Wearable Cardioverter-defibrillator Use Research Articles

A novel artificial intelligence based algorithm to reduce wearable cardioverter-defibrillator alarms.

The wearable cardioverter defibrillator (WCD) is an important tool in mitigating sudden cardiac death (SCD). The WCD provides patient alarms for detected arrhythmias or electrical noise/artifact. Some patients experience frequent alarms for artifact. We soughtto evaluate the effects of a novel artificial intelligence algorithm to reduce alarms related to electrical noise or artifact (advanced arrhythmia discrimination algorithm, AArD). A retrospective review of a large commercial database of prescribed WCD. Patients prescribed the WCD during the years 2017 (discrimination algorithm, DA group) or during 2019 (advanced arrhythmia discrimination algorithm, AArD) were analyzed. A total of 96,000 patients were sampled, 48,000 in the control group (using standard direct algorithm, DA) and compared to 48,000 in the intervention AArD (4000 per group per month) for 12 months. The AArD further discriminates ECG signals based on a machine-learning algorithm utilizing intensity and frequency beyond the standard DA. Outcomes regarding alarms, arrhythmias, and safety were analyzed. The AArD algorithm was associated with a significant decrease in frequency of alarms over the course of WCD use; 54% of patients in the AARD versus 27% of DA had 0 alarms (P < .001). In the entire cohort, there was a 56% relative reduction in alarms with the use of AArD. Appropriate arrhythmia treatment time was not significantly different between the groups (44 s DA vs 45 s AArD [p = ns]). A novel artificial intelligence algorithm reduces alarms without delaying appropriate therapy for VT/VF. These changes may improve compliance and quality of life in patients with a WCD.

Wearable cardioverter defibrillator after cardiac surgery: Analysis of real-life data from patients at transient risk of sudden cardiac death.

Especially in the first 3months after cardiac surgery, patients are at transient risk of sudden cardiac death (SCD). To close the gap between hospital discharge and the final implantable cardioverter-defibrillator (ICD) decision, guidelines recommend temporarily using a wearable cardioverter-defibrillator (WCD) to protect these patients from SCD. We investigated real-life data on the safety, effectiveness, and compliance of the WCD in this population. Data for analysis were collected via the Zoll Patient Management Network (ZPM) from patients who underwent cardiac surgery and who were discharged with a WCD between 2018 and 2021 at the Cardiac Surgery Center of the University of Erlangen in Germany. The majority of the 55 patients were male (90.9%) and underwent a coronary artery bypass graft (80.0%). The number of patients with left ventricular ejection fraction (LVEF) >35% increased from 9.1% at the beginning of WCD use to 58.2% at the end of WCD use. Six ventricular tachycardia (VT) episodes occurred in four patients. The WCD appropriately defibrillated two patients with VT episodes. There were no inadequate shocks and no fatalities during the observation time. WCD wearing compliance was high, with a median wear time of 23.3h/day. This retrospective analysis in a single cardiac surgery center confirms prior data on the safety and effectiveness of the WCD in patients in post-surgery care in a real-life setting. The WCD successfully protected patients from SCD during life-threatening VT episodes. WCD wearing compliance was high.

Abstract 13825: Clinical and Echocardiographic Outcomes Associated With Early Initiation of Beta Blockers Use Among Patients With Recently Diagnosed Non-Ischemic Cardiomyopathy Treated With a Wearable Cardioverter Defibrillator

Introduction: Beta-blocker (BB) therapy was shown to improve clinical outcomes among heart failure patients with reduced ejection fraction. However, there are limited data on the efficacy of BB use among patients with recently diagnosed non-ischemic heart cardiomyopathy (NICM) who are treated with the wearable cardioverter defibrillator (WCD) until a decision on the need for an ICD is made. Aim: Determine if BB use is associated with improved outcomes in patients with NICM treated with the WCD. Methods: The study population comprised 1195 patients with recently diagnosed NICM enrolled in the prospective WEARIT-II Registry. Clinical data, arrhythmia events, ICD implantation, and improvement in left ventricular ejection fraction (LVEF) were captured. Multivariate logistic regression was used to estimate the odds ratio (OR) of LVEF improvement to &gt;35% by BB usage. The risk of death at 1-year by BB use was assessed using a multivariate cox-proportional hazards modeling. Results: Patients treated with BBs at baseline were more likely to experience an improvement in LVEF to &gt;35% that patients who did not receive treatment with BB (43% vs 29%, respectively; adjusted OR=1.67 95% CI [1.15-2.41] p=0.007; Figure: panel A and were less likely to receive an ICD at the end of the WCD use (37% vs 47%; adjusted OR=0.64 95% CI [0.46-0.90] p=0.024; Figure: panel B). At 12 months of follow-up the probability of death was significantly lower among patients who received BB therapy during WCD use vs. those who did not.,(p=0.007 Figure: panel C), corresponding to a significant 59% lower risk of death at one year associated with early BB use (adjusted HR=0.41 95% CI [0.21-0.80] p&lt;0.01). Conclusions: Among patients newly diagnosed NICM who are treated with a WCD until a decision on the need for an ICD is made, early initiation of BB is independently associated with a greater likelihood of improvement in EF, a lower probability of needing an ICD at end of WCD use, and a lower risk of death at 1-year.

ECG as a risk stratification tool in patients with wearable cardioverter-defibrillator

BackgroundThe wearable cardioverter defibrillator (WCD) is increasingly used in patients at elevated risk for ventricular arrhythmias but not fulfilling the indications for an implantable cardioverter defibrillator (ICD). Currently, there is an insufficient risk prediction of fatal arrhythmias in patients at risk. In this study, we assessed the prognostic role of baseline electrocardiogram (ECG) in WCD patients. MethodsWCD patients from diverse clinical institutions in Germany (n = 227) were retrospectively enrolled and investigated for the incidences of death or ventricular arrhythmias during WCD wearing. In addition, the widely accepted ECG predictors of adverse outcome were analyzed in patients with arrhythmic events. ResultsLife-threatening arrhythmias occurred in 22 (9.7 %) patients, mostly in subjects with ischemic heart disease (15 of 22). There was no difference in baseline left ventricular ejection fraction (LVEF) in subjects with and without arrhythmic events (31.3 ± 7.9 % vs. 32.6 ± 8.3 %; p = 0,24). Patients with arrhythmia exhibited significantly longer QRS duration (109.5 ± 23.1 ms vs. 100.6 ± 22.3 ms, p = 0,04), Tpeak-Tend (Tp-e) (103.1 ± 15.6 ms vs. 93.2 ± 19.2 ms, p = 0,01) and QTc (475.0 ± 60.0 ms vs. 429.6 ± 59.4 ms, p < 0,001) intervals. In contrast, no significant differences were found for incidences of fragmented QRS (27.3 % vs. 24 %, p = 0.79) and inverted/biphasic T-waves (16.6 % vs. 22.7 %, p = 0,55). In multivariate regression analysis both Tp-e (HR 1.03; 95 % CI 1.001–1.057; p = 0.02) and QTc (HR 1.02; 95 % CI 1.006–1.026; p < 0.001) were identified as independent predictors of ventricular arrhythmias.After WCD use, the prophylactic ICD was indicated in 76 patients (33 %) with uneventful clinical course but persistent LVEF ≤35 %. The ECG analysis in these subjects did not reveal any relevant changes in arrhythmogenesis markers. ConclusionsECG repolarization markers Tp-e and QTc are associated with malignant arrhythmias in WCD patients and may be used - in addition to other established risk markers - to identify appropriate patients for ICD implantation.

Usage of the wearable cardioverter-defibrillator during pregnancy.

BackgroundPregnancy can trigger or aggravate the risk for life-threating arrhythmias in cardiac diseases. Pregnancy is associated with reluctance for implantable cardioverter-defibrillators (ICD) due to concerns about radiation. Thus, the wearable cardioverter-defibrillator (WCD) might be an option during pregnancy. Aim of the study was to collect experiences about the use of WCD in pregnancy.Methods and resultsThis study retrospectively included eight women who received a WCD during pregnancy. They suffered from ventricular tachycardia (VT) without known cardiac disease (n = 3), Brugada syndrome (n = 1), hypertrophic cardiomyopathy (n = 1), dilated cardiomyopathy (n = 1), non-compaction (n = 1), and survived sudden cardiac arrest during a preceding pregnancy (n = 1). WCD usage was started between 13 and 28 weeks of gestation. WCD wearing period ranged from 3 days to 30.9 weeks, WCD wearing time ranged from 13.0 to 23.7 h per day. Two women (25%) abandoned WCD already during pregnancy. Neither appropriate nor inappropriate WCD shocks were recorded. Antiarrhythmic management included beta-blockers (n = 5) and flecainide (n = 2). After delivery, ICD were implanted (n = 4), refused (n = 2) and estimated not necessary after successful catheter ablation (n = 2).ConclusionUneventful pregnancy is possible in women at risk for sudden cardiac death by interdisciplinary monitoring and diligent pharmacotherapy protected by the WCD. Since no WCD shocks were recorded, the effectiveness of WCD during pregnancy is still unclear. However, arrhythmia detection by WCD was very good despite the changed anatomy in pregnancy. Nevertheless, further studies are necessary to assess effectiveness of WCD in pregnant women. Furthermore, efforts should be made to increase the wearing adherence of WCD during pregnancy.

High Resting Heart Rates Are Associated with Early Posthospitalization Mortality in Low Ejection Fraction Patients.

Guideline-directed medical therapy (GDMT) is crucial in reducing mortality in patients with heart failure with heart rate lowering by a beta blocker (BB) being an important therapeutic concept. We aimed to assess the usefulness of a wearable cardioverter/defibrillator (WCD) to provide detailed information about heart rate for managing patients with reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure and to correlate mortality with the mean heart rate. A total of 4509 consecutive patients (mean age: 59 + 13 years, 88% male) were analyzed retrospectively. All patients had reduced LVEF and were prescribed a WCD for protection from sudden cardiac death (SCD) during GDMT uptitration awaiting LVEF recovery. The device continuously measured nighttime and daytime HR at the beginning and end of WCD use. Patients who died during wear time had significantly higher HRs compared with survivors: daytime beginning of use (BOU), 80 ± 15 bpm vs. 76 ± 13, p < 0.01; nighttime BOU, 76 ± 14 vs. 69 ± 13, p < 0.0001; daytime end of use (EOU), 84 ± 20 vs. 73 ± 13, p < 0.0001; nighttime EOU, 80 ± 20 vs. 65 ± 12, p < 0.0001). In conclusion, HR monitoring with a WCD yields important prognostic information and may assist in optimal usage of BB in patients with low LVEF.

P228 WEARABLE DEFIBRILLATOR IN CLINICAL PRACTICE. MULTIANNUAL MULTI–CENTER EXPERIENCE

Abstract Introduction Heart failure with reduced left ventricular ejection function (LVEF) represents a life–threatening condition for patients (pts). A period of time of 40–90 days, in optimal medical therapy, is indicated to evaluate the recovery of the LVEF and the indication to ICD implantation. In this period, from 1% to 5% of pts can experience sudden death. We evaluated the usefulness of the wearable cardioverter defibrillator (WCD) as a temporary antiarrhythmic therapy in the interval from discharge to the three–month follow–up. Methods From December 2015 to December 2021, 174 consecutive pts (141 M (81%); mean age 62 years ± 11.6 years) were discharged with reduced FE &amp;lt; 35% in OMT, with WCD and were re–evaluated within 3 months to establish indication for ICD implantation. Results 110 pts (63.2%) recovered LVEF at 3 months and left the indication to ICD. 9 pts refused and/or returned the WCD due to poor compliance (5.2%); 52 pts (29.9%) did not recover LVEF and were implanted with ICD. The WCD was worn continuously by the majority of pts with good compliance for 87.4 ± 52.0 days (range 1 ÷ 303 days), for 22.08 hours / day. 23 episodes of AF were correctly recognized; 10 TVNS&amp;gt; 10 sec; 1 episode of VF in 1 patient in which 1 shock was correctly delivered. 1 inappropriate shock was delivered on tachycardic AF. During the WCD wearing period, 3 deaths occurred (1.7%): in 2 pts due to refractory HF (one of these pts had VF correctly recognized and treated by the WCD but degenerated into pulseless activities); 1 death for terminal cancer). The use of WCD has progressively increased over the years (from 4.5 LV / yy in 2015–16 to 45 LV / yy in 2020–21). Conclusions The use of WCD has gradually increased in clinical practice for patients who have not yet developed clear indications for ICD implantation. In the majority of them, ventricular dysfunction is transient. Wearable cardioverter defibrillator represents additional security during this period. Continuous monitoring makes it possible to identify supraventricular and ventricular arrhythmias, improving therapeutic appropriateness and in general the patients have excellent compliance with the device. Further studies are needed to substantiate this strategy.

P24 WEAREBLE CARDIOVERTER – DEFIBRILLATOR : UTILITY AND USER FRIENDLINESS

Abstract Background Worldwide, cardiovascular disease are still a major mode of death, being sudden arrhythmic death (SCD)25 % of total death. Implantable cardioverter defibrillator (ICD) is an effective weapon for SCD prevention in high risk patients with reasonable expectation of survival with good functional status for &amp;gt;1 year. However sometimes the risk of SCD can be transient, so the use of a wearable cardioverter defibrillator (WCD) is considered. Methods We considered consecutively 40 patients discharged from our cardiology department of Piacenza and Castel san Giovanni that, for potentially transient high risk of SCD, weared a WCD from August 2017 to September 2021, after a systematic education session lasting 30 – 45 minutes. They are followed through remote monitoring. Results Out of 40 patients, with average age 66 years old and average left ventricular ejection fraction (LVEF) 29%, 88% were males, 70 % suffered from arterial hypertension, 32% diabetes mellitus, 17,5 % peripheral vascular disease, 35 % chronic renal failure, 55% heart failure, 7,5% previous stroke. 56% of these patients weared WCD for severe systolic disfunction in ischemic cardiac disease after recent myocardial infarction, after percutaneous coronary intervention or coronary artery bypass graft, 7% after removal of an infected ICD, 9 % whilst awaiting completion of diagnostic tests (chanalopathies/right arrhythmogenic ventricular cardiomyopathy), 34% after newly diagnosed cardiomyopathy.The patients were discharged in high risk mode of SCD with WCD protection.The average wearing time of WCD was 51 days and 22,98 hours daily. We received 953 trasmissions, with 21 events: 7 ventricular tachicardia, 4 Sopraventricular tachicardia and 5 T wave oversensing .Neither inappropriate shock and neither death were detected .After wearing time and after clinical evaluation, only 52% of patients were subjected to ICD implantation. Conclusions In our experience we may consider that WCD use is effective, safe and with a good adherence in all patients, considering wearing time. The WCD allows saving resources with less hospitalization time.

Wearable cardioverter defibrillator multicentre experience in a large cardiac surgery cohort at transient risk of sudden cardiac death.

OBJECTIVESThe wearable cardioverter defibrillator (WCD) is an established, safe, effective solution, protecting patients at risk of sudden cardiac death. We specifically investigated WCD use in cardiac surgery patients since data for this patient group are rare.METHODSRetrospective data analysis in 10 German cardiac surgery centres was performed. Cardiac surgery patients with left ventricular ejection fraction (LVEF) ≤35% or after implantable cardioverter defibrillator (ICD) explantation who received WCD between 2010 and 2020 were assessed using LifeVest Network data.RESULTSA total of 1168 patients with a median age of 66 years [interquartile range (IQR) 57–73] were enrolled; 87% were male. Clinical indications included coronary artery bypass grafting (43%), valve surgery (16%), combined coronary artery bypass graft/valve surgery (15%), ICD explantation (24%) and miscellaneous (2%). The median wear time of WCD was 23.4 h/day (IQR 21.7–23.8). A total of 106 patients (9.1%) exhibited ventricular tachycardia. A total of 93.2% of episodes occurred within the first 3 months. Eighteen patients (1.5%) received 26 adequate shocks. The inadequate shock rate was low (8 patients, 0.7%). LVEF improved from a median of 28% (IQR 22–32%) before WCD prescription to 35% (IQR 28–42%) during follow-up. Excluding ICD explant patients, 37% of patients received an ICD.CONCLUSIONSThe risk of sudden cardiac death is substantial within the first 3 months after cardiac surgery. Patients were protected effectively by WCD. Due to significant LVEF improvement, the majority did not require ICD implantation after WCD use. Compliance was high despite sternotomy. This multicentre experience confirms existing data regarding effectiveness, safety and compliance. Therefore, WCD should be considered in cardiac surgery patients with severely reduced LVEF.

Real-world experience with the wearable cardioverter defibrillator: clinical effectiveness and wear-time adherence in patients at high risk for sudden cardiac death.

Previous studies established arole for the wearable cardioverter defibrillator (WCD) to effectively and safely bridge temporary risk for sudden cardiac death (SCD) in patients with advanced heart failure. The prognostic relevance of the WCD remains controversial. The authors investigated adherence to, as well as the safety and effectiveness of, WCD use in areal-world cohort of patients at high risk for SCD. All consecutive patients (n = 83) receiving aWCD at aGerman tertiary care hospital between April 2012 and December 2019 were retrospectively included in this analysis. Patient characteristics were collected at the time of the index hospitalization. Using the Zoll® lifeVest® (ZOLL Medical Corporation, Chelmsford, MA, USA) network database, two separate investigators evaluated adherence to the WCD as well as arrhythmic events during WCD wear time. During 3680 wearing days (mean WCD wear time, 44days) with amedian daily wear time of 23.1 h, three arrhythmic events of relevance (sustained ventricular tachycardia, VT) occurred, one of which was sufficiently terminated by WCD shock. Another patient died from sudden cardiac death while pausing his WCD. Right bundle branch block correlated significantly with sustained VT occurrence (r = 0.3315; 95% CI -0.1265 to 0.3014; p = 0.0022). In 30patients (36.1%) acardioverter/defibrillator was implanted. In areal-life clinical setting, the use of WCD in patients at high risk for sudden cardiac death is effective and safe and adherence to the device is high. The event rate for VA was lower than in comparable patient cohorts. Adherence remains acrucial issue as one patient in the present series died while not wearing the device.

Wearable Cardioverter-Defibrillator-Measured Step Count for the Surveillance of Physical Fitness during Cardiac Rehabilitation.

Background: The wearable cardioverter–defibrillator (WCD) has a built-in accelerometer, which allows tracking of patients’ physical activity by remote monitoring. It is unclear whether WCD-measured physical activity, step count, and heart rate correlate with established tools for the assessment of cardiopulmonary fitness such as the 6-min walk test (6MWT). Objective: To correlate measurements of patient physical activity through the WCD with a supervised 6MWT during in-patient cardiac rehabilitation (CR) and to allow their use as surrogate parameters of cardiopulmonary fitness in an out-patient setting. Methods: Consecutive patients with a history of WCD use treated at our center and an in-patient CR following an index hospitalization were included. Baseline characteristics, measurements of WCD accelerometer (median daily step count, median daily activity level), median daily heart rate, and clinically supervised 6MWT at admission and discharge of CR were obtained. Results: Forty-one patients with a mean age of 55.5 (±11.5) years were included. Thirty-five patients (85.4%) were male and 28 patients (68%) had a primary prophylactic WCD-indication. The most common underlying heart diseases were ischemic heart disease (24 patients 58.6%) and dilated cardiomyopathy (13 patients, 31.7%). Median CR duration was 20 (IQR 19.75–26.25) days. 6MWT distance increased from a mean of 329 m (±107) to 470 m (±116) during CR (p < 0.0001). The median daily step count and activity level increased significantly, from 5542 steps (IQR 3718–7055) to 8778 (IQR 6229–12,920, p < 0.0001) and median 117 × 106 (IQR 96 × 106–142 × 106) threshold value exceedance (TVE) to 146 × 106 TVE (IQR 110 × 106–169 × 106, p < 0.0001), respectively. The median heart rate was 74.9 bpm (IQR 65.8–84.5) and 70.2 (IQR 64.1–77.3, p = 0.09) at admission and discharge, respectively. Of all three parameters, median daily step count showed the best correlation to the results of the 6MWT at admission and discharge (r = 0.32, p = 0.04 and 0.37, p = 0.02, respectively). Conclusions: Remote monitoring of median daily step count as assessed by the WCD’s accelerometer showed positive correlation with the 6MWT and could serve as a surrogate for cardiopulmonary exercise capacity. Assessment of daily step count and activity level measured remotely by the WCD could help to tailor optimal exercise instruction for patients not attending CR.

High incidence of inappropriate alarms in patients with wearable cardioverter-defibrillators: findings from the swiss WCD registry

Abstract Introduction The wearable cardioverter defibrillator (WCD) uses surface electrodes built into the vest to detect underlying arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. Purpose The aim of this study was to assess the alarm burden in patients and its possible impact on clinical outcomes. Methods The Swiss WCD Registry is a nationwide, retrospective, observational registry. Patients were included from December 2011 until February 2018. Clinical characteristics and data from the WCDs, including alarm burden were analysed. Recordings ≥30 seconds of length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia or artefact. Results A total of 10'653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0±1.6 months. Among these, the episode duration was 30 seconds or more in 2996 (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate arrhythmia detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) supraventricular tachycardia). Two-hundred and seven patients (45.0%) had 3 or more alarms per month, whereas 49 patients (10.7%) had 1 or more alarms per day. Body mass index (BMI) was significantly higher in patients with 3 or more alarms per month (p=0.002, 25.6 vs. 27.3 kg/m2) High alarm burden was not associated with a lower average daily wear time (20.8 hours vs 20.7 hours, p=0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs 47.3%, p=0.156). Conclusions In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden did not lead to a decreased adherence, as determined by average daily wear-times. Obesity was significantly associated with a higher alarm burden. Funding Acknowledgement Type of funding sources: None.

High Incidence of Inappropriate Alarms in Patients with Wearable Cardioverter-Defibrillators: Findings from the Swiss WCD Registry

Background: The wearable cardioverter defibrillator (WCD) uses surface electrodes to detect arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. Objective: The aim of this study is to assess the alarm burden in patients and its impact on clinical outcomes. Methods: Patients from the nationwide Swiss WCD Registry were included. Clinical characteristics and data were obtained from the WCDs. Arrhythmia recordings ≥30 s in length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia (SVT) or artefact. Results: A total of 10653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0 ± 1.6 months. Episode duration was 30 s or more in 2996 alarms (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) SVT). Two-hundred and seven patients (45%) had three or more alarms per month. Obesity was significantly associated with three or more alarms per month (p = 0.01, 27.7% vs. 15.9%). High alarm burden was not associated with a lower average daily wear time (20.8 h vs. 20.7 h, p = 0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs. 47.3%, p = 0.156). Conclusions: In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden was associated with obesity but did not lead to a decreased adherence.

Cost-minimization analysis of a wearable cardioverter defibrillator in adult patients undergoing ICD explant procedures: Clinical and economic implications.

AimsPatients with permanently increased risk of sudden cardiac death (SCD) can be protected by implantable cardioverter defibrillators (ICD). If an ICD must be removed due to infection, for example, immediate reimplantation might not be possible or indicated. The wearable cardioverter defibrillator (WCD) is an established, safe and effective solution to protect patients from SCD during this high‐risk bridging period. Very few economic evaluations on WCD use are currently available.MethodsWe conducted a systematic review to evaluate the available evidence of WCD in patients undergoing ICD explant/lead extraction. Additionally, a decision model was developed to compare use and costs of the WCD with standard therapy (in‐hospital stay). For this purpose, a cost‐minimization analysis was conducted, and complemented by a one‐way sensitivity analysis.ResultsIn the base case scenario, the WCD was less expensive compared to standard therapy. The cost‐minimization analysis showed a cost reduction of €1782 per patient using the WCD. If costs of standard care were changed, cost savings associated with the WCD varied from €3500 to €0, assuming costs for standard care of €6800 to €3600.ConclusionAfter ICD explantation, patients can be safely and effectively protected from SCD after hospital discharge through WCD utilization. Furthermore, the use of a WCD for this patient group is cost saving when compared to standard therapy.

B-PO02-180 HIGH BURDEN OF INAPPROPRIATE ALARMS BY THE WEARABLE CARDIOVERTER-DEFIBRILLATOR IN OBESE PATIENTS - FINDINGS FROM THE SWISS WCD REGISTRY

The wearable cardioverter-defibrillator (WCD) uses surface electrodes built into the vest to detect underlying arrhythmia before initiating a treatment sequence. Before a shock is administered an alarm consisting of vibratory and auditory signals is emitted to warn the patient. Some patients frequently experience alarms. The aim of this study is to assess the alarm burden in patients and its possible impact on clinical outcomes. The aim of this study is to assess the alarm burden in patients and its possible impact on clinical outcomes. The Swiss WCD Registry is a nationwide retrospective registry including patients with a history of WCD use. Patients were included since 2011 until February 2018. Baseline characteristics and data on WCD usage were analysed. As sustained ventricular tachycardia or fibrillation (VT/VF) requires arrhythmia duration of ≥30s, only recordings ≥30s of length were analysed and categorized as appropriate (VT/VF), or inappropriate (atrial fibrillation, supraventricular tachycardia and artefact). A total of 10’653 alarms were documented in the total registry including 456 patients over a mean WCD wear-time of 2 months (±1.6). One hundred and thirty-two patients (28.9%) had zero alarms. A recording with a length ≥30s was present in 2996. One hundred and eleven (3.7%) of these were VT/VF episodes. The remaining recordings were inappropriate arrhythmia detections: 2736 artefacts (91%), 117 atrial fibrillation episodes (3.7%) and 48 supraventricular tachycardia episodes (1.6%). Two-hundred and seven patients (45%) had ≥3 alarms per months, and 49 patients (10.7%) had ≥1 alarm per day. BMI ≥30kg/m2 was significantly associated with ≥3 alarms per month (p=0.002), and increasing BMI correlated with increasing total number of alarms (p<0.001). ≥3 alarms per months were not associated with a lower average daily wear time (20.8 vs 20.7 hours, p=0.785) or a decreased ICD implantation rate after stopping WCD use (48 vs 47.3%, p=0.156). Inappropriate alarms emitted by the WCD are frequent and significantly associated with obesity. They did not lead to a decreased adherence to WCD therapy.

Wearable Cardioverter Defibrillator (WCD) in Italy: results from the nationwide multicenter registry WEAR-ITA

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND The Wearable Cardioverter Defibrillators (WCD) has been used extensively in Italy since 2015, following long years of experience in other countries. This technology provides temporary protection from Sudden Cardiac Death (SCD) for patients with an evolving risk profile that may not yet be eligible for an Implantable Cardioverter Defibrillator (ICD). Collecting national data on use of the device can help build a picture that will enable an understanding on how to use the WCD appropriately in the future. PURPOSE Our purpose has been to investigate WCD usage on a nationwide level. This is in terms of target population, average wear time, patient compliance, diagnosed and treated arrhythmic events and patient outcome once they stopped wearing the device. METHODS WEAR-ITA is a nationwide, multi-centre retrospective observational project. Patient data was retrospectively collected from the Italian hospitals that agreed to take part in the data collection for all patients fitted with a WCD between April 2015 to May 2018. All data refers to the range from the first day of wear until the end of use. RESULTS We collected data for 411 patients from 15 (75%) Italian regions. WCD use among the different regions was heterogeneous with a median of 0.5 (0.2-1.2) WCD wore/105 inhabitants. The mean age of the population was 55(±14) and the majority of patients were male (79%). Main WCD indication was non-ischemic cardiomyopathy with reduced ejection fraction (51%), ischemic etiology with severe systolic dysfunction (31%), uncertain or unidentified diagnosis (10%) that then revealed to be predominantly channelopathies or myocarditis and after ICD extraction (8%). Patients wore the WCD for a median of 59 (33-90) days and the median daily weartime was 23 (22,7-23,8) hours. In 15 patients (4%), the WCD recorded non sustained ventricular tachycardia (VT), 10 patients (2%) had hemodynamically well-tolerated sustained VT not needing a shock. 8 patients (2%) received effective appropriate shocks. Time to episodes were respectively 61 (14-61) days for non-sustained VT and 28 (19-70) days for VT/VF. 2 patients (0.5%) received inappropriate shocks for sinus tachycardia and atrial fibrillation (AF) respectively. WCD recorded new onset of supra ventricular tachycardia episodes in 12 patients (3%) and of atrial fibrillation (AF) in 7 patients (2%). 7 patients (2%) died while wearing WCD; none of them from SCD. At the end of the WCD use, 195 patients (47%) did not receive an ICD while 209 patients (51%)were implanted. CONCLUSIONS WCD is an effective therapy for the treatment of SCD with a very low complication rates. The indication and penetration in Italy is quite heterogeneous. The patient’s compliance is high over time. The incidence of appropriate shock is not negligible; only half of patients, who wore WCD, received an ICD. There is however still a requirement to conduct further randomized trials to understand which patients could most benefit from the use of WCD. Abstract Figure. Wereable Cardioverter Defibrillator

Sex differences in arrhythmic burden with the wearable cardioverter-defibrillator

Data on the arrhythmic burden of women at risk for sudden cardiac death are limited, especially in patients using the wearable cardioverter-defibrillator (WCD). We aimed to characterize WCD compliance, atrial and ventricular arrhythmic burden, and WCD outcomes by sex in patients enrolled in the Prospective Registry of Patients Using the Wearable Cardioverter Defibrillator (WEARIT-II U.S. Registry). In the WEARIT-II Registry, we stratified 2000 patients by sex into women (n = 598) and men (n = 1402). WCD wear time, ventricular and atrial arrhythmic events during WCD use, and implantable cardioverter-defibrillator (ICD) implantation rates at the end of WCD use were evaluated. The mean WCD wear time was similar in women and men (94 days vs 90 days; P = .145), with longer daily use in women (21.4 h/d vs 20.7 h/d; P = .001). Burden of ventricular tachycardia or ventricular fibrillation was higher in women, with 30 events per 100 patient-years compared with 18 events per 100 patient-years in men (P = .017), with similar findings for treated and non-treated ventricular tachycardia/ventricular fibrillation. Recurrent atrial arrhythmias/sustained ventricular tachycardia was also more frequent in women than in men (167 events per 100 patient-years vs 73 events per 100 patient-years; P=.042). However, ICD implantation rate at the end of WCD use was similar in both women and men (41% vs 39%; P = .448). In the WEARIT-II Registry, we have shown a higher burden of ventricular and atrial arrhythmic events in women than in men. ICD implantation rates at the end of WCD use were similar. Our findings warrant monitoring women at risk for sudden cardiac death who have a high burden of atrial and ventricular arrhythmias while using the WCD.

Reassessment of practical usage and accumulation of real-world data of wearable cardioverter defibrillator (WCD) in Japan-Design paper for J-WCDR study.

Although implantable cardioverter defibrillators (ICDs) are a powerful preventive therapy for cardiac sudden death, there are some populations in whom ICDs cannot be applied because of a lack of a definitive indication (grey‐zone patients), such as in patients during the acute phase of cardiac injury with a susceptible risk for lethal arrhythmias. In such patients, wearable cardioverter defibrillators (WCDs) provide safer bridging period during the acute phase until the final decision‐making for the ICD use and it may eliminate any inappropriate overuse of ICDs in the subacute phase. The JCS/JHRS practical guidelines provide the criteria for WCD use in Japan. Nevertheless, the evidence for that is totally limited in Japan and is dependent on the accumulation of actual real‐world data from other countries in order to be able to discuss the appropriate criteria for WCD use. This study will be conducted retrospectively and/or prospectively, and is an observational and multicenter study among Japanese institutions (J‐WCDR, Japan WCD Registry). This will provide evidence for WCD use in our own country and contribute to upcoming updates for the future guideline revisions.

The impact of wearable cardioverter-defibrillator use on long-term decision for implantation of a cardioverter-defibrillator in a semirural acute care hospital

PurposeLarge-scale multi-center studies have reported on efficacy of the wearable cardioverter-defibrillator (WCD). However, outcomes focused on WCD patients treated at community-based acute care centers are lacking.MethodsPatients with cardiomyopathy were included when left ventricular ejection fraction (LVEF) at baseline was ≤ 35%. There were 120 patients meeting the criteria who also had LVEF measured at baseline and after 90 days of WCD use.ResultsAfter 90 days of WCD use, there were 44 (37%) patients in whom LVEF improved to > 35%. Comparison of patients, by whether LVEF improved or not, indicated that median days of WCD wear and hours of daily use were similar as well as characteristics, such as gender, age, and starting LVEF; and diagnoses leading to WCD prescription were similar between groups as were symptom-based prescription of medications. At the end of WCD use, improved LVEF > 35% correlated with fewer implantable cardioverter-defibrillator (ICD) implants. There were 4 (3%) episodes of new atrial fibrillation detected during WCD use. The WCD appropriately delivered a shock to 3 (2.5%) patients with VT/VF being terminated by the first shock. All shocked patients survived for at least 24 h post-shock.ConclusionsDuring WCD use, ischemic and non-ischemic cardiomyopathy patients manifest improved LVEF by 90 days. Long-term care decisions, such as implantation of an ICD, were influenced by LVEF improvement and occurrence of spontaneous VT/VF. The WCD protected patients from sudden cardiac death (SCD) until patient response to guideline-directed medical therapy could be determined.

Abstract 16194: Prior Atrial Fibrillation and WCD-detected Arrhythmic Outcomes - Data From the WEARIT-II Prospective Registry

Introduction: The Wearable Cardioverter Defibrillator (WCD) is utilized in patients with assumed but not yet confirmed risk for sudden cardiac death (SCD). Many of these patients also present with a history of atrial fibrillation (AF). However, the rate of WCD-detected ventricular or atrial arrhythmia events in this specific high-risk cohort is not well understood. Methods: In WEARIT-II, the cumulative probability of any sustained or non-sustained VT/VF (WCD-treated and non-treated), and atrial/supraventricular arrhythmias during WCD use was assessed using the Kaplan-Meier method, with comparisons by the log-rank test. The incidence of ventricular and atrial arrhythmia events were expressed as events per 100 patient-years, and were analyzed by negative binomial regression. Results: The WEARIT-II trial enrolled 2000 patients, 557 (28%) of whom had AF prior to enrollment. The cumulative probability of any sustained or non-sustained WCD-detected VT/VF during WCD use was significantly higher among patients with a history of AF than in patients without AF (6% vs. 3%, p=0.001, Figure). Similarly, the recurrent rate of any sustained or non-sustained VT/VF was significantly higher in patients with prior AF vs. no prior AF (131.5 events per 100 patient-years vs. 22.7 events per 100 patient-years, p=0.001). Patients with prior AF also had a significantly higher burden of WCD-detected atrial arrhythmias/SVT (64 events per 100 patient-years vs 13.7 events per 100 patient-years, p&lt;0.001). Conclusions: Our results demonstrate that patients with a history of AF wearing the WCD for risk assessment have a higher incidence of ventricular arrhythmias that may facilitate the decision making for ICD implantation.