Efficacy and Limitations of Quinidine in Patients with Brugada Syndrome

Andrea Mazzanti, Elisavietta Tenuta, Maira Marino, Eleonora Pagan, Massimo Morini, Mirella Memmi, Barbara Colombi, Valentina Tibollo, Samuele Frassoni, Antonio Curcio, Cristina Raimondo, Alice Maltret, Nicola Monteforte, Raffaella Bloise, Carlo Napolitano, Riccardo Bellazzi, Vincenzo Bagnardi, Silvia G. Priori

Research output: Contribution to journalArticle

Abstract

Background Quinidine at high dose is suggested as antiarrhythmic treatment in patients with Brugada Syndrome (BrS), but its efficacy to prevent life-threatening arrhythmic events (LAE) in this population is unproven and its use limited by frequent side effects. We assessed whether low-dose quinidine in patients with BrS reduces the following: (1) the occurrence of LAEs at follow-up, as compared to no therapy, in a population of both high-risk survivors of LAE and lower risk patients asymptomatic for LAEs and (2) the arrhythmic burden in the high-risk group of cardiac arrest survivors. Methods We compared the clinical course of 53 patients with BrS treated with quinidine to that of 441 untreated controls, matched by sex, age, symptoms, and the duration of observation. Furthermore, we calculated the annual incidence of LAE off-quinidine and on-quinidine in 123 patients with BrS who were cardiac arrest survivors. Results Fifty-three patients with BrS (89% males, median age 39.8 years) received quinidine (439±115 mg/d) for 5.0±3.7 years. Therapy was stopped in 3 cases (6%) for side effects. Quinidine reduced by 26% the risk of experiencing an LAE in cases versus controls (hazard ratio, 0.74; 95% CI, 0.22-2.48; P=0.62). Furthermore, in 27 of 123 patients with BrS symptomatic for LAEs who were treated for 7.0±3.5 years, the annual rate of LAEs decreased from 14.7% while off-quinidine to 3.9% while on-quinidine (P=0.03). Of note, recurrent LAEs were recorded in 4 (15%) cardiac arrest survivors while on-quinidine. Conclusions We demonstrated for the first time in the long-term that low-dose quinidine reduces recurrent LAEs in patients with BrS who had already survived an LAE, with few side effects. Remarkably, 15% of patients symptomatic for LAEs experience recurrent life-threatening arrhythmias while on-treatment, suggesting that quinidine cannot replace implantable defibrillators in high-risk subjects. Visual Overview A visual overview is available for this article.

Original languageEnglish
Article numbere007143
JournalCirculation: Arrhythmia and Electrophysiology
Volume12
Issue number5
DOIs
Publication statusPublished - May 1 2019

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Keywords

  • antiarrhythmic drugs
  • Brugada syndrome
  • cardiac arrhythmias
  • quinidine
  • sudden cardiac death

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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