Implanted defibrillators and primary prevention of sudden cardiac death: where are we today?

Implanted defibrillators have become a mainstream therapy for the prevention of sudden cardiac death (SCD) from ventricular tachyarrhythmias in patients with chronic coronary artery disease. A decade of studies has confirmed the superiority of ICDs over antiarrhythmic drug therapy in prolonging the life of patients with a prior history of sustained VT or VF. Furthermore, recent studies have examined the role of ICD therapy in the primary prophylaxis against sudden death in patients considered at high risk for ventricular tachyarrhythmias. These studies have revealed that in selected patients with the substrate of chronic coronary artery disease and a ventricular scar, ICDs lead to important relative and absolute reductions in mortality in such patients without a prior history of VT or VF. Clinicians caring for patients with chronic coronary artery disease (CAD) and severe LV dysfunction, who are at a risk of sudden cardiac death, need to carefully consider this information when managing this patient population.