Outcomes of Atrial Fibrillation Ablation Among Older Adults in the United States: A Nationwide Study.

BACKGROUND: Pulmonary vein isolation (PVI) is increasingly recommended as first-line therapy for atrial fibrillation. Recent data suggest growing PVI volumes but rising complication rates, although comprehensive real-world outcomes including both inpatient and outpatient encounters remain unclear. OBJECTIVES: The purpose of this study was to evaluate patient characteristics, population rates, and 30-day outcomes of PVI in a nationwide sample of U.S. adults aged >65 years. METHODS: First-time PVIs were identified among U.S. Medicare fee-for-service beneficiaries using Current Procedural Terminology procedural codes. Comorbidities were ascertained using International Classification of Diseases-10th Revision diagnosis codes associated with each procedural claim. Outcomes included periprocedural complications, all-cause hospitalizations, and mortality at 30 days. RESULTS: From January 2017 through December 2021, a total of 227,133 patients underwent PVI (mean age 72.5 years, 42% women, 92.7% White) with an increasing comorbidity burden over time. PVI volume increased from 83.8 (2017) to 111.6 per 100,000 patient-years (2021), which was driven by outpatient procedures (87.8% of all PVIs). Concurrently, there was a significant decrease in complication rates (3.9% in 2017 vs 3.1% in 2021; P < 0.001) and hospitalizations (8.8% vs 7.0%; P < 0.001), with no significant change in mortality (0.4%; P = 0.08). The most common periprocedural complications were bleeding (1.8%), pericardial effusion (1.4%), and vascular access damage (0.8%). CONCLUSIONS: The use of PVI has steadily increased among older patients in contemporary U.S. clinical practice; yet, cumulative complication and hospitalization rates at 30 days have decreased over time, with stably low rates of short-term mortality despite rising comorbidity burden among treated patients. These data may reassure patients and providers on the safety of PVI as an increasingly common first-line procedure for atrial fibrillation.

Risk of Adverse Outcomes Associated With Cardiac Sarcoidosis Diagnostic Schemes.

BACKGROUND: Multiple cardiac sarcoidosis (CS) diagnostic schemes have been published. OBJECTIVES: This study aims to evaluate the association of different CS diagnostic schemes with adverse outcomes. The diagnostic schemes evaluated were 1993, 2006, and 2017 Japanese criteria and the 2014 Heart Rhythm Society criteria. METHODS: Data were collected from the Cardiac Sarcoidosis Consortium, an international registry of CS patients. Outcome events were any of the following: all-cause mortality, left ventricular assist device placement, heart transplantation, and appropriate implantable cardioverter-defibrillator therapy. Logistic regression analysis evaluated the association of outcomes with each CS diagnostic scheme. RESULTS: A total of 587 subjects met the following criteria: 1993 Japanese (n = 310, 52.8%), 2006 Japanese (n = 312, 53.2%), 2014 Heart Rhythm Society (n = 480, 81.8%), and 2017 Japanese (n = 112, 19.1%). Patients who met the 1993 criteria were more likely to experience an event than patients who did not (n = 109 of 310, 35.2% vs n = 59 of 277, 21.3%; OR: 2.00; 95% CI: 1.38-2.90; P < 0.001). Similarly, patients who met the 2006 criteria were more likely to have an event than patients who did not (n = 116 of 312, 37.2% vs n = 52 of 275, 18.9%; OR: 2.54; 95% CI: 1.74-3.71; P < 0.001). There was no statistically significant association between the occurrence of an event and whether a patient met the 2014 or the 2017 criteria (OR: 1.39; 95% CI: 0.85-2.27; P = 0.18 or OR: 1.51; 95% CI: 0.97-2.33; P = 0.067, respectively). CONCLUSIONS: CS patients who met the 1993 and the 2006 criteria had higher odds of adverse clinical outcomes. Future research is needed to prospectively evaluate existing diagnostic schemes and develop new risk models for this complex disease.

Incidence, Treatment, and Outcomes of Symptomatic Device Lead-Related Venous Obstruction.

BACKGROUND: The incidence and clinical impact of lead-related venous obstruction (LRVO) among patients with cardiovascular implantable electronic devices (CIEDs) is poorly defined. OBJECTIVES: The objectives of this study were to determine the incidence of symptomatic LRVO after CIED implant; describe patterns in CIED extraction and revascularization; and quantify LRVO-related health care utilization based on each type of intervention. METHODS: LRVO status was defined among Medicare beneficiaries after CIED implant from October 1, 2015, to December 31, 2020. Cumulative incidence functions of LRVO were estimated by Fine-Gray methods. LRVO predictors were identified using Cox regression. Incidence rates for LRVO-related health care visits were calculated with Poisson models. RESULTS: Among 649,524 patients who underwent CIED implant, 28,214 developed LRVO, with 5.0% cumulative incidence at maximum follow-up of 5.2 years. Independent predictors of LRVO included CIEDs with >1 lead (HR: 1.09; 95% CI: 1.07-1.15), chronic kidney disease (HR: 1.17; 95% CI: 1.14-1.20), and malignancies (HR: 1.23; 95% CI: 1.20-1.27). Most patients with LRVO (85.2%) were managed conservatively. Among 4,186 (14.8%) patients undergoing intervention, 74.0% underwent CIED extraction and 26.0% percutaneous revascularization. Notably, 90% of the patients did not receive another CIED after extraction, with low use (2.2%) of leadless pacemakers. In adjusted models, extraction was associated with significant reductions in LRVO-related health care utilization (adjusted rate ratio: 0.58; 95% CI: 0.52-0.66) compared with conservative management. CONCLUSIONS: In a large nationwide sample, the incidence of LRVO was substantial, affecting 1 of every 20 patients with CIEDs. Device extraction was the most common intervention and was associated with long-term reduction in recurrent health care utilization.

Coronary Artery Occlusion Detection Using 3-Lead ECG System Suitable for Credit Card-Size Personal Device Integration.

Background: Early coronary occlusion detection by portable personal device with limited number of electrocardiographic (ECG) leads might shorten symptom-to-balloon time in acute coronary syndromes. Objectives: The purpose of this study was to compare the accuracy of coronary occlusion detection using vectorcardgiographic analysis of a near-orthogonal 3-lead ECG configuration suitable for credit card-size personal device integration with automated and human 12 lead ECG interpretation. Methods: The 12-lead ECGs with 3 additional leads ("abc") using 2 arm and 2 left parasternal electrodes were recorded in 66 patients undergoing percutaneous coronary intervention prior to ("baseline", n = 66), immediately before ("preinflation", n = 66), and after 90-second balloon coronary occlusion ("inflation", n = 120). Performance of computer-measured ST-segment shift on vectorcardgiographic loops constructed from "abc" and 12 leads, standard 12-lead ECG, and consensus human interpretation in coronary occlusion detection were compared in "comparative" and "spot" modes (with/without reference to "baseline") using areas under ROC curves (AUC), reliability, and sensitivity/specificity analysis. Results: Comparative "abc"-derived ST-segment shift was similar to two 12-lead methods (vector/traditional) in detecting balloon coronary occlusion (AUC = 0.95, 0.96, and 0.97, respectively, P = NS). Spot "abc" and 12-lead measurements (AUC = 0.72, 0.77, 0.68, respectively, P = NS) demonstrated poorer performance (P < 0.01 vs comparative measurements). Reliability analysis demonstrated comparative automated measurements in "good" agreement with reference (preinflation/inflation), while comparative human interpretation was in "moderate" range. Spot automated and human reading showed "poor" agreement. Conclusions: Vectorcardiographic ST-segment analysis using baseline comparison of 3-lead ECG system suitable for credit card-size personal device integration is similar to established 12-lead ECG methods in detecting balloon coronary occlusion.

Clinical management of conduction abnormalities following transcatheter aortic valve replacement: prospective evaluation of a standardized management pathway.

PURPOSE: Limited evidence guides management of conduction abnormalities following TAVR. Standardized clinical pathways may reduce variability in care while minimizing bradyarrhythmic morbidity, length of stay (LOS), and pacemaker (PPM) implantation rates. METHODS: A multidisciplinary consensus pathway to standardize post-TAVR management was developed. We evaluated (1) pathway adherence; (2) LOS; (3) PPM implantation rates; (4) 1-month survival, and (5) late heart block. Exploratory analyses evaluated factors associated with PPM implantation. RESULTS: A total of 181 consecutive patients without prior PPM who underwent TAVR between February 2020 and February 2021 (mean age 77.9 ± 9.1, 38% women) were included. Average LOS was 3.0 days (± 2.7), and no deaths related to syncope/bradyarrhythmia were reported by 1 month. Overall, 93% of the 181 patients were managed by pathway; deviations were due to failure of discharge with a heart monitor when it was clinically indicated for either pre-existing RBBB or new PR prolongation/new LBBB. PPM implantation occurred in 19 patients by discharge, and 21 by 1-month (13%). In our exploratory analysis, pre-existing RBBB, transient peri-procedural heart block, and LOTUS valves were associated with pacemaker implantation: OR (CI) of 8.16 (3.06-21.78), 6.83 (1.94-24.03), and 8.32 (1.11-62.49), respectively. CONCLUSIONS: This report illustrates that a standardized protocol for the management of conduction abnormalities after TAVR can be implemented with high compliance, safe management of conduction disturbance, and relatively short LOS with discharge supported by ambulatory monitoring.

Very early versus early referral for ablation in young patients with newly diagnosed paroxysmal atrial fibrillation.

BACKGROUND: Catheter ablation (CA) has emerged as an effective therapy for the treatment of paroxysmal atrial fibrillation (AF); however it is unclear whether proceeding expeditiously to CA improves clinical outcomes in a real-world population. This study compares outcomes of CA for new AF within 6 months of diagnosis (very early) 6 to 12 months after diagnosis (early) and 12 to 24 months after diagnosis (later). METHODS: A large nationally-representative sample of patients ages 18 to 64 who underwent CA from January 2011 to June 2019 was studied using the IBM MarketScan Database. The primary outcome was a composite of healthcare utilization over the following 24 months. Propensity score-matching was used to match patients in each cohort. Risk difference in outcomes were compared between matched patients. RESULTS: Two thousand six hundred thirty one patients were identified postmatching, with 1649 in the very early cohort and 982 in the early cohort. The very early referral group was less likely to experience the primary composite outcome postablation (Absolute risk difference [ARD]: -3.9%; 95% Confidence interval [CI]: -5.8%, -2.0%), with the difference driven by fewer cardioversions (ARD: -2.9%, 95% CI: -5.3%, -0.5%) and outpatient visits (ARD: -6.6%, 95% CI: -10.5%, -2.7%). There was no difference in outcomes between early and later referral groups, with only very early referral showing decreased healthcare utilization. CONCLUSIONS: Patients who underwent ablation within 6 months of diagnosis had lower healthcare utilization in the ensuing 24 months, driven by fewer outpatient visits and cardioversions, supporting expeditious referral for ablation for symptomatic AF.

Conduction Disturbances and Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: Predictors and Prevention.

Conduction disturbances and permanent pacemaker implantation (PPMI) remain a frequent and important consequence of transcatheter aortic valve replacement (TAVR). Understanding risk factors for TAVR-related conduction disturbances could improve patient selection, procedural techniques, and periprocedural efforts for monitoring and treatment of heart block. Several studies have identified patient-related and procedural factors associated with new-onset left bundle branch block, high-degree atrioventricular block, and the need for PPMI after TAVR. Notable patient-related predictors include preexisting right bundle branch block, membranous septal length, and calcification of the left ventricular outflow tract. Modifiable procedural predictors include device implantation depth, prosthesis oversizing, and valve type. This review aims to summarize the current literature examining predictors of conduction disturbances and PPMI after TAVR, particularly with regard to the newer-generation valve types. We also propose a management algorithm for the management of conduction disturbances postprocedure.

A Review of Cardiac Implantable Electronic Device Infections for the Practicing Electrophysiologist.

Cardiovascular implantable electronic device (CIED) infections are morbid, costly, and difficult to manage. This review explores the pathophysiology, diagnosis, and management of CIED infections. Diagnostic accuracy has been improved through increased awareness and improved imaging strategies. Pocket or bloodstream infection with virulent organisms often requires complete system extraction. Emerging prophylactic interventions and novel devices have expanded preventative strategies and options for re-implantation. A clear and nuanced understanding of CIED infection is important to the practicing electrophysiologist.

Limited duration of antiarrhythmic drug use for newly diagnosed atrial fibrillation in a nationwide population under age 65.

INTRODUCTION: Antiarrhythmic drugs (AADs) are commonly used for the treatment of newly diagnosed symptomatic atrial fibrillation (AF), however initial AAD choice, duration of therapy, rates of discontinuation, and factors associated with a durable response to therapy are poorly understood. This study assesses the initial choice and duration of antiarrhythmic drug therapy in the first 2 years after diagnosis of AF in a younger, commercially insured population. METHODS: A large nationally representative sample of patients age 20-64 was studied using the IBM MarketScan Database. Patients who started an AAD within 90 days of AF diagnosis with continuous enrollment for 1-year pre-index diagnosis and 2 years post-index were included. A Cox proportional hazards model was used to determine factors associated with AAD discontinuation. RESULTS: Flecainide was used most frequently (26.8%), followed by amiodarone (22.5%), dronedarone (18.3%), sotalol (15.8%), and propafenone (14.0%), with other AADs used less frequently. Twenty-two percent of patients who started on an AAD underwent ablation within 2 years, with 79% discontinuing the AAD after ablation. Ablation was the strongest predictor of AAD discontinuation (hazard ratio [HR], 1.70; 95% confidence interval [CI]: 1.61-1.80), followed by the male gender (HR, 1.10; CI: 1.02-1.19). Older patients (HR, 0.76; CI: 0.72-0.80; reference age 18-49) and those with comorbidities, including cardiomyopathy (HR, 075; CI: 0.61-0.91), diabetes (HR, 0.83; CI: 0.75-0.91), and hypertension (HR, 0.87; CI: 0.81-0.94) were less likely to discontinue AADs. CONCLUSION: Only 31% of patients remained on the initial AAD at 2 years, with a mean duration of initial therapy 7.6 months before discontinuation.

Risk of QT Interval Prolongation Associated With Use of Hydroxychloroquine With or Without Concomitant Azithromycin Among Hospitalized Patients Testing Positive for Coronavirus Disease 2019 (COVID-19).

IMPORTANCE: Administration of hydroxychloroquine with or without azithromycin for the treatment of coronavirus disease 2019 (COVID-19)-associated pneumonia carries increased risk of corrected QT (QTc) prolongation and cardiac arrhythmias. OBJECTIVE: To characterize the risk and degree of QT prolongation in patients with COVID-19 in association with their use of hydroxychloroquine with or without concomitant azithromycin. DESIGN, SETTING, AND PARTICIPANTS: This was a cohort study performed at an academic tertiary care center in Boston, Massachusetts, of patients hospitalized with at least 1 positive COVID-19 nasopharyngeal polymerase chain reaction test result and clinical findings consistent with pneumonia who received at least 1 day of hydroxychloroquine from March 1, 2020, through April 7, 2020. MAIN OUTCOMES AND MEASURES: Change in QT interval after receiving hydroxychloroquine with or without azithromycin; occurrence of other potential adverse drug events. RESULTS: Among 90 patients given hydroxychloroquine, 53 received concomitant azithromycin; 44 (48.9%) were female, and the mean (SD) body mass index was 31.5 (6.6). Hypertension (in 48 patients [53.3%]) and diabetes mellitus (in 26 patients [28.9%]) were the most common comorbid conditions. The overall median (interquartile range) baseline QTc was 455 (430-474) milliseconds (hydroxychloroquine, 473 [454-487] milliseconds vs hydroxychloroquine and azithromycin, 442 [427-461] milliseconds; P < .001). Those receiving concomitant azithromycin had a greater median (interquartile range) change in QT interval (23 [10-40] milliseconds) compared with those receiving hydroxychloroquine alone (5.5 [-15.5 to 34.25] milliseconds; P = .03). Seven patients (19%) who received hydroxychloroquine monotherapy developed prolonged QTc of 500 milliseconds or more, and 3 patients (8%) had a change in QTc of 60 milliseconds or more. Of those who received concomitant azithromycin, 11 of 53 (21%) had prolonged QTc of 500 milliseconds or more and 7 of 53 (13 %) had a change in QTc of 60 milliseconds or more. The likelihood of prolonged QTc was greater in those who received concomitant loop diuretics (adjusted odds ratio, 3.38 [95% CI, 1.03-11.08]) or had a baseline QTc of 450 milliseconds or more (adjusted odds ratio, 7.11 [95% CI, 1.75-28.87]). Ten patients had hydroxychloroquine discontinued early because of potential adverse drug events, including intractable nausea, hypoglycemia, and 1 case of torsades de pointes. CONCLUSIONS AND RELEVANCE: In this cohort study, patients who received hydroxychloroquine for the treatment of pneumonia associated with COVID-19 were at high risk of QTc prolongation, and concurrent treatment with azithromycin was associated with greater changes in QTc. Clinicians should carefully weigh risks and benefits if considering hydroxychloroquine and azithromycin, with close monitoring of QTc and concomitant medication usage.

Electrophysiology's Identity Crisis: What our Clinical Trials Do and Do Not Say About Us.

Although it has not always been this way, the impact of large, randomised clinical trials in electrophysiology is limited, at least compared with other disciplines in cardiology. This has been particularly true regarding procedural aspects of our field: successful randomised trials are rare and observational trials are small and typically without a proper active control group. In this article, the authors examine the reasons behind this circumstance, which include underinvestment from funding sources; lack of consensus on procedural endpoints; lack of consensus on techniques; and a therapeutic bias in favour of procedural intervention that stands in the way of investigator equipoise. Together, these factors have created a scientific culture dominated by small-scale, siloed, observational research and unwillingness to collaboratively advance the field with consensus and prospective trials. The authors feel that it is increasingly urgent to improve the scientific basis for clinical practice and explore strategies to accomplish this goal.

Preimplantation interlead ECG heterogeneity is superior to QRS complex duration in predicting mechanical super-response in patients with non-left bundle branch block receiving cardiac resynchronization therapy.

BACKGROUND: Reliable quantitative preimplantation predictors of response to cardiac resynchronization therapy (CRT) are needed. OBJECTIVE: We tested the utility of preimplantation R-wave and T-wave heterogeneity (RWH and TWH, respectively) compared to standard QRS complex duration in identifying mechanical super-responders to CRT and mortality risk. METHODS: We analyzed resting 12-lead electrocardiographic recordings from all 155 patients who received CRT devices between 2006 and 2018 at our institution and met class I and IIA American College of Cardiology/American Heart Association/Heart Rhythm Society guidelines with echocardiograms before and after implantation. Super-responders (n=35, 23%) had ≥20% increase in left ventricular ejection fraction and/or ≥20% decrease in left ventricular end-systolic diameter and were compared with non-super-responders (n=120, 77%), who did not meet these criteria. RWH and TWH were measured using second central moment analysis. RESULTS: Among patients with non-left bundle branch block (LBBB), preimplantation RWH was significantly lower in super-responders than in non-super-responders in 3 of 4 lead sets (P=.001 to P=.038) and TWH in 2 lead sets (both, P=.05), with the corresponding areas under the curve (RWH: 0.810-0.891, P<.001; TWH: 0.759-0.810, P≤.005). No differences were observed in the LBBB group. Preimplantation QRS complex duration also did not differ between super-responders and non-super-responders among patients with (P=.856) or without (P=.724) LBBB; the areas under the curve were nonsignificant (both, P=.69). RWHV1-3LILII ≥ 420 µV predicted 3-year all-cause mortality in the entire cohort (P=.037), with a hazard ratio of 7.440 (95% confidence interval 1.015-54.527; P=.048); QRS complex duration ≥ 150 ms did not predict mortality (P=.27). CONCLUSION: Preimplantation interlead electrocardiographic heterogeneity but not QRS complex duration predicts mechanical super-response to CRT in patients with non-LBBB.

Ablation of Reentry-Vulnerable Zones Determined by Left Ventricular Activation From Multiple Directions: A Novel Approach for Ventricular Tachycardia Ablation: A Multicenter Study (PHYSIO-VT).

BACKGROUND: The optimal method to identify the arrhythmogenic substrate of scar-related ventricular tachycardia (VT) is unknown. Sites of activation slowing during sinus rhythm (SR) often colocalize with the VT circuit. However, the utility and limitations of such approach for guiding ablation are unknown. METHODS: We conducted a multicenter study in patients with infarct-related VT. The left ventricular (LV) was mapped during activation from 3 directions: SR (or atrial pacing), right ventricular, and LV pacing at 600 ms. Ablation was applied selectively to the cumulative area of slow activation, defined as the sum of all regions with activation times of ≥40 ms per 10 mm. Hemodynamically tolerated VTs were mapped with activation or entrainment. The primary outcome was a composite of appropriate implanted cardioverter-defibrillator therapies and cardiovascular death. RESULTS: In 85 patients, the LV was mapped during activation from 2.4±0.6 directions. The direction of LV activation influenced the location and magnitude of activation slowing. The spatial overlap of activation slowing between SR and right ventricular pacing was 84.2±7.1%, between SR and LV pacing was 61.4±8.8%, and between right ventricular and LV pacing was 71.3±9.6% (P<0.05 between all comparisons). Mapping during SR identified only 66.2±8.2% of the entire area of activation slowing and 58% critical isthmus sites. Activation from other directions by right ventricular and LV stimulation unmasked an additional 33% of slowly conducting zones and 25% critical isthmus sites. The area of maximal activation slowing often corresponded to the site where the wavefront first interacted with the infarct. During a follow-up period of 3.6 years, the primary end point occurred in 14 out of 85 (16.5%) patients. CONCLUSIONS: The spatial distribution of activation slowing is dependent on the direction of LV activation with the area of maximal slowing corresponding to the site where the wavefront first interacts with the infarct. This data may have implications for VT substrate mapping strategies.

Trends and predictors of early ablation for Atrial Fibrillation in a Nationwide population under age 65: a retrospective observational study.

BACKGROUND: Catheter ablation (CA) has emerged as an effective treatment for symptomatic atrial fibrillation (AF). However practice patterns and patient factors associated with referral for CA within the first 12 months after diagnosis are poorly characterized. This study examined overall procedural trends and factors predictive of catheter ablation for newly-diagnosed atrial fibrillation in a young, commercially-insured population. METHODS: A large nationally-representative sample of patients age 20 to 64 from years 2010 to 2016 was studied using the IBM MarketScan® Commercial Database. Patients were included with a new diagnosis of AF in the inpatient or outpatient setting with continuous enrollment for at least 1 year pre and post index visit. Patients were excluded if they had prior history of AF or had filled an anti-arrhythmic drug (AAD) in the pre-index period. RESULTS: Early CA increased from 5.0% in 2010 to 10.5% in 2016. Patients were less likely to undergo CA if they were located in the Northeast (OR: 0.80, CI: 0.73-0.88) or North Central (OR: 0.91, CI: 0.83-0.99) regions (compared with the West), had higher CHA2DS2-VASc scores, or had Charlson Comorbidity Index (CCI) score of 3 or greater (OR: 0.61; CI: 0.51-0.72). CONCLUSIONS: CA within 12 months for new-diagnosed AF increased significantly from 2010 to 2016, with most patients still trialed on an AAD prior to CA. Patients are less likely to be referred for early CA if they are located in the Northeast and North Central regions, have more comorbidities, or higher CHA2DS2-VASc scores.