ANTIARRHYTHMIC THERAPIES FOR THE PREVENTION OF SUDDEN CARDIAC DEATH

Despite remarkable advances in cardiovascular therapeutics, sudden car diac death remains a significant problem. In this review, data from cl inical trials and other studies on antiarrhythmic therapies have been evaluated in order to determine effective strategies for the preventio n of sudden cardiac death in high risk patients. Overall, routine prop hylactic use of class I antiarrhythmic agents in high risk patients, m ostly survivors of acute myocardial infarction, is associated with inc reased risk of death [61 trials, 23 486 patients: odds ratio (OR) 1.13 ; 95% confidence interval (CI) 1.01 to 1.27, p < 0.05]. Conversely, be ta-blockers are associated with highly significant reductions in risk of death in postinfarction patients (56 trials, 53 521 patients: OR 0. 81; 95% CI 0.75 to 0.87, p < 0.00001). Overall data from the amiodaron e trials on high risk patients, including postinfarction patients, pat ients with congestive heart failure or survivors of cardiac arrest, su ggest that this agent is effective in reducing the risk of death (14 t rials, 5713 patients: OR 0.83; 95% CI 0.72 to 0.95, p = 0.01) although further studies are needed to better define which types of patients w ill potentially benefit most from this agent. No benefits were seen wi th calcium channel blockers (26 trials, 21 644 patients: OR 1.03; 95% CI 0.94 to 1.13, p = NS).The implantable cardioverter-defibrillator is a promising option for high risk patients, but definition of its role awaits the completion of ongoing clinical trials. Since causes of sud den death are heterogeneous, the clinician should pursue a multifactor ial approach to its prevention. Primary and secondary prevention of ca rdiac ischaemia, through the treatment of cardiovascular risk factors and maximising the use of aspirin, beta-blockers, lipid-lowering drugs , and angiotensin converting enzyme inhibitors after acute myocardial infarction, should lead to a future decrease in the incidence of sudde n cardiac death.