The search for effective treatment for preventing
sudden cardiac death (SCD) initially started with
anti-arrhythmic agents in high-risk patients, but the use of randomized controlled trials clearly led to the conclusion that an approach based on
anti-arrhythmic agents is not useful, and sometimes potentially harmful (the risk of arrhythmic death was increased up to 159% in CAST study). Today the approach to SCD prevention includes considering both the setting of patients who have already presented a
cardiac arrest or a malignant
ventricular tachyarrhythmias (
secondary prevention of SCD) and the much broader setting of primary prevention in patients at variable degrees of identifiable risk. For
secondary prevention of SCD, implantable cardioverter defibrillation is now the standard of care (the risk of overall mortality may be reduced by 20-31%), and
anti-arrhythmic agents, specifically
amiodarone, have only a complementary role (for reducing device activations or for preventing
atrial fibrillation). For primary prevention of SCD in high-risk patients, cardioverter
defibrillators have nowadays specific indications in patients with
left ventricular dysfunction (often in combination with
cardiac resynchronization therapy), where the risk of overall mortality may be reduced by 23-54%. For the large number of subjects who have some risk of SCD, but are not identified as at high risk of SCD, a series of drugs could exert a favorable effect (beta-blockers,
angiotensin-converting enzyme inhibitors,
angiotensin receptor blocker agents,
statins,
omega-3 fatty acids and
aldosterone antagonists), and for some of them evidence is emerging, from subgroup analysis, of possible SCD prevention capabilities.