- Email: [email protected]
No Utility of the Wearable Cardioverter-Defibrillator in Patients With Nonischemic Cardiomyopathy?
JACC VOL. 67, NO. 23, 2016
Letters
JUNE 14, 2016:2802–8
E-mail: [email protected]
The value of the WCD cannot be entirely assessed by
http://dx.doi.org/10.1016/j.jacc.2016.03.553
the number of appropriately delivered shocks.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES 1. Havakuk O, Viskin S. A tale of 2 diseases: the history of long-QT syndrome and Brugada syndrome. J Am Coll Cardiol 2016;67:100–8. 2. Coumel P, Fidelle J, Lucet V, et al. Catecholamine-induced severe ventricular arrhythmias with Adams-Stokes syndrome in children: report of four cases. Br Heart J 1978;40:28–37. 3. Zimdahl WT, Townsend CE. Bidirectional ventricular tachycardia due to digitalis poisoning; response to potassium therapy and evaluation of arrhythmia mechanism. Am Heart J 1954;47:304–12. 4. Priori SG, Napolitano C, Tiso N, et al. Mutations in the cardiac ryanodine receptor gene (hRyR2) underlie catecholaminergic polymorphic ventricular tachycardia. Circulation 2001;103:196–200. 5. Jackman WM, Friday KJ, Anderson JL, et al. The long QT syndromes: a critical review, new clinical observations and a unifying hypothesis. Prog Cardiovasc Dis 1988;31:115–72.
We would like to point out that in this study, during protection from sudden cardiac death, almost 40% of the 100 newly diagnosed NICM patients improved their left ventricular ejection fraction >35%, thus obviating ICD implantation. This demonstrates the real value of using the WCD in NICM as well as ICM patients. There are certain significant limitations of the current report. The authors do not report on episodes of nonsustained ventricular tachycardia (VT) or selfterminating sustained VT episodes. Further, the article does not report on the precise intention of WCD prescription or the clinical heart failure status, and we do not learn what the authors mean by “newly diagnosed cardiomyopathy”? We (2,3) agree with Dr. Epstein (4), the author of the accompanying editorial comment, that most
No Utility of the Wearable Cardioverter-Defibrillator in Patients With Nonischemic Cardiomyopathy?
likely the absence of VT/ventricular fibrillation events during the 70 days of WCD use was the “play of chance” in NICM patients. We support the authors’ request that better risk stratification in NICM is greatly needed. However, this is best studied separately with prospective randomized trials among the various underlying etiologies. The WCD will be a
The recently published paper by Singh et al. (1) about the experience using the wearable cardioverterdefibrillator (WCD) for patients with newly diagnosed cardiomyopathies has caught our interest, and we believe that some comments on the authors’ results and conclusions are necessary. During a 10-year period, the WCD was prescribed for 639 patients; however, retrospective analysis was reported only on 525 patients, hospitalized with newly diagnosed cardiomyopathy, 254 with nonischemic cardiomyopathy (NICM) and 271 with ischemic cardiomyopathy (ICM). Patients with NICM did not experience any appropriate shock delivery, whereas 6 patients (2.2%) with ICM had tachyarrhythmic events with WCD shocks. The authors conclude that the WCD is of “limited utility” for patients with NICM and that there is a “disconnection between the clinician-perceived risk and the actual risk of SCD.” Trying to understand the authors’ conclusion, we believe that they are subject to misunderstanding of the true value of the WCD. The WCD is neither a competitor to nor a replacement for the implantable cardioverter-defibrillator (ICD). The WCD is most helpful for risk stratification in patients with a presumed but not yet confirmed arrhythmic risk, to better select patients for primary prevention ICD therapy and to avoid unnecessary ICD implantation.
useful tool to perform such important studies. Helmut U. Klein, MD Wojciech Zareba, MD, PhD *Valentina Kutyifa, MD, PhD *Heart Research Follow-up Program University of Rochester Medical Center 265 Crittenden Boulevard, Box 653 Rochester, New York 14642 E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2016.02.080 Please note: Dr. Klein has received research grant support from ZOLL and lecture honoraria from ZOLL and Boston Scientific. Dr. Zareba has received research grant support from ZOLL, Boston Scientific, and Gilead Sciences. Dr. Kutyifa has received research grants support from ZOLL and Boston Scientific.
REFERENCES 1. Singh MS, Wang NC, Jain S, Voigt AH, Sabir S, Adelstein EC. Utility of the wearable cardioverter-defibrillator in patients with newly diagnosed cardiomyopathy. A decade-long single center experience. J Am Coll Cardiol 2015; 66:2607–13. 2. Kutyifa V, Moss AJ, Klein H, et al. Use of the wearable cardioverter defibrillator in high-risk cardiac patients: data from the prospective registry of patients using the Wearable Cardioverter-Defibrillator (WEARIT-II Registry). Circulation 2015;132:1613–9. 3. Klein HU, Goldenberg I, Moss AJ. Risk stratification for implantable cardioverter defibrillator therapy: the role of the wearable cardioverterdefibrillator. Eur Heart J 2013;34:2230–42. 4. Epstein EC. The wearable cardioverter-defibrillator in newly diagnosed cardiomyopathy. Treatment on the basis of perceived risk. J Am Coll Cardiol 2015;66:2614–7.
2807
Letters
JUNE 14, 2016:2802–8
E-mail: [email protected]
The value of the WCD cannot be entirely assessed by
http://dx.doi.org/10.1016/j.jacc.2016.03.553
the number of appropriately delivered shocks.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES 1. Havakuk O, Viskin S. A tale of 2 diseases: the history of long-QT syndrome and Brugada syndrome. J Am Coll Cardiol 2016;67:100–8. 2. Coumel P, Fidelle J, Lucet V, et al. Catecholamine-induced severe ventricular arrhythmias with Adams-Stokes syndrome in children: report of four cases. Br Heart J 1978;40:28–37. 3. Zimdahl WT, Townsend CE. Bidirectional ventricular tachycardia due to digitalis poisoning; response to potassium therapy and evaluation of arrhythmia mechanism. Am Heart J 1954;47:304–12. 4. Priori SG, Napolitano C, Tiso N, et al. Mutations in the cardiac ryanodine receptor gene (hRyR2) underlie catecholaminergic polymorphic ventricular tachycardia. Circulation 2001;103:196–200. 5. Jackman WM, Friday KJ, Anderson JL, et al. The long QT syndromes: a critical review, new clinical observations and a unifying hypothesis. Prog Cardiovasc Dis 1988;31:115–72.
We would like to point out that in this study, during protection from sudden cardiac death, almost 40% of the 100 newly diagnosed NICM patients improved their left ventricular ejection fraction >35%, thus obviating ICD implantation. This demonstrates the real value of using the WCD in NICM as well as ICM patients. There are certain significant limitations of the current report. The authors do not report on episodes of nonsustained ventricular tachycardia (VT) or selfterminating sustained VT episodes. Further, the article does not report on the precise intention of WCD prescription or the clinical heart failure status, and we do not learn what the authors mean by “newly diagnosed cardiomyopathy”? We (2,3) agree with Dr. Epstein (4), the author of the accompanying editorial comment, that most
No Utility of the Wearable Cardioverter-Defibrillator in Patients With Nonischemic Cardiomyopathy?
likely the absence of VT/ventricular fibrillation events during the 70 days of WCD use was the “play of chance” in NICM patients. We support the authors’ request that better risk stratification in NICM is greatly needed. However, this is best studied separately with prospective randomized trials among the various underlying etiologies. The WCD will be a
The recently published paper by Singh et al. (1) about the experience using the wearable cardioverterdefibrillator (WCD) for patients with newly diagnosed cardiomyopathies has caught our interest, and we believe that some comments on the authors’ results and conclusions are necessary. During a 10-year period, the WCD was prescribed for 639 patients; however, retrospective analysis was reported only on 525 patients, hospitalized with newly diagnosed cardiomyopathy, 254 with nonischemic cardiomyopathy (NICM) and 271 with ischemic cardiomyopathy (ICM). Patients with NICM did not experience any appropriate shock delivery, whereas 6 patients (2.2%) with ICM had tachyarrhythmic events with WCD shocks. The authors conclude that the WCD is of “limited utility” for patients with NICM and that there is a “disconnection between the clinician-perceived risk and the actual risk of SCD.” Trying to understand the authors’ conclusion, we believe that they are subject to misunderstanding of the true value of the WCD. The WCD is neither a competitor to nor a replacement for the implantable cardioverter-defibrillator (ICD). The WCD is most helpful for risk stratification in patients with a presumed but not yet confirmed arrhythmic risk, to better select patients for primary prevention ICD therapy and to avoid unnecessary ICD implantation.
useful tool to perform such important studies. Helmut U. Klein, MD Wojciech Zareba, MD, PhD *Valentina Kutyifa, MD, PhD *Heart Research Follow-up Program University of Rochester Medical Center 265 Crittenden Boulevard, Box 653 Rochester, New York 14642 E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2016.02.080 Please note: Dr. Klein has received research grant support from ZOLL and lecture honoraria from ZOLL and Boston Scientific. Dr. Zareba has received research grant support from ZOLL, Boston Scientific, and Gilead Sciences. Dr. Kutyifa has received research grants support from ZOLL and Boston Scientific.
REFERENCES 1. Singh MS, Wang NC, Jain S, Voigt AH, Sabir S, Adelstein EC. Utility of the wearable cardioverter-defibrillator in patients with newly diagnosed cardiomyopathy. A decade-long single center experience. J Am Coll Cardiol 2015; 66:2607–13. 2. Kutyifa V, Moss AJ, Klein H, et al. Use of the wearable cardioverter defibrillator in high-risk cardiac patients: data from the prospective registry of patients using the Wearable Cardioverter-Defibrillator (WEARIT-II Registry). Circulation 2015;132:1613–9. 3. Klein HU, Goldenberg I, Moss AJ. Risk stratification for implantable cardioverter defibrillator therapy: the role of the wearable cardioverterdefibrillator. Eur Heart J 2013;34:2230–42. 4. Epstein EC. The wearable cardioverter-defibrillator in newly diagnosed cardiomyopathy. Treatment on the basis of perceived risk. J Am Coll Cardiol 2015;66:2614–7.
2807