***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: We included 24 studies (9,997 participants). Eighteen studies evaluated amiodarone for primary prevention and six for secondary prevention. Only three studies used an ICD concomitantly with amiodarone for the comparison (all of them for secondary prevention). For primary prevention, amiodarone compared to placebo or no intervention (17 studies, 8383 participants) reduced SCD (RR 0.76; 95% CI 0.66 to 0.88), cardiac mortality (RR 0.86; 95% CI 0.77 to 0.96) and all-cause mortality (RR 0.88; 95% CI 0.78 to 1.00). The quality of the evidence was low. Compared to other antiarrhythmics (three studies, 540 participants), amiodarone reduced SCD (RR 0.44; 95% CI 0.19 to 1.00), cardiac mortality (RR 0.41; 95% CI 0.20 to 0.86) and all-cause mortality (RR 0.37; 95% CI 0.18 to 0.76). The quality of the evidence was moderate. For secondary prevention, amiodarone compared to placebo or no intervention (two studies, 440 participants) appeared to increase the risk of SCD (RR 4.32; 95% CI 0.87 to 21.49) and all-cause mortality (RR 3.05; 1.33 to 7.01). However, the quality of the evidence was very low. Compared to other antiarrhythmics (four studies, 839 participants) amiodarone appeared to increase the risk of SCD (RR 1.40; 95% CI 0.56 to 3.52; very low quality of evidence), but there was no effect in all-cause mortality (RR 1.03; 95% CI 0.75 to 1.42; low quality evidence). Amiodarone was associated with an increase in pulmonary and thyroid adverse events. There is low to moderate quality evidence that amiodarone reduces SCD, cardiac and all-cause mortality when compared to placebo or no intervention for primary prevention, and its effects are superior to other antiarrhythmics. It is uncertain if amiodarone reduces or increases SCD and mortality for secondary prevention because the quality of the evidence was very low.
Output:

We searched scientific databases for clinical trials comparing the effects of amiodarone versus other antiarrhythmics or placebo on SCD, mortality and any side effects. We included adult participants at high risk or who had previously presented with sudden cardiac arrest, a serious heart malfunction that causes the arrhythmia. The evidence is current to March 2015. We found 24 studies comprising 9,997 participants. In participants at high risk, the evidence showed that amiodarone may prevent SCD or mortality when compared to placebo, and it is probably better than other antiarrhythmics. On the other hand, in participants who have already suffered a prior cardiac arrest, it is uncertain whether amiodarone increases or reduces the risk of a new episode of cardiac arrest or death. Furthermore, amiodarone may lead to or worsen adverse effects in the thyroid or lungs, when compared with placebo or other antiarrhythmics. The overall quality of evidence of these studies was low.