Extension of generator longevity by use of high impedance ventricular leads

The resistance of a pacing lead negatively correlates to current consumptio n. A prospective, randomized trial was conducted to evaluate the effect of a high impedance ventricular lead (CapSure Z) on generator longevity compar ed to a conventional lead (CapSure SP) eighty-nine patients were included i n the study (51 male, 37 female, age 70.0 +/- 10.3 years). Forty-six patien ts received a CapSure SP lead (5024 bipolar), and 43 patients received a Ca pSure Z lead (5034 bipolar) in a randomized fashion. Follow-up data collect ed at 5 days, 3, 6, and 12 months postimplant included: lead impedance, pac ing and sensing thresholds, impulse energy, and estimated time to replaceme nt. All parameters were collected via pacemaker telemetry the time to repla cement was calculated automatically by a programmed algorithm of the pacema ker. There was no difference in the performance of the atrial lead when a d ual chamber device was indicated. The CapSure Z leads displayed statistical ly significant higher impedance values than the CapSure SP lead in all foll ow-up periods. There was no significant difference in lead related complica tions. No significant differences were observed between pacing and sensing thresholds in both groups. The CapSure Z leads provided a significant reduc tion in current drain, resulting in a reduction of mean energy consumption at the 12-month follow-up from 10.4 +/- 5.01 muJ in the CapSure SP group to 6.6 +/- 1.4 muJ in the CapSure Z group (median from 9.9 muJ to 6.9 muj, re spectively), providing an estimated increase in mean longevity of more than 1 year from 81.1 +/- 13.5 months in the CapSure SP group to 94.5 +/- 13.4 months in the CapSure Z group (median: 76.5 months to 95.0 months, respecti vely). The use of a high resistance lead for ventricular pacing appears to result in a clinically relevant extension of generator longevity.