Variabiliy in Prescribing Patterns of Wearable Cardiac Defibrillators: Current Data, Guidelines, Challenges, and Controversies.

Background Wearable cardioverter defibrillator (WCD) demonstrated an important role for prevention of sudden cardiac death in patients with advanced heart failure and reduced left ventricular ejection fraction. Although in randomized trial there are no gender difference in WCD use and defibrillator (ICD) implantation rate, real world data in female patients is lacking. Purposes: We aimed to describe the sex differences in WCD use, the rate of cardiac events detected with WCD and the rate of ICD implantation after WCD use in women in a real-world single center experience. nd reduced left ventricular ejection fraction or prior ventricular tachyarrhythmia. Methods and results According with the current guidelines indications, between August 2017 and June 2023 ninety-six consecutive patients (mean age 66.0±11.1 years) received a WCD at Piacenza Hospitals and were retrospectively included in this analysis. There were no differences in clinical characteristics between female (18 patients, 18,8%) and male: in particular baseline left ventricular ejection fraction (LV EF) were similar between the two groups (29.5±5.2 vs 27.9±7.9, p=0.23) and no differences were found in the rate of ischaemic cardiopathy (66,6% vs 69,2% p=0.51). After 3-months follow up with WCD use, a similar rate of ventricular arrhythmias were found in the two groups (5.5% vs 3.8%, p=0.48) and no ventricular fibrillation was detected. The WCD usage period and median daily wear time were not different between female and male (55.2±50.6 vs 56.2±34.8 days p=0.53, 21.0±6.4 vs 23.1±1.5 hours p=0.48, respectively). However women presented a better LV EF improvement (12.2±9.7 vs 7.2±6.8, p=0.01), with a significant lower ICD implantation rate at the end of WCD use (55.5% vs 43.8%; p< 0.01) Conclusions In this real word analysis women presented a nice compliance using WCD. In spite of a similar burden of ventricular arrhythmic events, women presented a better LV EF improvement with a significant lower ICD implantation rate.

Sudden cardiac death (SCD) accounts for >300 000 deaths in the United States annually.1 Although the majority of these deaths occur in low-risk populations2 in which aggressive interventions are not practical, some higher-risk populations have been established in whom intervention with an implantable cardioverter-defibrillator (ICD) has been shown in randomized trials to reduce mortality.3–7 Additionally, there is a population of patients who may benefit from automatic emergency cardioversion-defibrillation but are not deemed appropriate candidates for ICD implantation at the time of presentation. This group is defined by 2 populations. The first subgroup comprises those who are at perceived risk but for whom there may be optimism for clinical improvement (eg, patients soon after revascularization or those with a recent diagnosis of myocardial infarction [MI] or cardiomyopathy). Alternatively stated, the optimal management of these patients at risk (or perceived risk) during the waiting period before an ICD is indicated remains unknown. The second subgroup includes those who have a clear indication for ICD but also have a contraindication to immediate ICD placement (eg, active infection or unknown prognosis). The wearable cardioverter-defibrillator (WCD) is a device designed for patients at risk of SCD who are not immediate candidates for ICD therapy. By providing automatic therapy, the WCD does not depend on a second person to defibrillate, as required with a manual or automated external defibrillator (AED). Unlike the ICD (including both transvenous and subcutaneous devices), the WCD requires no surgical operation, can be provided for a short period of time, is temporary, and is easily removed. These characteristics of the WCD, along with safety and efficacy data presented to the US Food and Drug Administration (FDA), resulted in approval in the United States in 2002.8 Because of the increasing use of the WCD and uncertainty of indications …

REAL–WORLD SINGLE CENTER EXPERIENCE WITH THE WEARABLE CARDIOVERTER DEFIBRILLATOR: SEX DIFFERENCES IN RISK STRATIFICATION FOR SUDDEN CARDIAC DEATH

Each year, approximately 350 000 cases of out-of-hospital sudden cardiac arrest occur in Europe. The Vest Prevention of Early Sudden Death Trial (VEST) demonstrated the effectiveness and safety of the wearable cardioverter defibrillator (WCD) in preventing sudden cardiac death (SCD). Recent findings from a retrospective registry of Polish patients prescribed with the WCD further validated its efficacy in real-world settings. To assess the cost-effectiveness of using the LifeVest® WCD compared to standard of care for preventing SCD in post-myocardial infarction patients in Poland. Cost-effectiveness and cost-utility analyses were conducted from the perspective of the Polish public payer, the National Health Fund. A Markov model, reflecting current clinical practice, was utilized, incorporating data from the Vest Prevention of Early Sudden Death Trial, Polish healthcare costs, and health state utilities based on Polish norms. The analysis employed a lifetime horizon. One-way deterministic and probabilistic sensitivity analyses were performed to gauge parameter uncertainty. Results were compared against the official cost-effectiveness threshold in Poland. Sudden cardiac death prevention with WCD incurred additional costs of 51 300 PLN (12 100 EUR) compared to standard of care but resulted in gains of 0.49 life years and 0.39 quality-adjusted life years (QALYs). The incremental cost-utility ratio was 132 400 PLN/QALY (31 100 EUR/QALY), nearly 40% below the cost-effectiveness threshold. Sensitivity analyses confirmed the robustness of these findings. The strategy of preventing SCD through WCD usage proves to be cost-effective within the Polish healthcare context. The clinical benefits derived from WCD use justify the additional costs incurred, making it a viable option for SCD prevention in post-myocardial infarction patients in Poland.

The ESC Risk Score Is Less Reliable than ACC/AHA Risk Factors in Hypertrophic Cardiomyopathy: When Sensitivity Trumps Specificity

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

Long-term use of the wearable cardioverter defibrillator in patients with explanted ICD

Introduction: The wearable cardioverter-defibrillator (WCD) is approved for prevention of sudden cardiac death in patients with newly diagnosed cardiomyopathy and LVEF < 35% who do not yet meet criteria for implantation of an implantable cardioverter-defibrillator (ICD). While there are some data supporting WCD use in patients with ischemic cardiomyopathy (ICM), data in patients with nonischemic cardiomyopathy (NICM) are lacking. Methods: This was a retrospective review of outcomes for all NICM patients prescribed a WCD at a large tertiary academic center from 6/2004 - 1/2014 for a newly diagnosed cardiomyopathy and no prior sustained ventricular arrhythmia. During this time period, 454 patients were prescribed a WCD, of whom we excluded 161 patients with ICM. Results: The 183 (40%) patients with NICM consisted of 70% men, aged 57 +/- 15 years old, with mean EF 23% +/- 8% and LV end-diastolic dimension 4.5 +/- 2.8 cm. DM and HTN were prevalent (20% and 51%, respectively). At NICM diagnosis, 21% had LBBB and 36% had known history of AF. Patients wore the WCD for 13,124 patient-days, each averaging 72 +/- 55 days and with fairly high compliance (18.3 +/- 5.7 hours/day). Medication use consisted of 90% beta-blockers, 88% ACE inhibitors, 85% diuretics, 16% digoxin, and 17% anti-arrhythmic drugs. NSVT was documented in 42% of patients prior to WCD prescription. During follow-up, 60 (33%) patients improved LVEF to > 35%, obviating an indication for ICD implantation, whereas 79 (43%) patients received an ICD. The remainder died (n=17), were lost to follow-up (n=20), refused ICD implant (n=5), or are still wearing the WCD (n=2). No appropriate WCD shocks were delivered in any NICM patient, yet 3 inappropriate shocks were delivered (1.6%). Based on estimated rental costs provided by the manufacturer, the total cost of WCD use in this population was $1,449,360. Conclusions: In this large, tertiary care center registry of patients with newly recognized NICM, no patient received an appropriate shock from the WCD whereas several inappropriate shocks were delivered, despite nearly one-half of patients having documented significant ventricular ectopy. Given the significant expense and inconvenience of the WCD, its use in this population requires prospective study.

Background: The wearable cardioverter-defibrillator (WCD) is a an external, patient-controlled device that offers lifesaving protection against sudden cardiac death in patients with contraindications to immediate implantable cardioverter-defibrillator (ICD) placement. Racial disparities in cardiovascular care are well documented, with Black patients undergoing invasive procedures at lower rates than White patients, despite similar or higher disease burdens. These disparities may partly reflect patient preferences, as studies show that Black patients have greater aversion to invasive treatments. We therefore hypothesized that Black patients would have a higher utilization of WCD therapy compared to White patients. Methods: We analyzed discharge encounters from the National Inpatient Sample (2016-2020) for patients with clinical indications for implantable cardioverter-defibrillator placement who did not receive the device during hospitalization. Survey-weighted logistic regression estimated odds of WCD discharge. Results: Among 3,298,524 patients eligible for WCD at discharge, 71% were White and 16% were Black. Only 0.26% of these were discharged with WCD. In multi-variable analysis adjusting for demographics, co-morbidities, and hospital characteristics, Black patients remained 79% more likely to receive WCD (adjusted OR 1.79, 95% CI 1.59-2.01, p<0.001). Hispanic patients had 22% higher odds (OR 1.22, CI 1.04-1.43, p=0.01). Male gender, larger hospitals, and urban teaching centers were independently associated with increased WCD use. Adjusted predicted probabilities of WCD at discharge from 2016 to 2020 revealed that Black patients had the highest probability of getting WCD, with a steady increase over the 5-year period. Conclusions: A higher proportion of ICD-eligible Black patients received WCD compared to Whites. This supports our hypothesis and may be additional evidence that Black patients tend to prefer less invasive interventions. Given that WCD effectiveness is critically dependent on continuous adherence and that racial disparities in medical device adherence are well-documented, these patients may face excess risk of sudden cardiac death during the vulnerable period when relying on WCD protection. Further research should investigate targeted interventions to improve adherence and examine whether the preference for WCD over ICD compromises survival outcomes in Black patients.

ABSTRACTIntroduction: Ventricular tachyarrhythmias (ventricular tachycardia and ventricular fibrillation) can lead to aborted cardiac arrest or sudden cardiac death in patients with poor left ventricular function early after acute myocardial infarction (AMI). Although it has been shown that the implantable cardioverter defibrillator (ICD) can treat ventricular tachyarrhythmias and save lives in patients with ischemic cardiomyopathy, it’s use during the early phase post AMI has not been shown to reduce mortality. Current device guidelines require a waiting period of 40 days post AMI and 3 months post revascularization. Thus, there is a time gap where high-risk patients may not be protected.Areas covered: This review summarizes the characteristics of the wearable cardioverter-defibrillator (WCD) and its role in bridging the gap between an AMI and time of ICD eligibility. In addition, we focus on the efficacy of the WCD in treating ventricular tachyarrhythmias events, compliance and safety of the WCD use.Expert commentary: The WCD use during the early post AMI period can add crucial information to the process of risk stratification and decision-making whether an individual needs an implantation of an ICD or not. The WCD can serve as a safe and effective bridge during the interval preceding ICD placement.

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

Background Previous studies highlighted the importance of adequate heart rate control in heart failure patients, and suggested under-treatment with beta-blockers especially in women. However, data on women achieving effective heart rate control during beta-blocker therapy optimization are lacking. Methods The wearable cardioverter defibrillator (WCD) allows continuous monitoring of heart rate (HR) trends during WCD use. In the current study, we assessed resting HR trends (nighttime: midnight-7am) in women, both at the beginning of WCD use and at the end of WCD use to assess the adequacy of beta-blockade following a typical 3 months of therapy optimization with beta-blockers. An adequate heart rate control was defined as having a nighttime HR <70 bpm at the end of the 3 months. Results There were a total of 21,453 women with at least 30 days of WCD use (>140 hours WCD use on the first and last week). The mean age was 67 years (IQR 58–75). The mean nighttime heart rate was 72 bpm (IQR 65–81) at the beginning of WCD use, that decreased to 68 bpm (IQR 61–76) at the end of WCD use with therapy optimization. Women had an insufficient heart rate control with resting heart rate ≥70 bpm in 59% at the beginning of WCD use that decreased to 44% at the end of WCD use, but still remained surprisingly high. Interestingly, there were 21% of the women starting with HR ≥70 bpm at the beginning of use (BOU) who achieved adequate heart rate control by the end of use (EOU). Interestingly, 6% of women with adequate heart rate control at the start of therapy optimization ended up having higher heart rates >70 bpm at the end of the therapy optimization time period (Figure). Figure 1 Conclusions A significant proportion of women with heart failure and low ejection fraction do not reach an adequate heart rate control during the time of beta blocker initiation/titration. The wearble cardioverter defibrillator is a monitoring device that has been demonstrated in this study to appropriately identify patients with inadequate heart rate control at the end of the therapy optimization period. The WCD could be utilized to improve management of beta-blocker therapy in women and improve the achievement of adequate heart rate control in women.

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): ZOLL France supported with an unrestricted grant. Background The wearable cardioverter defibrillator (WCD) has been proven to have efficacy in treating sudden cardiac death (SCD) in patients soon after acute myocardial infarction (AMI) and left ventricular ejection fraction (LVEF) ≤35%. However, data regarding hospitalization rate and length of stay among these patients have not yet been evaluated. Purpose WCD can shorten hospital stays (total length, time in intensive care unit (ICU) and in cardiac intensive care unit (CICU)) of patients post-AMI, with severe reduced LVEF. Methods We performed a single center, retrospective observational study of patients prescribed WCD upon hospital discharge, from June 2016 to June 2022. We selected patients referred for management of SCD, post-AMI, with age over 18 years and LVEF ≤35%. Patients who already had ICD or CRT-D (or who had previously received it) were excluded from the analysis. Patients with the same characteristics, and who were discharged from the hospital without WCD or ICD served as a control group. Clinical characteristics were obtained from hospital electronic and WCD specific database. The clinical characteristics and length of index hospitalization of two groups were compared. An initial propensity score analysis was performed, then a weighted regression models for total hospitalization, days in ICU, and days in CICU were conducted. Results 101 patients in the WCD group and 29 in the control group were enrolled in the analysis (Figure 1). The two groups showed similar clinical characteristics (Table 1), even if patients in the WCD group had lower LVEF (p <0.001), more cardiogenic shocks (p = 0.045) and higher NT-proBNP values (p = 0.033). After a propensity score analysis and a weighted regression model, LVEF emerged as independent variable for WCD use (odds ratio (OR) 0.755, confidence interval (CI) 95% 0.654 – 0.872, p <0.001). Left ventricular thrombosis also affected the use of WCD (OR 5.574, CI 95% 1.139 – 27.267, p = 0.0339). In a weighted regression model, WCD significantly influenced the days spent in CICU (p<0.001), and those in ICU even without statistical significance (p = 0.251). Even after excluding all patients undergoing extracorporeal membrane oxygenation (ECMO) or heart transplantation, WCD reduced days spent in CICU (p<0.001). Furthermore, when excluding from the analysis all patients with very long hospitalizations (> 30 days), WCD patients showed significantly shorter total hospitalization (p=0.005) and days spent in CICU (p<0.001), compared with control group. Conclusions At the propensity score analysis, WCD reduce CICU length of stay for patients post-AMI with LVEF ≤35%. The association between WCD use and hospitalization is more relevant for days spent in CICU, but there is also a positive trend for the days spent in ICU. The study has the limitation of a retrospective analysis and can only serve as hypothesis-generating research, which will be verified with further randomized clinical trial.

AimsData on outcomes in patients using the wearable cardioverter-defibrillator (WCD) > 90 days are limited. We aimed to analyse the clinical course of patients with WCD use ≤90 days vs. WCD use >90 days.Methods and resultsWe assessed arrhythmia events during WCD use, and ejection fraction (EF) improvement/implantable cardioverter-defibrillator (ICD) implantation at the end of WCD use in patients with WCD use ≤90 days vs. WCD use >90 days enrolled in the WEARIT-II registry, further assessed by disease aetiology (ischaemic vs. non-ischaemic vs. congenital/inherited heart disease). There were 981 (49%) patients with WCD use >90 days, and 1019 patients with WCD use ≤90 days (median 120 vs. 55 days). There was a lower incidence of sustained ventricular tachycardia/ventricular fibrillation (VT/VF) events (11 vs. 50 events per 100 patient-years, P < 0.001), WCD treated VT/VF events (1 vs. 8 events per 100 patient-years, P < 0.001), and non-sustained VT events (21 vs. 51 events per 100 patient-years, P = 0.008) with WCD use >90 vs. WCD use ≤90 days. Non-ischaemic cardiomyopathy patients presented with similar rates of sustained VT/VF events during WCD use >90 vs. ≤90 days (13.4 vs. 13.7 events per 100 patient-years, P = 0.314), while most of these events terminated spontaneously. One-third of the patients with extended WCD use further improved their EF and they were not implanted with an ICD, with similar rates among ischaemic and non-ischaemic patients.ConclusionsIn WEARIT-II, patients with extended WCD use >90 days remain at risk for ventricular arrhythmia events. One-third of the patients with WCD use >90 days further improved their EF, avoiding the need to consider ICD implantation.

WEARABLE CARDIOVERTER DEFIBRILLATOR IN PATIENT WITH TRANSIENT RISK OF SUDDEN CARDIAC DEATH: SINGLE CENTRE EXPERIENCE