Noseworthy, Peter A.

Background Incidental mobile thrombi are commonly found on endovascular leads of cardiac implantable electronic devices ( CIED s). Transseptal puncture for catheter ablation of arrhythmia poses a risk for paradoxical embolism. We examined risk of ischemic stroke, transient ischemic attack ( TIA ), or systemic embolism after transseptal ablation in patients with and without CIED s. Methods and Results Using a national administrative claims database, 31 720 patients who underwent a transseptal catheter ablation between January 2004 and September 2014 were identified. Two propensity‐matched cohorts were created by matching demographic variables, administrative variables, Charlson Comorbidity Index, CHA 2 DS 2 ‐Vasc score, and year and indication for ablation (5533 and 11 300 patients with and without CIED s). Incidence rates and Cox proportional hazards models were used to estimate risk of ischemic stroke, TIA , or systemic embolism for patients with and without CIED s. Impact of oral anticoagulation ( OAC ) use on the endpoint was examined. Over a mean follow‐up of 2.1 years, the incidence of the combined endpoint was 1.9 per 100 person‐years in patients with CIED s and 1.5 per 100 person‐years in patients without CIED s ( P =0.03). Among patients not on OAC , presence of a cardiac device was associated with an increased risk (hazard ratio [ HR ], 1.71 [1.24–2.35]; P <0.01), whereas there was no association noted among patients treated with OAC ( HR , 0.98 [0.75–1.28]). Conclusion CIED s are associated with an increased risk of stroke, TIA , or systemic embolism after transseptal ablation, but this risk is attenuated with postablation OAC use. Role of anticoagulation post‐transseptal ablation in patients with CIED warrants further investigation.

Background In comparison to warfarin, non–vitamin K antagonist oral anticoagulants ( NOAC s) have the advantages of ease of dosing, fewer drug interactions, and lack of need for ongoing monitoring. We sought to evaluate whether these advantages translate to improved adherence and whether adherence is associated with improved outcomes in patients with atrial fibrillation. Methods and Results We performed a retrospective cohort analysis by using a large US commercial insurance database to identify 64 661 patients with atrial fibrillation who initiated warfarin, dabigatran, rivaroxaban, or apixaban treatment between November 1, 2010, and December 31, 2014. During a median of 1.1 y of follow‐up, 47.5% of NOAC patients had a proportion of days covered of ≥80%, compared with 40.2% in warfarin patients ( P <0.001). Patients with CHA 2 DS 2 ‐ VAS c (risk based on the presence of congestive heart failure, hypertension age 65–74 y, age ≥75 y, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, sex category) score ≥4 were at increased risk of stroke when they were not taking anticoagulation ≥1 month versus <1 week (1–3 months: hazard ratio [ HR ] 1.96, 3–6 months: HR 2.64, ≥6 months: HR 3.66; all P <0.001). Patients with CHA 2 DS 2 ‐ VAS c score 2 or 3 were at increased risk of stroke when they were not taking anticoagulation ≥6 months ( HR 2.73, P <0.001). In these patients with CHA 2 DS 2 ‐ VAS c score ≥2, nonadherence was not associated with intracranial hemorrhage. Among patients with CHA 2 DS 2 ‐ VAS c score 0 or 1, time not taking anticoagulation was not associated with stroke, but not taking anticoagulation ≥3 months was associated with a significant reduction of bleeding. Conclusions Adherence to anticoagulation is poor in practice and may be modestly improved with NOAC s. Adherence to therapy appears to be most important in patients with CHA 2 DS 2 ‐ VAS c score ≥2, whereas the benefits of anticoagulation may not outweigh the harms in patients with CHA 2 DS 2 ‐ VAS c score 0 or 1.

Dysrhythmias and Death in BiMVPIntroductionBileaflet mitral valve prolapse (BiMVP) is common among survivors of otherwise unexplained sudden cardiac death, but prognostic implications of BiMVP are unknown. This study evaluated whether patients with BiMVP are at higher risk for ventricular dysrhythmias, ICD placement, or death compared to controls with either single‐leaflet mitral valve prolapse (SiMVP) or no mitral valve prolapse (MVP).Methods and ResultsThis retrospective, matched cohort study included 18,786 patients who underwent echocardiography at Mayo Clinic between June 1990 and September 2014. The study included three cohorts: BiMVP, SiMVP, and controls without MVP. We assessed rates of ventricular dysrhythmias, ICD placement, and all‐cause mortality between groups. BiMVP was associated with higher rates of ventricular tachycardia compared to SiMVP and controls (adjusted HR 1.48 [1.14–1.92], P = 0.003 and 1.40 [1.04–1.88], P = 0.026, respectively); however, there were no statistically significant differences in rates of ventricular fibrillation/cardiac arrest or ICD placement between groups. BiMVP was associated with a lower rate of all‐cause mortality compared to SiMVP and controls (adjusted HR 0.86 [0.79–0.94], P = 0.0008, and 0.55 [0.50–0.60], P < 0.0001, respectively).ConclusionAlthough BiMVP is associated with ventricular tachycardia, it is not associated with an increased risk of cardiac arrest/ventricular fibrillation or ICD implantation and is, paradoxically, associated with a better survival compared to SiMVP or matched controls. The findings suggest that, despite its association with ventricular tachycardia, BiMVP in the absence of other risk factors does not seem to portend a poor prognosis at the population level.

Background There is significant practice variation in oral anticoagulation ( OAC ) use following catheter ablation for atrial fibrillation. It is not clear whether the risk of cardioembolism increases after discontinuation of OAC following catheter ablation. Methods and Results We identified 6886 patients within a large national administrative claims database who underwent catheter ablation for atrial fibrillation between January 1, 2005, and September 30, 2014. We assessed the effect of time off of OAC by CHA 2 DS 2 ‐ VAS c score (after adjusting for other comorbidities) on risk of cardioembolism, using Cox proportional hazards models. There was an increase in the use of non–vitamin K OAC after ablation from 0% in 2005 to 69.8% in 2014. OAC discontinuation was high, with only 60.5% and 31.3% of patients remaining on OAC at 3 and 12 months, respectively. The rate of discontinuation was higher in low‐risk patients (82% versus 62.5% at 12 months for CHA 2 DS 2 ‐ VAS c 0–1 versus ≥2, respectively; P <0.001). Stroke occurred in 1.4% of patients with CHA 2 DS 2 ‐ VAS c ≥2 and 0.3% of those with CHA 2 DS 2 ‐ VAS c 0 or 1 over the study follow‐up. The risk of cardioembolism in the first 3 months after ablation was increased among those with any time off OAC (hazard ratio 8.06 [95% CI 1.53–42.3], P <0.05). The risk of cardioembolism beyond 3 months was increased with OAC discontinuation among high‐risk patients (hazard ratio 2.48 [95% CI 1.11–5.52], P <0.05) but not low‐risk patients. Conclusion The overall risk of stroke in postablation patients is low; however, OAC discontinuation after ablation is common and is associated with increased risk of cardioembolism for all patients within the first 3 months and for high‐risk patients in the long term. Continuing OAC for at least 3 months in all patients and indefinitely in high‐risk patients appears to be the safest strategy.

Background— Transvenous lead removal (TLR) has made significant progress with respect to innovation, efficacy, and safety. However, limited data exist regarding trends in use and adverse outcomes outside the centers of considerable experience for TLR. The aim of our study was to examine use patterns, frequency of adverse events, and influence of hospital volume on complications. Methods and Results— Using the Nationwide Inpatient Sample, we identified 91 890 TLR procedures. We investigated common complications including pericardial complications (hemopericardium, cardiac tamponade, or pericardiocentesis), pneumothorax, stroke, vascular complications (consisting of hemorrhage/hematoma, incidents requiring surgical repair, and accidental arterial puncture), and in-hospital deaths described with TLR, defining them by the validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code. We specifically assessed in-hospital death (2.2%), hemorrhage requiring transfusion (2.6%), vascular complications (2.0%), pericardial complications (1.4%), open heart surgery (0.2%), and postoperative respiratory failure (2.4%). Independent predictors of complications were female sex and device infections. Hospital volume was not independently associated with higher complications. There was a significant rise in overall complication rates over the study period. Conclusions— The overall complication rate in patients undergoing TLR was higher than previously reported. Female sex and device infections are associated with higher complications. Hospital volume was not associated with higher complication rates. The number of adverse events in the literature likely underestimates the actual number of complications associated with TLR.

ObjectiveTo describe the effects of percutaneously implanted valve‐in‐valve in the tricuspid position for patients with pre‐existing transvalvular device leads.MethodsIn this case series, we describe implantation of the Melody valve and SAPIEN XT valve within dysfunctional bioprosthetic tricuspid valves in three patients with transvalvular device leads.ResultsIn all cases, the valve was successfully deployed and device lead function remained unchanged. In 1/3 cases with 6‐month follow‐up, device lead parameters remain unchanged and transcatheter valve‐in‐valve function remains satisfactory.ConclusionsTranscatheter tricuspid valve‐in‐valve is feasible in patients with pre‐existing transvalvular devices leads. Further study is required to determine the long‐term clinical implications of this treatment approach. © 2015 Wiley Periodicals, Inc.

Background: The addition of electroanatomic mapping to a standard echo-guided endomyocardial biopsy could identify areas of abnormal pathology and increase the diagnostic yield of the procedure. Methods and results: In this demonstration of a novel technique, a 45-year-old woman with clinical suspicion for cardiac sarcoidosis underwent right ventricular bipolar electroanatomical mapping with identification of areas of signal fractionation and low voltage. A bioptome, configured to record an electrogram from the tip, was then visualized on the three-dimensional electroanatomic mapping (3DEAM) system, and directed to these areas. The biopsy was assisted by the use of a steerable introducer sheath, and by recording unipolar and extended bipolar signals from the bioptome tip. A prominent change in the signal was detected by the electrode at the bioptome tip when the jaws closed on the endomyocardial tissue. Patient tolerated the procedure without complications, and the biopsied samples were appropriate for pathological analysis. Conclusions: Using existing technology, the 3DEAM, which integrates unipolar and bipolar signal from the bioptome tip, is feasible, and can be safely added to a standard echocardiographically guided endomyocardial biopsy. Future studies should investigate whether such a technique could increase the safety and diagnostic yield of endomyocardial biopsies in patients with suspected cardiomyopathies.

RVOT Atypical VariantsBackgroundRight ventricular outflow tract (RVOT) arrhythmias are a common form of ventricular tachycardia (VT) in patients with structurally normal heart. The underlying mechanism is due to triggered activity. Mapping and ablation is relatively straightforward targeting the earliest point of activation. Previously reported causes of difficult ablation in the RVOT region include under recognized right ventricular cardiomyopathy/sarcoidosis, presence of endocavitary structures, close proximity to the coronary vasculature, and origin from non‐RVOT structures.Methods and ResultsWe identified all patients undergoing PVCs/sustained RVOT VT ablation from January 2013 to December 2013. This included 33 patients. Of these, we identified procedures that were considered difficult despite a single morphology arrhythmia being targeted and no underlying cardiomyopathy present. Difficulty was specifically considered when ablation at the earliest site of activation was not successful and eventual successful ablation was at a distance of greater than 15 mm from the early activation site. We identified 3 patients (n = 3, 100% male) with evidence of reentrant arrhythmia based on slow conduction zones necessary for the tachycardia/arrhythmia, mid diastolic signals during VT or preceding bigeminal PVCs, pace mapping from the site abnormal signals reproducing the arrhythmia morphology but with prominent conduction delay, the entire cycle length of the tachycardia or coupling interval for the PVCs being mapping, or based on reset characteristics.ConclusionIn patients with atypical forms of RVOT VT, careful mapping and ablation of the myocardial sleeves near the pulmonic valve can eliminate the arrhythmia.