 ICD need careful and continuous evaluation because of the high probability for system and arrhythmia-related inappropriate therapies and failures. We could show that HM-based clinical decisions and, most importantly, therapeutic adjustments could be taken.2 months before the scheduled FU visits. This is in line with prior studies where experiences were reported with older patients with BS or heart failure Home monitoring may be the most appropriate modality to ensure a better management, particularly in children with BS, who are physically very active and not taking any medication. Conclusion Early recognition and treatment of ICD failures in the remote monitoring era is changing the scenario of the device FU, substantially improving the management of children with channelopathies such as BS. Study limitations The first limitation of this observational study is the small number of the population, which is not uncommon when encountered with rare disorders in the young population. The lack of a control group represents an additional limitation; however, nowadays very few children are followed without HM devices. Conflict of interest: C.dA., G.-B.C., A.S. and P.B. received compensation for consultation activity from Medtronic, Biotronik, St Jude Medical, Biosense Webster. References 1. Perings C, Bauer WR, Bondke HJ, Mewis C, James M, Böcker D et al. Remote monitoring ofimplantable-cardioverter defibrillators: resultsfromthereliabilityof IEGM Online Interpretation (RIONI) study. Europace 2011;13: Varma N, Michalski J, Epstein AE, Schweikert R. Automatic remote monitoring of implantable cardioverter-defibrillator lead and generator performance: the Lumos-T Safely RedUceS RouTine Office Device Follow-Up (TRUST) trial. Circ Arrhythm Electrophysiol 2010;3: BrugadaP, Brugada J. Right bundle branchblock, persistentst segment elevation and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report. J Am Coll Cardiol 1992;20: Korte T, Koditz H, Niehaus M, Paul T, Tebbenjohanns J. High incidence of appropriate and inappropriate ICD therapies in children and adolescents with implantable cardioverter defibrillator. Pacing Clin Electrophysiol 2004;27: Kleemann T, Becker T, Doenges K, Vater K, Senges J, Schneider S et al. Annual rate of transvenous defibrillation lead defects in implantable cardioverter-defibrillators over a period of 10 years. Circulation 2007;115: Stefanelli CB, BradleyDJ, Leroy S, Dick M2nd, SerwerGA, FischbachPS. Implantable cardioverter defibrillator therapy for life-threatening arrhythmias in young patients. J Interv Card Electrophysiol 2002;6: Link MS, Hill SL, Cliff DL, Swygman CA, Foote CB, Homoud MK et al. Comparison of frequency of complications of implantable cardioverter-defibrillators in children versus adults. Am J Cardiol 1999;83: Lawrence D, Von Bergen N, Law IH, Bradley DJ, Dick M 2nd, Frias PA et al. Inappropriate ICD discharges in single-chamber versus dual-chamber devices in the pediatric and young adult population. J Cardiovasc Electrophysiol 2009;20: Blom NA. Implantable cardioverter-defibrillators in children. Pacing Clin Electrophysiol 2008;31(Suppl 1):S Shah MJ. Implantable cardioverter defibrillator-related complications in the pediatric population. Pacing Clin Electrophysiol 2009;32(Suppl 2):S Alexander ME, Cecchin F, Walsh EP, Triedman JK, Bevilacqua LM, Berul CI. Implications of implantable cardioverter defibrillatortherapyin congenital heart disease and pediatrics. J Cardiovasc Electrophysiol 2004;15: Berul CI, Van Hare GF, Kertesz NJ, Dubin AM, Cecchin F, Collins KK et al. Results of a multicenter retrospective implantable cardioverter-defibrillator registryof pediatric and congenital heart disease patients. J Am Coll Cardiol 2008;51: Fischbach PS, Law IH, Dick M 2nd, Leroy S, Mosca RS, Serwer GA. Use of a single coil transvenouselectrodewith an abdominally placedimplantable cardioverter defibrillator in children. Pacing Clin Electrophysiol 2000;23: Res JC, Theuns DA, Jordaens L. The role of remote monitoring in the reduction of inappropriate implantable cardioverter defibrillator therapies. Clin Res Cardiol 2006; 95(Suppl 3):III Tzeis S, Andrikopoulos G, Kolb C, Vardas PE. Tools and strategies for the reduction of inappropriate implantable cardioverter defibrillator shocks. Europace 2008;10: Brugada P. What evidence do we have to replace in-hospital implantable cardioverter defibrillator follow-up? Clin Res Cardiol 2006;95(Suppl 3):III Sacher F, Probst V, Bessouet M, Wright M, Maluski A, Abbey S et al. Remote implantable cardioverter defibrillator monitoring in a Brugada syndrome population. Europace 2009;11: