DAVID II (Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial II)

The DAVID II Clinical Study evaluates the hypothesis that, in patients needing an ICD but without overt indications for pacing, AAI pacing with maximal concomitant drug therapy will not increase the rate of the combined endpoint of mortality or hospitalization for new or worsened heart failure, compared to patients with ventricular backup pacing (VVI), and that AAI pacing will result in a reduction of 0.425 years in median event-free survival compared to VVI pacing.

Enrollment and Randomization:

A total of 600 patients have been enrolled and randomized. All patients previously enrolled in the VVI arm of the DAVID Trial who were hemodynamically stable in the VVI-40 programmed mode and willing to participate have been randomized in equal numbers into the study. New patients (not previously randomized in DAVID) have also been enrolled and similarly randomized. The randomization was stratified for investigational site, for previous randomization in DAVID vs being newly-enrolled, for a history of CHF, and, among the new enrollees, for primary versus preventive eligibility criteria.

Patients were enrolled with the same indications used in the DAVID Trial, including MADIT II indications, with the exception that any patient in class III heart failure must have been on optimal heart failure therapy for at least 3 months prior to enrollment and randomization.

Any planned cardiac surgery (ablation, endocardial resection, valve, aneurysmectomy, revascularization) must have been completed before randomization. All patients have received commercially available St. Jude dual chamber ICD systems.