Prospective evaluation of cinefluoroscopy and chest radiography for Riata lead defects: implications for future lead screening

Cable externalization and electrical failure of the Riata family of implantable cardioverter-defibrillator leads: A systematic review and meta-analysis

BACKGROUND

The Riata class of defibrillator leads were placed under US Food and Drug Association (FDA) advisory as of November 2011 because of high rates of cable externalization (CE) and electrical failure (EF). The overall rates of these complications remain unknown.

OBJECTIVE

The purpose of this study was to systematically search the literature for rates of Riata lead failure and to perform a meta-analysis to estimate failure rates.

METHODS

We conducted a meta-analysis of observational studies examining the rates of EF, CE, and the interaction of the two. We identified 23 English language manuscripts addressing 1 or more of these questions.

RESULTS

Across 23 studies, the overall CE rate was 23.1% (95% confidence interval [CI] 19.0%-27.6%). The overall EF rate was 6.3% (95% CI 4.7%-8.2%). The presence of CE was associated with a more than 6-fold increase in the rate of EF compared to no CE (17.3% [95% CI 11.2%-25.9%] vs 2.7% [95% CI 1.4%-5.2%], respectively). The rate of CE was 3-fold higher for 8Fr leads compared to 7Fr leads, but rates of EF were similar (4.6%; 95% CI 3.2-6.6] and 3.9%; 95% CI 2.4-6.1], respectively). Rates of both CE and EF were higher in dual coil vs single coil leads, but confidence intervals overlapped.

CONCLUSION

In clinical practice, rates of CE in Riata leads are substantial. While CE is associated with a significant increase in the risk of EF, the incidence of EF without externalization is not trivial.

Mechanical and electrical dysfunction of Riata implantable cardioverter-defibrillator leads

AIM

Riata implantable cardioverter-defibrillator leads are prone to failure by conductor externalization and/or electrical dysfunction. The objectives of this study were to determine the predictors of the Riata lead failure, to assess the association of conductor externalization and electrical lead failure, and to analyse the rates of lead failure over time.

METHODS AND RESULTS

Of 273 implanted Riata leads in our centre, 197 were investigated according to the Riata recall protocol, including electrical measurements by device interrogation and annually fluoroscopy. During a mean follow-up period of 5.6 ± 1.4 years, Riata lead failure was 18.8% (37 of 197) for externalization and 17.3% (34 of 197) for electrical lead failure. Electrical lead failure was correlated with time after implant. Externalization and electrical dysfunction co-existed in only 6 of 197 (3%) patients and were not related (Phi's coefficient -0.013, P = 0.85). During the second annual screening, 145 (73.6%) patients underwent fluoroscopy and 9 patients had novel externalizations resulting in an incidence of 6.72%/patient/year which was higher than expected based on cross-sectional analysis. Besides, there was a significant increase in the extent of externalization (17.65 ± 11.14 mm vs. 21.77 ± 11.95 mm, P = 0.001). In multivariate Cox regression analysis, non-ischaemic cardiomyopathy and impaired LVEF were independent predictors of externalization, and 7 Fr lead was a predictor of electrical lead failure.

CONCLUSION

Riata leads show progressive and high externalization rates without correlation between externalization and electrical lead failure. Non-ischaemic cardiomyopathy and impaired LVEF are independent predictors of structural lead failure in cross-sectional analysis, whereas 7 Fr lead is a predictor of electrical lead failure.