Comprehensive Intraprocedural Unfractionated Heparin Protocol During Catheter Ablation of Atrial Fibrillation in the Presence of Direct Oral Anticoagulants and Wide Spectrum of Body Mass Index.

INTRODUCTION: Data on optimal dosing of unfractionated heparin (UFH) in the presence of a direct oral anticoagulant (DOAC) to achieve and maintain an activated clotting time (ACT) of ≥300 seconds during catheter ablation of atrial fibrillation (CA-AF) are limited and prevalence of obesity adds to the unpredictable response to UFH. METHODS AND RESULTS: One hundred seventeen consecutive patients undergoing CA-AF were prospectively administered weight-adjusted, weight-based UFH using a pre-specified detailed protocol and retrospectively analyzed. Due to lack of distribution of UFH into muscle or adipose tissue and lower degree of vascularity in the latter compartment, each patient's ideal and actual weights were used to determine the adjusted-weight for use in all UFH doses. A UFH bolus of 200 units/kg was administered intravenously followed by an infusion of 35 units/kg/hour. The mean age was 65 years, and 85 patients (72.6%) were male. The average body mass index (BMI) was 30 (range 18-50) kg/m2. After the initial UFH bolus dose, 99 patients (84.6%) achieved ACT ≥300 sec with a mean (± SD) of 380 ± 79 sec. The mean time to reach an ACT ≥300 in all patients was 14.6 ± 12.4 minutes. Among all measured ACT values, 423 (90.8%) were ≥300 seconds. These results were consistent within all BMI categories. There were no intraprocedural thrombotic or hemorrhagic complications. Two patients (1.7%) sustained groin vascular access site hematoma without subsequent intervention and 7 patients (6%) experienced minor oozing post-procedurally. CONCLUSIONS: Our comprehensive weight-adjusted, weight-based UFH protocol, during CA-AF in presence of a DOAC, rapidly achieved and maintained an effective ACT irrespective of BMI.

Inductionless or limited shock testing is possible in most patients with implantable cardioverter- defibrillators/cardiac resynchronization therapy defibrillators: results of the multicenter ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations).

BACKGROUND: Implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators have relied on multiple ventricular fibrillation (VF) induction/defibrillation tests at implantation to ensure that the device can reliably sense, detect, and convert VF. The ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations) is the first large, multicenter, prospective trial comparing vulnerability safety margin testing versus defibrillation safety margin testing with a single VF induction/defibrillation. METHODS AND RESULTS: A total of 426 patients receiving an implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator underwent vulnerability safety margin or defibrillation safety margin screening at 14 J in a randomized order. After this, patients underwent confirmatory testing, which required 2 VF conversions without failure at < or = 21 J. Patients who passed their first 14-J and confirmatory tests, irrespective of the results of their second 14-J test, had their devices programmed to a 21-J shock for ventricular tachycardia (VT) or VF > or = 200 bpm and were followed up for 1 year. Of 420 patients who underwent 14-J vulnerability safety margin screening, 322 (76.7%) passed. Of these, 317 (98.4%) also passed 21-J confirmatory tests. Of 416 patients who underwent 14-J defibrillation safety margin screening, 343 (82.5%) passed, and 338 (98.5%) also passed 21-J confirmatory tests. Most clinical VT/VF episodes (32 of 37, or 86%) were terminated by the first shock, with no difference in first shock success. In all observed cases in which the first shock was unsuccessful, subsequent shocks terminated VT/VF without complication. CONCLUSIONS: Although spontaneous episodes of fast VT/VF were limited, there was no difference in the odds of first shock efficacy between groups. Screening with vulnerability safety margin or defibrillation safety margin may allow for inductionless or limited shock testing in most patients.

Extraction of chronically implanted coronary sinus leads active fixation vs passive fixation leads.

BACKGROUND: The Medtronic model 4195 (StarFix) left ventricular lead is an active fixation lead that provides additional support within the coronary sinus (CS) via deployable lobes. While this lead has been shown to have excellent stability within the CS, concerns about its extractability have been raised. OBJECTIVE: The aim of this study was to compare the safety and efficacy of the extraction of the model 4195 lead vs other Medtronic CS leads in a prospective cohort study. METHODS: Patients undergoing extraction of this and other CS leads for standard indications were prospectively enrolled and studied. The primary outcomes of interest were the removal success rates and associated complication rates. Patients were followed for a month postprocedure. RESULTS: The overall left ventricular lead extraction success rate was 97.6% (n = 205). Among 40 patients with chronic model 4195 leads, there were 37 successful extractions (92.5%) as compared to 98.8% for the 165 non-4195 leads. However, in 2 of the 3 StarFix lead extraction failures, standard extraction techniques were not used. All 10 of the model 4195 leads that had been implanted for less than 6 months were extracted without incident. CONCLUSION: In this largest study of CS lead extractions published to date, the overall success rate of the extraction of chronically implanted CS leads is high and the complication rate is similar in these lead models. The extraction of the model 4195 lead is clearly more challenging, but it can be accomplished in high-volume extraction centers with experienced operators. It is recommended that the model 4195 lead be extracted by experienced operators.

Use of an active-fixation coronary sinus lead to implant a biventricular pacemaker via the femoral vein.

Cardiac resynchronization therapy, which involves the placement of a pacing lead in the right atrium and in each ventricle, is effective in treating heart failure that is caused by left bundle branch block and cardiomyopathy. The left ventricular lead is usually placed into a lateral branch of the coronary sinus via the subclavian route. When the subclavian route is unavailable, insertion of a standard, passive-fixation coronary sinus lead via the femoral approach is feasible; however, the likelihood of subsequent dislodgment is high. Herein, we describe the placement of a novel, self-retaining, active-fixation coronary sinus lead--the Attain StarFix Model 4195 OTW Lead--in an elderly heart-failure patient, via the femoral approach. We believe that this is the 1st report of this procedure.

Coronary sinus lead extraction in the era of cardiac resynchronization therapy: single center experience.

As the number of coronary sinus (CS) lead implantations for cardiac resynchronization therapy increases so will the need for extraction of these leads. The safety of extraction of leads from the branches of the CS has not been reported. We reviewed our database of patients undergoing pacemaker lead extraction from January 2002 through February 2004 at our institution. Of 149 patients referred for lead extraction, 14 (9%) had a biventricular device. The indications for lead extraction were infection, lead malfunction, and exit block. The duration of CS lead implants ranged between 2 and 43 months (mean 17 months). All 14 CS leads were removed successfully using nonsurgical lead extraction techniques. Three leads that were in place the longest (> or =27 months) were removed via the femoral vein approach due to fibrous attachment of the CS lead body to the other pacemaker leads. The leads were structurally intact and without any significant fibrosis of their tips upon visual inspection. There were no major complications of CS laceration, hypotension, pericardial effusion, or excessive blood loss associated with any of the extraction procedures. CS leads were removed safely, successfully and with relative ease based on our experience in this small cohort of patients.