A comparative study of the action of dexamethasone sodium phosphate and dexamethasone acetate in steroid-eluting pacemaker leads.

The aim of this study was to characterize acute and medium-term pacemaker lead performance with the two most commonly used glucocorticosteroids: dexamethasone sodium phosphate and dexamethasone acetate. Forty sets of atrial and ventricular passive-fixation leads containing either dexamethasone sodium phosphate or dexamethasone acetate were implanted as dual chamber pacemakers. Randomization was equally distributed to both arms of the study. Stimulation thresholds, lead impedance, and sensing were measured on the day of implant, day 1, 1 month, 3 months, and 6 months following the implant. For the dexamethasone sodium phosphate arm, the atrial stimulation thresholds were 0.9 +/- 0.1 V at implant and 0.8 +/- 0.1 V at 6 months, and in the ventricle 0.5 +/- 0.1 V at implant and 0.6 +/- 0.1 V at 6 months. In the dexamethasone acetate arm, the atrial stimulation thresholds were 0.7 +/- 0.1 V at implant and at 6 months, and in the ventricle 0.5 +/- 0.1 V at implant and at 6 months. There were no significant differences between dexamethasone sodium phosphate or dexamethasone acetate leads for stimulation thresholds at any of the intervals of follow-up. P- and R-wave sensing were similarly maintained over the duration of follow-up with no significant differences between groups at any of the intervals of follow-up. Pacing lead impedance showed a trend towards lower values in the dexamethasone acetate arm, which only reached statistical significance at 3 months and beyond for ventricular leads. Leads containing dexamethasone sodium phosphate and dexamethasone acetate demonstrate equivalent and excellent acute and medium-term pacemaker lead performance characteristics.