An update on amiodarone treatment for atrial fibrillation: efficacy versus safety

PhD ceremony: Ms. S. Ahmed, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: An update on amiodarone treatment for atrial fibrillation: efficacy versus safety

Promotor(s): prof. I.C. van Gelder, prof. D.J. van Veldhuisen, prof. T.P. Links

Faculty: Medical Sciences

Atrial fibrillation is the most prevalent cardiac arrhythmia and the most effective antiarrhythmic drug is amiodarone. It is, however, often accompanied by substantial adverse events, which may be associated with high dosage and long-term use. The current PhD research has studied amiodarone-associated adverse events and possible treatment strategies to reduce these. In addition, efficacy of these amiodarone treatments for atrial fibrillation and the effect on quality of life was investigated.

The conventional amiodarone treatment for atrial fibrillation was compared to short-term amiodarone treatment for only two months peri-cardioversion and to discontinuation of amiodarone therapy after at least six months sinus rhythm maintenance on amiodarone treatment. These novel strategies did not reveal any additional benefit. The most frequent adverse event is thyrotoxicosis with a comparable incidence of adverse events. These strategies are also not more effective for sinus rhythm maintenance with comparable effect on quality of life. Hypertension is furthermore an important factor in atrial fibrillation recurrence. A subgroup of patients with Type D personality (a combination of social inhibition and negative affectivity) have more recurrences and undergo more cardioversions without a positive effect on quality of life.

The incidence and predictors of amiodarone-associated thyrotoxicosis and hypothyroidism were investigated in a population with long-term amiodarone use. It was shown that the incidence of thyrotoxicosis is higher than hypothyriodism. In addition, only general predictors of amiodarone-associated thyroid dysfunction have been found. Lastly, effective treatment of thyrotoxicosis is not dependent on discontinuation of amiodarone with comparable time to normalization of thyroid function.