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

Predictors of ventricular tachyarrhythmia in patients with a wearable cardioverter defibrillator: an international multicenter registry

BACKGROUND AND AIMS

Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmias and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicenter WCD registry was to identify predictors of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) in this population.

METHODS

One thousand six hundred seventy-five patients with WCD were included in a multicenter registry from 9 European centers, with a median follow-up of 440 days (IQR 120-893). The primary study end point was the occurrence of sustained VT/VF.

RESULTS

Sustained VT was detected by WCD in 5.4% and VF in 0.9% of all patients. Of the 30.3% of patients receiving ICD implantation during follow-up, sustained VT was recorded in 9.3% and VF in 2.6%. Non-ischemic cardiomyopathy (HR 0.5, p < 0.001), and medication with angiotensin-converting enzyme inhibitors (HR 0.7, p = 0.027) and aldosterone antagonists (HR 0.7, p = 0.005) were associated with a significantly lower risk of VT/VF.

CONCLUSIONS

Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of VT/VF in the presence of non-ischemic cardiomyopathy. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for VT/VF.

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

BACKGROUND

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 sought to evaluate the effects of a novel artificial intelligence algorithm to reduce alarms related to electrical noise or artifact (advanced arrhythmia discrimination algorithm, AArD).

METHODS

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.

RESULTS

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]).

CONCLUSIONS

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.

ANMCO position paper: guide to the appropriate use of the wearable cardioverter defibrillator in clinical practice for patients at high transient risk of sudden cardiac death

Extended risk stratification and optimal management of patients with a permanently increased risk of sudden cardiac death (SCD) are becoming increasingly important. There are several clinical conditions where the risk of arrhythmic death is present albeit only transient. As an example, patients with depressed left ventricular function have a high risk of SCD that may be only transient if there will be a significant recovery of function. It is important to protect the patients while receiving and titrating to the optimal dose the recommended drugs that may lead to an improved left ventricular function. In several other conditions, a transient risk of SCD can be observed even if the left ventricular function is not compromised. Examples are patients with acute myocarditis, during the diagnostic work-up of some arrhythmic conditions or after extraction of infected catheters while eradicating the associated infection. In all these conditions, it is important to offer a protection to these patients. The wearable cardioverter defibrillator (WCD) is of particular importance as a temporary non-invasive technology for both arrhythmia monitoring and therapy in patients with increased risk of SCD. Previous studies have shown the WCD to be an effective and safe therapy for the prevention of SCD caused by ventricular tachycardia/fibrillation. The aim of this ANMCO position paper is to provide a recommendation for clinical utilization of the WCD in Italy, based upon current data and international guidelines. In this document, we will review the WCD functionality, indications, clinical evidence, and guideline recommendations. Finally, a recommendation for the utilization of the WCD in routine clinical practice will be presented, in order to provide physicians with a practical guidance for SCD risk stratification in patients who may benefit from this device.

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.

Real life experience with the wearable cardioverter-defibrillator in an international multicenter Registry

Patients at high risk for sudden cardiac death (SCD) may benefit from wearable cardioverter defibrillators (WCD) by avoiding immediate implantable cardioverter defibrillator (ICD) implantation. Different factors play an important role including patient selection, compliance and optimal drug treatment. We aimed to present real world data from 4 centers from Germany and Switzerland. Between 04/2012 and 03/2019, 708 patients were included in this registry. Patients were followed up over a mean time of 28 ± 35.5 months. Outcome data including gender differences and different etiologies of cardiomyopathy were analyzed. Out of 708 patients (81.8% males, mean age 61.0 ± 14.6), 44.6% of patients had non-ischemic cardiomyopathy, 39.8% ischemic cardiomyopathy, 7.9% myocarditis, 5.4% prior need for ICD explantation and 2.1% channelopathy. The mean wear time of WCD was 21.2 ± 4.3 h per day. In 46% of patients, left ventricular ejection fraction (LVEF) was > 35% during follow-up. The younger the patient was, the higher the LVEF and the lower the wear hours per day were. The total shock rate during follow-up was 2.7%. Whereas an appropriate WCD shock was documented in 16 patients (2.2%), 3 patients received an inappropriate ICD shock (0.5%). During follow-up, implantation of a cardiac implantable electronic device was carried out in 34.5% of patients. When comparing German patients (n = 516) to Swiss patients (n = 192), Swiss patients presented with longer wear days (70.72 ± 49.47 days versus 58.06 ± 40.45 days; p = 0.001) and a higher ICD implantation rate compared to German patients (48.4% versus 29.3%; p = 0.001), although LVEF at follow-up was similar between both groups. Young age is a negative independent predictor for the compliance in this large registry. The most common indication for WCD was non-ischemic cardiomyopathy followed by ischemic cardiomyopathy. The compliance rate was generally high with a decrease of wear hours per day at younger age. Slight differences were found between Swiss and German patients, which might be related to differences in mentality for ICD implantation.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

Extended follow-up after wearable cardioverter-defibrillator period: the PROLONG-II study

AIM

The wearable cardioverter-defibrillator (WCD) is used for temporary protection from sudden cardiac death (SCD) in patients with newly diagnosed heart failure with reduced ejection fraction before considering an implantable cardioverter-defibrillator (ICD). However, the prognostic significance of the WCD remains controversial due to conflicting evidence. The aim of the present study was to evaluate prognosis of patients receiving life-saving WCD shocks.

METHODS AND RESULTS

All patients receiving a WCD at Hannover Medical School for heart failure with reduced ejection fraction between 2012 and 2017 were included. Data were acquired at baseline, at 3 months and at last available follow-up (FU). Three hundred and fifty-three patients were included (69% male; age 56 ± 15 years; left ventricular ejection fraction 25 ± 8%). FU after the WCD was 2.8 ± 1.5 years with a maximum of 6.8 years. Daily WCD wear time was 22 ± 4 h. Fourteen patients (4%) received appropriate WCD shocks. Two patients (0.6%) died during the WCD period. Thirty patients (9%) died during extended FU. Mean estimated survival after the WCD was similar between patients with and without WCD shocks. Patients without an ICD recommendation after WCD prescription did not experience SCD during FU.

CONCLUSIONS

Patients with WCD shocks showed a favourable survival. Patients without an ICD recommendation after WCD prescription had no SCD during FU. These findings support the practice of careful risk stratification before considering an ICD and the use of the WCD for temporary protection from SCD.

Protected risk stratification with the wearable cardioverter-defibrillator: results from the WEARIT-II-EUROPE registry

Background

The prospective WEARIT-II-EUROPE registry aimed to assess the value of the wearable cardioverter-defibrillator (WCD) prior to potential ICD implantation in patients with heart failure and reduced ejection fraction considered at risk of sudden arrhythmic death.

Methods and results

781 patients (77% men; mean age 59.3 ± 13.4 years) with heart failure and reduced left ventricular ejection fraction (LVEF) were consecutively enrolled. All patients received a WCD. Follow-up time for all patients was 12 months. Mean baseline LVEF was 26.9%. Mean WCD wearing time was 75 ± 47.7 days, mean daily WCD use 20.3 ± 4.6 h. WCD shocks terminated 13 VT/VF events in ten patients (1.3%). Two patients died during WCD prescription of non-arrhythmic cause. Mean LVEF increased from 26.9 to 36.3% at the end of WCD prescription (p < 0.01). After WCD use, ICDs were implanted in only 289 patients (37%). Forty patients (5.1%) died during follow-up. Five patients (1.7%) died with ICDs implanted, 33 patients (7%) had no ICD (no information on ICD in two patients). The majority of patients (75%) with the follow-up of 12 months after WCD prescription died from heart failure (15 patients) and non-cardiac death (15 patients). Only three patients (7%) died suddenly. In seven patients, the cause of death remained unknown.

Conclusions

Mortality after WCD prescription was mainly driven by heart failure and non-cardiovascular death. In patients with HFrEF and a potential risk of sudden arrhythmic death, WCD protected observation of LVEF progression and appraisal of competing risks of potential non-arrhythmic death may enable improved selection for beneficial ICD implantation.

Graphic abstract

The Wearable Cardioverter-Defibrillator: Experience in 153 Patients and a Long-Term Follow-Up

Background: The wearable cardioverter-defibrillator (WCD) is available for patients at high risk for sudden cardiac death (SCD) when immediate implantable cardioverter-defibrillator (ICD) implantation is not possible or indicated. Patient selection remains challenging especially in primary prevention. Long-term data on these patients is still lacking.

METHODS

153 patients were included in this study. They were prescribed the WCD between April 2012 and March 2019 at the University Medical Center, Mannheim, Germany. The mean follow-up period was 36.2 ± 15.6 months. Outcome data, including all-cause mortality, were analyzed by disease etiology and ICD implantation following WCD use.

RESULTS

We analyzed 56 patients with ischemic cardiomyopathy, 70 patients with non-ischemic cardiomyopathy, 16 patients with prior need for ICD/CRT-D (device for cardiac resynchronization therapy with defibrillator) explanation, 8 patients with acute myocarditis and 3 patients with congenital diseases. 58% of the patients did not need ICD/CRT-D implantation after WCD use. 4% of all patients suffered from appropriate WCD shocks. 2 of these patients (33%) experienced appropriate ICD shocks after implantation due to ventricular tachyarrhythmias. Long-term follow-up shows a good overall survival. All-cause mortality was 10%. There was no significant difference between patients with or without subsequent ICD implantation (p = 0.48). Patients with ischemic cardiomyopathy numerically showed a higher long-term mortality than patients with non-ischemic cardiomyopathy (14% vs. 6%, p = 0.13) and received significantly more ICD shocks after implantation (10% of ischemic cardiomyopathy (ICM) patients versus 3% of non-ischemic cardiomyopathy (NICM) patients, p = 0.04). All patients with ventricular tachyarrhythmias during WCD use or after ICD implantation survived the follow-up period.

CONCLUSION

Following WCD use, ICD implantation could be avoided in 58% of patients. Long-term follow-up shows good overall survival. The majority of all patients did not suffer from WCD shocks nor did receive ICD shocks after subsequent implantation. Patient selection regarding predictive conditions on long-term risk of ventricular tachyarrhythmias needs further risk stratification.

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.