Durability of bipolar coaxial endocardial pacemaker leads compared with unipolar leads

BACKGROUND The coaxial design allows for thinner bipolar endocardial pacemaker leads, but recent reports have suggested a higher incidence of failure for this sophisticated configuration.

OBJECTIVE To compare the long-term survival of bipolar coaxial and unipolar leads.

METHODS Retrospective follow-up.

RESULTS Between January 1, 1980 and June 30, 1991, 1142 bipolar coaxial leads and 1181 unipolar leads were implanted at the Cleveland Clinic. The mean follow-up was 33 ± 32 months (range 1 to 138 months). Ten bipolar coaxial leads failed (0.88%), as did 9 unipolar leads (0.76%). At 5 years the cumulative survival was 98.6% for both types of leads; however, at 10 years the survival of bipolar coaxial leads was only 92.4% compared with 98.6% of unipolar leads (P = .03; relative risk 2.7, 95% confidence interval = 1.1 to 6.9).

CONCLUSIONS The sophisticated design of bipolar coaxial leads could be the cause of their increased vulnerability. The benefit- to-risk ratio of this design should be prospectively reevaluated.