Multicenter experience with a bipolar tined polyurethane ventricular lead.
A multicenter study was undertaken to determine the failure rate of a specific bipolar tined polyurethane ventricular pacing lead, the Medtronic 4004/4004M pacing lead. Seven centers in the United States and Canada implanted 586 Medtronic 4004/4004M pacing leads. The study was designed to determine the probability and clinical manifestations of lead failure. Only failures compatible with an insulation problem were included. The Kaplan-Meier estimate of the percentage of 4004/4004M lead failures within 4 years after implantation was 14.1% (95% confidence interval: 8.5%-19.3%). Failures were manifested as sensing abnormalities, failure to capture, early battery depletion, and significant decrease in measured impedance compared with previous impedance measurements. The observed rate of failure is unacceptable, and strong consideration should be given to replacing the 4004/4004M pacing lead in pacemaker dependent patients and closely monitoring nondependent patients.