Steroid elution improves the stimulation threshold in an active-fixation atrial permanent pacing lead. A randomized, controlled study. Model 4068 Investigators.
BACKGROUND
Prior work suggests that the addition of a steroid-eluting reservoir to a passive-fixation permanent pacemaker lead improves the stimulation threshold; however, no large randomized study has addressed this tissue. Over the last several years, there has been an increase in enthusiasm for the use of active-fixation permanent pacemaker leads for various reasons in spite of the generally accepted notion that active-fixation leads have higher stimulation thresholds.


RESULTS
This multicenter, randomized, controlled study examined the difference in performance between a standard active-fixation atrial lead (Medtronic model 4058) and a steroid-eluting lead (Medtronic model 4068). Stimulation thresholds were obtained in a four-point strength-duration fashion. Evaluations of sensing and impedance were performed as well. These evaluations were performed at implantation, at weeks 1 through 4, and at weeks 6, 12, 24, and 52. Stimulation thresholds were significantly better in the steroid lead than in the nonsteroid lead at each measurement point from 1 week to 12 months. The mean 1.6-V stimulation threshold at 12 months was 0.19 +/- 0.2 ms in the steroid lead and 0.41 +/- 0.30 ms in the control lead. No acute peaking was observed with the steroid lead, whereas significant peaking was observed with the control lead. There was no difference in long-term sensing or impedance.


CONCLUSIONS
Inclusion of a steroid-eluting reservoir in an active-fixation permanent pacing lead improved stimulation thresholds in both the subacute and chronic periods and therefore should extend pulse-generator longevity.
Crossley
G H
GH
Department of Medicine, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1045, USA.
Brinker
J A
JA
Reynolds
D
D
Spencer
W
W
Johnson
W B
WB
Hurd
H
H
Tonder
L
L
Zmijewski
M
M
D000368:Aged; D003907:Dexamethasone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage*; D006325:Heart Atria; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D013997:Time Factors
D005938:Glucocorticoids; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone