Der tragbare Kardioverter/Defibrillator (WCD) – Indikationen und Einsatz

Expanded application of wearable cardioverter defibrillators beyond current guidelines: proposal for a European register explained through single clinical scenarios

The wearable cardioverter defibrillator (WCD) is becoming a more and more widely used instrument for the prevention of sudden cardiac death of patients either with a secondary prevention implantable cardioverter defibrillator indication or with a transient high risk of sudden cardiac death. Although clinical practice has demonstrated a benefit of protecting patients for a period as long as 3-6 months with such devices, the current European guidelines concerning ventricular arrhythmias and sudden cardiac death are still extremely restrictive in the patient selection in part because of the costs derived from such a prevention device, in part because of the lack of robust randomised trials.To illustrate expanded use cases for the WCD, four real-life clinical cases are presented where patients received the device slightly outside the established guidelines. These cases demonstrate the broader utility of WCDs in situations involving acute myocarditis, thyrotoxicosis, pre-excited atrial fibrillation and awaiting staging/prognosis of a lung tumour. The findings prompt expansion of the existing guidelines for WCD use to efficiently protect more patients whose risk of arrhythmic cardiac death is transient or uncertain. This could be achieved by establishing a European register of the patients who receive a WCD for further analysis.

Use of the Wearable Cardioverter-Defibrillator Among Patients With Myocarditis and Reduced Ejection Fraction or Ventricular Tachyarrhythmia: Data From a Multicenter Registry

Background Data on the use of the wearable cardioverter-defibrillator (WCD) among patients with myocarditis remain sparse. Consequently, evidence for guideline recommendations in this patient population is lacking. Methods and Results In total, 1596 consecutive patients were included in a multicenter registry from 8 European centers, with 124 patients (8%) having received the WCD due to myocarditis and reduced left ventricular ejection fraction or prior ventricular tachyarrhythmia. The mean age was 51.6±16.3 years, with 74% being male. Patients were discharged after index hospitalization on heart failure medication: Angiotensin-converting enzyme inhibitors (62.5%), angiotensin-receptor-neprilysin inhibitor (22.9%), aldosterone-antagonists (51%), or beta blockers (91.4%). The initial median left ventricular ejection fraction was 30% (22%-45%) and increased to 48% (39%-55%) over long-term follow-up (P<0.001). The median BNP (brain natriuretic peptide) level at baseline was 1702 pg/mL (565-3748) and decreased to 188 pg/mL (26-348) over long-term follow-up (P=0.022). The mean wear time was 79.7±52.1 days and 21.0±4.9 hours per day. Arrhythmic event rates documented by the WCD were 9.7% for nonsustained ventricular tachycardia, 6.5% for sustained ventricular tachycardia, and 0% for ventricular fibrillation. Subsequently, 2.4% of patients experienced an appropriate WCD shock. The rate of inappropriate WCD shocks was 0.8%. All 3 patients with appropriate WCD shock had experienced ventricular tachycardia/ventricular fibrillation before WCD prescription, with only 1 patient showing a left ventricular ejection fraction <35%. Conclusions Patients with myocarditis and risk for occurrence of ventricular tachyarrhythmia may benefit from WCD use. Prior ventricular arrhythmia might appear as a better risk predictor than a reduced left ventricular ejection fraction <35% in this population.

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

BACKGROUND

Especially in the first 3 months after cardiac surgery, patients are at transient risk of sudden cardiac death (SCD). To close the gap between hospital discharge and the final implantable cardioverter-defibrillator (ICD) decision, guidelines recommend temporarily using a wearable cardioverter-defibrillator (WCD) to protect these patients from SCD. We investigated real-life data on the safety, effectiveness, and compliance of the WCD in this population.

METHODS

Data for analysis were collected via the Zoll Patient Management Network (ZPM) from patients who underwent cardiac surgery and who were discharged with a WCD between 2018 and 2021 at the Cardiac Surgery Center of the University of Erlangen in Germany.

RESULTS

The majority of the 55 patients were male (90.9%) and underwent a coronary artery bypass graft (80.0%). The number of patients with left ventricular ejection fraction (LVEF) >35% increased from 9.1% at the beginning of WCD use to 58.2% at the end of WCD use. Six ventricular tachycardia (VT) episodes occurred in four patients. The WCD appropriately defibrillated two patients with VT episodes. There were no inadequate shocks and no fatalities during the observation time. WCD wearing compliance was high, with a median wear time of 23.3 h/day.

CONCLUSION

This retrospective analysis in a single cardiac surgery center confirms prior data on the safety and effectiveness of the WCD in patients in post-surgery care in a real-life setting. The WCD successfully protected patients from SCD during life-threatening VT episodes. WCD wearing compliance was high.

Guideline Directed Medical Therapy at Discharge and Further Uptitration Leading to Reduction in Indication for Prophylactic ICD Implantation during Protected Waiting Period

Heart failure with reduced ejection fraction (LV-EF < 35%) is diagnosed in app. 11,000,000 patients worldwide. For the treatment of these patients, guideline directed medical therapy has proven to reduce mortality and rehospitalization regardless of the disease’s etiology. It is implemented to treat clinical symptoms by improving the left ventricular ejection fraction. Patients with a transient risk of ventricular tachycardia and sudden cardiac death can be protected by a defibrillator vest. The defibrillator vest is capable to detect and terminate ventricular arrhythmias during Guideline Directed Medical Therapy (GDMT). It is based on the recommendations of the European society of cardiology for 3 months. Afterwards, the WCD wear time could be prolonged, or, in case of persistent low ejection fraction (LV-EF ≤ 35%), an implantable cardioverter defibrillator (ICD) should be implanted, as shown in the WEARIT-II-registry. Our goal was to evaluate the effects of GDMT on LV-recovery and reduction of ICD implantations under protection with a defibrillator vest—depending on the uptitration of GDMT. Methods: 339 consecutive patients between August 2017 and September 2020 with newly diagnosed cardiomyopathy and an EF ≤ 35% were analyzed retrospectively by chart review. All patients were protected by a wearable cardioverter defibrillator (WCD). GDMT as recommended by the ESC started at discharge from hospital. The left ventricular ejection fraction (LV-EF) was determined by transthoracic echocardiography at week 4, 8 and at week 12 (in case of prolonged WCD wear time). Uptitration was performed after 4 and 8 weeks during patient visits. We focused on baseline medication as per GDMT and the dosage increase at week 4, 8 and 12. The aim was the uptitration to the maximum dosage tolerated by the patient. We also compared the LV-EF improvement in the group with and without uptitration of medication dosage. Results: The patient age was, on average, 63.2 years (SD ± 11.9 years). A total of 129 pts (38%) had ICM, 196 (58%) had NICM (incl 66 pts (19%) with DCM and 51 pts (15%) with Myocarditis, 79 pts (24%) with unknown origin) and 14 pts (4%) had other entities (e.g., Tachycardiomyopathy). In total, 21 pts (6%) had an LV-EF of less than 16%, 130 pts (38%) between 16−25% and 183 pts (54%) between 26−35%. GDMT started at discharge from the hospital included treatment with beta blocker for 327 pts (96.5%), ACE-inhibitors/Angiotensin/ARNI for 283 pts (83.5%) and Mineralcorticoid receptor antagonists (MRA) for 334 pts (88.4%). Uptitration was performed in all groups at a rate of 82.3%, 91.1% and 81.0% after 4 weeks and 64.7%, 50.3% and 66.3% after 8 weeks, respectively. After 4 weeks, 25 pts (7.4%) and, after 8 weeks, 171 pts (50.4%) had an EF increase of 5% or more (mean 14.2%). After 4 weeks, 81 patients had an LV-EF more than 35%. A total of 169 pts had a wear time of 12 weeks and an improvement of LVEF of more than 35%. Interestingly, in our study we did not find a significant difference in LV-EF improvement between the group with no uptitration and the group with uptitration. Conclusions: Guideline-directed medical therapy under protection with a WCD from ventricular arrhythmia can reduce the need for implantation of an ICD and can lead to an improvement of ejection fraction. Interestingly, the LV-EF improvement depends on the GDMT at discharge. Current guidelines recommend an initiation of all therapy columns of GDMT (sacubitril/valsartan, ACE-inhibitor/AT1-blocker, mineralcorticoidreceptorblocker, beta blocker) at once and further uptitration to the maximal dosage (ESC Guidelines 2021). A further uptitration of all drugs of GDMT should lead to improvement of LV-EF and consequently to a reduction in ICD implantations.

Usage of the wearable cardioverter-defibrillator during pregnancy

Background

Pregnancy can trigger or aggravate the risk for life-threating arrhythmias in cardiac diseases. Pregnancy is associated with reluctance for implantable cardioverter-defibrillators (ICD) due to concerns about radiation. Thus, the wearable cardioverter-defibrillator (WCD) might be an option during pregnancy. Aim of the study was to collect experiences about the use of WCD in pregnancy.

Methods and results

This study retrospectively included eight women who received a WCD during pregnancy. They suffered from ventricular tachycardia (VT) without known cardiac disease (n = 3), Brugada syndrome (n = 1), hypertrophic cardiomyopathy (n = 1), dilated cardiomyopathy (n = 1), non-compaction (n = 1), and survived sudden cardiac arrest during a preceding pregnancy (n = 1). WCD usage was started between 13 and 28 weeks of gestation. WCD wearing period ranged from 3 days to 30.9 weeks, WCD wearing time ranged from 13.0 to 23.7 h per day. Two women (25%) abandoned WCD already during pregnancy. Neither appropriate nor inappropriate WCD shocks were recorded. Antiarrhythmic management included beta-blockers (n = 5) and flecainide (n = 2). After delivery, ICD were implanted (n = 4), refused (n = 2) and estimated not necessary after successful catheter ablation (n = 2).

Conclusion

Uneventful pregnancy is possible in women at risk for sudden cardiac death by interdisciplinary monitoring and diligent pharmacotherapy protected by the WCD. Since no WCD shocks were recorded, the effectiveness of WCD during pregnancy is still unclear. However, arrhythmia detection by WCD was very good despite the changed anatomy in pregnancy. Nevertheless, further studies are necessary to assess effectiveness of WCD in pregnant women. Furthermore, efforts should be made to increase the wearing adherence of WCD during pregnancy.

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.

Feasibility and First Results of Heart Failure Monitoring Using the Wearable Cardioverter-Defibrillator in Newly Diagnosed Heart Failure with Reduced Ejection Fraction

The wearable cardioverter-defibrillator (WCD) is used in patients with newly diagnosed heart failure and reduced ejection fraction (HFrEF). In addition to arrhythmic events, the WCD provides near-continuous telemetric heart failure monitoring. The purpose of this study was to evaluate the clinical relevance of additionally recorded parameters, such as heart rate or step count. We included patients with newly diagnosed HFrEF prescribed with a WCD. Via the WCD, step count and heart rate were acquired, and an approximate for heart rate variability (HRV5) was calculated. Multivariate analysis was performed to analyze predictors for an improvement in left ventricular ejection fraction (LVEF). Two hundred and seventy-six patients (31.9% female) were included. Mean LVEF was 25.3 ± 8.5%. Between the first and last seven days of usage, median heart rate fell significantly (p < 0.001), while median step count and HRV5 significantly increased (p < 0.001). In a multivariate analysis, a delta of HRV5 > 23 ms was an independent predictor for LVEF improvement of ≥10% between prescription and 3-month follow-up. Patients with newly diagnosed HFrEF showed significant changes in heart rate, step count, and HRV5 between the beginning and end of WCD prescription time. HRV5 was an independent predictor for LVEF improvement and could serve as an early indicator of treatment response.

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.

Wenn die Weste einige Nummern zu groß ist: Sinn und Unsinn der LifeVest bei Postinfarktpatienten

Die LifeVest ist eine tragbare Kardioverter-Defibrillator-Weste (WCD), die eine zeitlich limitierte diagnostische und therapeutische, nicht invasive Option für Patienten mit einem hohen Risiko für den plötzlichen Herztod (PHT) auf dem Boden von lebensbedrohlichen anhaltenden ventrikulären Tachyarrhythmien darstellt. Hierbei hat sich die LifeVest sowohl bei Patienten mit transienter höhergradiger linksventrikulärer Dysfunktion als auch bei Patienten zur Überbrückung bis zur endgültigen Versorgung mit einem implantierbaren Kardioverter-Defibrillator (ICD) in der klinischen Praxis etabliert. Unklar waren bislang die Effektivität und der zusätzliche Benefit der WCD innerhalb der ersten Wochen nach stattgehabtem Myokardinfarkt bei Patienten mit reduzierter linksventrikulärer Pumpfunktion. In der prospektiven, randomisierten und kontrollierten VEST-Studie konnte kein Zusatznutzen der WCD bezüglich der Verhinderung des PHT in dieser Patientengruppe aufgezeigt werden.