Background and purpose: Riata(TM) defibrillation leads are susceptible to conductor externalization. The point prevalence of insulation defect in Riata(TM) leads is up to 33 %, but prospective data concerning incidence of new lead abnormalities are lacking. The purpose of our study was to determine the annual incidence of new conductor externalizations and electrical lead failure.
Methods: A prospective observational study was conducted at a single tertiary center. One hundred forty-one patients were followed over 12 months. A posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming was performed at baseline and at 12 months to screen for conductor externalization. Electrical abnormalities and clinical outcome were also assessed.
Results: The overall incidence of new insulation defects was 8.5 % at 12 months. High-risk leads for new conductor externalization were lead models 1580, 1582, and 1590 with an annual rate of 11.9, 11.1, and 10 %, respectively. New conductor externalizations were three times more common in 8 Fr leads compared to 7 Fr leads. The overall incidence of new electrical dysfunction was 6.4 % at 12 months. Electrical dysfunction was significantly higher in abnormal leads (25 % [3/12], 4.7 % [6/129]; p = 0.03) and mostly driven by high ventricular pacing thresholds. There was no difference in inappropriate shock or failure of high-voltage therapy.
Conclusion: The annual incidence of new insulation defects in Riata(TM) leads is much higher than previously reported. Lead models 1580, 1582, and 1590 are at highest risk for new conductor externalization. Electrical dysfunction in Riata(TM) leads is also much higher than reported and is associated with conductor externalization.