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Background: Approximately 268,000 Fidelis leads were implanted worldwide until distribution was suspended because of a high rate of early failure. Careful analyses of predictors of increased lead failure hazard are required to help direct future lead design and also to inform decision making on lead replacement. We sought to perform a comprehensive analysis of all potential predictors in a multicenter study., Methods and Results: A total of 3169 Sprint Fidelis leads were implanted in 11 centers with a total of 251 failures. Lead failure rates at 3, 4, and 5 years were 5.3%, 10.6%, and 16.8%, respectively. The rate of lead failure continues to accelerate (P<0.001). There were 4 independent predictors of failure: center, sex, access vein, and previous lead failure. Women had a higher hazard of failure (hazard ratio 1.51; 95% confidence interval, 1.14-2.04; P=0.005). Both axillary and subclavian access increased the hazard of failure (P=0.007); hazard ratio for axillary was 1.94, (95% confidence interval, 1.23-3.04) and for subclavian 1.63 (95% confidence interval, 1.08-2.46). Previous lead failure increased the hazard of a subsequent Fidelis failure with a hazard ratio of 3.12 (95% confidence interval, 1.80-5.41; P<0.001)., Conclusions: The rate of Fidelis failure continues to increase over time, with failures approaching 17% at 5 years. Women, patients with leads inserted via the subclavian or axillary vein, and those with a previous lead fracture were at greatest risk of Fidelis failure. Our data suggest that Fidelis replacement should be strongly considered at the time of generator replacement.

Background: Following recent cases of nonphysiologic noise noted early after defibrillator implantation, the Canadian Heart Rhythm Society Device Committee decided to evaluate the implications of this problem., Objective: To determine the incidence and consequences of nonphysiologic noise early after defibrillator implantation., Methods: The Canadian Heart Rhythm Society Device Committee surveyed all Canadian defibrillator implanting centers regarding their implant volumes and number of cases where nonphysiologic noise had been noted early (< 24 hours) after implant over the preceding 2 years. For such cases, information regarding the manufacturer and occurrence of inappropriate shock or inhibition of pacing was reported., Results: Responses were obtained from 20 of 23 surveyed implanting centers, with a total implant volume of 4960 defibrillators per year. The occurrence of nonphysiologic noise early after implantation was noted in 25 cases over the preceding 2 years (0.25%). Noise was detected in devices of all 3 of the leading volume device manufacturers. There were 2 cases of inappropriate shocks and 2 cases of symptomatic pacing inhibition. In 4 cases, removal of the lead from the header and retesting with the analyzer confirmed normal lead function. In all cases, the noise resolved within 24 hours., Conclusion: Nonphysiologic noise early after defibrillator implantation was noted in 0.25% of procedures and was not limited to one specific manufacturer. This noise may result in an inappropriate shock or inhibition of pacing in a pacemaker-dependent patient. This transient phenomenon, possibly related to fluid and/or air in the header, appears to always resolve without surgical intervention., (Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: It has been observed that replacement of an implantable cardioverter-defibrillator generator in response to a device advisory may be associated with a substantial rate of complications, including death. The risk of lead revision in response to a lead advisory has not been determined previously., Methods and Results: Twenty-five implantable cardioverter-defibrillator implantation and follow-up centers from the Canadian Heart Rhythm Society Device Advisory Committee were surveyed to assess complication rates as a result of lead revisions due to the Sprint Fidelis advisory issued in October 2007. As of June 1, 2009, there had been 310 lead failures found in 6237 Sprint Fidelis leads in Canada (4.97%) over a follow-up of 40 months. There were 469 leads to be revised, 66% for confirmed fracture. Of the patients who underwent revision, 95% had a new lead inserted, whereas 4% had a pace/sense lead added. The lead was removed in 248 cases (53%), by simple traction in 61% and by laser lead extraction in 33%. Complications were encountered in 14.5% of the lead revisions; 7.25% of these were major, whereas 7.25% were minor. There were 2 deaths (0.43%). The overall risk of complications (19.8%) was greater in those who underwent lead removal at the time of revision than in those whose leads were abandoned (8.6%; P=0.0008)., Conclusions: The overall rate of major complications that arose from lead revision due to the Sprint Fidelis advisory was significant. This must be taken into account when lead revision is planned in those patients who have not yet demonstrated an abnormality in lead performance.

Background/objective: The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned in 2006 to develop a mechanism for responding to advisories regarding cardiac rhythm device and lead performance., Methods: In the event of an advisory, the Chair classifies the advisory as urgent, semi-urgent, or routine based on the nature of the threat to the patient and the number of patients affected. The Chair uses an e-mail network with the committee members to disseminate advisory information and to assemble a consensus recommendation. Committee membership is broadly representative of the Canadian device community, including both academic and nonacademic centers, adult and pediatric specialists, and includes balanced regional representation. Recommendations are approved by the CHRS executive and made available to all implant and follow-up centers on the CHRS website., Results: With the Medtronic Fidelis lead advisory of October 15, 2007, the Chair classified the advisory as semi-urgent and initiated an e-mail discussion and preliminary survey of all Canadian implantable cardioverter-defibrillator (ICD) centers within 3 hours of advisory announcement. A CHRS membership statement was issued within 48 hours. Within 5 working days, sample letters to physicians and patients were posted for local adaptation and distribution. Complete data collection was obtained from all Canadian defibrillator centers. Analyses at 20, 25, 30, and 32 months suggest an accelerating course of failures (3.91% at 32 months, P <.0001), with a reduced likelihood of presentation with inappropriate shocks (from 56% to 21%, P = .0003)., Conclusion: A collaborative approach using an e-mail network provides a mechanism for a rapid national response to device advisories. The network allows collection of focused data on implanted device system performance and facilitates timely reporting of clinically relevant data to patients and clinicians.

Objective: To assess the impact of adverse drug reactions on antiarrhythmic drug substitution in ambulatory patients., Setting: Tertiary care dysrhythmia clinic., Patients and Methods: A total of 671 medical records were reviewed. Sex of the study population was equally distributed, with an average age of 53 years. Follow-up averaged 26 months for patients seen more than once. Suspected adverse drug reactions and substitution of antiarrhythmic agent were used to ascertain events in patients' charts. Patients were exposed to 1253 treatment courses. The number of successive antiarrhythmic agents per patient averaged 1.8 and varied from one to seven., Results: One hundred and thirty-nine (20%) patients experienced a total of 194 adverse events (15.5% of drug courses), of which only eight (4%) were serious. Ninety-four per cent of the mostly benign adverse drug reactions were followed by a therapeutic modification: discontinuation or replacement in 87% and dosage reduction in 7%. The influence of successive drug changes was evident: the risk of a reaction was 7% in patients exposed to one agent compared with 100% in patients exposed to a seventh agent., Conclusions: First, therapeutic substitution in response to adverse drug reactions appears to be determined more by the combined expected benefit, the product of arrhythmia severity and drug efficacy, than by the severity alone of the adverse reaction; and second, the probability of an adverse drug reaction is proportional to the number of agents tried consecutively, possibly as a result of patient selection, drug selection and increased patient and doctor awareness.