Outcomes of catheter ablation for ventricular tachycardia in patients with sarcoidosis: Insights from the National Inpatient Sample database (2002-2018).

INTRODUCTION: Data on utilization, major complications, and in-hospital mortality of catheter ablation (CA) for sarcoidosis-related ventricular tachycardia (VT) are limited. We sought to determine the outcomes of sarcoidosis-related VT, and incidence and predictors of complications associated with the CA procedure. METHODS: We queried the 2002-2018 National Inpatient Sample database to identify patients aged ≥18 years with sarcoidosis admitted with VT. A 1:3 propensity score-matched (PSM) analysis was used to compare patient outcomes between CA and medically managed groups. Multivariable regression was performed to determine independent predictors of in-hospital mortality and procedural complications associated with the CA procedure. RESULTS: Of 3220 sarcoidosis patients with VT, 132 (4.1%) underwent CA. Patients who underwent CA were younger, male predominant, more likely Caucasian, had differences in baseline comorbidities including more likely to have heart failure, less likely to have prior myocardial infarction, COPD, or severe renal disease, had a higher mean household income, and more likely admitted to a larger/urban teaching hospital. After PSM, we examined 106 CA cases and 318 medically managed cases. There was a trend toward a lower in-hospital mortality rate in the CA group when compared to the medically managed group (1.9% vs. 6.6%, p = 0.08). The most common complications were pericardial drainage (5.3%), postoperative hemorrhage (3.8%), accidental puncture periprocedure (3.0%), and cardiac tamponade (2.3%). Independent predictors of in-hospital mortality and procedural complications among the CA group included congestive heart failure (odds ratio [OR], 13.2; 95% confidence interval [CI], 1.7-104.2) and mild to moderate renal disease (OR, 3.9; 95% CI, 1.1-13.3). CONCLUSIONS: Compared to patients with sarcoidosis-related VT who received medical therapy alone, those who underwent CA have a trend for a lower mortality rate despite procedure-related complications occurring as high as 9.1%. Additional studies are recommended to better evaluate the benefits and risks of VT ablation in this group.

Unique technique to relieve left ventricular assist device electromagnetic interference with an implantable cardioverter defibrillator.

We introduced a simple technique to eliminate electromagnetic interference between a left ventricular assist device (LVAD) and an implantable cardioverter defibrillator (ICD). A 43-year-old male with heart failure and a reduced ejection fraction who had an ICD presented with decompensated heart failure and received an LVAD as a bridge to transplant. Remote monitoring showed persistent atrial fibrillation causing an inappropriate ICD shock leading to a decision to disable shock therapies. However, an in-office interrogation was unsuccessful due to electromagnetic interference. Patient was instructed to extend his arm above his head on the ipsilateral side of the ICD, thus increasing the distance between LVAD and ICD, eliminating the interaction to allow reprogramming of the device.

Subclinical atrial fibrillation detection with a floating atrial sensing dipole in single lead implantable cardioverter-defibrillator systems: Results of the SENSE trial.

INTRODUCTION: Subclinical atrial fibrillation (AF), in the form of cardiac implantable device-detected atrial high rate episodes (AHREs), has been associated with increased thromboembolism. An implantable cardioverter-defibrillator (ICD) lead with a floating atrial dipole may permit a single lead (DX) ICD system to detect AHREs. We sought to assess the utility of the DX ICD system for subclinical AF detection in patients, with a prospective multicenter, cohort-controlled trial. METHODS AND RESULTS: One hundred fifty patients without prior history of AF (age 59 ± 13 years; 108 [72%] male) were enrolled into the DX cohort and implanted with a Biotronik DX ICD system at eight centers. Age-, sex-, and left ventricular ejection fraction-matched single- and dual-chamber ICD cohorts were derived from a Cornell database and from the IMPACT trial, respectively. The primary endpoint were AHRE detection at 12 months. During median 12 months follow-up, AHREs were detected in 19 (13%) patients in the DX, 8 (5.3%) in the single-chamber, and 19 (13%) in the dual-chamber cohorts. The rate of AHRE detection was significantly higher in the DX cohort compared to the single-chamber cohort (P = .026), but not significantly different compared to the dual-chamber cohort. There were no inappropriate ICD therapies in the DX cohort. At 12 months, only 3.0% of patients in the DX cohort had sensed atrial amplitudes less than 1.0 mV. CONCLUSION: Use of a DX ICD lead allows subclinical AF detection with a single lead DX system that is superior to that of a conventional single-chamber ICD system.

Treatment of Ventricular Arrhythmias and Use of Implantable Cardioverter-Defibrillators to Improve Survival in Older Adult Patients with Cardiac Disease.

Ventricular arrhythmia (VA) and sudden cardiac death (SCD) are well-recognized problems in the overall heart failure population, but treatment decisions can be more complex and nuanced in older patients. Sustained VA does not always lead to SCD, but identifies a higher risk population and may cause significant symptoms. Antiarrhythmic drugs (AAD) and catheter ablation are the mainstays for prevention of VA, but have not been shown to improve mortality. The value of implantable cardiac defibrillators (ICDs) may be influenced by patient age. This article discusses long-term treatment of VA and the use of ICDs in the elderly.

Regional variation in the incidence and outcomes of in-hospital cardiac arrest in the United States.

BACKGROUND: Regional variation in the incidence and outcomes of in-hospital cardiac arrest (IHCA) is not well studied and may have important health and policy implications. METHODS AND RESULTS: We used the 2003 to 2011 Nationwide Inpatient Sample databases to identify patients≥18 years of age who underwent cardiopulmonary resuscitation (International Classification of Diseases, Ninth Edition, Clinical Modification procedure codes 99.60 and 99.63) for IHCA. Regional differences in IHCA incidence, survival to hospital discharge, and resource use (total hospital cost and discharge disposition among survivors) were analyzed. Of 838,465 patients with IHCA, 162,270 (19.4%) were in the Northeast, 159,581 (19.0%) were in the Midwest, 316,201 (37.7%) were in the South, and 200,413 (23.9%) were in the West. Overall IHCA incidence in the United States was 2.85 per 1000 hospital admissions. IHCA incidence was lowest in the Midwest and highest in the West (2.33 and 3.73 per 1000 hospital admissions, respectively). Compared with the Northeast, risk-adjusted survival to discharge was significantly higher in the Midwest (odds ratio, 1.33; 95% confidence interval, 1.31-1.36), South (odds ratio, 1.21; 95% confidence interval, 1.19-1.23), and West (odds ratio, 1.25; 95% confidence interval, 1.23-1.27). IHCA survival increased significantly from 2003 to 2011 in the United States and in all regions (all Ptrend<0.001). Total hospital cost was highest in the West, whereas discharge to skilled nursing facility and use of home health care among survivors was highest in the Northeast. CONCLUSIONS: We observed significant regional variation in IHCA incidence, survival, and resource use in the United States. This variation was explained only partially by differences in patient and hospital characteristics. Further studies are needed to identify other potential factors responsible for these regional differences to improve outcomes after IHCA.

Anticoagulation for Atrial Fibrillation: A Review of Current Literature and Views.

Atrial fibrillation is a common supraventricular tachyarrhythmia with uncoordinated atrial activation and ineffective atrial contraction. This leads to an increased risk of atrial thrombi, most commonly in the left atrial appendage, and increased risks of embolic strokes and/or peripheral thromboembolism. It is associated with significant morbidity and mortality. To meet the concerns of thrombi and stroke, anticoagulation has been the mainstay for prevention and treatment thereof. Historically, anticoagulation involved the use of aspirin or vitamin K antagonists, mainly warfarin. Since early 2010s, direct oral anticoagulants (DOACs) including dabigatran, rivaroxaban, apixaban, and edoxaban have been introduced and approved for anticoagulation of atrial fibrillation. DOACs demonstrated a dramatic reduction in the rate of intracranial hemorrhage as compared to warfarin, and offer the advantages of absolution of monitoring therefore avoid the risk of hemorrhages in the context of narrow therapeutic window and under-treatment characteristic of warfarin, particularly in high-risk patients. One major concern and disadvantage for DOACs was lack of reversal agents, which have largely been ameliorated by the approval of Idarucizumab for dabigatran and Andexanet alfa for both apixaban and rivaroxaban, with Ciraparantag as a universal reversal agent for all DOACs undergoing Fast-Track Review from FDA. In this article, we will be providing a broad review of anticoagulation for atrial fibrillation with a focus on risk stratification schemes and anticoagulation agents (warfarin, aspirin, DOACs) including special clinical considerations.

Temporal associations between thoracic volume overload and malignant ventricular arrhythmias: a study of intrathoracic impedance.

BACKGROUND: Acute exacerbations of heart failure (HF) are believed to trigger malignant ventricular arrhythmias, but the temporal association between fluid accumulation and ventricular arrhythmias has not been evaluated in an objective manner. We hypothesized that increased intrathoracic fluid accumulation in patients with HF, as measured by an index of intrathoracic impedance, is associated with an increased risk of ventricular arrhythmias. METHODS AND RESULTS: We analyzed interrogations in a cohort of 96 patients with left ventricular dysfunction (EF ≤ 35%) with devices that monitor intrathoracic impedance (OptiVol fluid index). Treated episodes of ventricular tachycardia or fibrillation (VT/VF) were adjudicated and stratified according to predetermined fluid index thresholds (OptiVol indices of 15, 30, 45, 60 Ω-days). VT/VF episodes occurred in 16 patients (17%). VT/VF was more common on days when the fluid index was elevated using threshold values of 15, 30, and 45 Ω-days (P = 0.006, 0.04, 0.02, respectively). There were no differences in the percent of time above any threshold between patients with and without VT/VF. CONCLUSIONS: In patients with HF who develop VT/VF, volume overload, as detected by an index incorporating changes in intrathoracic impedance, was temporally associated with malignant ventricular tachyarrhythmias.

Utilization and programming of an automatic MRI recognition feature for cardiac rhythm management devices.

BACKGROUND: Cardiac implantable electronic devices (CIED)-ie, pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy devices-have recently been designed to allow for patients to safely undergo magnetic resonance imaging (MRI) when specific programming is implemented. MRI AutoDetect is a feature that automatically switches CIED's programming into and out of an MR safe mode when exposed to an MRI environment. OBJECTIVE: The purpose was to analyze de-identified daily remote transmission data to characterize the utilization of the MRI AutoDetect feature. METHODS: Home Monitoring transmission data collected from MRI AutoDetect-capable devices were retrospectively analyzed to determine the workflow and usage in patients experiencing an MRI using the MRI AutoDetect feature. RESULTS: Among 48,756 capable systems, 2197 devices underwent an MRI using the MRI AutoDetect feature. In these 2197 devices, the MRI AutoDetect feature was used a total of 2806 times with an average MRI exposure of 40.83 minutes. The majority (88.9%) of MRI exposures occurred on the same day as the MRI AutoDetect programming. A same day post-MRI exposure follow-up device interrogation was performed 8.6% of the time. A device-related complaint occurred within 30 days of the MRI exposure in 0.25% of MRI exposures using MRI AutoDetect but with no adverse clinical outcome. CONCLUSION: As a result of automation in device programming, the MRI AutoDetect feature eliminated post-MRI device reprogramming in 91.4% of MRI exposures and, while less frequent, allowed for pre-MRI interrogations prior to the day of the MRI exposure-reducing resource utilization and creating workflow flexibility.

Brugada syndrome clinical update.

Brugada syndrome (BrS) was initially described in southeast Asians with a structurally normal heart presenting with polymorphic ventricular tachycardia and fibrillation. This condition is marked by J-point elevation ≥ 2 mm with coved-type ST segment elevation followed by negative T wave inversions in at least one precordial lead (V1 or V2) when other etiologies have been excluded. These changes on electrocardiogram (EKG) can either be spontaneous or manifest after sodium channel blockade. The worldwide prevalence of BrS is about 0.4%; however, it is higher in the Asian population at 0.9%. This article will review the current hypotheses regarding the pathophysiology, spectrum of clinical presentation, strategies for prevention of sudden cardiac death and the treatment for recurrent arrhythmias in BrS.

Survival of a Patient with an Esophagopericardial Fistula After Catheter Ablation for Atrial Fibrillation: A Case Report and Literature Review.

Esophageal injury leading to esophagopericardial fistula (EPF) or atrioesophageal fistula is a very rare and dreaded complication of catheter ablation for atrial fibrillation that carries a high mortality rate. We present a case of EPF following radiofrequency catheter ablation for atrial fibrillation and an extensive review of the literature regarding catheter ablation-related esophageal injury.

Noninvasive Radioablation of Ventricular Tachycardia.

Ventricular tachycardia (VT) occurs most commonly in the presence of structural heart disease or myocardial scarring from prior infarction. It is associated with increased mortality, especially when it results in cardiac arrest outside of a hospital. When not due to reversible causes (such as acute ischemia/infarction), placement of an implantable cardioverter-defibrillator for prevention of future sudden death is indicated. The current standard of care for recurrent VT is medical management with antiarrhythmic agents followed by invasive catheter ablation for VT that persists despite appropriate medical therapy. Stereotactic arrhythmia radioablation (STAR) is a novel, noninvasive method of treating VT that has been shown to reduce VT burden for patients who are refractory to medical therapy and/or catheter ablation, or who are unable to tolerate catheter ablation. STAR is the term applied to the use of stereotactic body radiation therapy for the treatment of arrhythmogenic cardiac tissue and requires collaboration between an electrophysiologist and a radiation oncologist. The process involves identification of VT substrate through a combination of electroanatomic mapping and diagnostic imaging (computed tomography, magnetic resonance imaging, positron emission tomography) followed by carefully guided radiation therapy. In this article, we review currently available literature describing the utilization, efficacy, safety profile, and potential future applications of STAR for the management of VT.

Left Atrial Appendage Occlusion in the Management of Stroke in Patients With Atrial Fibrillation.

Atrial fibrillation (AF) is associated with a substantially higher risk of thromboembolism, particularly stroke events, resulting in significant morbidity and mortality. Oral anticoagulation (OAC), while effective in reducing embolic events in AF patients, is associated with an increased bleeding risk. Thus, not all patients with AF are candidates for OAC and some are only candidates for OAC in the short term. Of the available nonpharmacologic strategies for the management of AF, left atrial appendage occlusion (LAAO) has emerged as a potential approach for reducing the risk of systemic thromboembolism in AF patients eligible for OAC. LAAO can be achieved either surgically or percutaneously using an epicardial, endocardial, or a combined approach. Although available data are limited, currently available LAAO devices, and those being developed, have shown promise in reducing bleeding risk in AF patients because of the reduced overall need for anticoagulation, while maintaining efficacy in preventing thromboembolism. The optimal device will reduce both embolic and hemorrhagic strokes, and other bleeds, with a high implant success rate and a low complication rate. Until that time, anticoagulation remains the gold standard that these devices strive to surpass, and thus LAAO devices are currently indicated in patients with relative contraindication to OAC therapy.

Relationship of reverse anatomical remodeling and ventricular arrhythmias after cardiac resynchronization.

INTRODUCTION: Cardiac resynchronization (CRT) affects reverse anatomical remodeling in patients with heart failure. CRT has also been associated with fewer ventricular arrhythmias and reduced sudden death in some clinical trials, but the predictors and mechanism of the antiarrhythmic actions of CRT have not been well defined. The purpose of this study is to investigate the relationship of reverse anatomical remodeling to ventricular arrhythmias in CRT patients. METHODS AND RESULTS: A retrospective analysis was performed of the InSync III Marquis study, a prospective, randomized, multicenter CRT trial. Echocardiographic data from 198 patients were obtained at baseline and after 6 months of CRT, and anatomical responders were defined as a reduction in left ventricular end systolic volume (LVESV) of >or=15%. Anatomical responders (n = 71, 36%) demonstrated 29% fewer single premature ventricular contractions beats (PVCs) (P = 0.0001), 48% fewer PVC runs (p = 0.0096), and fewer treated episodes of ventricular tachycardia or fibrillation (VT/VF) (P = 0.050) than nonresponders. Multiple regression analysis demonstrated that responder status significantly predicted single PVCs and PVC runs. Gender was the most important predictor of treated VT/VF with females having no episodes over 6 months of follow-up. CONCLUSIONS: Anatomic responders to CRT demonstrate significantly fewer single PVCs and runs of PVCs. The implication of these observations is that anatomic remodeling is linked to electrical remodeling.

Sudden Cardiac Death Risk Stratification and the Role of the Implantable Cardiac Defibrillator.

Hypertrophic cardiomyopathy (HCM) is associated with an increased risk of sudden cardiac death (SCD), although perhaps not as significantly as previously believed. Given the heterogeneous nature of this disease entity, risk stratification of individuals with HCM remains challenging. The recent HCM risk-SCD prediction model seems to perform well in assessing individual SCD risk. Even though implantable cardiac defibrillators (ICDs) are effective in preventing SCD in patients at increased risk, the importance of shared decision making in deciding whether or not to undergo ICD implantation cannot be understated.

Sensing failure associated with the Medtronic Sprint Fidelis defibrillator lead.

INTRODUCTION: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progressively smaller over time. However, the long-term performance characteristics of these smaller ICD leads are unknown. METHODS: We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis defibrillating lead at two separate centers between September 2004 and October 2006. Lead characteristics were measured at implant, at early follow-up (1-4 days post implant), and every 3-6 months thereafter. RESULTS: During the study period, 357 patients underwent implantation of the Medtronic Sprint Fidelis lead. The mean R-wave measured at implant through the device was not different (P = NS) when compared with that measured at first follow-up (10.5 +/- 5.0 mV vs 10.7 +/- 5.1 mV). Forty-one patients (13%) had an R-wave amplitude

Multidetector row computed tomography for identification of left atrial appendage filling defects in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation: comparison with transesophageal echocardiography.

BACKGROUND: Advances in multidetector computed tomography (MDCT) technology now permit three-dimensional cardiac imaging with high spatial and temporal resolution. Historically, transesophageal echocardiography (TEE) has been the gold standard for assessment of the left atrial appendage (LAA) in patients with atrial fibrillation and other atrial arrhythmias. Findings on TEE, including demonstration of LAA thrombus and dense nonclearing spontaneous echocardiographic contrast (SEC), predict future fatal and nonfatal thromboembolic events. OBJECTIVE: The purpose of this study was to compare the diagnostic performance of 64-detector row MDCT in detecting LAA thrombus and dense nonclearing SEC as identified by TEE in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation. METHODS: A total of 72 consecutive patients (69.4% male; mean age 56.1 +/- 10.3 years) underwent both MDCT and TEE for evaluation of the LAA (median intertest interval 0 days, interquartile range 0-5 days). MDCT assessment of the LAA was performed by two methods: (1) comparison of Hounsfield unit (HU) densities in the LAA apex to the ascending aorta (AscAo) in the same axial plane and (2) nonquantitative visual identification of a filling defect in the LAA. TEE evaluation of the LAA included identification of echodense intracavitary masses in the LAA as well as pulsed-wave Doppler interrogation of the LAA ostium. RESULTS: Patients with LAA thrombus or dense nonclearing SEC by TEE exhibited significantly lower LAA/AscAo HU ratios than patients who did not (0.82 +/- 0.22 vs 0.39 +/- 0.19, P <.001). LAA/AscAo HU cutoff ratios < or = 0.75 correlated to LAA thrombus or dense nonclearing SEC by TEE, with 100% sensitivity, 72.2% specificity, 28.6% positive predictive value, and 100% negative predictive value. HU ratios < or = 0.75 were associated with pulsed-wave Doppler velocities <50 cm/s of the LAA ostium (P <.001). In multivariable analysis, LAA/AscAo HU ratio < or = 0.75 remained a robust predictor of LAA thrombus or dense nonclearing SEC by TEE (P <.001). In contrast, MDCT identification of TEE-identified LAA thrombus or dense nonclearing SEC by visual detection of LAA filling defects resulted in lower sensitivity (50%) and negative predictive value (95.1%). CONCLUSION: Current-generation MDCT successfully identifies LAA thrombus and dense nonclearing SEC with high sensitivity and moderate specificity. Importantly, LAA/AscAo HU ratios >0.75 demonstrate 100% negative predictive value for exclusion of LAA thrombus or dense nonclearing SEC. These results suggest that in patients undergoing pulmonary vein isolation procedures, MDCT examinations that demonstrate LAA/AscAo HU ratios >0.75 may preclude the need for preprocedural TEE.

ICD implantation and arrhythmia-free survival in patients with depressed LV function following surgery for valvular heart disease.

BACKGROUND: Although prophylactic implantable cardioverter-defibrillator (ICD) implantation is beneficial in patients with severe ischemic cardiomyopathy, it is unclear whether patients with cardiomyopathy due to valvular heart disease have a similar benefit. METHODS: We followed 17 patients (14 men/three women, age 62 +/- 13 years, left ventricular ejection fraction [LVEF] 29 +/- 10%) who had nonischemic valvular cardiomyopathy, underwent valvular heart surgery (aortic valve replacement, mitral valve replacement, and/or mitral valve repair), and subsequently had an electrophysiology study (EPS), for a median of 2.8 years. These patients were compared with 34 patients with prior myocardial infarction and no significant valvular heart disease, who were matched (1:2) for age, gender, LVEF, EPS result, T-wave alternans result, and ICD placement. Occurrence of arrhythmias was ascertained from ICD device clinic follow-up and vital status was determined using the National Death Index. RESULTS: There were no differences between the groups in overall survival (P = 0.24) or arrhythmia-free survival (P = 0.38), and the 2-year arrhythmia-free survival was 82% for the valvular patients versus 73% for the ischemic patients. Among patients with ICDs, there was no difference between the groups in overall survival (P = 0.34), time to first appropriate ICD therapy (P = 0.54), and arrhythmia-free survival (P = 0.51). CONCLUSION: Patients with valvular cardiomyopathy and residual left ventricular dysfunction following valvular surgery who underwent a tailored approach to ICD implantation had similar overall and arrhythmia-free survival as patients with ischemic cardiomyopathy.