Methods To address this issue, we conducted a randomized comparison of these two treatment strategies in patients who had been resuscitated from near-fatal ventricular fibrillation or who had undergone cardioversion from sustained ventricular tachycardia. Patients with ventricular tachycardia also had either syncope or other serious cardiac symptoms, along with a left ventricular ejection fraction of 0.40 or less. One group of patients was treated with implantation of a cardioverter–defibrillator; the other received class III antiarrhythmic drugs, primarily amiodarone at empirically determined doses.

Fifty-six clinical centers screened all patients who presented with ventricular tachycardia or ventricular fibrillation during a period of nearly four years. Of 1016 patients (45 percent of whom had ventricular fibrillation, and 55 percent ventricular tachycardia), 507 were randomly assigned to treatment with implantable cardioverter–defibrillators and 509 to antiarrhythmic-drug therapy. The primary end point was overall mortality. Results Follow-up was complete for 1013 patients (99.7 percent). Rats For Sale. Overall survival was greater with the implantable defibrillator, with unadjusted estimates of 89.3 percent, as compared with 82.3 percent in the antiarrhythmic-drug group at one year, 81.6 percent versus 74.7 percent at two years, and 75.4 percent versus 64.1 percent at three years (P. Figure 4 Hazard Ratios (and 95 Percent Confidence Limits) for Death from Any Cause in the Defibrillator Group as Compared with the Antiarrhythmic-Drug Group in Prespecified Subgroup Analyses in the Univariate Model.

No subgroup differed significantly from the entire population. The solid vertical line represents equal effectiveness of the two treatments; points to the left indicate better survival in the defibrillator group, and points to the right better survival in the antiarrhythmic-drug group. The dotted vertical line represents the results for the entire study (hazard ratio = 0.62). LVEF denotes left ventricular ejection fraction, and CAD coronary artery disease. Survivors of ventricular fibrillation or symptomatic, sustained ventricular tachycardia have a high risk of recurrence of arrhythmia, which is often fatal. Commonly prescribed treatments for the prevention of fatal recurrences are the implantable cardioverter–defibrillator and a variety of antiarrhythmic drugs. Whether the implantable cardioverter–defibrillator or antiarrhythmic-drug therapy is more effective in reducing mortality has not been shown.

The results of the use of most antiarrhythmic drugs in the prevention of life-threatening ventricular tachyarrhythmias have been disappointing — even in the case of drugs that effectively reduce spontaneous ventricular arrhythmias. The implantable defibrillator effectively terminates sustained ventricular tachyarrhythmias, but its effectiveness as compared with antiarrhythmic drugs in prolonging survival has been demonstrated only in a small subgroup of patients at high risk for sudden death who had persistently inducible ventricular arrhythmias in the electrophysiology laboratory — a feature not required of our patients.