Long-term electrical survival analysis of Riata and Riata ST silicone leads: National Veterans Affairs experience

Background

A medical device advisory issued by St Jude Medical in November 2011 estimated 0.63% all-cause abrasion rate on their Riata and Riata ST silicone high-voltage lead families (Riata/ST), leading to Food and Drug Administration class I recall. We performed an independent comparative, long-term electrical survival analysis of Riata/ST and 3 other high-voltage lead families in a large national cohort of patients.

Objective

To evaluate long-term electrical survival of Riata/ST leads relative to other commonly evaluated high-voltage leads.

Methods

Failure rates of Riata/ST, Sprint Quattro Secure (Quattro), Sprint Fidelis (Fidelis), and Endotak Reliance G/SG (Endotak) leads from the Veterans Administration's National Cardiac Device Surveillance Center database, consisting of 24,145 patients with remote transmissions since 2003, were analyzed. Survival Probabilities were determined with Kaplan-Meier survival analysis and compared using the log-rank test.

Results

Of 1,403 Riata/ST, 6,091 Quattro, 5,073 Fidelis, and 2,401 Endotak leads identified, 5-year survival probability of Riata/ST leads (97.5%) was significantly lower than that of Quattro (99.3%) and Endotak (99.4%) leads (P <.0001) but higher than that of Fidelis leads (89.6%) (P <.0001). Riata ST leads showed a 5-year survival of 95.5% (95% confidence interval 92.4–97.4) compared to 98.4% (95% confidence interval 97.1–99.1) in Riata leads (P = .003).

Conclusions

There is decreased survival probability of Riata/ST leads compared to other contemporary high-voltage leads, with decreased survival of Riata ST silicone compared to Riata lead series. Careful long-term follow-up should be maintained in patients with Riata/ST leads in order to prevent inappropriate shocks or failed device interventions. Our results were determined in advance of Food and Drug Administration class I recall, which suggested that large-scale remote monitoring may be an effective tool for continued implantable cardioverter-defibrillator system surveillance.

Introduction

Although implantable cardioverter-defibrillator (ICD) systems provide valuable, lifesaving therapies for patients with life-threatening tachyarrhythmias,¹ mechanical problems and failure of high-voltage leads can compromise device function, cause inappropriate shocks, and, in rare cases, lead to loss of pacing, failure of defibrillation, or fatal proarrhythmia.2, 3, 4 Medtronic's Sprint Fidelis (Fidelis) lead failure is the prototypical example of modern lead failure, with one study reporting 87% survival of Fidelis leads at 4 years compared to 98.7% survival of Medtronic's Quattro Secure (Quattro) leads,⁵ resulting in inappropriate shocks that may lead to increased morbidity and mortality.6, 7, 8 The inadequacy of current postmarket approval device surveillance is highlighted by the fact that more than 172,000 Fidelis leads were implanted in the United States alone before the Food and Drug Administration (FDA) issued a class I recall of the device.⁹

In 2002, St Jude Medical introduced the Riata lead, an 8-F high-voltage lead, followed by the Riata ST silicone lead, a smaller caliber 7-F high-voltage lead. Although initial concerns with this family of leads were mainly limited to perforation risk, particularly with Riata ST leads,10, 11, 12 on November 28, 2011, St Jude Medical issued a medical device advisory regarding increased failure rates of Riata and Riata ST (Riata/ST) leads, specifically highlighting externalized conductors.¹³ This advisory became an FDA class I recall on December 14, 2011.

The Veterans Administration's National Cardiac Device Surveillance Center (VANCDSC) provides remote monitoring service to veterans with ICDs and cardiac resynchronization therapy devices. With 24,145 patients enrolled since 2002, the VANCDSC is one of the largest surveillance systems that provide active longitudinal monitoring of device performance. In order to accurately identify patients who are at greater risk for lead failure and resulting complications, we performed an independent evaluation on the long-term incidence of Riata/ST lead failure in the VANCDSC database, focusing on electrical malfunction, and compared the results to 2 other contemporary high-voltage leads as well as Fidelis leads. We also examined failure presentations and treatment approaches to provide some insight on the management of this critical safety problem.