Wearable Cardioverter-defibrillator Use Research Articles

One-year follow-up of the prospective registry of patients using the wearable defibrillator (WEARIT-II Registry).

The WEARIT-II Registry demonstrated efficacy and safety of the wearable cardioverter defibrillator (WCD) for at-risk cardiac patients. However, 1-year outcomes in this population have not been reported. The WEARIT-II Registry enrolled 2,000 U.S. patients prescribed the WCD. One-year mortality data from start of WCD use were prospectively collected for 1,846 patients (93%). Outcome data were analyzed by disease etiology and implantable cardioverter defibrillator (ICD) implantation following WCD use. During 12 months of follow-up, 73 patients died (4%). Kaplan-Meier survival analysis showed differences in all-cause mortality from WCD prescription between patients with ischemic versus nonischemic cardiomyopathy versus congenital/inherited heart disease (4%vs 3%vs 7%, P=0.013). Patients with ventricular arrhythmia events during WCD use had a higher 1-year mortality (10%vs 3%, P=0.042). Renal disease, increasing age, prior syncope, and nonbeta-blocker use predicted mortality. One-year mortality was similar in patients who did versus did not receive an ICD following WCD use in ischemic (3%vs 4%, P=0.470) and nonischemic cardiomyopathy (3%vs 3%, P=0.892). Patients with congenital/inherited heart disease with no implanted ICD had a trend toward a higher rate of mortality than those who received an ICD (8%vs 3%, P=0.082). Multivariate models confirmed these findings. One-year follow-up from the WEARIT-II Registry shows an overall good survival in patients prescribed the WCD. Short-term use of WCD allows appropriate risk stratification for decision on an ICD implantation in at-risk ischemic and nonischemic cardiomyopathy patients. Congenital/inherited heart disease patients had a higher risk of 1-year mortality even without an implanted ICD post-WCD.

The US Experience of the Wearable Cardioverter-Defibrillator in Pediatric Patients

Certain pediatric patients are at risk for sudden cardiac death. The wearable cardioverter-defibrillator (WCD) can be used in clinical situations in which implantable cardioverter-defibrillator placement is not ideal. The objectives of the study are to examine the effectiveness, safety, and compliance of the WCD in the identification and treatment of life-threatening ventricular arrhythmias in pediatric patients. All United States pediatric patients <18 years who wore a WCD, from 2009 to 2016 were retrospectively reviewed. In total, 455 patients were identified. The median age was 15 (3-17) years, median duration of WCD use was 33 (1-999) days and median patient wear time was 20.6 (0.3-23.8) hours per day. The population was divided into 2 groups: (1) patients with implantable cardioverter-defibrillator problem, n=63 and (2) patients with nonimplantable cardioverter-defibrillator problem, n=392. Wear time per day was >20 hours in both groups. Wear duration was shorter in the implantable cardioverter-defibrillator problem group, 26 days versus 35 days, P<0.05. There were 7 deaths (1.5%); all not wearing WCD at time of death. Eight patients (1.8%) received at least 1 WCD shock treatment. Of the 6 patients (1.3%) who had appropriate therapy, there were 7 episodes of either polymorphic ventricular tachycardia or ventricular fibrillation with a total of 13 treatments delivered. All episodes were successfully converted and the patients survived. The WCD has overall adequate compliance with appropriate wear times and wear durations in pediatric patients. The WCD is safe and effective in treating ventricular arrhythmias that can lead to sudden cardiac death in pediatric patients.

Clinical Usefulness of Wearable Cardioverter Defibrillator (WCD) and Current Understanding of Its Clinical Indication in Japan.

Prevention of sudden cardiac death (SCD) has become an important issue in today's cardiovascular field, together with various developments in secondary prevention of basic cardiac diseases. The importance of the implantable cardioverter defibrillator (ICD) is now widely accepted because it has exhibited significant improvement in patients' prognoses in ischemic and non-ischemic cardiovascular diseases. However, there is an unignorable gap between the ICD indication in the guidelines and real-world high-risk patients for SCD, especially in the acute recovery phase of cardiac injury. Although various studies have demonstrated a clinical benefit of defibrillation devices, the studies of immediate ICD use in the acute recovery phase have failed to exhibit a benefit in patients from the point of the view of a decrease in total deaths. To bridge this gap, the wearable cardioverter defibrillator (WCD) provides a safer observation period in the acute phase and eliminates inappropriate overuse of ICD in the subacute phase. Here, we discuss the usefulness of the WCD and current understanding of its indications based on various clinical data. In conclusion, WCD is a feasible bridge to therapy and/or safe observation for patients at high risk of SCD, especially in the acute recovery phase of cardiac diseases.

Use of the wearable cardioverter-defibrillator (WCD) and WCD-based remote rhythm monitoring in a real-life patient cohort.

The wearable cardioverter-defibrillator (WCD) was introduced to provide protection from sudden cardiac death (SCD) in patients with transiently elevated risk or during ongoing risk stratification. Benefits and clinical characteristics of routine WCD use remain to be assessed in larger patient populations. This study aims to identify determinants of WCD compliance, therapies, and inappropriate alarms in a real-life cohort. A total of 106 cases (68.9% male) were included between 11/2010 and 04/2016. WCD therapies, automatically recorded arrhythmia episodes, inappropriate WCD alarms, patient compliance, and outcome after WCD prescription were analyzed. Median duration of WCD use was 58.5days. Average daily wearing time was 22.7h. Compliance was reduced in patients ≤ 50years. Three patients received WCD therapies (2.8%). In one case ventricular fibrillation (VF) was appropriately terminated with the first shock. Two patients received inappropriate WCD therapies due to WCD algorithm activation during ventricular pacemaker stimulation. One patient died of asystole while carrying a WCD (0.9%). Additional arrhythmias detected comprised self-terminating sustained ventricular tachycardia (VT; 2.8%), non-sustained VT (2.8%), and supraventricular arrhythmias (5.7%). Inappropriate WCD alarms due to over-/undersensing occurred in 77/106 patients (72.6%), of which 41 (38.7%) experienced ≥ 10 inappropriate WCD alarms during the prescription period. Thirteen patients (12.3%) displayed a mean of > 1 inappropriate alarms/day. WCD use was associated with high compliance and provided protection from VT/VF-related SCD. The majority of patients experienced inappropriate WCD alarms. Alterations in QRS morphology during pacemaker stimulation require consideration in WCD programming to prevent inappropriate alarms.

Wearable Cardioverter-defibrillators for the Prevention of Sudden Cardiac Death: A Meta-analysis.

Wearable cardioverter-defibrillators (WCDs) protect patients from sudden cardiac death (SCD) by detecting and treating life-threatening ventricular tachycardia/fibrillation (VT/VF). Recently, two large studies evaluating WCDs were published. However, the results of older and newer studies have yet to be systematically summarized. The objective of the current study was to conduct a meta-analysis assessing the use and effectiveness of WCDs. We searched MEDLINE and Scopus (January 1998–July 2017) as well as the gray literature. We included registry/observational studies that (1) evaluated adult patients using WCDs; (2) provided data on one or more outcomes of interest; and (3) were full-text studies published in English. We calculated pooled incidence and/or rate [with 95% confidence intervals (CIs)] estimates from nonoverlapping populations using a random-effects meta-analysis model. Statistical heterogeneity was assessed via the I2 statistic. We identified 11 studies (19,882 patients) with nonoverlapping populations/endpoints; seven of them evaluated WCD use across various indications, while the remaining studies restricted their focus to a single indication. Most of the studies were retrospective (82%) and multicenter (64%) in nature, with 45% using manufacturers’ registry data. The median duration of WCD use was three or more months in nine (82%) studies, and daily wear time ranged from a mean/median of 17 hours to 24 hours per day across included studies. Seven (64%) studies reported a mean/median daily wear time of more than 20 hours. This meta-analysis showed that the incidences of all-cause and SCD-related mortality among WCD patients were 1.4% (95% CI: 0.7%–2.4%) and 0.2% (95% CI: 0.1%–0.3%), respectively. VT/VF occurred in 2.6% (95% CI: 1.8%–3.5%) of patients. Across patients, 1.7% (95% CI: 1.4%–2.0%) received appropriate WCD treatment, corresponding to a rate of 9.1 patients/100 person-years (95% CI: 6.2–11.9 patients/100 person-years). Successful VT/VF termination following appropriate treatment occurred in 95.5% of patients (95% CI: 92.0%–98.0%) and the incidence of inappropriate treatment was infrequent (0.9%; 95% CI: 0.5%–1.4%). A moderate-to-high degree of statistical heterogeneity was observed in pooled analyses of mortality, VT/VF occurrence, and appropriate/inappropriate treatment (I2 ≥ 41% for all). In conclusion, WCDs appear to be successful in terms of terminating VT/VF in patients with an elevated risk of SCD and are appropriate for use while long-term risk management strategies are being identified.

Experience with the wearable cardioverter-defibrillator in older patients: Results from the Prospective Registry of Patients Using the Wearable Cardioverter-Defibrillator

Use of the wearable cardioverter-defibrillator (WCD) in older patients has not been described previously. The purpose of this study was to assess WCD wear time, risk of arrhythmic events during WCD use, and implantable cardioverter-defibrillator (ICD) implantation rates after the end of WCD use in patients with age ≥65 years vs <65 years. We stratified 1732 patients with ischemic and nonischemic cardiomyopathy from the Prospective Registry of Patients Using the Wearable Defibrillator Registry into 2 subgroups by age: those with age ≥65 years and those with age <65 years. Wear time, arrhythmic events, and end-of-use decisions, specifically ICD implantation or improvement in ejection fraction, were evaluated for each age group. There were 722 patients with age ≥65 years (41.7%) and 1010 patients with age <65 years (58.3%). Daily WCD wear time was longer in the older population (median 22.8 h/d (IQR 21.5 - 23.2) vs 22.3 h/d (IQR 19.5 - 23.0); P < .001). Patients with age ≥65 years experienced higher eventrates, per 100 patient-years, for any sustained ventricular tachycardia/ventricular fibrillation (31.95 vs 9.82; P = .027) and ventricular tachycardia/ventricular fibrillation treated with WCD shock (6.92 vs 2.37; P = .034), particularly with ischemic cardiomyopathy. Younger patients experienced a trend toward a higher event rate for atrial arrhythmias with nonischemic cardiomyopathy (150.07 vs 74.86; P = .055). At the end of WCD use, ICD implantation was more frequent in older patients (41.8% vs 36.5%; P=.034). Older patients had good compliance with the WCD, presented with more frequent ventricular arrhythmias, and were more likely to receive an ICD at the end of WCD use. The WCD may play a role in risk stratification of the older population.

Management of sudden cardiac death in cardiac sarcoidosis using the wearable cardioverter defibrillator.

BackgroundPatients with cardiac sarcoidosis are at increased risk of ventricular tachycardia/fibrillation.ObjectiveWe tested the hypothesis that the wearable cardioverter defibrillator can be used to mitigate the risk of sudden cardiac death among cardiac sarcoidosis patients.MethodsA retrospective review of the commercial database identified cardiac sarcoidosis patients who wore the wearable cardioverter defibrillator. Evidence for cardiac sarcoidosis diagnosis as well as demographic, co-morbidity and left ventricular ejection fraction were provided by patient clinical records. Clinical data also included daily wearable cardioverter defibrillator wear, shock treatment and survival information.ResultsThe wearable cardioverter defibrillator was worn by 46 cardiac sarcoidosis patients, 24 (52%) male. The median age was 48 years and median left ventricular ejection fraction was 30%. The wearable cardioverter defibrillator was worn a median of 23.6 hours each day. There were 11 ventricular tachycardia/fibrillation episodes occurring in 10 (22%) patients. Ventricular tachycardia/fibrillation occurred over a range of 1 to 79 days, median 24 days. First-shock success for conversion of ventricular tachycardia/fibrillation was 100%. Patient survival 24 hours after shock treatment was 100%. Follow up to determine the reason for discontinuing wearable cardioverter defibrillator use indicated that among shocked patients 7 received an implantable cardioverter defibrillator, 1 patient was admitted to the hospital ending in death 2 weeks after discontinuing wearable cardioverter defibrillator use, and 2 patients were lost to follow up. Among the not shocked patients, there were 16 who received an implantable cardioverter defibrillator while 7 achieved improved left ventricular ejection fraction.ConclusionManagement of sudden cardiac death among cardiac sarcoidosis patients was aided by the wearable cardioverter defibrillator resulting in successful termination of ventricular tachycardia/fibrillation upon delivery of shock.

Outcome of Patients With In-Hospital Ventricular Tachycardia and Ventricular Fibrillation Arrest While Using a Wearable Cardioverter Defibrillator

In-hospital sudden cardiac arrests occurring during nighttime and weekend hours or within unmonitored hospital areas have been reported to have a poorer outcomes than monitored cardiac arrest. This study sought to assess the outcome of in-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF) arrest by time of day, day of week, and within-hospital location when using a wearable cardioverter defibrillator (WCD). We retrospectively identified and reviewed consecutive in-hospital VT/VF arrests from January 2011 to May 2015 experienced by patients wearing a WCD using the manufacturer's postmarket registry. An index shockable sudden cardiac arrest event was defined as the first arrest caused by VT/VF. Event location and clinical outcome were extracted from patient call logs. Survival analysis was performed using the Kaplan-Meier method. A total of 234 in-hospital VT/VF arrests were included (mean age = 65 ± 12 years, male = 74%); 50% had a history of congestive heart failure. The median follow-up time was 6 days (interquartile range 1-4). In the 128 (55%) daytime events (7:00 a.m. to 7:00 p.m.), 24-hour survival was 91%. The 106 (45%) nighttime events (7:01 p.m. to 6:59 a.m.) had 89% 24-hour survival (p = 0.54). Survival outcome by monitored or unmonitored hospital locations were similar. Kaplan-Meir analyses showed no difference in 30-day survival either between weekend and weekday events (72% vs 65%, p = 0.79), or between daytime and nighttime events (64% vs 69%, p = 0.37). In conclusion, WCD use during in-hospital VT/VF arrest correlated with high survival rates regardless of event time or location inside a hospital. Use of a WCD appears to mitigate some of the risks associated with in-hospital VT/VF arrest.

P6417Extended wearable cardioverter defibrillator use in patients at-risk for sudden death

P6417Extended wearable cardioverter defibrillator use in patients at-risk for sudden death

P1492Improvements in ejection fraction during wearable cardioverter defibrillator use influences ICD implant rate

P1492Improvements in ejection fraction during wearable cardioverter defibrillator use influences ICD implant rate

A real world wearable cardioverter defibrillator experience – Very high appropriate shock rate in ischemic cardiomyopathy patients at a European single-center

BackgroundThe wearable cardioverter defibrillator (WCD) has emerged as a valuable tool to protect patients with increased risk of sudden cardiac death (SCD). We sought to characterize WCD patients and to analyze predictors of ventricular arrhythmia (VA) occurrence and WCD shock delivery. Methods and resultsOne hundred fourteen patients with WCD use were included in the study. Indications were mainly ischemic cardiomyopathy (ICM; 31.6%), non-ICM (45.6%) and explantation of implantable cardioverter defibrillator due to device infection (11.4%). We observed sustained VA in 9.6% of the study population and 6.1% received an appropriate shock. VA occurred in 16.7% of ICM, 3.8% of non-ICM and 15.4% of patients with device infection. ConclusionsOur data demonstrate a very high rate of sustained VA in patients at risk for SCD during WCD use. ICM patients, including those with recent MI, bore the highest risk.

Real world utilization and impact of the wearable cardioverter-defibrillator in a community setting

IntroductionThe wearable cardioverter-defibrillator (WCD) is used in patients at risk for sudden cardiac death (SCD) but not immediate candidates for intracardiac defibrillator (ICD) implantation. MethodsWe performed a single center retrospective study of patients prescribed WCD upon hospital discharge from January 2002 to October 2015. Clinical characteristics were obtained from the hospital electronic database and device data from Zoll LifeVest database. ResultsOf 140 patients, 62% were men, 85.9% were African-American and mean age was 58.2 ± 15.5 years. Ischemic cardiomyopathy was present in 45 (32%) and non-ischemic cardiomyopathy in 64 patients (46%). Mean left ventricular ejection fraction (EF) was 0.28 ± 0.4. WCD was worn for 7657 patient-days (21 patient-years), with each patient using WCD for median of 43 days (IQR: 7–83 days), and daily mean use 17.3 ± 7.5 h. There were a total of 6 (4.2%) WCD shocks of which 2 (1.4%) were appropriate (one for VT, one for VF) and 4 (2.8%) were inappropriate (2 had supraventricular tachycardia, 2 had artifact). Two patients who received appropriate shocks were African-American with non-ischemic cardiomyopathy (EF<20%), non-sustained VT and wide QRS duration. Upon termination of WCD use, 45 (32%) received ICD while EF improved in 34 patients (32%). ConclusionsIn a predominantly minority, community setting, WCD compliance is high and use is effective in aborting SCD. However, inappropriate shocks do occur. A significant proportion of patients did not ultimately require ICD implantation suggesting this may be a cost-effective strategy in patients at risk of SCD.

The wearable defibrillator: current technology, indications and future directions.

The wearable cardioverter-defibrillator has been available for over a decade. In recent years, the device has been prescribed increasingly for a wide range of indications. The purpose of this review is to describe the technical and clinical aspects of the wearable cardioverter-defibrillator. The available literature on safety, efficacy and cost-effectiveness is reviewed, and indications for use will be discussed. The wearable cardioverter-defibrillator has been used successfully in more than 100 000 patients for a variety of indications. These include high-risk patients after myocardial infarction or revascularization or with heart failure and newly diagnosed cardiomyopathy. It has also been used to bridge the time period of postponed implantable cardioverter-defibrillator implantation or reimplantation, or until heart transplantation. It has been shown that the device safely and effectively terminates ventricular tachycardia and fibrillation with high first shock success. Patient compliance has been high. Although no randomized trial has been published yet, several guidelines recommend wearable cardioverter-defibrillator use in different patient populations and clinical scenarios. The wearable cardioverter-defibrillator effectively bridges a limited time period in patients with a real or perceived high risk for sudden cardiac arrest and may become a helpful tool for risk stratification to better select patients for primary prevention implantable cardioverter-defibrillator placement.

The wearable cardioverter-defibrillator in a real-world clinical setting: experience in 102 consecutive patients.

The wearable cardioverter-defibrillator (WCD) is used for temporary protection of patients deemed to be at high risk for sudden death (SCD) not yet meeting indications for the implantable defibrillator (ICD). To evaluate the efficacy, safety, and compliance of/to WCD use and subsequent medium-term outcome of patients in a single-center observational study. A total of 102 consecutive patients were fitted with the WCD from 2012 to 2015 and followed for a mean of 11months (±8months). The most common clinical indication for WCD-prescription (63%) was a new diagnosis of severely impaired LV function (LVEF ≤35%). The median wear time of the WCD was 54days with a daily use of 23h. Appropriate WCD therapy occurred in four patients (seven shocks for VF, one shock for VT). An ICD was finally implanted in 56 patients (55%). Improvement in LV function was the most common reason not to implant an ICD (HR 0.37; 95% CI 0.19-0.73; p=0.004). Two patients had inappropriate shocks from their WCD due to atrial fibrillation/flutter. Five patients fitted with an ICD after the end of WCD therapy suffered VT/VF episodes. After wearing the WCD, six patients died (five ICD recipients and one non-ICD recipient). WCD therapy was well accepted by patients and provided temporary protection against ventricular tachyarrhythmias in patients at risk for SCD. The WCD may help to avoid unnecessary ICD implantations in a significant proportion of patients.

Wearable Cardioverter Defibrillators.

The use of implantable cardioverter defibrillators (ICD) has favorably impacted the prevention and treatment of sudden cardiac death (SCD) associated with ventricular arrhythmias. However, there are situations where an ICD cannot be immediately implanted, even though the patient is at high risk for SCD. The wearable cardioverter defibrillator (WCD) is a unique technology that can bridge this gap for patients. The WCD has been demonstrated to terminate ventricular tachycardia/fibrillation if worn and used correctly. With proper training, it is relatively easy to put on, maintain, and use. Most patients are compliant and are able to consistently wear the device. The WCD negates the infection risk or procedural complications associated with insertion and possible extraction of leads, as with an ICD. In terms of primary prevention of ventricular tachycardia/fibrillation in patients with a left ventricular ejection fraction ≤35%, prospective, randomized studies evaluating the survival of patients utilizing the WCD will need to be performed before evidenced-based criteria for its use can be established. On the basis of current data, WCD use for those awaiting heart transplant, for those with ICD indications status post-ICD explant, and for high-risk SCD patients with possible reversible cardiomyopathy appears to be a reasonable approach on the basis of current data.

National experience with long-term use of the wearable cardioverter defibrillator in patients with cardiomyopathy.

The wearable cardioverter defibrillator (WCD) is generally used for short periods of sudden cardiac death (SCD) risk; circumstances may occasionally result in prolonged use (over 1year). The aim of this study was to determine the benefits and risks of prolonged use in patients with systolic heart failure (HF). ZOLL's post-market US database included adult patients (≥18years) with ischemic and/or non-ischemic cardiomyopathy (ICM, NICM) and at least 1year of use. Cox-regression was used to identify factors associated with survival with WCD use, and reasons for stopping use were entered as time-dependent factors. Among 220 patients, age (mean ± SD) 55.4 ± 14.8years, WCD use 451.4 ± 289.9days, and 67.3% were male and their left ventricle ejection fraction (EF) averaged 20.9 ± 7.2%. Eighty-nine (40.5%) were continuing WCD use at the last follow-up. Thirty-six (16.4%) and 56 (25.5%) patients discontinued WCD use because of EF recovery and implantable cardioverter (ICD) implantation, respectively. Nine patients (4.1%) received appropriate shock therapy for 13 episodes of sustained ventricular tachyarrhythmia with 12 (92.3%) successful shocks. One patient died of refractory ventricular fibrillation. One patient died from sinus bradycardia transitioning to asystole. Eight patients (3.6%) had nine episodes of non-fatal inappropriate shocks. Long-term use of the WCD is safe and effective. Recovery of EF was seen in significant number of patients even after 1year of WCD use.

Potential roles of the wearable cardioverter-defibrillator in acute phase care of patients at high risk of sudden cardiac death: A single-center Japanese experience

BackgroundThe wearable cardioverter-defibrillator (WCD) has been expected to play a role as an effective bridge therapy to implantable cardioverter-defibrillator (ICD) implantation in patients at high risk of ventricular tachyarrhythmias (VA). Although WCD has been available since April 2014 in Japan, its usefulness remains unclear. Methods and resultsDuring the early period after hospitalization, patients at high risk of VA after excluding some elderly patients were prescribed WCD. The consecutive 50 patients with WCD use (median age 56 years, 38 for secondary prevention) were studied. We analyzed clinical efficacy and safety of WCD, and examined its potential roles. Of the 50 patients, 38 used WCD only during hospitalization. During WCD use [median 16 (IQR 8–33) days], all patients wore WCD for 98% of a day regardless of in or out-of-hospital use. Sustained VA was detected in 4 patients (8%; for primary prevention in 1) with 7 episodes, and 6 of 7 episodes required shock therapy. Of the 6 shock therapies, 4 were for sustained ventricular tachycardia with the median rate of 236beats/min (IQR 203–250), and the other 2 for ventricular fibrillation. Subsequently, only 27 patients (54%) of all underwent ICD implantation following the WCD use, because of reduced risk of VA after optimal pharmacological therapy or improvement in the left ventricular function. ConclusionsThe WCD use for the acute phase care of patients at high risk of VA can be safe and effective, and may be useful for evaluating indication of ICD implantation.

Experience With the Wearable Cardioverter-Defibrillator in Patients at High Risk for Sudden Cardiac Death.

This study evaluated the wearable cardioverter-defibrillator (WCD) for use and effectiveness in preventing sudden death caused by ventricular tachyarrhythmia or fibrillation. From April 2010 through October 2013, 6043 German WCD patients (median age, 57 years; male, 78.5%) were recruited from 404 German centers. Deidentified German patient data were used for a retrospective, nonrandomized analysis. Ninety-four patients (1.6%) were treated by the WCD in response to ventricular tachyarrhythmia/fibrillation. The incidence rate was 8.4 (95% confidence interval, 6.8-10.2) per 100 patient-years. Patients with implantable cardioverter-defibrillator explantation had an incidence rate of 19.3 (95% confidence interval, 12.2-29.0) per 100 patient-years. In contrast, an incidence rate of 8.2 (95% confidence interval, 6.4-10.3) was observed in the remaining cardiac diagnosis groups, including dilated cardiomyopathy, myocarditis, and ischemic and nonischemic cardiomyopathies. Among 120 shocked patients, 112 (93%) survived 24 hours after treatment, whereas asystole was observed in 2 patients (0.03%) with 1 resulting death. This large cohort represents the first nationwide evaluation of WCD use in patients outside the US healthcare system and confirms the overall value of the WCD in German treatment pathways.

Frequency and Implications of Ischemia Prior to Ventricular Tachyarrhythmia in Patients Treated With a Wearable Cardioverter Defibrillator Following Myocardial Infarction.

Autopsy studies imply that recurrent myocardial infarction (MI) accounts for the majority of sudden death early after acute MI, rather than primary arrhythmia. However, diagnosis of recurrent MI by autopsy is challenging and excludes electrocardiographic data to adjudicate arrhythmic causes. We examined the frequency of ischemia prior to treated ventricular tachycardia/fibrillation (VT/VF) and outcomes in patients using the wearable cardioverter defibrillator (WCD) following acute MI. Primary arrhythmia, rather than ischemia, is a frequent contributor to sudden death following MI. All patients treated for VT/VF over a 6-year period while wearing a WCD following acute MI with advanced left ventricular dysfunction (ejection fraction ≤35%) were included. Patients with ST-segment changes ≥0.1 mV before VT/VF were classified ischemic. Demographics and clinical outcomes were compared between those with ischemia-mediated vs primary arrhythmia. Among 273 patients fulfilling study criteria, 15.4% had ischemia prior to VT/VF. Clinical and WCD use characteristics did not significantly differ between ischemic and primary VT/VF groups. Termination of VT/VF by WCD treatment approximated 96% in both groups. Survival 24 hours post-treatment was 88% and 84% (P = 0.54) for patients with and without ischemic VT/VF, respectively. Furthermore, 30-day cumulative survival for those with and without ischemic VT/VF was 77% and 70%, respectively (P = 0.57). Ischemia is an infrequent cause of VT/VF following MI, contradicting previous study conclusions that recurrent MI is responsible for most post-MI sudden death. Etiology of VT/VF, however, did not influence defibrillation success or survival, which was high for both groups.

176-42: First Clinical Experience with the Wearable Cardioverter Defibrillator in Left Ventricular Assist Device Patients

Introduction: There are currently no data on the use of the wearable cardioverter defibrillator (WCD) in left ventricular assist device (LVAD) patients for the protection from sudden cardiac death (SCD). We aimed to review data available on the use of the WCD in LVAD patients. Methods: The WCD Medical Order Registry was screened for patients with implanted LVAD at the time of WCD use. Indication for WCD use in this cohort, compliance data, arrhythmia events, and end of use decision are reported. Conclusions: In this first clinical experience of the WCD in LVAD patients, WCD use was feasible in the majority of the patients. WCD might be an alternative for temporary monitoring and protection from SCD in LVAD patients.