Background: Lead-associated complications and technical issues in patients with cardiac implantable electronic devices are common but underreported in the literature.
Methods: All patients undergoing implantation of the Osypka QT-5® ventricular lead at the University Clinic St. Pölten between 1 January 2006 and 31 December 2012 were retrospectively analyzed (n = 211). Clinical data including pacemaker follow-up examinations and the need for lead revisions were assessed. Kaplan-Meier analysis to estimate the rate of lead dysfunction during long-term follow-up was conducted.
Results: Patients were followed for a median of 5.2 years (interquartile range (IQR) 2.0-8.7). R-wave sensing properties at implantation, compared to last follow-up, remained basically unchanged: 9.9 mV (IQR 6.8-13.4) and 9.6 mV (IQR 5.6-12.0), respectively). Ventricular pacing threshold significantly increased between implantation (0.5 V at 0.4 ms; IQR 0.5-0.8) and the first follow-up visit (1.0 V at 0.4 ms; IQR 0.8-1.3; p < 0.001) and this increase persisted throughout to the last check-up (0.9 V at 0.4 ms; IQR 0.8-1.2). Impedance significantly declined from 1142 Ω (IQR 955-1285) at implantation to 814 Ω (IQR 701-949; p < 0.001) at the first check-up, followed by a further decrease to 450 Ω (IQR 289-652; p < 0.001) at the last check-up. Overall, the Osypka QT-5® ventricular lead was replaced in 36 patients (17.1%).
Conclusions: This report shows an unexpected high rate of technical issues of the Osypka QT-5® ventricular lead during long-term follow-up.
Keywords: impedance decline; lead replacement; pacemaker malfunction; reoperation.