Antibacterial Envelope to Prevent Cardiac Implantable Device Infection.

BACKGROUND: Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections. METHODS: We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months. RESULTS: A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P = 0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P<0.001 for noninferiority). The mean (±SD) duration of follow-up was 20.7±8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98). CONCLUSIONS: Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications. (Funded by Medtronic; WRAP-IT ClinicalTrials.gov number, NCT02277990.).

Low-temperature electrocautery reduces adverse effects from secondary cardiac implantable electronic device procedures: Insights from the WRAP-IT trial.

BACKGROUND: Cardiac device procedures require tissue dissection to free existing device lead(s). Common techniques include blunt dissection, standard electrocautery, and low-temperature electrocautery (PlasmaBlade, Medtronic); however, data on the type of electrosurgical tool used and the development of procedure- or lead-related adverse events are limited. OBJECTIVE: The purpose of this study was to determine whether standard or low-temperature electrocautery impacts the development of an adverse event. METHODS: We evaluated patients enrolled in WRAP-IT (Worldwide Randomized Antibiotic EnveloPe Infection PrevenTion Trial) undergoing cardiac implantable electronic device (CIED) revision, upgrade, or replacement. All adverse events were adjudicated by an independent physician committee. Data were analyzed using Cox proportional hazard regression modeling. RESULTS: In total, 5641 patients underwent device revision/upgrade/replacement. Electrocautery was used in 5205 patients (92.3%) (mean age 70.6 ± 12.7 years; 28.8% female), and low-temperature electrocautery was used in 1866 patients (35.9%). Compared to standard electrocautery, low-temperature electrocautery was associated with a 23% reduction in the incidence of a procedure- or lead-related adverse event through 3 years of follow up (hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.65-0.91; P = .002). After controlling for the number of active leads, degree of capsulectomy, degree of lead dissection, and renal dysfunction, low-temperature electrocautery was associated with a 32% lower risk of lead-related adverse events (HR 0.68; 95% CI 0.52-0.89; P = .004). These effects were consistent across a spectrum of lead-related adverse event types. CONCLUSION: This study represents one of the largest assessments of electrocautery use in patients undergoing CIED revision, upgrade, or replacement procedures. Compared to standard electrocautery, low-temperature electrocautery significantly reduces adverse effects from these procedures.

Cost-Effectiveness of an Antibacterial Envelope for Cardiac Implantable Electronic Device Infection Prevention in the US Healthcare System From the WRAP-IT Trial.

BACKGROUND: In the WRAP-IT trial (Worldwide Randomized Antibiotic Envelope Infection Prevention), adjunctive use of an absorbable antibacterial envelope resulted in a 40% reduction of major cardiac implantable electronic device infection without increased risk of complication in 6983 patients undergoing cardiac implantable electronic device revision, replacement, upgrade, or initial cardiac resynchronization therapy defibrillator implant. There is limited information on the cost-effectiveness of this strategy. As a prespecified objective, we evaluated antibacterial envelope cost-effectiveness compared with standard-of-care infection prevention strategies in the US healthcare system. METHODS: A decision tree model was used to compare costs and outcomes of antibacterial envelope (TYRX) use adjunctive to standard-of-care infection prevention versus standard-of-care alone over a lifelong time horizon. The analysis was performed from an integrated payer-provider network perspective. Infection rates, antibacterial envelope effectiveness, infection treatment costs and patterns, infection-related mortality, and utility estimates were obtained from the WRAP-IT trial. Life expectancy and long-term costs associated with device replacement, follow-up, and healthcare utilization were sourced from the literature. Costs and quality-adjusted life years were discounted at 3%. An upper willingness-to-pay threshold of $150 000 per quality-adjusted life year was used to determine cost-effectiveness, in alignment with the American College of Cardiology/American Heart Association practice guidelines and as supported by the World Health Organization and contemporary literature. RESULTS: The base case incremental cost-effectiveness ratio of the antibacterial envelope compared with standard-of-care was $112 603/quality-adjusted life year. The incremental cost-effectiveness ratio remained lower than the willingness-to-pay threshold in 74% of iterations in the probabilistic sensitivity analysis and was most sensitive to the following model inputs: infection-related mortality, life expectancy, and infection cost. CONCLUSIONS: The absorbable antibacterial envelope was associated with a cost-effectiveness ratio below contemporary benchmarks in the WRAP-IT patient population, suggesting that the envelope provides value for the US healthcare system by reducing the incidence of cardiac implantable electronic device infection. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02277990.

Performance of an automatic external cardioverter-defibrillator algorithm in the discrimination of supraventricular from ventricular tachycardia.

An automatic external cardioverter-defibrillator (AECD) with a programmable supraventricular-ventricular tachycardia (VT) zone underwent evaluation of arrhythmia discrimination performance in the electrophysiologic laboratory during induced supraventricular tachycardia (SVT) and unipolar and bipolar atrial pacing. The AECD SVT zone was programmed so that the induced SVT rate would fall within this zone. Atrial pacing was also performed at a rate within this zone. The ability of the AECD to accurately discriminate between VT and SVT and to recommend shock delivery was assessed. A total of 98 patients underwent conventional diagnostic electrophysiologic studies (49 men, age 59 +/- 19 years) with a total of 55 inducible sustained SVTs. High right atrial pacing was performed in 56 patients in unipolar and in 82 patients in bipolar fashion. In response to induced sustained SVT, the AECD correctly classified 47 episodes as nonshockable, 4 incorrectly as shockable, and 4 episodes correctly as shockable with a resultant sensitivity of 100% and specificity of 92%. Bipolar high right atrial pacing was correctly identified as nonshockable in 75 episodes, incorrectly identified as shockable in 5 episodes, and correctly identified as shockable in 2 episodes with a resultant sensitivity of 100% and specificity of 94%. The Powerheart AECD accurately discriminates SVT from VT and is expected to correctly deliver automatic external shocks rapidly in the presence of spontaneous life-threatening tachycardia and appropriately withhold therapy during SVT.

Lead extraction in the contemporary setting: the LExICon study: an observational retrospective study of consecutive laser lead extractions.

OBJECTIVES: This study sought to examine the safety and efficacy of laser-assisted lead extraction and the indications, outcomes, and risk factors in a large series of consecutive patients. BACKGROUND: The need for lead extraction has been increasing in direct relationship to the increased numbers of cardiovascular implantable electronic devices. METHODS: Consecutive patients undergoing transvenous laser-assisted lead extraction at 13 centers were included. RESULTS: Between January 2004 and December 2007, 1,449 consecutive patients underwent laser-assisted lead extraction of 2,405 leads (20 to 270 procedures/site). Median implantation duration was 82.1 months (0.4 to 356.8 months). Leads were completely removed 96.5% of the time, with a 97.7% clinical success rate whereby clinical goals associated with the indication for lead removal were achieved. Failure to achieve clinical success was associated with body mass index <25 kg/m(2) and low extraction volume centers. Procedural failure was higher in leads implanted for >10 years and when performed in low volume centers. Major adverse events in 20 patients were directly related to the procedure (1.4%) including 4 deaths (0.28%). Major adverse effects were associated with patients with a body mass index <25 kg/m(2). Overall all-cause in-hospital mortality was 1.86%; 4.3% when associated with endocarditis, 7.9% when associated with endocarditis and diabetes, and 12.4% when associated with endocarditis and creatinine > or =2.0. Indicators of all-cause in-hospital mortality were pocket infections, device-related endocarditis, diabetes, and creatinine > or =2.0. CONCLUSIONS: Lead extraction employing laser sheaths is highly successful with a low procedural complication rate. Total mortality is substantially increased with pocket infections or device-related endocarditis, particularly in the setting of diabetes, renal insufficiency, or body mass index <25 kg/m(2). Centers with smaller case volumes tended to have a lower rate of successful extraction.