Predictors of perforation during lead extraction: Results of the Canadian Lead ExtrAction Risk (CLEAR) study.

BACKGROUND: Transvenous lead extraction can have serious adverse events, such as cardiac or vascular perforation. Risk factors have not been well characterized. OBJECTIVE: The purpose of this study was to identify factors associated with perforation and death, and to characterize lead extraction in a large contemporary population. METHODS: We performed a retrospective multicenter study examining patients undergoing lead extraction at 8 Canadian institutions from 1996 through 2016. Demographic and clinical data were used to identify variables associated with perforation and mortality using logistic regression modeling. RESULTS: A total of 2325 consecutive patients (age 61.9 ±16.5 years) underwent extraction of 4527 leads. Perforation rate was 2.7% (63/2325) and 30-day mortality was 1.6% (38/2325), with mortality of 0.4% due to perforation (10/2325). Variables associated with perforation included no previous cardiac surgery (odds ratio [OR] 3.33; 95% confidence interval [CI] 1.54-7.19; P = .002), female sex (OR 3.27; 95% CI 1.91-5.60; P <.001); left ventricular ejection fraction ≥40% (OR 2.81; 95% CI 1.28-6.14; P = .010); lead age >8 years (OR 2.64; 95% CI 1.52-4.60; P <.001); ≥2 leads extracted (OR 2.49; 95% CI 1.23-5.04; P = .011); and diabetes (OR 2.12; 95% CI 1.16-3.86; P = .014). Variables associated with death included infection as indication for extraction (OR 3.85; 95% CI 1.38-10.73; P = .010); anemia (OR 3.14; 95% CI 1.38-6.61; P = .003), and patient age (OR 1.04; 95% CI 1.01-1.07; P = .012). CONCLUSION: Risk factors associated with perforation in lead extraction include no history of cardiac surgery, female sex, preserved left ventricular ejection fraction, lead age >8 years, ≥2 leads extracted, and diabetes.

Classification and Surgical Repair of Injuries Sustained During Transvenous Lead Extraction.

BACKGROUND: Injuries to cardiac and venous structures during pacemaker and defibrillator lead extraction are serious complications that have been studied poorly. The incidence of these injuries is unknown but likely underestimated. No systematic multicenter review of these injuries or their management has been undertaken. METHODS AND RESULTS: We interrogated our mandatory administrative database for all excimer laser extractions that sustained a cardiac or venous injury in the province of British Columbia. Injuries were classified according to presentation and compared with respect to nature of injury, type of repair, utilization of cardiopulmonary bypass, and outcome. Of 1082 excimer laser extractions over 19 years, 33 sustained an injury (3.0%). The majority of injuries occurred in women (21/33; 63.6%), and median age of oldest lead extracted was 10.8 (7.5, 12.2) years. A type 1 presentation, defined as circulatory collapse, was found in 12/33 patients (36.4%). A type 2 presentation, defined as progressive hypotension responsive to treatment, was found in 20/33 patients (60.6%). Over half the patients had a moderate or large injury, and cardiopulmonary bypass was required in 13 patients with extensive injury. Despite the presence of devastating injuries, the immediate availability of aggressive salvage measures resulted in a survival of 87.9% of patients at 30 days. CONCLUSIONS: The immediate availability of a cardiovascular surgeon, perfusionist, and cardiopulmonary bypass pump facilitates lifesaving repair of injuries sustained during laser lead extraction. The size and complexity of injury correlates closely with the presentation, blood loss, and need for cardiopulmonary bypass to facilitate repair.

Clinical experience with pacemaker pulse generators and transvenous leads: an 8-year prospective multicenter study.

BACKGROUND: Pacemakers have improved the lives of patients worldwide. Unfortunately, the medical community has had little independent information regarding the performance of these vital medical devices. OBJECTIVES: The purpose of this study was to examine the reasons pacemaker pulse generators and transvenous leads were removed from service. We evaluated the causes and major adverse clinical events associated with device end-of-service life behavior and how they were detected and managed. METHODS: Pulse generator and lead data were entered prospectively using a web-based format. Normal battery depletion was signified by the elective replacement indicator appearing >3 years after implant. Lead failure was a device defect causing pacing, sensing, or fixation malfunction, high threshold, or abnormal impedance. Major adverse clinical events were death, angina, heart failure, syncope, and perioperative surgical complications. RESULTS: From 1998 to 2006, 2,652 pulse generator and 615 leads were removed from service. The average pulse generator was implanted for 7.3 +/- 3.1 years (range <1 day to 26 years). The majority of pulse generators (n = 2,317 [87%]) were replaced for normal battery depletion. Severe and accelerated battery depletion, manufacturers' advisories, and electronic or connector defects accounted for 13% of pulse generator removals. The proportion of pulse generators removed from service as a result of manufacturers' advisories, electronic failure, and housing defects were 4%, 2%, and 1%, respectively. Models with rate response capability had shorter battery longevities than those without rate response capability. Major adverse clinical events due to pulse generator end-of-service life behavior were related to electronic and connector defects, and both normal and severe battery depletion. Median time to lead failure was 7.2 +/- 5.2 years. Insulation defects caused the majority of lead failures, and most of these leads used polyurethane materials. Lead failure was associated with a 16% incidence of major adverse clinical events. No major adverse clinical events occurred when impending lead failure was detected at routine follow-up. Lead extraction was associated with a 5.6% complication rate, including one death. CONCLUSION: Overall pulse generator performance was satisfactory. Differences in battery longevity were observed among models. In some patients, elective replacement indicators signifying normal battery depletion resulted in major adverse clinical events. Pacemaker follow-up effectively identified pulse generator end-of-service life and often detected impending lead failure, thus avoiding major adverse clinical events. Long-term studies are needed to assess chronic lead performance so that appropriate clinical management strategies, including recommendations for lead extraction, can be developed.

Multicenter experience with failed and recalled implantable cardioverter-defibrillator pulse generators.

BACKGROUND: Despite the widespread and growing use of implantable cardioverter-defibrillators (ICDs), little information is available regarding their performance or the impact of advanced pacing functions on ICD reliability and longevity. OBJECTIVES: The purpose of this study was to examine the performance of contemporary ICD pulse generators that failed or were replaced because of manufacturers recalls. METHODS: ICD data were entered prospectively by nine participating centers. ICD pulse generator failure was defined as removal from service because the device was not functioning according to the manufacturer's specifications. A recalled ICD was a normally functioning pulse generator that was replaced as the result of a recall or advisory. RESULTS: From 1998 to 2005, 1,220 ICDs failed and 135 were recalled and replaced. The average implant time of failed ICDs was 4.4 +/- 1.5 years and of recalled ICDs was 1.7 +/- 0.8 years. The average implant time of single- and dual-chamber ICDs with rate responsive or cardiac resynchronization (CRT-D) pacing capabilities was significantly shorter than the average implant time of single- or dual-chamber devices without these features (P <.001). ICDs that provided rate responsive or CRT-D pacing failed earlier because of battery depletion (P <.001) and were significantly more prone to unexpected electronic or housing failure (9% vs 5%, P = .008) and recalls (25% vs 1%, P <.0001). Major adverse events included death (n = 2), failure to convert ventricular tachyarrhythmias (n = 6), and inappropriate shocks (n = 11). CONCLUSION: Based on our analysis of failed and recalled devices, the performance of contemporary ICDs has been adversely affected by premature battery depletion, electronic failure, and manufacturers' recalls. Additional studies are needed to precisely estimate ICD longevity and to determine the incidence of unexpected ICD failure.

Use of physiologic pacing after the Canadian trial of physiologic pacing.

The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers. It was examined for mode selection trends from 1997 to 2002. At examination, there were data on 22,446 pulse generators (PG) and 29,898 leads. New implant rates per M population were 1997:473; 1998:456; 1999:505; 2000:513; 2001:486; 2002:510. PG replacements also increased, resulting in a total implant rate of 667 PG per M in 2002. Over the 6-year period, DDD use decreased from 321 to 306, but DDDR use, more than doubled from 317 to 750 PG/year. VVI use steadily decreased from 741 to 410 PG/year, while VVIR use increased more modestly from 1997 to 1999, then remained stable. During the 6-year period bracketing CTOPP, use of modes maintaining AV synchrony increased by over 32%, to 53% of PG implanted in 2002. Our PG implant rate was much higher than expected from prior retrospective surveys, and similar to rates in Belgium, France, and Germany. CTOPP did not decrease our use of physiologic pacing but, instead, was associated with a brief pause, then progressively increased in both academic and community centers. Patients' need and widely accepted standards of care proved more important in clinical decision making than the results of a flawed randomized trial.

Coronary sinus lead extraction.

Complications are reported more frequently with the implantation of coronary sinus (CS) than other types of leads, and attempts to extract CS leads may also be associated with increased risks. The authors have performed nonthoracotomy lead extraction (LE) since 1981 and maintained a detailed database. By November 2001, 796 leads had been removed from 401 patients. We undertook review of our CS-LE experience to evaluate prevalence, safety, and efficacy. Of 14 patients referred for CS-LE, 7 were treated in the last year. In six the lead had been placed in the CS intentionally, and in eight inadvertently. One recent patient treated with biventricular pacing was septic and died before LE was undertaken. In nine men and four women (mean age 66 years) had one each CS lead and a total of 34 LEs (2.6/patient). Four CS leads had been in place for < 6 months (mean 1.5 month), whereas nine had been in place for between 6 months and 27 years. Several LE methods were used, from simple traction to the use of intraluminal locking stylets and powered sheaths. Complete removal of all leads was achieved in all patients. CS-LE required a mean of 13 minutes, including 1.8 minutes of fluoroscopy. There were no serious complications during the procedures, and the mean hospital stay was 4 days.

Long-term structural failure of coaxial polyurethane implantable cardioverter defibrillator leads.

Transvene models 6936/6966, a coaxial polyurethane ICD lead, may be prone to structural failure. These models comprise 54% of ICD lead failures in the authors' Multicenter Registry database. Because ICD leads perform a vital function, the clinical features, causes, and probability of Transvene 6936/6966 lead failure were determined. The Registry and United States Food and Drug Administration databases were queried for the clinical features and structural causes of the Transvene 6936/6966 lead failure, and a five-center substudy estimated the survival probability for 521 Transvene 6936/6966 implants. The mean time to failure was 4.8 +/- 2.1 years, and the estimated survival at 60 and 84 months after implant were 92% and 84%, respectively. Oversensing was the most common sign of failure (76%), and 24 patients experienced inappropriate shocks. The manufacturer's reports indicated that high voltage coil fracture and 80A polyurethane defects were the predominant causes of lead failure. Transvene models 6936 and 6966 coaxial polyurethane ICD leads are prone to failure over time. Patients who have these leads should be evaluated frequently. Additional studies are needed to identify safe management strategies.