5-Year Results From the AMPLATZER Amulet Left Atrial Appendage Occluder Randomized Controlled Trial.

Background: The Amulet IDE trial (AMPLATZER Amulet Left Atrial Appendage Occluder [LAAO] Investigational Device Exemption [IDE] Trial) evaluated the safety and effectiveness of the Amulet occluder (Abbott) in patients with nonvalvular atrial fibrillation. The Amulet IDE trial is the largest randomized LAAO trial, comparing the Amulet occluder with the Watchman 2.5 device (Boston Scientific).

3-Year Outcomes From the Amplatzer Amulet Left Atrial Appendage Occluder Randomized Controlled Trial (Amulet IDE).

Background: The Amulet (Abbott) left atrial appendage occluder investigational device exemption trial is the largest randomized trial evaluating the safety and effectiveness of the Amulet left atrial appendage occluder compared with the Watchman 2.5 device (Boston Scientific) through 5 years.

Objectives: This analysis evaluated the device effect on 3-year outcomes in the Amulet investigational device exemption trial.

Mechanisms, predictors, and evolution of severe peri-device leaks with two different left atrial appendage occluders.

Aims: Incomplete left atrial appendage occlusion (LAAO) due to peri-device leak (PDL) is a limitation of the therapy. The Amulet IDE trial is the largest randomized head-to-head trial comparing the Amulet and Watchman 2.5 LAAO devices with fundamentally different designs.

Peridevice Leak After Transcatheter Left Atrial Appendage Occlusion: An Analysis of the Amulet IDE Trial.

Background: Peridevice leak (PDL) is a limitation of left atrial appendage occlusion.

Objectives: The aim of this study was to assess the incidence of and outcomes associated with PDL in the Amulet IDE (AMPLATZER™ Amulet™ LAA Occluder Trial) randomized controlled trial.

Methods: Patients with atrial fibrillation at increased stroke risk were randomly assigned to undergo either Amulet (dual occlusive mechanism) or Watchman 2.

Thromboembolism after treatment with 4-factor prothrombin complex concentrate or plasma for warfarin-related bleeding.

Limited data exist in large, representative populations about whether the risk of thromboembolic events varies after receiving four-factor human prothrombin complex concentrate (4F-PCC) versus treatment with human plasma for urgent reversal of oral vitamin K antagonist therapy. We conducted a multicenter observational study to compare the 45-day risk of thromboembolic events in adults with warfarin-associated major bleeding after treatment with 4F-PCC (Kcentra®) or plasma. Hospitalized patients in two large integrated healthcare delivery systems who received 4F-PCC or plasma for reversal of warfarin due to major bleeding from January 1, 2008 to March 31, 2020 were identified and were matched 1:1 on potential confounders and a high-dimensional propensity score.

Rates of Acute Myocardial Infarction During the COVID-19 Pandemic.

Background: During the early phases of the COVID-19 pandemic pandemic, stay-at-home orders and fear of acquiring COVID-19 may have led to an avoidance of care for medical emergencies, including acute myocardial infarction (AMI). We evaluated whether a decline in rates of AMI occurred during the COVID-19 stay-at-home order.

Methods: Rates of AMI per 100,000 member-weeks were calculated for Kaiser Permanente Southern California patients from January 1 to March 3, 2020 (prepandemic period) and from March 20 to July 31, 2020 (pandemic period), and during the same periods in 2019.

Diagnostic Yield, Outcomes, and Resource Utilization With Different Ambulatory Electrocardiographic Monitoring Strategies.

Accurate diagnosis of arrhythmias is improved with longer monitoring duration but can risk delayed diagnosis. We compared diagnostic yield, outcomes, and resource utilization by arrhythmia monitoring strategy in 330 matched adults (mean age 64 years, 40% women, and 30% non-White) without previously documented atrial fibrillation or atrial flutter (AF/AFL) who received ambulatory electrocardiographic monitoring by 14-day Zio XT (patch-based continuous monitor), 24-hour Holter, or 30-day event monitor (external loop recorder) between October 2011 and May 2014. Patients were matched by age, gender, site, likelihood of receiving Zio XT patch, and indication for monitoring, and subsequently followed for monitoring results, management changes, clinical outcomes, and resource utilization.

Usefulness of Multisite Ventricular Pacing in Nonresponders to Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients with myocardial dysfunction and delayed ventricular activation, but approximately 25% to 40% of patients do not respond to CRT. Left ventricular (LV) multisite pacing (MSP) has been proposed as a tool to improve CRT response. The goal of this study is to examine the safety and efficacy of LV MSP in CRT nonresponders.

Patients With a History of a Cardiac Implantable Electronic Device Have a Higher Likelihood of 90-Day Cardiac Events After Total Joint Arthroplasty: A Matched Cohort Study.

Introduction: We sought to identify the incidence of new 90-day cardiac events, 90-day mortality, 90-day unplanned readmissions, and 30-day emergency department (ED) visits after total joint arthroplasty (TJA) in patients with a history of a cardiac implantable electronic device (CIED) and compare these outcomes in TJA patients without a CIED.

Methods: Kaiser Permanente's Cardiac Device and Total Joint Replacement Registries were used to identify elective primary TJA performed for osteoarthritis. TJA with a CIED was matched with TJA without a CIED (n = 365 pairs) on patient characteristics, demographics, and procedure type.

Predictors of conduction recovery after permanent pacemaker implantation following transcatheter aortic valve replacement.

Purpose: Conduction disturbances after transcatheter aortic valve replacement (TAVR) requiring pacemaker (PPM) implantation are a known complication and may be reversible. Therefore, we sought to evaluate the incidence and predictors for atrioventricular (AV) conduction recovery after TAVR.

Methods: A single-center, retrospective study of patients undergoing PPM implantation for conduction disorders after TAVR between June 2011 and March 2019.

Comparison of Long-Term Adverse Outcomes in Patients With Atrial Fibrillation Having Ablation Versus Antiarrhythmic Medications.

The impact of atrial fibrillation (AF) catheter ablation versus chronic antiarrhythmic therapy alone on clinical outcomes such as death and stroke remains unclear. We compared adverse outcomes for AF ablation versus chronic antiarrhythmic therapy in 1,070 adults with AF treated between 2010 and 2014 in the Kaiser Permanente Northern California and Southern California healthcare delivery systems. Patients who underwent AF catheter ablation were matched to patients treated with only antiarrhythmic medications, based on age, gender, history of heart failure, history of coronary heart disease, history of hypertension, history of diabetes, and high-dimensional propensity score.

Influence of Multimorbidity on Burden and Appropriateness of Implantable Cardioverter-Defibrillator Therapies.

Objective: To determine whether burden of multiple chronic conditions (MCCs) influences the risk of receiving inappropriate vs appropriate device therapies.

Design: Retrospective cohort study.

Setting: Seven US healthcare delivery systems.

Association of Burden of Atrial Fibrillation With Risk of Ischemic Stroke in Adults With Paroxysmal Atrial Fibrillation: The KP-RHYTHM Study.

Importance: Atrial fibrillation is a potent risk factor for stroke, but whether the burden of atrial fibrillation in patients with paroxysmal atrial fibrillation independently influences the risk of thromboembolism remains controversial.

Objective: To determine if the burden of atrial fibrillation characterized using noninvasive, continuous ambulatory monitoring is associated with the risk of ischemic stroke or arterial thromboembolism in adults with paroxysmal atrial fibrillation.

Design, Setting, And Participants: This retrospective cohort study conducted from October 2011 and October 2016 at 2 large integrated health care delivery systems used an extended continuous cardiac monitoring system to identify adults who were found to have paroxysmal atrial fibrillation on 14-day continuous ambulatory electrocardiographic monitoring.

Device Therapies Among Patients Receiving Primary Prevention Implantable Cardioverter-Defibrillators in the Cardiovascular Research Network.

Background: Primary prevention implantable cardioverter-defibrillators (ICDs) reduce mortality in selected patients with left ventricular systolic dysfunction by delivering therapies (antitachycardia pacing or shocks) to terminate potentially lethal arrhythmias; inappropriate therapies also occur. We assessed device therapies among adults receiving primary prevention ICDs in 7 healthcare systems.

Methods And Results: We linked medical record data, adjudicated device therapies, and the National Cardiovascular Data Registry ICD Registry.

Contemporary Procedural Complications, Hospitalizations, and Emergency Visits After Catheter Ablation for Atrial Fibrillation.

Contemporary data on complications and resource utilization after atrial fibrillation (AF) ablation are limited. We evaluated rates and risk factors for procedural complication, rehospitalization, and emergency department visits after AF ablation. We identified all adult patients who underwent isolated AF ablation between 2010 and June 2014 in 2 large integrated health-care delivery systems and evaluated rates of acute inpatient complication, 30-day, and 1-year readmission and emergency evaluation.

Performance of Anatomically Designed Quadripolar Left Ventricular Leads: Results from the NAVIGATE X4 Clinical Trial.

Introduction: The safety and efficacy of a novel family of quadripolar left ventricular (LV) pacing leads designed to pace from nonapical regions of the LV with low pacing capture thresholds was studied in patients undergoing implantation of a cardiac resynchronization therapy defibrillator (CRT-D).

Methods And Results: Patients receiving a CRT-D were implanted with 1 of 3 ACUITY X4 leads (Spiral Long, Spiral Short, or Straight), designed to address coronary venous anatomical variability. Electrical performance and LV lead related complications were evaluated 3 and 6 months post implantation, respectively.

Multi-Center, Community-Based Cardiac Implantable Electronic Devices Registry: Population, Device Utilization, and Outcomes.

Background: The purpose of this study is to describe key elements, clinical outcomes, and potential uses of the Kaiser Permanente-Cardiac Device Registry.

Methods And Results: This is a cohort study of implantable cardioverter defibrillators (ICD), pacemakers (PM), and cardiac resynchronization therapy (CRT) devices implanted between January 1, 2007 and December 31, 2013 by ≈400 physicians in 6 US geographical regions. Registry data variables, including patient characteristics, comorbidities, indication for procedures, complications, and revisions, were captured using the healthcare system's electronic medical record.

Longitudinal study of implantable cardioverter-defibrillators: methods and clinical characteristics of patients receiving implantable cardioverter-defibrillators for primary prevention in contemporary practice.

Background: Implantable cardioverter-defibrillators (ICDs) are increasingly used for primary prevention after randomized, controlled trials demonstrating that they reduce the risk of death in patients with left ventricular systolic dysfunction. The extent to which the clinical characteristics and long-term outcomes of unselected, community-based patients with left ventricular systolic dysfunction undergoing primary prevention ICD implantation in a real-world setting compare with those enrolled in the randomized, controlled trials is not well characterized. This study is being conducted to address these questions.

One tachycardia with two entrainment responses: what is the mechanism?

The patient presented for electrophysiology study and ablation for a history of narrow complex tachycardia. Both typical and atypical atrioventricular nodal reentrant tachycardia (AVNRT) were induced. For the atypical AVNRT, two different entrainment responses were recorded owing to different timing in delivering the ventricular pacing train.