RESUMEN

Ventricular arrhythmias are common in the early period after myocardial infarction (MI), with the highest risk occurring in the immediate postinfarct window. The wearable cardioverter-defibrillator (WCD) has been proven to have efficacy in treating sudden cardiac arrest in patients soon after MI. However, data concerning clinical and health economic outcomes of WCD usage among Medicare patients have not been evaluated. The aim of this study was therefore to investigate the clinical and health economic impacts of WCD use among Medicare patients hospitalized for MI. A 5% sample of Medicare's Standard Analytical Files (2010-2012) was used to identify patients. Beneficiaries with an acute inpatient admission for acute MI were stratified by WCD presence and absence, respectively. Baseline clinical history, all-cause mortality, and the total cost of health-care expenditures over one year were collected. In total, 16,935 patients were included in the final analysis; of these, 89 were placed in the WCD group and 16,846 were placed in the non-WCD group. Overall, WCD patients were younger (70 versus 74 years of age; p < 0.001), more likely to be male (74.2% versus 57.4%; p = 0.002), and more likely to have congestive heart failure and/or ventricular arrhythmias prior to the indexed acute MI. At 30 days, the mortality rate in the WCD group (not reported due to volume < 11 Medicare beneficiaries) was lower in comparison with the non-WCD group (10.4%; p = 0.18). At one year, the adjusted mortality rates were 11.5% for the WCD group and 19.8% for the non-WCD group (hazard ratio: 0.46; p = 0.017). For the WCD group, the one-year incremental cost-effectiveness ratio was $12,373 per life-year gained. Among Medicare beneficiaries, WCD use after an acute MI was associated with better 30-day and one-year survival. Thus, our findings indicate that WCD use was cost-effective in the present sample of Medicare patients.

RESUMEN

OBJECTIVES: To evaluate the effectiveness of wearable cardioverter defibrillator (WCD) use in protecting patients from sudden cardiac arrest (SCA) while they were treated in nonhospital settings until re-implantation of an Implantable cardioverter-defibrillator (ICD) was feasible. We sought to determine whether the WCD could be successfully utilized long term (≥1 year) after ICD extraction in patients at continued risk of SCD in which ICD re-implantation was not practical. BACKGROUND: ICDs have proven to improve mortality in patients for both secondary and primary prevention of SCA. Increased ICD implantation in older patients with comorbid conditions has resulted in higher rates of cardiac device infections. Currently, a wearable cardioverter defibrillator (WCD) is an alternative management for SCA prevention in specific cases. METHODS: This a retrospective analysis based on consecutive WCD patients who underwent ICD explant due to device-related infections or mechanical reasons between April 2007 and July 2014. A total of 102 patients were identified from the national database maintained by ZOLL (Pittsburgh, PA, USA). We analyzed the reason for WCD use, demographic information, device data, compliance and duration of WCD use, detected arrhythmias and therapies, and reason for discontinuing WCD use. RESULTS: In these long term WCD users, average length of WCD use was 638 ±â€¯361 days. Nine patients (8.8%) had a sustained ventricular arrhythmia that was successfully resuscitated by the WCD. Six patients (5.8%) experienced inappropriate shocks. Two patients (1.9%) died of asystole events while wearing the WCD and an additional 10 patients died while not monitored by the WCD. Thirty-nine patients (38.2%) ended WCD use when a new ICD was implanted and 15 patients (14.7%) were still wearing the WCD at the time of analysis. CONCLUSIONS: We found that extending use of the WCD to ≥1 year is a safe and effective alternative treatment for patients with explanted ICDs who are not pacemaker dependent.

Asunto(s)

Muerte Súbita Cardíaca/prevención & control , Desfibriladores/tendencias , Cardioversión Eléctrica/instrumentación , Cardioversión Eléctrica/tendencias , Dispositivos Electrónicos Vestibles/tendencias , Adulto , Anciano , Desfibriladores/normas , Cardioversión Eléctrica/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Dispositivos Electrónicos Vestibles/normas

RESUMEN

INTRODUCTION: The wearable cardioverter defibrillator (WCD) may allow stabilization until reassessment for an implantable cardioverter defibrillator (ICD) among high-risk heart failure (HF) patients. However, there are limited data on the WCD benefit in the acute decompensated HF setting. METHODS AND RESULTS: The Study of the Wearable Cardioverter Defibrillator in Advanced Heart Failure Patients (SWIFT) was a prospective clinical trial carried out at two medical centers. Patients hospitalized with advanced HF symptoms and reduced left ventricular ejection function (LVEF) were enrolled and prescribed a WCD prior to discharge for a total of 3 months. Outcome measures included arrhythmic events, WCD discharge, and death. Study patients (n = 75, mean age 51 ± 14 years, 31% women) had a mean LVEF of 21.5 ± 10.4%. Non-ischemic cardiomyopathy was present in 66% of patients. The median WCD wearing time was 59 (interquartile range 17-97) days, and 80% of patients wore the device >50% of daily hours. WCD interrogations showed a total of 8 arrhythmic events in 5 patients, including 3 nonsustained or self-terminating ventricular tachycardia (VT) events, and one polymorphic VT successfully terminated by the WCD. None of the patients died while wearing the device and no inappropriate device therapies occurred. Upon termination of treatment with the WCD, 21 patients (28%) received an ICD. At 3 years, the cumulative death rate was 20% in the ischemic and 21% in non-ischemic cardiomyopathy patients. CONCLUSION: A management strategy incorporating the WCD can be safely used to bridge the decision regarding the need for ICD implantation in high-risk patients with advanced HF.

Asunto(s)

Desfibriladores/tendencias , Cardioversión Eléctrica/instrumentación , Cardioversión Eléctrica/tendencias , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Adulto , Anciano , Estudios de Cohortes , Desfibriladores Implantables/tendencias , Femenino , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos

RESUMEN

BACKGROUND: The impact of body mass index (BMI) on the shock efficacy and patient adherence among patients using a wearable cardioverter defibrillator (WCD) is unknown. METHODS: Patients prescribed the WCD between January 1, 2008 and June 1, 2013, who experienced at least one episode of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and who received appropriate WCD therapy, were identified within a registry maintained by the manufacturer for regulatory, reimbursement, and administrative purposes. The registry contained patients' Body Mass Index (BMI) which was categorized as normal (18.0

Asunto(s)

Índice de Masa Corporal , Desfibriladores , Cooperación del Paciente , Taquicardia Ventricular/terapia , Fibrilación Ventricular/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Sobrepeso/complicaciones , Estudios Retrospectivos , Taquicardia Ventricular/complicaciones , Factores de Tiempo

RESUMEN

PURPOSE: The wearable cardioverter defibrillator (WCD) is generally used for short periods of sudden cardiac death (SCD) risk; circumstances may occasionally result in prolonged use (over 1 year). The aim of this study was to determine the benefits and risks of prolonged use in patients with systolic heart failure (HF). METHODS: ZOLL's post-market US database included adult patients (≥18 years) with ischemic and/or non-ischemic cardiomyopathy (ICM, NICM) and at least 1 year of use. Cox-regression was used to identify factors associated with survival with WCD use, and reasons for stopping use were entered as time-dependent factors. RESULTS: Among 220 patients, age (mean ± SD) 55.4 ± 14.8 years, WCD use 451.4 ± 289.9 days, and 67.3 % were male and their left ventricle ejection fraction (EF) averaged 20.9 ± 7.2 %. Eighty-nine (40.5 %) were continuing WCD use at the last follow-up. Thirty-six (16.4 %) and 56 (25.5 %) patients discontinued WCD use because of EF recovery and implantable cardioverter (ICD) implantation, respectively. Nine patients (4.1 %) received appropriate shock therapy for 13 episodes of sustained ventricular tachyarrhythmia with 12 (92.3 %) successful shocks. One patient died of refractory ventricular fibrillation. One patient died from sinus bradycardia transitioning to asystole. Eight patients (3.6 %) had nine episodes of non-fatal inappropriate shocks. CONCLUSIONS: Long-term use of the WCD is safe and effective. Recovery of EF was seen in significant number of patients even after 1 year of WCD use.

Asunto(s)

Cardiomiopatías/mortalidad , Cardiomiopatías/terapia , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/prevención & control , Desfibriladores/estadística & datos numéricos , Sistema de Registros , Adulto , Anciano , Anciano de 80 o más Años , Comorbilidad , Desfibriladores/clasificación , Femenino , Humanos , Incidencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Resultado del Tratamiento , Estados Unidos/epidemiología , Adulto Joven

RESUMEN

OBJECTIVES: This study reports on the time course of reimplantation and benefits of the wearable cardioverter-defibrillator (WCD) in patients post implantable cardioverter-defibrillator (ICD) explantation. BACKGROUND: The WCD is used to treat patients at high risk for ventricular tachycardia (VT) and ventricular fibrillation (VF), including patients with ICD-related infections who undergo device removal and cannot be immediately reimplanted. METHODS: This retrospective study included consecutive patients from 2002 to 2014 who underwent ICD removal because of device-related infection and were prescribed a WCD. WCD-stored electrocardiograms were reviewed. Event outcome was assessed through either the manufacturer WCD registry or the Social Security death index search. RESULTS: A total of 8,058 patients (mean age 62 ± 14 years, 75% male) were included in the analysis. Median time to reimplantation of an ICD was 50 days (interquartile range: 24 to 83 days). While wearing the WCD, 334 patients (4%) experienced 406 VT/VF events, of which 348 events were treated. Shocks were averted in 54 events by conscious patients. The overall 24-h survival, both treated and nontreated, was 93% (312 of 334). VT/VF occurrence was the highest in the initial weeks after ICD removal (0.9%, 0.7%, and 0.7% per week for weeks 1, 2, and 3, respectively). The 12-month cumulative event rate was 10%. For all patients, the 30-day post-event survival was 81%. An ICD was reimplanted in 80% of patients. CONCLUSIONS: The risk of VT/VF reaches 4% during the first 2 months and 10% at 1 year after ICD removal. WCD demonstrated a high efficacy for protecting patients from VT/VF. Clinicians may use the WCD as an ICD alternative when reimplantation is medically delayed.

Asunto(s)

Desfibriladores Implantables/efectos adversos , Taquicardia Ventricular/terapia , Fibrilación Ventricular/terapia , Dispositivos Electrónicos Vestibles/efectos adversos , Anciano , Desfibriladores Implantables/microbiología , Desfibriladores Implantables/estadística & datos numéricos , Remoción de Dispositivos , Cardioversión Eléctrica/estadística & datos numéricos , Cardioversión Eléctrica/tendencias , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevención Primaria , Infecciones Relacionadas con Prótesis/epidemiología , Infecciones Relacionadas con Prótesis/cirugía , Sistema de Registros , Reimplantación/estadística & datos numéricos , Estudios Retrospectivos , Medición de Riesgo , Análisis de Supervivencia , Taquicardia Ventricular/mortalidad , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/fisiopatología , Fibrilación Ventricular/prevención & control

RESUMEN

BACKGROUND: This study evaluated the wearable cardioverter-defibrillator (WCD) for use and effectiveness in preventing sudden death caused by ventricular tachyarrhythmia or fibrillation. METHODS: From April 2010 through October 2013, 6043 German WCD patients (median age, 57 years; male, 78.5%) were recruited from 404 German centers. Deidentified German patient data were used for a retrospective, nonrandomized analysis. RESULTS: Ninety-four patients (1.6%) were treated by the WCD in response to ventricular tachyarrhythmia/fibrillation. The incidence rate was 8.4 (95% confidence interval, 6.8-10.2) per 100 patient-years. Patients with implantable cardioverter-defibrillator explantation had an incidence rate of 19.3 (95% confidence interval, 12.2-29.0) per 100 patient-years. In contrast, an incidence rate of 8.2 (95% confidence interval, 6.4-10.3) was observed in the remaining cardiac diagnosis groups, including dilated cardiomyopathy, myocarditis, and ischemic and nonischemic cardiomyopathies. Among 120 shocked patients, 112 (93%) survived 24 hours after treatment, whereas asystole was observed in 2 patients (0.03%) with 1 resulting death. CONCLUSIONS: This large cohort represents the first nationwide evaluation of WCD use in patients outside the US healthcare system and confirms the overall value of the WCD in German treatment pathways.

Asunto(s)

Muerte Súbita Cardíaca/epidemiología , Desfibriladores , Fibrilación Ventricular/epidemiología , Fibrilación Ventricular/terapia , Anciano , Estudios de Cohortes , Muerte Súbita Cardíaca/prevención & control , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Fibrilación Ventricular/diagnóstico

RESUMEN

BACKGROUND: Life-threatening ventricular arrhythmias (VAs) and sudden cardiac death (SCD) are common in patients awaiting heart transplantation (HT), and the implantable cardioverter-defibrillator (ICD) is often used for primary prevention in this setting. Use of ICDs in these patients is not without risks and is sometimes contraindicated. The wearable cardioverter-defibrillator (WCD) may be a reasonable alternative to bridge the period of risk leading up to HT. METHODS: We obtained a convenience sample of patients prescribed an WCD as a bridge therapy to HT. The available data consisted of demographics, cardiac transplantation status, associated comorbidities, device use, device-stored electrocardiogram (ECG) and reason for discontinuing the WCD. Statistical analyses were performed using SPSS version 17 and GraphPad PRISM 5. RESULTS: The registry included 121 patients consisting of 83 (69%) men and 38 (31%) women. The mean age was 44 ± 18 years. Mean ejection fraction was 25 ± 15%. Non-ischemic cardiomyopathy (CMP) was the underlying diagnosis in 67 (55%) patients, whereas 21 (17%) patients had ischemic CMP and 33 (27%) had a mixed or uncharacterized CMP. New York Heart Association Class III heart failure was present in 32% and 34% were in Class IV. Eighty-eight patients (73%) were being evaluated for HT or were on an HT waiting list, and 33 patients (27%) had had a prior HT, experienced rejection, and were awaiting re-transplantation. The patients wore the WCD for an average of 127 ± 392 days (median 39 days) with average daily use of 17 ± 7 hours (median 20 hours). Seven patients (6%) received appropriate WCD shocks. Fifty-one patients (42%) ended use after ICD implantation and 13 patients (11%) after HT. There were 11 deaths (9%). CONCLUSIONS: A significant proportion of patients on the HT waiting list will have VA. WCD use in our study showed high compliance and efficacy and a low complication rate, suggesting that the WCD is a reasonable bridge therapy for preventing SCD in patients awaiting HT.

Asunto(s)

Cardiomiopatías/terapia , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Insuficiencia Cardíaca/terapia , Taquicardia Ventricular/prevención & control , Adulto , Cardiomiopatías/complicaciones , Bases de Datos Factuales , Electrocardiografía , Femenino , Insuficiencia Cardíaca/complicaciones , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estados Unidos

RESUMEN

BACKGROUND: The survival outcome following a sudden cardiac arrest (SCA) in hemodialysis (HD) patients is poor regardless of whether an event takes place in or out of a dialysis center. The characteristics of SCA and post-SCA survival with HD patients using a wearable cardioverter defibrillator (WCD) are unknown. METHODS: All HD patients who were prescribed a WCD between 2004 and 2011 and experienced at least one SCA event were included in this study. Demographics, clinical background, characteristics of SCA events were identified from the manufacturer's database. An SCA event was defined as all sustained ventricular tachycardia/fibrillation (VT/VF) or asystole occurring within 24 hours of the index arrhythmia episode. The social security death index was used to determine mortality after WCD use. RESULTS: A total of 75 HD patients (mean age = 62.9 ± 11.7 years, female = 37.3%) experienced 84 SCA events (119 arrhythmia episodes) while wearing the WCD. Sixty six (78.6%) SCA events were due to VT/VF and 18 (21.4%) were due to asystole. Most SCA episodes occurred between 09:00 and 10:00 (RR = 2.82, 95% CI [1.05, 7.62], P < 0.0001), followed by the 13:00-14:00 time interval (RR = 2.22, 95% CI [0.79, 6.21], P = 0.006). Acute 24-hour survival was 70.7% for all SCA events; 30-day and 1-year survival were 50.7% and 31.4%, respectively. Women had a better post-SCA survival than men (HR = 2.41, 95% CI [1.09, 5.36], P = 0.03). CONCLUSIONS: The use of WCD in HD patients was associated with improved post-SCA survival when compared to historical data.

Asunto(s)

Muerte Súbita Cardíaca/epidemiología , Desfibriladores Implantables/estadística & datos numéricos , Fallo Renal Crónico/terapia , Diálisis Renal/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores Sexuales , Tasa de Supervivencia , Estados Unidos/epidemiología

RESUMEN

Congenital disorders, such as dextrocardia and persistent left superior vena cava, are rare. However, their presence is often associated with other cardiac anomalies, and may lead to lethal ventricular tachyarrhythmias, which result in sudden cardiac death. Treating patients with these disorders can present a challenge to clinicians, as it may cause technical difficulties during interventional procedures, and more often, altered defibrillation techniques in a setting of prehospital sudden cardiac arrest. This report describes the first case of successful defibrillation therapy delivered by the wearable cardioverter defibrillator to a patient with dextrocardia and persistent left superior vena cava during a ventricular tachycardia arrest.

Asunto(s)

Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Desfibriladores , Dextrocardia/complicaciones , Taquicardia Ventricular , Vena Cava Superior/anomalías , Adulto , Electrocardiografía/métodos , Humanos , Masculino , Resultado del Tratamiento

RESUMEN

OBJECTIVES: The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA). BACKGROUND: Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken. METHODS: We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data. RESULTS: Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients. CONCLUSIONS: During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.

Asunto(s)

Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Infarto del Miocardio/complicaciones , Taquicardia Ventricular/terapia , Función Ventricular Izquierda , Muerte Súbita Cardíaca/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Taquicardia Ventricular/etiología , Taquicardia Ventricular/fisiopatología

RESUMEN

BACKGROUND: Implantation of implantable cardioverter defibrillator for prevention of sudden cardiac death is deferred for 90 days after coronary revascularization, but mortality may be highest early after cardiac procedures in patients with ventricular dysfunction. We determined mortality risk in postrevascularization patients with left ventricular ejection fraction ≤35% and compared survival with those discharged with a wearable cardioverter defibrillator (WCD). METHODS AND RESULTS: Hospital survivors after surgical (coronary artery bypass graft surgery) or percutaneous (percutaneous coronary intervention [PCI]) revascularization with left ventricular ejection fraction ≤35% were included from Cleveland Clinic and national WCD registries. Kaplan-Meier, Cox proportional hazards, propensity score-matched survival, and hazard function analyses were performed. Early mortality hazard was higher among 4149 patients discharged without a defibrillator compared with 809 with WCDs (90-day mortality post-coronary artery bypass graft surgery 7% versus 3%, P=0.03; post-PCI 10% versus 2%, P<0.0001). WCD use was associated with adjusted lower risks of long-term mortality in the total cohort (39%, P<0.0001) and both post-coronary artery bypass graft surgery (38%, P=0.048) and post-PCI (57%, P<0.0001) cohorts (mean follow-up, 3.2 years). In propensity-matched analyses, WCD use remained associated with lower mortality (58% post-coronary artery bypass graft surgery, P=0.002; 67% post-PCI, P<0.0001). Mortality differences were not attributable solely to therapies for ventricular arrhythmia. Only 1.3% of the WCD group had a documented appropriate therapy. CONCLUSIONS: Patients with left ventricular ejection fraction ≤35% have higher early compared to late mortality after coronary revascularization, particularly after PCI. As early hazard seemed less marked in WCD users, prospective studies in this high-risk population are indicated to confirm whether WCD use as a bridge to left ventricular ejection fraction improvement or implantable cardioverter defibrillator implantation can improve outcomes after coronary revascularization.

Asunto(s)

Puente de Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/terapia , Muerte Súbita Cardíaca/prevención & control , Desfibriladores , Cardioversión Eléctrica/instrumentación , Intervención Coronaria Percutánea/mortalidad , Disfunción Ventricular Izquierda/mortalidad , Función Ventricular Izquierda , Anciano , Distribución de Chi-Cuadrado , Puente de Arteria Coronaria/efectos adversos , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/fisiopatología , Enfermedad de la Arteria Coronaria/cirugía , Muerte Súbita Cardíaca/etiología , Diseño de Equipo , Femenino , Humanos , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Intervención Coronaria Percutánea/efectos adversos , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Sistema de Registros , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Volumen Sistólico , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología , Disfunción Ventricular Izquierda/fisiopatología

RESUMEN

BACKGROUND: Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD. METHODS: Ten enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality). RESULTS: Out of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD. CONCLUSIONS: In conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Asunto(s)

Desfibriladores , Insuficiencia Cardíaca/terapia , Adulto , Anciano , Muerte Súbita Cardíaca/epidemiología , Femenino , Insuficiencia Cardíaca/complicaciones , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Volumen Sistólico , Función Ventricular Izquierda

RESUMEN

BACKGROUND: Peripartum cardiomyopathy (PPCM) mortality rates vary between 2% and 56%, with half occurring ≤12 weeks'; postpartum. Although risk factors for PPCM have been identified, predicting sudden cardiac death among PPCM patients remains difficult. This study describes the characteristics and outcomes of PPCM patients and controls referred for a wearable cardioverter defibrillator (WCD). METHODS AND RESULTS: Deidentified WCD medical orders between 2003 and 2009 and death index searches were used to characterize women (ages 17-43) with PPCM (n = 107) or matched nonpregnant women with nonischemic dilated cardiomyopathy (NIDCM; n = 159). Demographics were similar. WCD use averaged 124 ± 123 days and 96 ± 83 days among PPCM and NIDCM patients, respectively. No PPCM patients received an appropriate shock for ventricular tachycardia/ventricular fibrillation; 1 NIDCM patient received 2 successful shocks. No PPCM patient died during WCD use versus 11 concurrent NIDCM deaths. After WCD use, 3 PPCM and 13 NIDCM patients died, respectively. CONCLUSIONS: The mortality rate of 2.8% (over 3.0 ± 1.2 years) in PPCM patients is low compared to published data. The role of WCD therapy among PPCM patients deserves further study.

Asunto(s)

Cardiomiopatías/terapia , Desfibriladores , Complicaciones Cardiovasculares del Embarazo/terapia , Trastornos Puerperales/terapia , Adolescente , Adulto , Cardiomiopatías/mortalidad , Cardiomiopatías/fisiopatología , Estudios de Casos y Controles , Bases de Datos Factuales , Muerte Súbita Cardíaca , Femenino , Humanos , Mortalidad Materna , Persona de Mediana Edad , Embarazo , Complicaciones Cardiovasculares del Embarazo/mortalidad , Complicaciones Cardiovasculares del Embarazo/fisiopatología , Trastornos Puerperales/mortalidad , Trastornos Puerperales/fisiopatología , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Estados Unidos , Adulto Joven

RESUMEN

Patients with congenital structural heart disease (CSHD) and inherited arrhythmias (IAs) are at high risk of ventricular tachyarrhythmias and sudden cardiac death. The present study was designed to evaluate the short- and long-term outcomes of patients with CSHD and IA who received a wearable cardioverter-defibrillator (WCD) for the prevention of sudden cardiac death. The study population included 162 patients with CSHD (n = 43) and IA (n = 119) who were prospectively followed up in a nationwide registry from 2005 to 2010. The mortality rates were compared using Kaplan-Meier survival analysis. The mean age of the study patients was 38 ± 27 years. The patients with CSHD had a greater frequency of left ventricular dysfunction (ejection fraction <30%) than did the patients with IA (37% vs 5%, respectively; p = 0.002). The predominant indication for WCD was pending genetic testing in the IA group and transplant listing in the CSHD group. Compliance with the WCD was similar in the 2 groups (91%). WCD shocks successfully terminated 3 ventricular tachyarrhythmias in the patients with IA during a median follow-up of 29 days of therapy (corresponding to 23 appropriate WCD shocks per 100 patient-years). No arrhythmias occurred in the patients with CSHD during a median follow-up of 27 days. No patients died while actively wearing the WCD. At 1 year of follow-up, the survival rates were significantly lower among the patients with CSHD (87%) than among the patients with IA (97%, p = 0.02). In conclusion, our data suggest that the WCD can be safely used in high-risk adult patients with IA and CSHD. Patients with IA showed a greater rate of ventricular tachyarrhythmias during therapy but significantly lower long-term mortality rates.

Asunto(s)

Arritmias Cardíacas/terapia , Desfibriladores , Cardiopatías Congénitas/terapia , Adulto , Arritmias Cardíacas/genética , Arritmias Cardíacas/mortalidad , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/prevención & control , Diseño de Equipo , Femenino , Estudios de Seguimiento , Cardiopatías Congénitas/mortalidad , Cardiopatías Congénitas/fisiopatología , Humanos , Incidencia , Masculino , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología

RESUMEN

OBJECTIVES: The purpose of this study was to determine patient compliance and effectiveness of antiarrhythmic treatment by the wearable cardioverter-defibrillator (WCD). BACKGROUND: Effectiveness of the WCD for prevention of sudden death is dependent on event type, patient compliance, and appropriate management of ventricular tachycardia/ventricular fibrillation (VT/VF). METHODS: Compliance and events were recorded in a nationwide registry of post-market release WCDs. Survival, using the Social Security Death Index, was compared with survival in implantable cardioverter-defibrillator (ICD) patients. RESULTS: Of 3,569 patients wearing the WCD (age 59.3+/-14.7 years, duration 52.6+/-69.9 days), daily use was 19.9+/-4.7 h (>90% of the day) in 52% of patients. More days of use correlated with higher daily use (p<0.001). Eighty sustained VT/VF events occurred in 59 patients (1.7%). First-shock success was 76 of 76 (100%) for unconscious VT/VF and 79 of 80 (99%) for all VT/VF. Eight patients died after successful conversion of unconscious VT/VF (89.5% survival of VT/VF events). Asystole occurred in 23 (17 died), pulseless electrical activity in 2, and respiratory arrest in 1 (3 died), representing 24.5% of sudden cardiac arrests. During WCD use, 3,541 of 3,569 patients (99.2%) survived overall. Survival occurred in 72 of 80 (90%) VT/VF events and 78 of 106 (73.6%) for all events. Long-term mortality was not significantly different from first ICD implant patients but highest among patients with traditional ICD indications. CONCLUSIONS: Compliance was satisfactory with 90% wear time in >50% of patients and low sudden death mortality during use. Survival was comparable to that of ICD patients. However, asystole was an important cause of mortality in sudden cardiac arrest events.

Asunto(s)

Desfibriladores , Cooperación del Paciente , Muerte Súbita Cardíaca/prevención & control , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taquicardia Ventricular/mortalidad , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/mortalidad , Fibrilación Ventricular/prevención & control

RESUMEN

BACKGROUND: Wearable cardioverter defibrillators (WCDs) provide protection from sudden cardiac death. The efficacy of a WCD detection algorithm has not been reported outside of clinical trial. METHODS: The efficacy of the algorithm was reviewed through a retrospective analysis of appropriate shocks, inappropriate shocks, and arrhythmia detections during a 1-year period. RESULTS: WCD patients had an appropriate shock rate of 1.58 per 100 patient-months and an inappropriate shock rate of 0.99 per 100 patient-months. Most of the arrhythmia detections in a 3-month period were short in length, with only 2.7% of the detections lasting over 25 seconds, the time at which a shock becomes possible. CONCLUSIONS: By incorporating a patient responsiveness test, as well as features that eliminate or reduce signal interference common to external electrocardiogram electrodes, the WCD detection algorithm has a low risk of inappropriate shocks.

Asunto(s)

Algoritmos , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/prevención & control , Cardioversión Eléctrica/instrumentación , Cardioversión Eléctrica/métodos , Electrocardiografía Ambulatoria/instrumentación , Electrocardiografía Ambulatoria/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Diseño Asistido por Computadora , Diagnóstico por Computador/instrumentación , Diagnóstico por Computador/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Terapia Asistida por Computador/instrumentación , Terapia Asistida por Computador/métodos , Resultado del Tratamiento , Adulto Joven

RESUMEN

The implantable cardioverter defibrillator (ICD) is able to reduce sudden arrhythmic death in patients who are considered to be at high risk. However, the arrhythmic risk may be increased only temporarily as long as the proarrhythmic conditions persist, left ventricular ejection fraction remains low, or heart failure prevails. The wearable cardioverter defibrillator (WCD) represents an alternative approach to prevent sudden arrhythmic death until either ICD implantation is clearly indicated or the arrhythmic risk is considered significantly lower or even absent. The WCD is also indicated for interrupted protection by an already implanted ICD, temporary inability to implant an ICD, and lastly refusal of an indicated ICD by the patient. The WCD is not an alternative to the ICD, but a device that may contribute to better selection of patients for ICD therapy. The WCD has the characteristics of an ICD, but does not need to be implanted, and it has similarities with an external defibrillator, but does not require a bystander to apply lifesaving shocks when necessary. The WCD was introduced into clinical practice about 8 years ago, and indications for its use are currently expanding. This article describes the technological aspects of the WCD, discusses current indications for its use, and reviews the clinical studies with the WCD. Additionally, data are reported on the clinical experience with the WCD based on 354 patients from Germany hospitalized between 2000 and 2008 who wore the WCD for a mean of 3 months.

Asunto(s)

Muerte Súbita Cardíaca/prevención & control , Cardioversión Eléctrica/instrumentación , Taquicardia Ventricular/terapia , Desfibriladores Implantables , Diseño de Equipo , Falla de Equipo , Humanos , Satisfacción del Paciente , Medición de Riesgo

RESUMEN

In the present study, we have retrospectively analyzed the corrected QT (QTc) interval before spontaneous episodes of sudden cardiac arrest in patients with a wearable cardioverter defibrillator. Corrected QT interval was measured for all normal beats from 32 recordings of baseline rhythm and compared to normal rhythm before a paired spontaneous cardiac arrhythmia. Before arrhythmia, the QTc (505 +/- 73 ms) was not significantly longer than the baseline rhythm (497 +/- 73 ms) (P = .23). Considering ventricular tachycardia (VT) events only (12 patients), event QTc (526 +/- 75 ms) was not significantly longer than baseline QTc (520 +/- 74 ms) (P = .41). Considering fast VT/ventricular fibrillation (VF) events only (20 patients), event QTc (494 +/- 70 ms) was not significantly longer than baseline QTc (483 +/- 71 ms) (P = .26). The influence of QTc as a measure to indicate an impending VT event in a variety of VT/VF patients remains unclear.

Asunto(s)

Algoritmos , Diagnóstico por Computador/métodos , Electrocardiografía/métodos , Taquicardia Ventricular/diagnóstico , Fibrilación Ventricular/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

The wearable cardioverter defibrillator (WCD) was introduced into clinical practice about 8 years ago as an alternative approach to protect patients with a temporary high risk of sudden arrhythmic death. The WCD has the characteristics of an implantable defibrillator (ICD) but does not need to be implanted, and it has similarities with an external defibrillator, but does not require a bystander to apply lifesaving shocks when necessary. Based on current clinical experience, the WCD is not an alternative to the ICD, but a device that will contribute to better selection of patients for ICD therapy and may be indicated in case of interrupted protection by an already implanted ICD, temporary inability to implant an ICD, or refusal of an indicated ICD.