Cardioversion for atrial fibrillation in the real world: there is room for improvement

Abstract

sientischaemicattack(TIA),1%,majorbleeding,1.05%,heartfailure, 0.83%] within 14 days after enrollment. Cardioversion was more successful for AF of recent (,48 h) onset vs. longer duration (585 of the 696 or 84% vs. 836 of the 1105 or 76%). At 1-year follow-up, sinus rhythm was present in 893 of the 1271 (70%) of patients. Patients with paroxysmal AF were more likely to maintain sinus rhythm after 1 year. The authors conclude that ‘contemporary cardioversion of AF is routinely successfully and safely performed, with a high proportion of patients in sinus rhythm at 1 year follow-up’. In our opinion, these conclusions should be put into perspective. Regarding the overall safety of cardioversion, we believe that a 4.2% major complication rate cannot be considered as ‘a few major complications’. This percentage of complications is as high as the overall major complication rate observed for an invasive procedure such as ablation of AF (4.5%). 3 Some of the reported complications (TIA or stroke, major bleedings and heart failure) could be reduced with better adherence to the guidelines. Although, in patients with AF lasting .48 h undergoing electrical cardioversion, appropriate anticoagulation was administered in 90%, in patients undergoing pharmacological cardioversion (intravenously or orally) only 42 and 52%, respectively, were properly anticoagulated. This may suggest that physicians feel that the risk of embolic events is lower for chemical than for electrical cardioversion and that strict anticoagulation is of less importance. However, 13 of the 1089 patients (1.2%) undergoing pharmacological cardioversion developed TIA compared with 2 of the 712 (0.2%) in the electrical cardioversion group. Nevertheless, we should keep in mind that even when appropriate anticoagulation is used, the risk of thromboembolic events after cardioversion can be reduced to 0.5‐0.8%, but it can never be completely avoided. 4,5 Regarding the use of antiarrhythmic drugs, up to 18.2% of patients received agents that are considered inappropriate according to the guidelines (e.g. class I drugs in the presence of structural heart disease or the use of sotalol for pharamacological cardioversion). Acute proarrhythmia was extremely rare but the negative inotropic properties of most antiarrhythmic drugs could have contributed to the development of heart failure early after cardioversion. In this observational study, an acute efficacy of cardioversion was 79%. Comparing different strategies in this context has limitations, but it is striking that irrespective of AF duration, electrical cardioversion was always more successful than chemical cardioversion (for AF , 48 h 97 vs. 82%, for AF . 48 h 87 vs. 61%), suggesting that electrical cardioversion might have an incremental benefit even after failed chemical cardioversion. Interestingly, in patients treated with non-antiarrhythmic drugs (beta-blocking agents, calcium channel blockers, digitalis, magnesium) restoration of sinus rhythm occurred in 128 of the 165 (78%). In our opinion, this highlights the importance of accepting a reasonable waiting