Drug-eluting collar--a new approach to reducing threshold.

Area of Science:

• Cardiovascular medicine
• Biomedical engineering
• Implantable electronic devices

Background:

• Pacing lead performance is crucial for effective cardiac rhythm management.
• Early threshold rise and chronic lead performance can be affected by inflammation at the electrode-tissue interface.
• Drug-eluting collars offer a potential solution to mitigate these issues.

Purpose of the Study:

• To evaluate the clinical performance of pacing leads incorporating a drug-eluting collar (DEC).
• To assess the efficacy of a low-dose dexamethasone sodium phosphate (less than 0.5 mg) delivered via the DEC in reducing pacing thresholds.
• To compare the performance of DEC leads against standard control leads.

Main Methods:

• A prospective study involving 20 patients undergoing transvenous implantation.
• Ten patients received ventricular silicone DEC leads with a drug-eluting collar adjacent to a 4-mm2 Pt/Ir electrode.
• Ten patients received control leads; early and chronic thresholds, and lead impedances were monitored via pacer telemetry.

Main Results:

• DEC leads demonstrated substantially lower pacing thresholds in the initial weeks post-implantation (P < 0.0005).
• Significantly lower chronic thresholds were observed in the DEC lead group compared to controls (P < 0.025).
• No significant difference in lead impedances was noted, suggesting comparable lead stability.

Conclusions:

• A drug dose of less than 0.5 mg of dexamethasone sodium phosphate released from a DEC is effective in reducing acute and chronic pacing thresholds.
• DEC leads represent a promising advancement for improving long-term pacing lead performance and potentially reducing complications.
• The findings support the use of drug-eluting technology in cardiac pacing leads.