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. METHODS: The medication regimen and key clinical outcomes were reported through 3 years including: 1) the composite of ischemic stroke or systemic embolism (SE); 2) the composite of all strokes, SE, or cardiovascular (CV) death; 3) major bleeding; and 4) all-cause death and CV death. RESULTS: A total of 1,878 patients at 108 sites were randomized. A significantly higher percentage of patients were free of oral anticoagulation usage at 3 years with Amulet (96.2%) vs Watchman (92.5%) (P < 0.01). Clinical outcomes were comparable for the composite of ischemic stroke or SE (5.0% vs 4.6%; P = 0.69); the composite of all strokes, SE, or CV death (11.1% vs 12.7%; P = 0.31); major bleeding (16.1% vs 14.7%; P = 0.46); all-cause death (14.6% vs 17.9%; P = 0.08); and CV death (6.6% vs 8.5%; P = 0.14) for Amulet and Watchman, respectively. Through 3 years, device factors (device-related thrombus or peridevice leak ≥3 mm) preceded ischemic stroke events and CV deaths more frequently in Watchman compared with Amulet patients. CONCLUSIONS: The Amulet occluder demonstrated continued safety and effectiveness with over 96% free of oral anticoagulation usage through 3 years in a high-risk population compared to the Watchman device. (AMPLATZER Amulet LAA Occluder Trial [Amulet IDE]; NCT02879448).

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. The predictors and mechanistic factors impacting differences in PDLs within the Amulet IDE trial are assessed in the current analysis. METHODS AND RESULTS: An independent core lab analysed all images for the presence or absence of severe PDL (>5 mm). The incidence, mechanistic factors, predictors using propensity score-matched controls, and evolution of severe PDLs through 18 months were assessed. Of the 1878 patients randomized in the trial, the Amulet occluder had significantly fewer severe PDLs than the Watchman device at 45 days (1.1 vs. 3.2%, P < 0.001) and 12 months (0.1 vs. 1.1%, P < 0.001). Off-axis deployment or missed lobes were leading mechanistic PDL factors in each device group. Larger left atrial appendage (LAA) dimensions including orifice diameter, landing zone diameter, and depth predicted severe PDL with the Watchman device, with no significant anatomical limitations noted with the Amulet occluder. Procedural and device implant predictors were found with the Amulet occluder attributed to the learning curve with the device. A majority of Watchman device severe PDLs did not resolve over time through 18 months. CONCLUSION: The dual-occlusive Amplatzer Amulet LAA occluder provided improved LAA closure compared with the Watchman 2.5 device. Predictors and temporal observations of severe PDLs were identified in the Amulet IDE trial. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov Unique identifier NCT02879448.

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 2.5 (single occlusive mechanism) device implantation. Transesophageal echocardiography was performed at 45 days and 12 months postprocedure. Clinically significant PDL was defined as ≥3 mm. The primary endpoint was ischemic stroke or systemic embolism, and the secondary endpoint was stroke, systemic embolism, or cardiovascular death. The Kaplan-Meier method was used to estimate 18-month cumulative event rates landmarked at day 45 postprocedure. RESULTS: A total of 1,593 patients underwent successful left atrial appendage occlusion and had an evaluable transesophageal echocardiographic studies at 45 days. The dual-occlusive mechanism device provided superior closure (defined as leak <3 mm) compared with the single-occlusive mechanism device at 45 days (88.9% vs 74.1%; P < 0.01) and 12 months (90.5% vs. 78.3%; P < 0.01). Through 18 months, PDL was associated with a higher, but not statistically significant, risk for the primary endpoint (3.6% vs 1.8%; adjusted HR: 1.98; 95% CI: 0.93-4.19; P = 0.07) and a statistically significantly higher risk for the secondary endpoint (8.1% vs. 4.7%; adjusted HR: 1.66; 95% CI: 1.02-2.69; P = 0.04). CONCLUSIONS: The dual-occlusive mechanism device provided superior closure compared with the single-occlusive mechanism device at both 45 days and 1 year postprocedure. PDL ≥3 mm was associated with a significantly increased 18-month risk for the composite of stroke, systemic embolism, or cardiovascular death. Completeness of closure of the left atrial appendage has important implications for patient outcomes. (AMPLATZER™ Amulet™ LAA Occluder Trial [Amulet IDE]; NCT02879448).

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. Arterial and venous thromboembolic events were identified up to 45 days after receiving 4F-PCC or plasma from electronic health records and adjudicated by physician review. Among 1119 patients receiving 4F-PCC and a matched historical cohort of 1119 patients receiving plasma without a recent history of thromboembolism, mean (SD) age was 76.7 (10.5) years, 45.6% were women, and 9.4% Black, 14.6% Asian/Pacific Islander, and 15.7% Hispanic. The 45-day risk of thromboembolic events was 3.4% in those receiving 4F-PCC and 4.1% in those receiving plasma (P = 0.26; adjusted hazard ratio 0.76; 95% confidence interval 0.49-1.16). The adjusted risk of all-cause death at 45 days post-treatment was lower in those receiving 4F-PCC compared with plasma. Among a large, ethnically diverse cohort of adults treated for reversal of warfarin-associated bleeding, receipt of 4F-PCC was not associated with an excess risk of thromboembolic events at 45 days compared with plasma therapy.

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. Between January 2018, and September 2019, the Strategic Management to Improve CRT Using Multi-Site Pacing trial prospectively enrolled 584 CRT-defibrillator recipients for established indications at 52 sites across the United States and evaluated their response at 6 months using the clinical composite score (CCS). Of the nonresponders, 102 patients had the LV MSP feature turned on and 78 patients completed the 12-month CCS evaluation. The LV MSP feature-related complication-free rate was 99.0% with a lower 95% confidence interval limit of 94.9%, which was higher than the performance goal of 90%. The proportion of nonresponders with an improved CCS from 6 to 12 months was 51.3% with a lower 95% confidence interval limit of 41.4%, which was higher than the performance goal of 5%. The estimated mean reduction in battery longevity with the LV MSP feature was about 3.6 months (estimated battery longevity of 8.87 ± 2.08 years at 6 months and 8.07 ± 2.23 years at 12 months). In conclusion, in CRT nonresponders, the use of the LV MSP feature is safe and associated with a ∼50% conversion rate with a small projected reduction in CRT-defibrillator battery longevity. LV MSP should be considered in the management of CRT nonresponders.

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. AF/AFL ≥30 seconds was noted in 6% receiving Zio XT versus 0% by Holter (p = 0.04) and 3% by event monitor (p = 0.07). Nonsustained ventricular tachycardia was noted in 24% for Zio XT patch versus 8% (p <0.001) for Holter and 4% (p <0.001) for event monitor. No significant differences between monitoring strategies in outcomes or resource utilization were observed. Prolonged monitoring with 14-day Zio XT patch or 30-day event monitor was superior to 24-hour Holter in detecting new AF/AFL but not different from each other. Documented nonsustained ventricular tachycardia was more frequent with Zio XT than 24-hour Holter and 30-day event monitor without apparent increased risk of adverse outcomes or excess utilization. In conclusion, additional efforts are needed to further personalize electrocardiographic monitoring strategies that optimize clinical management and outcomes.

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. Rate ratios (RRs) were calculated comparing the time periods using Poisson regression. Case fatality rates (CFRs) were also compared. RESULTS: Rates of AMI were lower during the pandemic period of 2020 compared to the same period of 2019 [3.20 vs 3.76/100,000 member-weeks; RR, 0.85; 95% confidence interval (CI) 0.80-0.90]. There was no evidence that rates of AMI differed during the 2020 prepandemic period compared to the same period in 2019 (4.45 vs 4.24/100,000 member-weeks; RR, 0.95; 95% CI, 0.88-1.03). AMI rates were lower during the early pandemic period (March 20-May 7: RR, 0.70; 95% CI, 0.66-0.77), but not during the later pandemic period (May 8-July 31: RR, 0.95; 95% CI, 0.88-1.02) compared to 2019. In-hospital and 30-day case fatality rates were higher during the pandemic period of 2020 compared to 2019 (8.8% vs 6.1% and 6.5% vs 5.0%, respectively). CONCLUSION: AMI rates were lower during the COVID-19 pandemic compared to the same period in 2019. During stay-at-home orders, public health campaigns that encourage people to seek care for medical emergencies are warranted.

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. Conduction recovery was defined as ≤ 1% ventricular pacing (VP) on follow-up PPM interrogation. RESULTS: A total of 110 patients (mean age 83.6 ± 6.6 years, 46.8% female) were included. At a median follow-up of 438 days (interquartile range [IQR] 111-760 days), 35 patients (32%) had conduction recovery, with 50% of these occurring within the first 6 months. On multivariate analysis, predictors of conduction recovery include female sex (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.01-6.4, p = 0.048), non-VP/non-complete heart block rhythm immediately post-TAVR (HR 5.2, 95% CI 1.5-18.1, p = 0.011), normal sinus rhythm 7 days post-TAVR (HR 3.9, 95% CI 1.7-9.2, p = 0.002), and smaller valve size (mm) (HR 0.81, 95% CI 0.7-0.996, p = 0.045). Significant narrowing of the QRS and resolution of new-onset left bundle branch block within 1 month post-TAVR occurred in those with conduction recovery on PPM interrogation. CONCLUSIONS: One-third of patients receiving new PPM implantation have conduction recovery after TAVR, with 50% occurring within the first 6 months. Patient gender, valve size, and rhythm on serial ECGs after TAVR can help identify patients that may recover AV conduction. A conservative approach rather than immediate PPM implantation may be considered in these patients.

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. A McNemar test was used to evaluate categorical outcomes. RESULTS: Of the TJA with a CIED, there were 24 cardiac events (6.6%), 1 mortality (0.3%), 30 readmissions (8.2%), and 39 ED visits (10.7%). TJA patients with a CIED had a higher likelihood of cardiac events (odds ratio [OR] = 3.14, 95% confidence interval [CI] = 1.28 to 8.08). No difference was observed in mortality (OR = 0.50, 95% CI = 0.02 to 6.98), readmissions (OR = 1.26, 95% CI = 0.71 to 2.25), or ED visits (OR = 1.15, 95% CI = 0.71 to 1.88). CONCLUSION: In our matched cohort study, TJA patients with a history of a CIED had a higher likelihood of incident 90-day cardiac events when compared with patients without a CIED without a difference observed for 90-day mortality, unplanned readmission, and 30-day ED visit. LEVEL OF EVIDENCE: Level III.

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. We compared crude and adjusted rates of death, ischemic stroke or transient ischemic attack, intracranial hemorrhage, and hospitalization. The matched cohort of 535 patients treated with AF ablation and 535 treated with antiarrhythmic therapy had a median follow-up of 2.0 (interquartile range 1.1 to 3.5) years. There was no significant difference in adjusted rates of death (adjusted hazard ratio [HR] 0.24, 95% confidence interval [CI] 0.03 to 1.95), intracranial hemorrhage (adjusted HR 0.17, CI 0.02 to 1.71), ischemic stroke or transient ischemic attack (adjusted HR 0.53, CI 0.18 to 1.60), and heart failure hospitalization (adjusted HR 0.85, CI 0.34 to 2.12), although there was a trend toward improvement in these outcomes with ablation. However, there was a significantly increased risk of all-cause hospitalization following ablation (adjusted HR 1.60, CI 1.25 to 2.05). In a contemporary, multicenter, propensity-matched observational cohort, AF ablation was not significantly associated with death, intracranial hemorrhage, ischemic stroke or transient ischemic attack, or heart failure hospitalization, but was associated with a higher rate of all cause-hospitalization.

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. PARTICIPANTS: Adults with left ventricular systolic dysfunction receiving an implantable cardioverter-defibrillator (ICD) for primary prevention. MEASUREMENTS: Data on 24 comorbid conditions were captured from electronic health records and categorized into quartiles of comorbidity burden (0-3, 4-5, 6-7 and 8-16). Incidence of ICD therapies (shock and antitachycardia pacing [ATP] therapies), including appropriateness, was collected for 3 years after implantation. Outcomes included time to first ICD therapy, total ICD therapy burden, and risk of inappropriate vs appropriate ICD therapy. RESULTS: Among 2235 patients (mean age = 69 ± 11 years, 75% men), the median number of comorbidities was 6 (interquartile range = 4-8), with 98% having at least two comorbidities. During a mean 2.2 years of follow-up, 18.3% of patients experienced at least one appropriate therapy and 9.9% experienced at least one inappropriate therapy. Higher comorbidity burden was associated with an increased risk of first inappropriate therapy (adjusted hazard ratio [HR] = 1.94 [95% confidence interval {CI} = 1.14-3.31] for 4-5 comorbidities; HR = 2.25 [95% CI = 1.25-4.05] for 6-7 comorbidities; and HR = 2.91 [95% CI = 1.54-5.50] for 8-16 comorbidities). Participants with 8-16 comorbidities had a higher total burden of ICD therapy (adjusted relative risk [RR] = 2.12 [95% CI = 1.43-3.16]), a higher burden of inappropriate therapy (RR = 3.39 [95% CI = 1.67-6.86]), and a higher risk of receiving inappropriate vs appropriate therapy (RR = 1.74 [95% CI = 1.07-2.82]). Comorbidity burden was not significantly associated with receipt of appropriate ICD therapies. Patterns were similar when separately examining shock or ATP therapies. CONCLUSIONS: In primary prevention ICD recipients, MCC burden was independently associated with an increased risk of inappropriate but not appropriate device therapies. Comorbidity burden should be considered when engaging patients in shared decision making about ICD implantation.

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. Exposures: The burden of atrial fibrillation was defined as the percentage of analyzable wear time in atrial fibrillation or flutter during the up to 14-day monitoring period. Main Outcomes and Measures: Ischemic stroke and other arterial thromboembolic events occurring while patients were not taking anticoagulation were identified through November 2016 using electronic medical records and were validated by manual review. We evaluated the association of the burden of atrial fibrillation with thromboembolism while not taking anticoagulation after adjusting for the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) or CHA2DS2-VASc stroke risk scores. Results: Among 1965 adults with paroxysmal atrial fibrillation, the mean (SD) age was 69 (11.8) years, 880 (45%) were women, 496 (25%) were persons of color, the median ATRIA stroke risk score was 4 (interquartile range [IQR], 2-7), and the median CHA2DS2-VASc score was 3 (IQR, 1-4). The median burden of atrial fibrillation was 4.4% (IQR ,1.1%-17.23%). Patients with a higher burden of atrial fibrillation were less likely to be women or of Hispanic ethnicity, but had more prior cardioversion attempts compared with those who had a lower burden. After adjusting for either ATRIA or CHA2DS2-VASc stroke risk scores, the highest tertile of atrial fibrillation burden (≥11.4%) was associated with a more than 3-fold higher adjusted rate of thromboembolism while not taking anticoagulants (adjusted hazard ratios, 3.13 [95% CI, 1.50-6.56] and 3.16 [95% CI, 1.51-6.62], respectively) compared with the combined lower 2 tertiles of atrial fibrillation burden. Results were consistent across demographic and clinical subgroups. Conclusions and Relevance: A greater burden of atrial fibrillation is associated with a higher risk of ischemic stroke independent of known stroke risk factors in adults with paroxysmal atrial fibrillation.

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. Survival analysis evaluated therapy probability and predictors after ICD implant from 2006 to 2009, with attention to Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups: left ventricular ejection fraction, 31% to 35%; nonischemic cardiomyopathy <9 months' duration; and New York Heart Association class IV heart failure with cardiac resynchronization therapy defibrillator. Among 2540 patients, 35% were <65 years old, 26% were women, and 59% were white. During 27 (median) months, 738 (29%) received ≥1 therapy. Three-year therapy risk was 36% (appropriate, 24%; inappropriate, 12%). Appropriate therapy was more common in men (adjusted hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.43-2.35). Inappropriate therapy was more common in patients with atrial fibrillation (adjusted HR, 2.20; 95% CI, 1.68-2.87), but less common among patients ≥65 years old versus younger (adjusted HR, 0.72; 95% CI, 0.54-0.95) and in recent implants (eg, in 2009 versus 2006; adjusted HR, 0.66; 95% CI, 0.46-0.95). In Centers for Medicare and Medicaid Services Coverage With Evidence Development analysis, inappropriate therapy was less common with cardiac resynchronization therapy defibrillator versus single chamber (adjusted HR, 0.55; 95% CI, 0.36-0.84); therapy risk did not otherwise differ for Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups. CONCLUSIONS: In this community cohort of primary prevention patients receiving ICD, therapy delivery varied across demographic and clinical characteristics, but did not differ meaningfully for Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups.

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. We used multivariable logistic regression to identify predictors of procedural complications, 30-day readmission, or 30-day emergency department evaluation. In 811 AF ablation patients, procedural complications occurred in 2.5% of patients, 9.7% of patients were rehospitalized within 30 days, and 19.1% of patients had an emergency visit within 30 days. At 1 year after AF ablation, 28.9% of patients were readmitted, with 18% of patients readmitted for AF or atrial flutter. At 1 year, 44.5% of patients were seen in an emergency department, with 37.1% related to AF or atrial flutter. Vascular complications and perforation or tamponade were the most common complications, and Hispanic ethnicity, mitral or aortic valvular disease, and diabetes mellitus were the strongest risk factors for adverse outcomes at 30 days after AF ablation. Contemporary rates of acute complication and 1-year readmission after AF ablation have markedly decreased compared with previous community-based studies.

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. 764 patients (68 ± 11 years, 66% male) were enrolled; 738 (97%) successfully implanted with an ACUITY X4 lead (Spiral L, n = 239, 31%; Spiral S, n = 281, 37%; Straight, n = 218, 29%). A targeted threshold ≤2.5 V was achieved in 644 (94%) patients. The median threshold from the best proximal electrode was lower than the tip electrode (0.9 V [IQR 0.7, 1.3] vs. 1.3 V [IQR 0.7, 2.5], p< 0.001) on Spiral leads. Irrespective of lead implanted, one of the proximal electrodes was the programmed cathode in most patients. The overall LV complication-free rate was 98%. LV lead dislodgment occurred in 8 (1%) patients. PNS occurred in 58 (8%) patients, but only 3 (0.4%) patients required surgical intervention. CONCLUSION: The ACUITY X4 LV leads had low pacing thresholds particularly from proximal electrodes, a high incidence of pacing from the nondistal electrode, and low likelihood of dislodgment or PNS requiring surgical intervention. (ClinicalTrials.gov Identifier: NCT02071173).

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. Outcomes were identified using electronic screening algorithms and adjudicated via chart review. There were 11 924 ICDs, 33 519 PMs, 4472 CRTs, and 66 067 leads registered. A higher proportion of devices were implanted in males: 75.1% (ICD), 55.0% (PM), and 66.7% (CRT), with mean patient age 63.2 years (ICD), 75.2 (PM), and 67.2 (CRT). The 30-day postoperative incidence of tamponade, hematoma, and pneumothorax were ≤0.3% (ICD), ≤0.6% (PM), and ≤0.4% (CRT). Device failures requiring revision occurred at a rate of 2.17% for ICDs, 0.85% for PMs, and 4.93% for CRTs, per 100 patient observation years. Superficial infection rates were <0.03% for all devices; deep infection rates were 0.6% (ICD), 0.5% (PM), and 1.0% (CRT). Results were used to monitor vendor-specific variations and were systematically shared with individual regions to address potential variations in outcomes, utilization, and to assist with the management of device recalls. CONCLUSIONS: The Kaiser Permanente-Cardiac Device Registry is a robust tool to monitor postprocedural patient outcomes and postmarket surveillance of implants and potentially change practice patterns.

Age and sex differences in long-term outcomes following implantable cardioverter-defibrillator placement in contemporary clinical practice: findings from the Cardiovascular Research Network.

BACKGROUND: Patient sex and age may influence rates of death after receiving an implantable cardioverter-defibrillator for primary prevention. Differences in outcomes other than mortality and whether these differences vary by heart failure symptoms, etiology, and left ventricular ejection fraction are not well characterized. METHODS AND RESULTS: We studied 2954 patients with left ventricular ejection fraction ≤0.35 undergoing first-time implantable cardioverter-defibrillator for primary prevention within the Cardiovascular Research Network; 769 patients (26%) were women, and 2827 (62%) were aged >65 years. In a median follow-up of 2.4 years, outcome rates per 1000 patient-years were 109 for death, 438 for hospitalization, and 111 for heart failure hospitalizations. Procedure-related complications occurred in 8.36%. In multivariable models, women had significantly lower risks of death (hazard ratio 0.67, 95% CI 0.56 to 0.80) and heart failure hospitalization (hazard ratio 0.82, 95% CI 0.68 to 0.98) and higher risks for complications (hazard ratio 1.38, 95% CI 1.01 to 1.90) than men; patients aged >65 years had higher risks of death (hazard ratio 1.55, 95% CI 1.30 to 1.86) and heart failure hospitalization (hazard ratio 1.25, 95% CI 1.05 to 1.49) than younger patients. Age and sex differences were generally consistent in strata according to symptoms, etiology, and severity of left ventricular systolic dysfunction, except the higher risk of complications in women, which differed by New York Heart Association classification (P=0.03 for sex-New York Heart Association interaction), and the risk of heart failure hospitalization in older patients, which differed by etiology of heart failure (P=0.05 for age-etiology interaction). CONCLUSIONS: The burden of adverse outcomes after receipt of an implantable cardioverter-defibrillator for primary prevention is substantial and varies according to patient age and sex. These differences in outcome generally do not vary according to baseline heart failure characteristics.

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. METHODS AND RESULTS: The study cohort includes consecutive patients undergoing primary prevention ICD placement between January 1, 2006 and December 31, 2009 in 7 health plans. Baseline clinical characteristics were acquired from the National Cardiovascular Data Registry ICD Registry. Longitudinal data collection is underway, and will include hospitalization, mortality, and resource use from standardized health plan data archives. Data regarding ICD therapies will be obtained through chart abstraction and adjudicated by a panel of experts in device therapy. Compared with the populations of primary prevention ICD therapy randomized, controlled trials, the cohort (n=2621) is on average significantly older (by 2.5-6.5 years), more often female, more often from racial and ethnic minority groups, and has a higher burden of coexisting conditions. The cohort is similar, however, to a national population undergoing primary prevention ICD placement. CONCLUSIONS: Patients undergoing primary prevention ICD implantation in this study differ from those enrolled in the randomized, controlled trials that established the efficacy of ICDs. Understanding a broad range of health outcomes, including ICD therapies, will provide patients, clinicians, and policy makers with contemporary data to inform decision-making.