Jakob Lüker1, Kathrin Kuhr2, Arian Sultan1, Georg Nölker3, Hazem Omran3, Stephan Willems4, René Andrié5, Jan W Schrickel5, Stefan Winter6, Dirk Vollmann7, Roland R Tilz8, Alexander Jobs8,9, Christian-H Heeger8, Andreas Metzner10, Sven Meyer11, Karl Mischke12, Andreas Napp13, Andreas Fahrig14, Susanne Steinhauser2, Johannes Brachmann15, Stephan Baldus16, Rajiv Mahajan17, Prashanthan Sanders17, Daniel Steven1. 1. University of Cologne, University Hospital Cologne, Department of Electrophysiology (J.L., A.S., D.S.), Germany. 2. Institute of Medical Statistics and Computational Biology (IMSB) (K.K., S.S.), Germany. 3. Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Clinic for Electrophysiology, Bad Oeynhausen, Germany (G.N., H.O.). 4. Department of Electrophysiology, University Heart Center, Hamburg, Germany (S.W.). 5. Department of Internal Medicine II, University Hospital Bonn, Germany (R.A., J.W.S.). 6. St. Vinzenz Hospital, Cologne, Germany (S.W.). 7. Herz- & Gefäßzentrum Göttingen, Germany (D.V.). 8. Department of Cardiology, University Hospital Lübeck, Germany (R.R.T., A.J., C.H.H.). 9. Department of Internal Medicine/Cardiology, Heart Center Leipzig at University of Leipzig, Germany (A.J.). 10. Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany (A.M.). 11. Department of Cardiology, Heart Center Oldenburg, European Medical School Oldenburg-Groningen, Germany (S.M.). 12. Medical Clinic I, Leopoldina Hospital, Schweinfurt, Germany (K.M.). 13. Department of Internal Medicine I, RWTH Aachen University Hospital, Germany (A.N.). 14. Klinikum Leverkusen, Germany (A.F.). 15. Medical Clinic II, Coburg Hospital, Germany (J.B.). 16. Department of Cardiology (S.B.), Germany. 17. Center for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Australia (R.M., P.S.).
Abstract
BACKGROUND: Atrial arrhythmias are common in patients with implantable cardioverter-defibrillator (ICD). External shocks and internal cardioversion through commanded ICD shock for electrical cardioversion are used for rhythm-control. However, there is a paucity of data on efficacy of external versus internal cardioversion and on the risk of lead and device malfunction. We hypothesized that external cardioversion is noninferior to internal cardioversion for safety, and superior for successful restoration of sinus rhythm. METHODS:Consecutive patients with ICD undergoing elective cardioversion for atrial arrhythmias at 13 centers were randomized in 1:1 fashion to either internal or external cardioversion. The primary safety end point was a composite of surrogate events of lead or device malfunction. Conversion of atrial arrhythmia to sinus rhythm was the primary efficacy end point. Myocardial damage was studied by measuring troponin release in both groups. RESULTS:N=230 patients were randomized. Shock efficacy was 93% in the external cardioversion group and 65% in the internal cardioversion group (P<0.001). Clinically relevant adverse events caused by external or internal cardioversion were not observed. Three cases of pre-existing silent lead malfunction were unmasked by internal shock, resulting in lead failure. Troponin release did not differ between groups. CONCLUSIONS: This is the first randomized trial on external vs internal cardioversion in patients with ICDs. External cardioversion was superior for the restoration of sinus rhythm. The unmasking of silent lead malfunction in the internal cardioversion group suggests that an internal shock attempt may be reasonable in selected ICD patients presenting for electrical cardioversion. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03247738.
RCT Entities:
BACKGROUND:Atrial arrhythmias are common in patients with implantable cardioverter-defibrillator (ICD). External shocks and internal cardioversion through commanded ICD shock for electrical cardioversion are used for rhythm-control. However, there is a paucity of data on efficacy of external versus internal cardioversion and on the risk of lead and device malfunction. We hypothesized that external cardioversion is noninferior to internal cardioversion for safety, and superior for successful restoration of sinus rhythm. METHODS: Consecutive patients with ICD undergoing elective cardioversion for atrial arrhythmias at 13 centers were randomized in 1:1 fashion to either internal or external cardioversion. The primary safety end point was a composite of surrogate events of lead or device malfunction. Conversion of atrial arrhythmia to sinus rhythm was the primary efficacy end point. Myocardial damage was studied by measuring troponin release in both groups. RESULTS: N=230 patients were randomized. Shock efficacy was 93% in the external cardioversion group and 65% in the internal cardioversion group (P<0.001). Clinically relevant adverse events caused by external or internal cardioversion were not observed. Three cases of pre-existing silent lead malfunction were unmasked by internal shock, resulting in lead failure. Troponin release did not differ between groups. CONCLUSIONS: This is the first randomized trial on external vs internal cardioversion in patients with ICDs. External cardioversion was superior for the restoration of sinus rhythm. The unmasking of silent lead malfunction in the internal cardioversion group suggests that an internal shock attempt may be reasonable in selected ICDpatients presenting for electrical cardioversion. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03247738.