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Unusual failure of a multilumen, small-diameter implantable cardioverter-defibrillator lead

Implantable cardioverter-defibrillators (ICDs) represent transformational technology, arguably the most significant advance in cardiovascular medicine in 50 years. The vision and determination of pioneers Mirowski and Mower was fundamental to this monumental achievement, working with limited resources and confronted by skepticism/criticism from medical establishment. The inventors were followed >35 years in which a multitude of innovative clinical scientists and engineers introduced technological advances leading to the sophisticated devices in practice today. A pivotal patient experiment with automated termination of ventricular fibrillation (1980) led to U.S. Food and Drug Administration approval. Transvenous lead systems converted ICDs from thoracotomy-based secondary prevention to primary prevention of sudden death devices in countless patients worldwide. ICD acceptance was solidified by prospective randomized controlled trials showing reduced mortality superior to antiarrhythmic drugs. ICDs eventually expanded from coronary disease to inherited arrhythmia conditions (eg, hypertrophic cardiomyopathy). The ICD breakthrough story demonstrates how significant progress is possible in medicine against all odds, given fearless imagination to pursue novel ideas that conflict with accepted wisdom.

In November 2011, the Food and Drug Administration issued a class I recall of Riata and Riata ST implantable cardioverter-defibrillator leads. Management recommendations regarding the recall have remained controversial.

Data regarding the safety and feasibility of extraction of Riata implantable cardioverter-defibrillator leads are limited.

We performed a retrospective study of patients undergoing extraction of Riata/Riata ST leads at 11 centers.

Between July 2003 and April 2013, 577 Riata/Riata ST leads were extracted from 577 patients (Riata 467, [84%]; Riata ST 89, [16%]). Complete procedural success achieved in 99.1%. The cohort was 78% men, with a mean age of 60 years and a mean left ventricular ejection fraction of 34% ± 14%. The mean implant duration was 44.7 months (range 0–124.6 months). The majority of leads extracted were for infection (305 [53.0%]) and 220 (35.7%) for lead malfunction. Evaluation for lead integrity was performed in 295 cases. Of these, 34.9% were found to have externalized cables. Implant duration was significantly longer in leads with externalized cables (P < .0001). No difference in lead integrity was noted between Riata and Riata ST leads (11.7% vs 17.7% failure; P = .23). Among leads in which cable externalization was noted, laser sheaths were used more frequently (P = .01). Major complications included 3 superior vena cava/right ventricular perforations requiring surgical intervention with 1 death 12 days after the procedure and 1 pericardial effusion requiring percutaneous drainage (0.87%).

Extraction of the Riata/Riata ST leads can be challenging, and leads with externalized cables may require specific extraction techniques. Extraction of the Riata/Riata ST leads can be performed safely by experienced operators at high-volume centers with a complication rate comparable to published data.

Recently, several cases of symptomatic and/or electrically detectable intracardiac inside-out abrasions in silicon-coated Riata® and Riata® ST leads have been described. However, the prevalence in asymptomatic patients with unremarkable implantable cardioverter defibrillator (ICD) interrogation is unknown. The aim of this study was to determine the prevalence of asymptomatic and electrically undetectable intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads.

All 52 patients with an active silicone-coated Riata® and Riata® ST lead followed up in our outpatient clinic were scheduled for a premature ICD interrogation and a biplane chest radiograph. When an intracardiac inside-out abrasion was suspected, this finding was confirmed by fluoroscopy.

Mean time since implantation was 71 ± 18 months. An intracardiac inside-out abrasion was confirmed by fluoroscopy in 6 patients (11.5%). Mean time from lead implantation to detection of intracardiac inside-out abrasion was 79 ± 14 months. In all patients with an intracardiac inside-out abrasion, ICD interrogation showed normal and stable electrical parameters. Retrospectively, in 4 of these 6 patients, a coronary angiography performed 25 ± 18 months before diagnosis of intracardiac inside-out abrasion already showed the defect. Despite undetected intracardiac inside-out abrasion, 2 of these 4 patients experienced adequate antitachycardia pacing and ICD-shocks. ICD leads were replaced in all 6 patients.

The prevalence of asymptomatic intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads is higher than 10% when assessed by fluoroscopy, and most intracardiac inside-out abrasions are not detectable by ICD interrogation.

The natural history of insulation defects with inside-out conductor externalization in recalled St Jude Medical Riata defibrillator leads is not well understood.

To determine the prevalence of externalization in a nationwide screening. Secondary aims were to examine time dependence and location of externalization, association with electrical failure, and fluoroscopic diagnostic performance.

All 299 patients with recalled Riata leads in Denmark were identified, and all except one underwent fluoroscopy and device interrogation. Externalizations were confirmed by multiple investigators.

The prevalence of externalization was 32 of 298 (11%) at a mean dwell time of 5.1 years. The prevalence was 21 of 98 (21%) for 8-F leads and 11 of 200 (6%) for 7-F leads; however, 8-F leads had longer dwell times. The degree of externalization was correlated with dwell time (Spearman’s ρ = .37; P = .03). Externalization more often included the lead segment below the tricuspid annulus in dual coil leads than in single coil leads (69% vs 16%; P = .004). No association was observed between externalization and electrical function. Fluoroscopic diagnostic performance was good with positive and negative predictive values of 88% and 99%, respectively.

The prevalence of externalization in a nationwide screening is at the same level as reported in previous studies with similar lead dwell times. The degree of externalization is time dependent, and location seems to differ between single and dual coil leads. Long-term lead performance and association with electrical failure need further clarification. Fluoroscopy has a good diagnostic performance in clinical practice.

Riata and Riata ST leads (St Jude Medical, Sylmar, CA) are prone to failure. There are no independent multicenter reports regarding Riata or Riata ST lead performance.

To conduct a retrospective multicenter study of Riata and Riata ST leads that were implanted and followed at 7 centers.

The study included adults who received St Jude Medical Riata or Riata ST leads. Data for Quattro Secure leads were obtained from an earlier study.

From 2002 to 2010, 1081 patients received a Riata (n = 774) or Riata ST (n = 307) lead. Follow-up was longer for Riata than Riata ST leads (4.2±2.4 years vs 3.3±1.7 years; P<.0001). During the study, 67 leads failed (6.2%), including 62 of 774 Riata (8.0%) and 5 of 307 Riata ST (1.6%) leads. Forty-seven of 67 lead failures (70.1%) were caused by electrical malfunction, and 20 lead failures (29.9%) were due to externalized conductors (ECs) that were electrically intact. Of 110 leads examined fluoroscopically, ECs were found in 26 of 81 Riata (32%) and 1 of 29 Riata ST (3.4%) leads. Of 26 Riata leads with ECs, 7 (27%) were malfunctioning. Riata leads had lower overall and malfunction free survival compared to Quattro leads (P<.0001), while Riata ST lead survival was not different (P = .422).

The survival of Riata (but not Riata ST) leads was lower than Quattro leads; however, Riata ST leads had significantly shorter follow-up than Riata leads. ECs were common in Riata leads, and more than a quarter of Riata leads that had ECs were malfunctioning. Our observations suggest that systematic fluoroscopic examination of patients with Riata leads is appropriate.