Related Experiment Videos
[Long-term effect of amiodarone therapy following myocardial infarct in patients with complex ventricular
W Kiowski1, H Brunner, M Pfisterer
1Abteilung für Kardiologie, Universitätsspital Basel.
Insights
Low-dose amiodarone improved survival in patients with asymptomatic complex ventricular arrhythmias initially. However, this survival benefit did not persist long-term after drug discontinuation, suggesting limited long-term value.
Area of Science:
- Cardiology
- Clinical Trials
- Pharmacology
Background:
- The BASIS study demonstrated a 1-year survival benefit for low-dose amiodarone in asymptomatic complex ventricular arrhythmias.
- Long-term survival and causes of death beyond the initial treatment period were not fully established.
Purpose of the Study:
- To evaluate the long-term survival and mode of death in patients from the BASIS study after amiodarone discontinuation.
- To determine if the initial survival benefit of amiodarone persists beyond one year.
Main Methods:
- Follow-up phone calls to physicians, patients, and hospitals for 91 amiodarone survivors and 99 control survivors.
- Median follow-up of 72 months (range 55-125 months).
- Analysis of causes of death: sudden, non-sudden cardiac, non-cardiac, and unknown.
Main Results:
- Overall mortality was significantly lower in the amiodarone group at 84 months (30% vs. 45%, p=0.024) and cardiac mortality was also lower (p=0.027).
- This mortality reduction was attributed solely to the first year of amiodarone treatment.
- Survival curves did not differ significantly during the late follow-up period after treatment cessation.
Conclusions:
- The initial survival benefit of low-dose amiodarone in asymptomatic complex ventricular arrhythmias is not sustained long-term after discontinuation.
- Cardiac death risk appears low after the first year post-myocardial infarction.
- Continued antiarrhythmic therapy may not be justified for patients with initially complex asymptomatic ventricular arrhythmias beyond the first year.
Abstract:
In the BASIS study, an improvement in 1 year survival of patients with asymptomatic complex ventricular arrhythmias with low-dose amiodarone was shown in comparison with an untreated control group. To assess whether this beneficial effect would last for a longer follow-up despite discontinuation of amiodarone therapy after one year, we assessed long-term survival and mode of death in the 91 survivors of the first year in the amiodarone treatment group and the 99 survivors in the control group by phone calls to private physicians, patients and hospitals. During a median follow-up of 72 (55-125) months, 184/193 patients (95%) could be reached. Causes of death during the follow-up were sudden (6 vs 14), non-sudden cardiac (8 vs 9), non cardiac (5 vs 9) and unknown (7 vs 6) in patients initially treated with amiodarone versus the control group respectively. The probability of death after 84 months was 30% in the amiodarone group and 45% in the control group, and was significantly lower in amiodarone treated patients with respect to all deaths (p = 0.024) as well as cardiac deaths (p = 0.027). This mortality reduction was only due to amiodarone treatment during the first year after the index infarction, whereas the survival curves did not differ significantly during the late follow-up. Thus, the risk of cardiac death is low after the first year after myocardial infarction and may not justify continued antiarrhythmic therapy in patients with initially complex asymptomatic ventricular arrhythmias.