Permanent Implantable Cardioverter-defibrillators Research Articles

Current status of wearable cardioverter-defibrillator use in Japan.

The current status of wearable cardiovascular defibrillators (WCD) use in Japan is unclear. Using a nationwide claims database of Japan, we assessed characteristics of patients using WCD and factors influencing subsequent implantable cardioverter-defibrillator (ICD) implantation. In 1049 cases, those with prior cardiopulmonary arrest (CPA) or ventricular arrhythmia, cardiomyopathy, or device-related issues were more likely to require permanent ICDs, whereas females were less likely. Prior CPA or fatal arrhythmia, underlying cardiomyopathy, or device-related issues were associated with future permanent ICD implantation. These findings offer insights into the current status of WCD use in Japan.

Wearable cardioverter-defibrillators in pediatric cardiomyopathy: A cost-utility analysis

Dilated cardiomyopathy (DCM) is the most common cardiomyopathy in children. Patients with severe cardiac dysfunction are thought to be at risk of sudden cardiac arrest (SCA). After diagnosis, a period of medical optimization is recommended before permanent implantable cardioverter-defibrillator (ICD) implantation. Wearable cardioverter-defibrillators (WCDs) provide an option for arrhythmia protection as an outpatient during this optimization. The purpose of this study was to determine the strategy that optimizes cost and survival during medical optimization of a patient with DCM before ICD placement. A Markov state transition model was constructed for the 3 clinical approaches to compare costs, clinical outcomes, and quality of life: (1) "Inpatient," (2) "Home-WCD," and (3) "Home-No WCD." Transitional probabilities, costs, and utility metrics were extracted from the existing literature. Cost-effectiveness was assessed comparing each paradigm's incremental cost-effectiveness ratio against a societal willingness-to-pay threshold of $50,000 per quality-adjusted life year. The cost-utility analysis illustrated that Home-WCD met the willingness-to-pay threshold with an incremental cost-effectiveness ratio of $20,103 per quality-adjusted life year and 4 mortalities prevented per 100 patients as compared with Home-No WCD. One-way sensitivity analyses demonstrated that Home-No WCD became the most cost-effective solution when the probability of SCA fell below 0.2% per week, the probability of SCA survival with a WCD fell below 9.8%, or the probability of SCA survival with Home-No WCD quadrupled from base-case assumptions. Based on the existing literature probabilities of SCA in pediatric patients with DCM undergoing medical optimization before ICD implantation, sending a patient home with a WCD may be a cost-effective strategy.

Experts of the Heart Rhythm Section of the Polish Cardiac Society: opinion on the use of wearable cardioverter-defibrillators in Poland.

Sudden cardiac death (SCD) is one of the main causes of mortality in developed countries. Implantable cardioverter-defibrillators (ICDs) have become a widely used and efficient method for SCD prevention in high-risk populations. Nevertheless, there are clinical situations in which the benefit of ICD is uncertain, such as: early postinfarction left ventricular dysfunction, reversible causes of cardiomyopathy, presence of temporary or permanent ICD contraindications in high-risk populations, or when ICD is not accepted by SCD prevention candidates. Wearable cardioverter-defibrillator (WCD) can be an alternative option in these clinical circumstances. However, even though WCDs are available in the United States and many countries of Western Europe, they are still not available in Poland. The authors present clinical and organisational recommendations for WCD use in Poland, with respect to medical evidence.

Wearable Cardioverter-Defibrillators following Cardiac Surgery-A Single-Center Experience.

A wearable cardioverter-defibrillator (WCD) can terminate ventricular fibrillation and ventricular tachycardias via electrical shock and thus give transient protection from sudden cardiac death. We investigated its role after cardiac surgery. We retrospectively analyzed all patients who were discharged with a WCD from cardiac surgery department. The WCD was prescribed for patients with a left ventricular ejection fraction (LVEF) of ≤35% or an explanted implantable cardioverter-defibrillator (ICD). A total of 100 patients were included in this study, the majority (n = 59) had received coronary artery bypass graft surgery. The median wearing time of a WCD patient was 23.5 hours per day. LVEF was 28.9 ± 8% after surgery and improved in the follow-up to 36.7 ± 11% (p < 0.001). Three patients were successfully defibrillated. Ten patients experienced ventricular tachycardias. No inappropriate shocks were given. An ICD was implanted in 25 patients after the WCD wearing period. Ventricular arrhythmias occurred in 13% of the investigated patients. LVEF improved significantly after 3 months, and thus a permanent ICD implantation was avoided in several cases. Sternotomy did not impair wearing time of the WCD. A WCD can effectively protect patients against ventricular tachyarrhythmias after cardiac surgery.

Use of the Wearable Cardioverter Defibrillator as a Bridge to Implantable Cardioverter Defibrillator.

The wearable cardioverter defibrillator has been shown to be effective in terminating ventricular arrhythmias in patients at risk for sudden cardiac death. There are numerous scenarios in which implant of a permanent implantable cardioverter defibrillator is temporarily contraindicated or not advisable and a wearable cardioverter defibrillator may be beneficial. There are no prospective randomized studies published that provide conclusive guidance toward the use of the wearable cardioverter defibrillator, and thus, patient management needs to be individualized based on the available data.

Wearable Cardioverter-Defibrillator Therapy for the Prevention of Sudden Cardiac Death: A Science Advisory From the American Heart Association.

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 …

First experience with the wearable cardioverter defibrillator in the Netherlands.

The implantable cardioverter defibrillator (ICD) has significantly improved survival in patients with an increased risk of sudden cardiac death (SCD). The wearable cardioverter defibrillator (WCD) is an alternative to the ICD in patients with a transient ICD indication or those in whom an ICD temporarily cannot be implanted. We describe here the technical details of the WCD and report three patients who were treated with a WCD in an outpatient setting. The WCD allowed the cardiac condition of two patients to improve to such an extent that permanent ICD implantation was deemed unnecessary. This new form of therapy may result in significant cost reduction, avoidance of unnecessary ICD implantation, and increased patient satisfaction.

How to Respond to an Implantable Cardioverter-Defibrillator Recall

The implantable cardioverter-defibrillator (ICD) has consistently demonstrated a life-saving benefit in patients at risk for sudden cardiac arrest. Quality-of-life outcomes with the ICD may be directly related to coping successfully with ICD shocks. Although most people are able to tolerate a shock to some extent, the experience of shock is discomforting and can prompt feelings of anxiety, depression, or fear. The purpose of this article is to review patient and family preparations and responses to ICD shock to limit its impact on quality of life. The ICD provides continuous monitoring and treatment for cardiac arrhythmias (abnormal heartbeats). The ICD automatically detects an abnormal heartbeat and will deliver small rapid pacing impulses or an electric shock to the heart to restore a normal heart rhythm. During the first year after implantation, the chances of receiving at least one ICD shock can range from one third to one half of all ICD recipients.1,2 The shock sensation has been likened to a swift kick in the chest and rated a “6” on a 0 to 10 pain scale.1,3 Nonetheless, quality-of-life research indicates that the ICD is at least equal to or better than antiarrhythmic medications on most indicators of quality of life.2,4–8 Most research has pointed to ICD shock as the primary culprit if reductions in quality of life occur.2 ### Psychological Responses to Shock ICD-specific fears and symptoms of anxiety (for example, excessive worry, increased muscle tension, sweating, and increased heart rate and respiratory rate) are the most common psychological symptoms experienced by ICD recipients, with approximately 13% to 38% of recipients …