Author + information
- Received June 15, 2018
- Revision received October 11, 2018
- Accepted October 15, 2018
- Published online March 18, 2019.
- Navraj Malhi, MDa,
- Christopher C. Cheung, MDa,
- Bishoy Deif, MDb,
- Jason D. Roberts, MD, MASb,
- Lorne J. Gula, MDb,
- Martin S. Green, MDc,
- Benjamin Pang, MDc,
- Omar Sultan, MDd,
- Kaja M. Konieczny, MDe,
- Paul Angaran, MDe,
- Paul Dorian, MDe,
- Ilan Lashevsky, MDf,
- Jeff S. Healey, MDg,
- Aiman Alak, MDg,
- Rafik Tadros, MDh,
- Antoine Andorin, MDh,
- Christian Steinberg, MDi,
- Felix Ayala-Paredes, MDj,
- Christopher S. Simpson, MDk,
- Joseph Atallah, MDl and
- Andrew D. Krahn, MDa,∗ ()
- aUniversity of British Columbia, Vancouver, British Columbia, Canada
- bWestern University, London, Ontario, Canada
- cUniversity of Ottawa Heart Institute, Ottawa, Ontario, Canada
- dUniversity of Saskatchewan, Regina Qu’Appelle Health Region, Regina, Saskatchewan, Canada
- eSt. Michael’s Hospital, Toronto, Ontario, Canada
- fSchulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
- gPopulation Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- hDepartment of Medicine, University of Montreal, Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
- iLaval University, Quebec Heart and Lung Institute, Inherited Arrhythmia Clinic, Quebec City, Quebec, Canada
- jUniversité de Sherbrooke, Faculté de Médecine et des Sciences de la Santé, Montreal, Quebec, Canada
- kQueen's University, Kingston, Ontario, Canada
- lUniversity of Alberta School of Public Health, Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
- ↵∗Address for correspondence:
Dr. Andrew Krahn, Heart Rhythm Vancouver, 211-1033 Davie Street, Vancouver, British Columbia V6E 1M7, Canada.
Objectives This study sought to determine the nature of quinidine use and accessibility in a national network of inherited arrhythmia clinics.
Background Quinidine is an antiarrhythmic medication that has been shown to be beneficial in select patients with Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation. Because of the low prevalence of these conditions and restricted access to quinidine through a single regulatory process, quinidine use is rare in Canada.
Methods Subjects prescribed quinidine were identified through the Hearts in Rhythm Organization that connects the network of inherited arrhythmia clinics across Canada. Cases were retrospectively reviewed for patient characteristics, indications for quinidine use, rate of recurrent ventricular arrhythmia, and issues with quinidine accessibility.
Results In a population of 36 million, 46 patients are currently prescribed quinidine (0.0000013%, age 48.1 ± 16.1 years, 25 are male). Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation constituted a diagnosis in 13 subjects (28%), 6 (13%), and 21 (46%), respectively. Overall, 37 subjects (81%) had cardiac arrest as an index event. After initial presentation, subjects experienced 7.47 ± 12.3 implantable cardioverter-defibrillator shocks prior to quinidine use over 34.3 ± 45.9 months, versus 0.86 ± 1.69 implantable cardioverter-defibrillator shocks in 43.8 ± 41.8 months while on quinidine (risk ratio: 8.7, p < 0.001). Twenty-two patients access quinidine through routes external to Health Canada’s Special Access Program.
Conclusions Quinidine use is rare in Canada, but it is associated with a reduction in recurrent ventricular arrhythmias in patients with Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation, with minimal toxicity necessitating discontinuation. Drug interruption is associated with frequent breakthrough events. Access to quinidine is important to deliver this potentially lifesaving therapy.
The study was supported by the Heart and Stroke Foundation of Canada (G-13-0002775 and G-14-0005732), and the Canadian Institute of Health Research (MOP-142218 and SRG-15-P09-001), and the Canadian Arrhythmia Network (CANet SRG-15- P09-001). Dr. Krahn receives support from the Heart and Stroke Foundation of Canada, the Sauder Family and Heart and Stroke Foundation Chair in Cardiology, the Paul Brunes Chair in Heart Rhythm Disorders, and the Paul Albrechtson Foundation. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received June 15, 2018.
- Revision received October 11, 2018.
- Accepted October 15, 2018.
- 2019 American College of Cardiology Foundation
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