LONG-TERM PERFORMANCE OF ENDOCARDIAL PACING LEADS

To assess the performance of endocardial pacemaker leads and to identi fy factors associated with structural lead failure, medical records of 2,611 endocardial pacing leads fin 1,518 patients) implanted between 1980 and 1991, having at least 1 month of follow-up, were reviewed. Le ads without structural failure had normal function at the last follow- up date, or were discontinued for reasons other than structural failur e (patient death, infection, dislodgment, lead-pacemaker incompatibili ty, operative complication, or abandonment by telemetry not related to failure). Leads with suspected structural failures were invasively or noninvasively disconnected because of clinical malfunction (loss of c apture or sensing, oversensing, elevated thresholds, or skeletal muscu lar stimulation). Leads with verified structural failures met the crit eria for suspected lead failure and also had a visible defect seen in the operating room or on chest roentgenograms, a change in the impedan ce interpreted by the physician as lead disruption, or a manufacturer' s return product report that confirmed structural failure. Variables a nalyzed included patients' age and gender, paced chamber, venous acces s, insulation materials, fixation mechanism, coaxial design, polarity and different lead models. The cumulative lead survival at 5 and 10 ye ars were 97.4% and 92.9%, respectively, for suspected failures; and 98 .7% and 97.3%, respectively, for verified failures. Leads in older pat ients greater than or equal to 65 years old), and leads in atrial posi tion had fewer verified failures IP = 0.014 and P = 0.007, respectivel y). Unipolar leads else fended to perform better according to the veri fied definition (P = 0.07). The lead Medtronic 4012 had more suspected IP < 0.05) and more verified failures (P < 0.01), the lead CPI 4010 h ad more verified failures (P < 0.05) than the entire group of ventricu lar leads. Conclusions: Endocardial pacing leads implanted in atrial p osition, and implanted in older patients (greater than or equal to 65 years old) seems to have better long-term survival. Some lead models ( Medtronic 4012 and CPI 4010) had poor survival rates, that could not b e explained by the analyzed variables. The expect ed performance of en docardial pacing leads varies according to how failure is defined.