Amiodarone Against ICD Therapy in Chagas Cardiomyopathy for Primary Prevention of Death

The primary objective is to compare the efficacy of the treatment using implantable cardioverter defibrillator (ICD) implantation to that of the treatment using amiodarone in the primary prevention of all-cause mortality in high-risk patients with Chagas cardiomyopathy and non-sustained ventricular tachycardia (NSVT).

Chagas disease is an endemic problem in Latin America, where millions of people are chronically infected by Trypanosoma cruzi. The disease has also recently become clinically and epidemiologically relevant in several other countries due to social factors related to individuals migration and globalization. Chagas cardiomyopathy occurs in 30%-50% of the infected individuals, leading to considerable morbidity and mortality rates. Sudden cardiac death is the major cause of death in patients with Chagas cardiomyopathy. While implantable cardioverter defibrillator and treatment with amiodarone have been recommended and performed empirically for the secondary prevention in patients with Chagas cardiomyopathy, no consistent scientific evidence exists on the role of these therapeutic strategies for the primary prevention of Sudden cardiac death in patients with Chagas cardiomyopathy and high mortality risk.

The main hypothesis of this study is that implantable cardioverter defibrillator implantation is more efficient in the primary prevention of death in Chagas cardiomyopathy than drug therapy with amiodarone in patients with documented non-sustained ventricular tachycardia.

We should point out that the death risk will be assessed using the Rassi risk score for death prediction validated based on non-invasive variables and, depending on the results of this study, it may guide the indication of implantable cardioverter defibrillator in Chagas cardiomyopathy.

Eligibility Criteria:
Inclusion Criteria:

* Written informed consent prior to randomization and any study procedure;
* Both genders, age \> 18 years and \< 75 years;
* Recent (previous 6 months) documented positive serologic test for Chagas disease in at least two different tests (indirect hemagglutination, indirect immunofluorescence, or ELISA);
* Presence of at least 10 points in Rassi risk score for death prediction;
* Presence of at least 1 episode of NSVT on Holter monitoring, defined as \> 3 successive beats and duration \< 30 seconds, with HR \> 120 bpm is mandatory.

Exclusion Criteria:

* Participation in another study currently or \< 1 year ago, except for totally unrelated observational studies;
* Other concomitant cardiovascular disease, including uncontrolled diabetes mellitus (systemic hypertension without target-organ impairment is allowed);
* Renal dysfunction (serum creatinine \> 1.5 mg/dL or glomerular filtration rate (GFR) \< 60 mL/min/1.73m2) or liver dysfunction with diagnosis of cirrhosis or portal hypertension or elevated serum enzymes (AST or ALT) \> 3 x the upper normal limit;
* Moderate or severe chronic obstructive pulmonary disease;
* Peripheral polyneuropathy;
* Hypo or hyper-thyroidism;
* Current alcoholism or quit for \<2 years;
* Mental disorder or illicit drug addiction;
* Life expectancy \< 1 year, because of the disease itself or of comorbidities (including NYHA class IV CHF);
* Pregnancy or breastfeeding;
* Childbearing potential during the study (non-menopausal patients who have not undergone a safe and permanent birth control method);
* Other contraindications for the use of amiodarone: previous intolerance to the drug; HR \< 55bpm; sinus node disease; type II Mobitz; fixed 2:1 AV block; advanced degree atrioventricular block (AV) block; Complete AV block; QTc \> 500mseg;
* Formal indication for the use of amiodarone or defibrillator (NSVT and very disturbing palpitations, presyncope or syncope; SVT; recovery from cardiac arrest);
* Use of amiodarone in the past 6 months, except if started for \< 2 weeks and if loading dose had been \<10g and maintenance dose ≤100mg/day;
* Current use of betablocker considered clinically indispensable, with bradycardia \< 55/min or AV block ≥ 1st degree, without pacemaker implantation;
* Current use of other medications with contraindication to the concomitant use of amiodarone;
* Persistent or permanent atrial fibrillation;
* Previous withdrawal from this study.