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

Perspectives of Japanese elders and their healthcare providers on use of wearable technology to monitor their health at home: A qualitative exploration

BACKGROUND

With 24 million Japanese elderly aging at home, the challenges of managing chronic conditions are significant. As many Japanese elders manage multiple chronic conditions, investigating the usefulness of wearable health devices for this population is warranted.

AIM

The purpose of this qualitative study, using grounded theory, was to explore the perspectives of Japanese elders, their caretakers, and their healthcare providers on the use of technology and wearable devices to monitor health conditions and keep Japanese elders safe at home.

METHODS

In conducting this study, a community advisory board was first established to guide the research design; six focus groups and two one-on-one interviews were conducted, with a total of 21 participants.

RESULTS

Four major themes emerged from the analysis: 1) Current Status of Health Issues Experienced by Japanese Elders and Ways of Being Monitored; 2) Current Use of Monitoring Technology and Curiosity about Use of the Latest Digital Technology to Keep Elderly Healthy at Home; 3) Perceived Advantages of Wearing Sensor Technology; and 4) Perceived Disadvantages of Wearing Technology. Many of the elderly participants were interested in using monitoring devices at home, particularly if not complicated. Healthcare workers found monitoring technologies particularly useful during the isolation of the COVID-19 pandemic. Elderly participants felt cost and technical issues could be barriers to using monitoring devices.

CONCLUSION

While there are challenges to utilizing monitoring devices, the potential to aid the aging population of Japan justifies further investigation into the effectiveness of these devices. This study was not registered with a research trial registry.

Fatal ventricular arrhythmias in myocarditis: A review of current indications for defibrillator devices

Historically, patients with myocarditis were considered for implantable cardioverter defibrillator (ICD) utilization only in the chronic phase of the disease following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease, challenging the long-standing perception that this disease process was largely reversible. Given this changing environment of information, the latest US and European guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. Additionally, several studies with small subgroups of patients have demonstrated a possible benefit of wearable cardioverter defibrillators (WCDs) in this patient demographic. Assuming that larger studies confirm their utility, it is possible that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation, while providing temporary protection for a small percentage of patients before the development of a major arrhythmic event. This review ultimately serves as a comprehensive review of the most recent guidelines for defibrillator use in acute and chronic myocarditis. OPINION STATEMENT: The latest US and European guidelines support ICD use for myocarditis patients following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. Previously, patients in the acute phase were excluded from ICD utilization even after experiencing malignant ventricular tachycardia or ventricular fibrillation due to the long-standing perception that this disease process was largely reversible. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease. Additionally, we found that the myocardial damage that is inflicted persists many years after the initial episode. Given this changing environment of information, guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. We support possible ICD utilization for secondary prevention during the acute phase of myocarditis given the elevated risk of arrhythmia recurrence and the fact that any ventricular arrhythmia can induce sudden cardiac death. Future prospective studies are needed to assess which patients may benefit most from early ICD implantation. WCDs have improved survival in patient populations at high-risk for sudden cardiac death who are not candidates for ICD implantation. After analyzing several recent studies with small subgroups of patients, WCDs appear to demonstrate similar efficacy for myocarditis patients as well. Assuming that larger studies confirm their utility, we believe that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation. Furthermore, WCDs have the additional benefit of acting as primary prevention by providing temporary protection for a small percentage of myocarditis patients before they develop a major arrhythmic event.

Cardiovascular Rehabilitation With a WCD-Data From the CR3 Study (Cardiac Rehab Retrospective Review)

PURPOSE

Patients at risk for sudden cardiac death may temporarily need a wearable cardioverter-defibrillator (WCD). Exercise-based cardiac rehabilitation (CR) has a class I recommendation in patients with cardiac disease. The aim of this study was to evaluate the safety and feasibility of undergoing CR with a WCD.

METHODS

We performed a retrospective analysis of all patients with a WCD who completed a CR in Austria (2010-2020).

RESULTS

Patients (n = 55, 60 ± 11 yr, 16% female) with a median baseline left ventricular ejection fraction (LVEF) of 36 (30, 41)% at the start of CR showed a daily WCD wearing duration of 23.4 (22, 24) hr. There were 2848 (8 [1, 26]/patient) automatic alarms and 340 (3 [1, 7]/patient) manual alarms generated. No shocks were delivered by the WCD during the CR period. One patient had recurrent hemodynamically tolerated ventricular tachycardias that were controlled with antiarrhythmic drugs.No severe WCD-associated adverse events occurred during the CR stay of a median 28 (28, 28) d. The fabric garment and the device setting needed to be adjusted in two patients to diminish inappropriate automatic alarms. Left ventricular ejection fraction after CR increased significantly to 42 (30, 44)% ( P < .001). Wearable cardioverter-defibrillator therapy was stopped due to LVEF restitution in 53% of patients. In 36% of patients an implantable cardioverter-defibrillator was implanted, 6% had LVEF improvement after coronary revascularization, one patient received a heart transplantation (2%), two patients discontinued WCD treatment at their own request (4%).

CONCLUSION

Completing CR is feasible and safe for WCD patients and may contribute positively to the restitution of cardiac function.

Prevention of Early Sudden Cardiac Death after Myocardial Infarction Using the Wearable Cardioverter Defibrillator-Results from a Real-World Cohort

BACKGROUND

After acute myocardial infarction (AMI), patients are at risk of sudden cardiac death. The VEST trial failed to show a reduction in arrhythmic mortality in AMI patients with an LVEF ≤ 35% prescribed with a WCD, having a lower-than-expected WCD wearing compliance.

OBJECTIVES

The aim was to investigate on outcomes of patients in a real-world Austrian cohort with good compliance.

METHODS

A retrospective analysis of all eligible Austrian WCD patients according to the VEST trial inclusion and exclusion criteria between 2010 and 2020 was performed.

RESULTS

In total, 105 Austrian patients (64 ± 11 years, 12% female; LVEF 28 ± 6%) received a WCD for a median of 69 (1; 277) days after AMI (wearing duration 23.5 (0; 24) hours/day). Within the first 90 days, 4/105 (3.8%) patients received 9 appropriate shocks (2 (1; 5) shocks). No inappropriate shocks were delivered, and 3/105 (2.9%) patients died during follow-up. Arrhythmic mortality (1.9% Austria vs. 1.6% VEST, p = 0.52), as well as all-cause mortality (2.9% vs. 3.1%, p = 0.42) was comparable in both cohorts.

CONCLUSIONS

The WCD is a safe treatment option in a highly selected cohort of patients with LVEF ≤ 35% after AMI. However, despite excellent WCD wearing duration in our cohort, the arrhythmic mortality rate was not significantly different.

Wearable cardioverter defibrillator for preventing sudden cardiac death in patients at risk: An updated systematic review of comparative effectiveness and safety

Objectives

To synthesise the available evidence of wearable cardioverter defibrillator (WCD) therapy as an add-on measure to optimal medical therapy (OMT) or as a replacement of hospital stay.

Methods

An update systematic review (SR) of comparative effectiveness and safety of WCD therapy was conducted. We included randomised controlled trials (RCT), prospective comparative studies and prospective uncontrolled studies with at least 100 patients. A narrative synthesis of the evidence was conducted.

Results

One RCT (n = 2348) and further eleven observational studies (n = 5345) fulfilled our inclusion criteria. In the only available RCT, the use of the WCD was not statistically associated with a clinical benefit on arrhythmic mortality in post-myocardial infarction (MI) patients with an ejection fraction of ≤35%. The compliance with WCD therapy was low in the RCT and high in observational studies, with ten observational studies reporting on a daily wear time between 20 and 23.5 h. The range of percentage of patients receiving at least one appropriate shock was 1-4.8% and the rate of first shock success was reported to be 100% in three studies. Serious adverse events (SAEs) such as inappropriate shocks occurred rarely, with between 0% and 2% of patients being inappropriately shocked within ten observational studies. In one of the observational studies, two patients (2%) were allergic to nickel developing skin rash and false alarms occurred in 58 patients (57%) in this study. Another registry study (n = 448) reported milder AEs, such as dermatitis and pressure marks, occurring in 0.9% and 0.2% of enrolled patients, respectively.

Conclusion

The only available RCT failed to show superiority of add-on use of WCD in post MI patients. Observational evidence shows that the compliance with WCD is good, but the evidence is afflicted with selection bias and the inclusion of diverse mixed patient populations diluting the ability to draw indication-specific conclusions on the utility of the device. More comparative data is needed to justify continuing or expanding use of WCD therapy.

A Wearable Cardioverter Defibrillator with a Low False Alarm Rate

BACKGROUND

A wearable cardioverter defibrillator (WCD) is indicated in appropriate patients to reduce risk for sudden cardiac death. Challenges for patients wearing a WCD have been frequent false shock alarms primarily due to ECG noise and wear discomfort.

OBJECTIVE

To test a contemporary WCD designed for reduced false shock alarms and improved comfort.

METHODS

130 patients with LVEF ≤ 40% and an active implantable cardioverter defibrillator (ICD) were fitted with the ASSURE WCD (Kestra Medical Technologies) and followed 30 days. WCD detection was enabled and shock alarm markers recorded, but shocks and shock alarms disabled. All WCD episodes and ICD VT/VF episodes were adjudicated. The primary endpoint was the false positive shock alarm rate with a performance goal of 1 every 3.4 days (0.29 per patient-day).

RESULTS

Of 163 WCD episodes, 4 were VT/VF and 159 non-VT/VF (121 rhythms with noise, 32 uncertain with noise, 6 atrial flutter without noise). Only 3 false positive shock alarm markers were recorded; 1 false positive shock alarm every 1,333 patient-days (0.00075 per patient-day, 95% CI: 0.00015-0.00361; p < 0.001). No ICD recorded VT/VF episodes meeting WCD detection criteria (≥ 170 bpm for ≥ 20 seconds) were missed by the WCD during 3,501 patient-days of use. Median wear was 31.0 days (IQR 2.0) and median daily use 23.0 hours (IQR 1.7). Adverse events were mostly mild: skin irritation (19.4%) and musculoskeletal discomfort (8.5%).

CONCLUSION

The ASSURE WCD demonstrated a low false positive shock alarm rate, low patient-reported discomfort, and no serious adverse events. This article is protected by copyright. All rights reserved.

Multiparameter Monitoring with a Wearable Cardioverter Defibrillator

A wearable cardioverter-defibrillator (WCD) is a temporary treatment option for patients at high risk for sudden cardiac death (SCD) and for patients who are temporarily not candidates for an implantable cardioverter defibrillator (ICD). In addition, the need for telemedical concepts in the detection and treatment of heart failure (HF) and its arrhythmias is growing. The WCD has evolved from a shock device detecting malignant ventricular arrhythmias (VA) and treating them with shocks to a heart-failure-monitoring device that captures physical activity and cardioacoustic biomarkers as surrogate parameters for HF to help the treating physician surveil and guide the HF therapy of each individual patient. In addition to its important role in preventing SCD, the WCD could become an important tool in heart failure treatment by helping prevent HF events by detecting imminent decompensation via remote monitoring and monitoring therapy success.

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

BACKGROUND

Previous studies established a role 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.

OBJECTIVES

The authors investigated adherence to, as well as the safety and effectiveness of, WCD use in a real-world cohort of patients at high risk for SCD.

MATERIAL AND METHODS

All consecutive patients (n = 83) receiving a WCD at a German 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.

RESULTS

During 3680 wearing days (mean WCD wear time, 44 days) with a median 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 30 patients (36.1%) a cardioverter/defibrillator was implanted.

CONCLUSION

In a real-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 a crucial issue as one patient in the present series died while not wearing the device.

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

Aims

Patients 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.

Methods

We 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.

Results

In 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.

Conclusion

After 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.

Wearable cardioverter-defibrillator: friend or foe in suspected myocarditis?

Aim

Wearable cardioverter defibrillator (WCD, LifeVest, and Zoll) therapy has become a useful tool to bridge a temporarily increased risk for sudden cardiac death. However, despite extensive use, there is a lack of evidence whether patients with myocarditis and impaired LVEF may benefit from treatment with a WCD.

Methods and results

We conducted a single‐centre retrospective observational study analysing patients with a WCD prescribed between September 2015 and April 2020 at our institution. In total, 135 patients were provided with a WCD, amongst these 76 patients (mean age 48.9 ± 13.7 years; 84.2% male) for clinically suspected myocarditis. Based on the results of the endomyocardial biopsy and, where available cardiac magnetic resonance imaging, 39 patients (51.3%) were diagnosed with myocarditis and impaired LVEF and 37 patients (48.7%) with dilated cardiomyopathy (DCM) without evidence of cardiac inflammation. The main immunohistopathological myocarditis subtype was lymphocytic myocarditis in 36 (92.3%) patients, and four patients (10.3%) of this group had an acute myocarditis. Three patients had cardiac sarcoidosis (7.7%). Ventricular tachycardia occurred in seven myocarditis (in total 41 VTs; 85.4% non‐sustained) and one DCM patients (in total one non‐sustained ventricular tachycardia). Calculated necessary WCD wearing time until ventricular tachycardia occurrence is 86.41 days in myocarditis compared with 6.46 years in DCM patients.

Conclusions

Our data suggest that myocarditis patients may benefit from WCD therapy. However, as our study is not powered for outcome, further randomized studies powered for the outcome morbidity and mortality are necessary.

Benefit of a wearable cardioverter defibrillator for detection and therapy of arrhythmias in patients with myocarditis

Aims

Myocarditis may lead to malignant arrhythmias and sudden cardiac death. As of today, there are no reliable predictors to identify individuals at risk for these catastrophic events. The aim of this study was to evaluate if a wearable cardioverter defibrillator (WCD) may detect and treat such arrhythmias adequately in the peracute setting of myocarditis.

Methods and results

In this observational, retrospective, single centre study, we reviewed patients presenting to the Charité Hospital from 2009 to 2017, who were provided with a WCD for the diagnosis of myocarditis with reduced ejection fraction (<50%) and/or arrhythmias. Amongst 259 patients receiving a WCD, 59 patients (23%) were diagnosed with myocarditis by histology. The mean age was 46 ± 14 years, and 11 patients were women (19%). The mean WCD wearing time was 86 ± 63 days, and the mean daily use was 20 ± 5 h. During that time, two patients (3%) had episodes of sustained ventricular tachycardia (VT; four total) corresponding to a rate of 28 sustained VT episodes per 100 patient‐years. Consequently, one of these patients underwent rhythm stabilization through intravenous amiodarone, while the other patient received an implantable cardioverter defibrillator. Two patients (3.4%) were found to have non‐sustained VT.

Conclusions

Using a WCD after acute myocarditis led to the detection of sustained VT in 2/59 patients (3%). While a WCD may prevent sudden cardiac death after myocarditis, our data suggest that WCD may have impact on clinical management through monitoring and arrhythmia detection.

Effectiveness, efficacy, and safety of wearable cardioverter-defibrillators in the treatment of sudden cardiac arrest - Results from a health technology assessment

OBJECTIVES

To assess the effectiveness, efficacy, and safety of a wearable cardioverter-defibrillator (WCD) in adult persons with high risk for sudden cardiac arrest and for which an implantable cardioverter is currently not applicable.

METHODS

We performed a systematic literature search in Medline, Embase, Cochrane Library, and CRD-databases. Study selection was performed by two reviewers independently. Data were presented quantitatively; due to heterogeneity of studies no meta-analysis was performed.

RESULTS

One randomized-controlled trial (RCT), one non-randomized comparative trial, and forty-four non-comparative trials were included. The RCT reported an overall mortality of 3.1 percent in the WCD group versus 4.9 percent in controls (relative risk [RR]: .64; 95 percent confidence interval [CI], .43-.98, p = .04), but no significant effect on arrhythmia-related mortality. The RR for arrhythmia-related mortality amounted to .67 (95 percent CI, .37-1.21, p = .18) as assessed in the RCT. Appropriate shocks were observed in 1.3 percent of patients in both comparative studies, and inappropriate shocks in .6 percent of patients in the RCT. Termination of ventricular tachycardia (VT) or ventricular fibrillation (VF) was successful in 75 to 100 percent of appropriate shocks in all studies. Adverse events assessed in the RCT showed a lower incidence of shortness of breath (38.8 percent vs. 45.3 percent; p = .004), higher incidence of rash at any location (15.3 percent vs. 7.1 percent; p < .001), and higher incidence of itching at any location (17.2 percent vs. 6.4 percent; p < .001) for WCD.

CONCLUSIONS

Available evidence demonstrates that the WCD detects and terminates VT/VF events reliably and shows a high rate of appropriate shocks in mixed patient populations. Data of large registries confirm that the WCD is a safe intervention.

Use of wearable cardioverter-defibrillator in association with catheter ablation for atrial fibrillation-related tachycardiomyopathy

Implantable cardioverter-defibrillator (ICD) is an effective therapy in patients known to be at high risk for sudden cardiac death (SCD). Nevertheless, ICD implantation is not indicated in transient or reversible causes of SCD. Wearable cardioverter-defibrillator is increasingly used for SCD prevention in patients with a transient risk of ventricular arrhythmia.

Prognostic impact of recurrences of ventricular tachyarrhythmias and appropriate ICD therapies in a high-risk ICD population

PURPOSE

The study sought to evaluate the prognostic impact of recurrences of ventricular tachyarrhythmias in consecutive ICD recipients with ventricular tachyarrhythmias on admission.

METHODS

All consecutive patients surviving at least one episode of ventricular tachyarrhythmias from 2002 to 2016 and discharged with an ICD (pre-existing ICD or ICD implantation at index hospitalization) were included. The primary endpoint was all-cause mortality according to the presence or absence of recurrences of ventricular tachyarrhythmias at 5 years. Secondary endpoints comprised the impact of different types of recurrences, appropriate ICD therapies, as well as predictors of recurrences and appropriate ICD therapies. Kaplan-Meier, multivariable Cox regression and propensity score matching analyses were applied.

RESULTS

A total of 592 consecutive ICD recipients was included (44% with recurrences of ventricular tachyarrhythmias and 56% without). Recurrences of ventricular tachyarrhythmias were associated with increased all-cause mortality at 5 years (HR = 1.498; 95% CI = 1.052-2.132; p = 0.025). Worst survival was observed in patients with sustained VT or VF as first recurrences compared to non-sustained VT, as well as in patients with cumulative recurrences of non-sustained or sustained VT plus VF, whereas mortality was not affected by the number of recurrences of ventricular tachyarrhythmias (> 4 vs. ≤ 4). Moreover, appropriate ICD therapies were associated with increased all-cause mortality (HR = 1.874; 95% CI = 1.318-2.666; p = 0.001), mainly attributed to secondary preventive ICDs. Finally, atrial fibrillation, LVEF < 35% and non-ischemic cardiomyopathy were identified as predictors of recurrences of ventricular tachyarrhythmias and appropriate ICD therapies.

CONCLUSIONS

Recurrences of ventricular tachyarrhythmias and recurrent appropriate ICD therapies are associated with increased long-term all-cause mortality in consecutive ICD recipients. Non-ischemic cardiomyopathy, AF and LVEF < 35% revealed to be significant predictors of both endpoints.

Wearable Cardioverter-Defibrillator Therapy for the Prevention of Sudden Cardiac Death: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to synthesize the available evidence on the use of the wearable cardioverter-defibrillator (WCD).

BACKGROUND

Observational WCD studies for the prevention of sudden cardiac death have provided conflicting data. The VEST (Vest Prevention of Early Sudden Death) trial was the first randomized controlled trial (RCT) showing no reduction in sudden cardiac death as compared to medical therapy only.

METHODS

We searched PubMed, EMBASE, and Google Scholar for studies reporting on the outcomes of patients wearing WCDs from January 1, 2001, through March 20, 2018. Rates of appropriate and inappropriate WCD therapies were pooled. Estimates were derived using DerSimonian and Laird's method.

RESULTS

Twenty-eight studies were included (N = 33,242; 27 observational, 1 RCT-WCD arm). The incidence of appropriate WCD therapy was 5 per 100 persons over 3 months (95% confidence interval [CI]: 3.0 to 6.0, I² = 93%). In studies on ischemic cardiomyopathy, the appropriate WCD therapy incidence was lower in the VEST trial (1 per 100 persons over 3 months; 95% CI: 1.0 to 2.0) as compared with observational studies (11 per 100 persons over 3 months; 95% CI: 11.0 to 20.0; I² = 93%). The incidence of inappropriate therapy was 2 per 100 persons over 3 months (95% CI: 1.0 to 3.0; I² = 93%). Mortality while wearing WCD was rare at 0.7 per 100 persons over 3 months (95% CI: 0.3 to 1.7; I² = 94%).

CONCLUSIONS

The rate of appropriately treated WCD patients over 3 months of follow-up was substantial; higher in-observational studies as compared with the VEST trial. There was significant heterogeneity. More RCTs are needed to justify continued use of WCD in primary prevention.

Extended Use of the Wearable Cardioverter-Defibrillator: Which Patients Are Most Likely to Benefit?

BACKGROUND

Wearable cardioverter-defibrillators (WCD, LifeVest, ZOLL) can protect from sudden cardiac death bridging a vulnerable period until a decision on implantable cardioverter-defibrillator (ICD) implantation can be reached. WCD is commonly used for 3 months or less. It is unknown, which patients use WCD longer and which patients are most likely to benefit from it.

HYPOTHESIS

Extended use of WCD is reasonable in selected cases based on underlying heart disease and overall patient risk profile.

METHODS

We conducted a systematic and comprehensive research of all published clinical studies on PubMed reporting on the use of the WCD. Only original articles reporting on wear times and time to appropriate shocks were included in our analysis.

RESULTS

The search resulted in 127 publications. 14 parameters were reported necessary for inclusion in our analysis. Median wear times ranged from 16 to 394 days. The median wear time was especially long for patients suffering from nonischemic cardiomyopathy (NICM) (range: 50-71 days) and specifically peripartum cardiomyopathy (PPCM) (120 days) and for heart transplant candidates. There was a large variation of appropriate shocks according to indication for WCD use. In contrast to NICM in general, the number of appropriate shocks was particularly high in patients with PPCM (0 in 254 patients and 5 in 49 patients, respectively). The median and maximal time periods to the first appropriate shock were longest in patients with PPCM (median time to the first appropriate shock: 68 days).

CONCLUSIONS

Prolonged use of WCD is not uncommon in available literature. Patients suffering from NICM and specifically PPCM seem most likely to have longer therapy duration with WCD with success. Careful patient selection for prolonged use may decrease the need for ICD implantation in the future; however, prospective data are needed to confirm this hypothesis.

[Wearable defibrillator : Current evidence]

The wearable cardioverter/defibrillator (WCD) is safe and effective in the prevention of sudden cardiac death, and has found its way into international guidelines and clinical practice. Nearly 40,000 patients with a WCD have been published in clinical registries and one randomized study has recently been presented. Especially patients with newly diagnosed cardiomyopathy with severely reduced left ventricular function show an increased risk for ventricular tachyarrhythmias and may benefit from a WCD. In these patients without an indication for an implantable cardioverter-defibrillator (ICD), the WCD offers protection from sudden cardiac death during initiation and optimization of heart failure medication. Critical patient selection and structured patient management is crucial for successful WCD prescription. This review gives an overview of the current data and recommendations on WCD.

Misunderstood or Mistrusted? The Under-Utilization of the Wearable Cardioverter Defibrillator in Clinical Practice

Annually in the United States, sudden cardiac death (including out-of-hospital cardiac arrests) is responsible for over 300,000 deaths, comprising 40%-50% of total mortality rates from cardiovascular disease. Among the highest-risk patients are those with ischemic and nonischemic cardiomyopathy who have a reduced left ventricular ejection fraction (≤ 35%-40%). However, not everyone is a candidate for an implantable cardioverter defibrillator. In 2002, the wearable cardioverter defibrillator (WCD) gained Food and Drug Administration approval for its efficacy in the prevention of sudden cardiac arrest or death in certain at-risk populations and has been making its way into national guidelines with Class IIa to IIb strength of evidence. Despite the prevalence of sudden cardiac death and the demonstrated efficacy of the WCD, this technology remains under-prescribed. This study seeks to explicate the potential causes for under-utilization of WCDs and offer means of overcoming barriers to its use. Among these reasons include confusion about the guidelines and when to prescribe, who can prescribe the device, and debate about whether the WCD is efficacious based on recent studies. Other social barriers to prescription include cost and adherence to therapy by the patient. This study sets the stage for further research on the improvement of education about the device and opens discourse about its prescription in clinical practice.

Impairment of Quality of Life among Patients with Wearable Cardioverter Defibrillator Therapy (LifeVest®): A Preliminary Study

Background

Wearable cardioverter defibrillator (WCD) therapy is feasible and safe in patients as a transient protection against sudden cardiac death (SCD). However, the impact of WCD therapy on quality of life (QoL) has not been studied.

Methods

In our single-centre study, 109 consecutive patients with a prescription of WCD were retrospectively analysed. Quality of life has been assessed by a standardized questionnaire (EQ-5D-3L, modified). Additionally, clinical baseline and follow-up data and recorded arrhythmic episodes were evaluated.

Results

Mean WCD therapy time was 56.2 (± 42.4) days, with a daily wear time of 19.7 (± 5) hours. A total of 3441 arrhythmia episodes were detected. Of these, 27 (1%) were adequate but did not require shock therapy. Likewise, no inadequate shock therapy occurred. WCD therapy negatively affected quality of life: 43% of patients reported mental health issues. 37% reported pain or discomfort. Self-care, usual activities, and mobility were restricted in 17%, 48%, and 36%, respectively. 29% were afraid of receiving shock therapy, and 48% suffered from sleep disturbance. However, 64% indicated having felt safe during WCD therapy. Accordingly, average quality of life was rated 70/100 points.

Conclusion

In our cohort, no SCD was prevented by WCD therapy. In contrast, in this preliminary study quality of life was reduced. Thus, careful recommendation of WCD therapy for high risk patients should be considered.

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 58.5 days. Average daily wearing time was 22.7 h. Compliance was reduced in patients ≤ 50 years. 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.

Therapy optimization in patients with heart failure: the role of the wearable cardioverter-defibrillator in a real-world setting

Background

The wearable cardioverter-defibrillator (WCD) has emerged as a valuable tool to temporarily protect patients at risk for sudden cardiac death (SCD). The aim of this study was to determine the value of the WCD for therapy optimization of heart failure patients.

Methods

One hundred five consecutive patients that received WCD between 4/2012 and 9/2016 were included in the study. All patients were followed for clinical outcome and echocardiographic parameters during WCD therapy and had continued follow-up after WCD therapy, irrespective of subsequent implantable cardioverter-defibrillator (ICD) implantation.

Results

The most common indication for WCD were newly diagnosed ischemic (ICM) or non-ischemic cardiomyopathy (NICM) with left ventricular ejection fraction (LVEF) ≤35%. Mean WCD wear time was 68.8 ± 50.4 days with a mean daily use of 21.5 ± 3.5 h. Five patients (4.8%) received a total of five appropriate WCD shocks.

During WCD wear, patients with ICM and NICM showed significant improvement in LVEF, reducing the proportion of patients with a need for primary preventive ICD implantation to 54.8% (ICM) and 48.8% (NICM). An ICD was finally implanted in 51.4% of the study patients (24 trans-venous ICDs, 30 subcutaneous ICDs).

After discontinuation of WCD therapy, all patients were followed for a mean of 18.6 ± 12.3 months. 5.6% of patients with implanted ICDs received appropriate therapies. No patient with subcutaneous ICD needed change to a trans-venous device. None of the patients without an implanted ICD suffered from ventricular tachyarrhythmias and no patient died suddenly.

In patients with NICM a significant LVEF improvement was observed during long-term follow-up (from 34.8 ± 11.1% to 41.0 ± 10.2%).

Conclusions

WCD therapy successfully bridged all patients to either LVEF recovery or ICD implantation. Following WCD, ICD implantation could be avoided in almost half of the patients. In selected patients, prolongation of WCD therapy beyond 3 months might further prevent unnecessary ICD implantation. The WCD as an external monitoring system contributed important information to optimize device selection in patients that needed ICD implantation.

Usefulness of the WCD in patients with suspected tachymyopathy

AIMS

The wearable cardioverter defibrillator (WCD) is used for temporary protection of patients deemed to be at high risk for sudden death. There is limited experience regarding the clinical development of patients with tachymyopathy. We aimed to evaluate the clinical development of tachymyopathy patients protected with a WCD in a single-center non-randomized patient cohort.

METHODS AND RESULTS

We fitted 130 consecutive patients deemed to be at high risk for ventricular tachyarrhythmias with the WCD. Of these, 20 patients (15%) presenting with newly diagnosed heart failure in the setting of rapidly conducted atrial fibrillation/flutter were suspected to suffer from tachymyopathy. The control group consisted of the remaining 110 patients with other indications for WCD therapy. LVEF increased by more than 10% in 13/20 (65%) tachymyopathy patients compared to 40/110 (36%) patients in the control population (p = 0.01). Similarly, BNP levels decreased in 15/20 (75%) tachymyopathy patients compared to 41/110 (37%) in the control group (p = 0.05). ICD implantation rates were lower in the tachymyopathy group (3/20) compared to the control population (40/110; p = 0.04). On further follow-up (mean 12 ± 8 months), patients with suspected tachymyopathy had no sustained ventricular arrhythmias. Compared to 5/110 patients in the control group, no tachymyopathy patient died.

CONCLUSION

Most of the patients with suspected tachymyopathy have a favorable clinical outcome. The WCD is useful for temporary protection while LV function recovers.

Clinical scores for outcomes of rhythm control or arrhythmia progression in patients with atrial fibrillation: a systematic review

Patients with atrial fibrillation (AF) are commonly managed with rhythm control strategy, but the natural history of this common arrhythmia leads itself to progression from paroxysmal to persistent or permanent AF, and recurrences are evident despite rhythm control treatments using cardioversion or catheter ablation. Numerous clinical factors have been associated with outcomes of rhythm control or arrhythmia progression in patients with AF. The more common factors have been used to formulate risk stratification scores, to help predict the outcomes of rhythm control treatments or AF progression. This review article provides an overview on the published clinical risk scores related to outcomes of rhythm control strategy or AF progression.

Risk for life-threatening arrhythmia in newly diagnosed peripartum cardiomyopathy with low ejection fraction: a German multi-centre analysis

Introduction

Peripartum cardiomyopathy (PPCM) is a rare cardiomyopathy characterized by an acute reduction in left ventricular ejection fraction (LVEF). Sudden deaths during the course of PPCM are reported to be elevated, the underlying mechanisms remains unknown. The aim of the present multi-centre study was to evaluate the arrhythmia burden in a multi-centre approach in patients with PPCM using a wearable cardioverter/defibrillator (WCD).

Methods and results

Forty-nine patients from 16 German centres with newly diagnosed PPCM and LVEF ≤35% receiving a WCD were included in this retrospective analysis. Mean follow-up was 15 ± 10 months. At diagnosis, mean age was 33 ± 5 years, parity was 2.1 ± 1.6, LVEF was 21 ± 7%, NYHA functional class was 3.4 ± 0.7. Mean wear time was 120 ± 106 days, mean wear time per day was 21.4 ± 3.3 h. Six (12%) patients presented eight ventricular tachyarrhythmias during WCD period: five episodes of VF, two sustained ventricular tachycardia (VT) and one non-sustained VT occurred.

Conclusion

This multicentre study underpins the elevated risk for ventricular tachyarrhythmias in patients with newly diagnosed PPCM and reduced LVEF. A WCD should be considered for 3–6 months in these patients to prevent sudden cardiac death from ventricular tachyarrhythmias.