Cardiovascular Journal of Africa: Vol 32 No 6 (NOVEMBER/DECEMBER 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 6, November/December 2021 332 AFRICA all 38 patients on placebo were still in AF at the moment of DCC (absolute difference 21%, CI: 10–29%, p = 0.002). At eight weeks following successful DCC, amiodarone was more effective in the maintenance of SR compared to placebo [63/123 (51%) vs 6/38 (16%), p < 0.001]. After one year, more patients on long- term amiodarone remained in SR versus patients on short-term amiodarone [30/61 (49%) vs 21/62 (33%), p = 0.085]. However a higher rate of adverse effects requiring discontinuation was noted for long-term amiodarone (18%) compared to short-term treatment (8%) or placebo (3%). 73 Overall, the six random, controlled trials supported the use of amiodarone for long-term maintenance of SR with minor side effects. Efficacy of amiodarone in AF recurrence after catheter ablation Catheter ablation has gained a significant role in restoring SR in patients with symptomatic AF. Although a high success rate with catheter ablation is achievable, it may vary between 60 and 80% for paroxysmal AF and between 50 and 60% for persistent AF. 86-88 One of the most frequent causes of early recurrence of arrythmias post ablation is inflammation due to tissue damage inflicted by the radiofrequency energy. 89 While early recurrence is not considered a sign of failure in catheter ablation treatment, it is strongly indicative of potential late arrythmia recurrence. As a potential solution to this issue, the short-term use of AADs has been suggested. 90,91 This would serve both as a preventative mechanism for early arrythmia recurrence, as well as facilitating left atrium reverse remodelling in the long term. The most important studies on the use of amiodarone for the prevention of recurrent AF after conversion of AF are listed in Table 5. Critical appraisal The literature search resulted in 2 887 publications on the efficacy of amiodarone in AF recurrence after catheter ablation, out of which we included eight studies (Table 5). All of them were randomised, controlled trials and were published between 2007 and 2018. Eight were open label and one was double blind. 95 Four studies included patients from a single centre, one study was from two centres, 95 and three studies were multicentre trials. 92,94,97 In two studies pulmonary vein isolation (PVI) was used, 92,95 while in the other six PVI + other ablation techniques, such as mitral isthmus line, cavo-tricuspid line or complex fractionated atrial electrograms (CFAE) were used. In all eight trials amiodarone was given after catheter ablation and compared to placebo or other anti-arrhythmic drug. One study included only patients with paroxysmal AF, 92 one study only patients with persistent AF, 97 and the other six studies both patients with paroxysmal and persistent AF. Patients were followed for two to 17 months after catheter ablation. Amiodarone did reduce AF recurrence during short-term follow up (six to 12 weeks) but did not improve freedom from AF during the mean follow-up period of eight months. While effective in reducing recurrence of arrythmias in the early stages post ablation, amiodarone did not appear to be an effective long-term solution. The potential negative side effects in patients presenting with structural heart diseases or heart failure, as well as elderly patients, strike a delicate balance between advantages and drawbacks. In the EAST-AF (Efficacy of Antiarrhythmic Drugs Short- Term Use After Catheter Ablation for Atrial Fibrillation) trial with over a 90-day use of AADs, a significant reduction in early arrythmias was confirmed, however, this did not translate into improvements in the later stages. 94 The AMIOdarone After CATheter Ablation for Atrial Fibrillation (AMIO-CAT) trial reported similar results with no difference in the AF-free rate at six months after six or eight weeks, respectively, of AAD use. 95 Mohanty et al. investigated the impact of peri-procedural amiodarone on the outcome of AF ablation for 112 patients with long-standing persistent AF. 97 The patients were randomised to two groups: one that discontinued amiodarone four months before ablation, and a control group that underwent AF ablation without amiodarone discontinuation. For the patients in the off-amiodarone group, a higher number of non-pulmonary vein triggers were revealed compared to the other group (75 vs 43%, p < 0.001). Patients in the on-amiodarone group had however lower fluoroscopy, radiofrequency and procedural times than those who discontinued amiodarone Table 5. The most important randomised and non-randomised trials on the use of amiodarone for the prevention of AF recurrences after catheter ablation Trial AAD administration Number Mean age (years) Main results POWDER AF 2018 92 Anti-arrhythmic drugs vs no drug after catheter ablation of recurrent AF 173 62 2.7 vs 21.9% AF recurrence at 1 year Kettering 2017 93 Short-term amiodarone after catheter ablation of persistent AF 230 61 16.5 vs 29.6% within first 3 months 18.3 vs 27% at 1 year arrhythmia recurrence between amiodarone and no AAD EAST AF 2016 94 Short-term (90 days) amiodarone or class I vs placebo after catheter ablation of AF 2 038 63 59.0 vs 52.1% at 90 days 69.5 vs 67.8% at 1 year free rate from recurrent atrial tachyarrhythmias AMIO-CAT 2016 95 Short-term amiodarone after catheter ablation of AF 212 61 39 vs 48% atrial tachyarrhythmia at 6 months between amiodarone and placebo Lodzinski 2014 96 Amiodarone or sotalol vs no AAD vs last ineffective AAD used before PVI, after catheter ablation of paroxysmal AF 180 50 47.5 vs 54.3 vs 45.5% SR at 2 months Mohanty 2014 97 Amiodarone discontinuation 4 months before ablation vs ablation performed without amiodarone discontinuation 112 61 57 vs 79% AF termination during ablation 66 vs 48% SR at 32 months Wu 2008 98 AAD vs placebo after catheter ablation of AF 74 62 13.5 vs 37.8% AF recurrence at 3 months 29.7 vs 24.3% at 12 months 8.1 vs 8.1% at more than 12 months Turco 2007 99 Amiodarone vs no drug after catheter ablation of AF 107 57 30 vs 34% AF recurrence at 12 months AAD, anti-arrhythmic drug; AF, atrial fibrillation; SR, sinus rhythm; PVI, pulmonary vein isolation.