Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry.

BACKGROUND: The safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. OBJECTIVE: The purpose of this study was to assess the contemporary real-world practice approach and long-term outcomes of RF CA for PAF through a prospective multicenter registry. METHODS: Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380-420 for posterior and 500-550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. RESULTS: A total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation + ablation approaches. The complication rate was 1.9%. CONCLUSION: Refinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Arrhythmia and Time of Day in Maintenance Hemodialysis: Secondary Analysis of the Monitoring in Dialysis Study.

Rationale & Objective: The incidence of arrhythmia varies by time of day. How this affects individuals on maintenance dialysis is uncertain. Our objective was to quantify the relationship of arrhythmia with the time of day and timing of dialysis. Study Design: Secondary analysis of the Monitoring in Dialysis study, a multicenter prospective cohort study. Settings & Participants: Loop recorders were implanted for continuous cardiac monitoring in 66 participants on maintenance dialysis with a follow up of 6 months. Exposure: Time of day based on 6-hour intervals. Outcomes: Event rates of clinically significant arrhythmia. Analytical Approach: Negative binomial mixed effects regression models for repeated measures were used to evaluate data from the Monitoring in Dialysis study for differences in diurnal patterns of clinically significant arrhythmia among those with end-stage kidney disease with heart failure and end-stage kidney disease alone. We additionally analyzed rates according to presence of heart failure, time of dialysis shift, and dialysis versus nondialysis day. Results: Rates of clinically significant arrhythmia peaked between 12:00 AM and 5:59 AM and were more than 1.5-fold as frequent during this interval than the rest of the day. In contrast, variations in atrial fibrillation peaked between 6:00 AM and 11:59 AM, but variations across the day were qualitatively small. Clinically significant arrhythmia occurred at numerically higher rate in individuals with end-stage kidney disease and heart failure (5.9 events/mo; 95% CI, 1.3-26.8) than those without heart failure (4.0 events/mo; 95% CI, 0.9-17.9). Although differences in overall rate were not significant, their periodicity was significantly different (P < 0.001), with a peak between 12:00 AM and 6:00 AM with kidney failure alone and between 6:00 AM and 11:59 AM in those with heart failure. Although the overall clinically significant arrhythmia rate was similar in morning compared with evening dialysis shifts (P = 0.43), their periodicity differed with a peak between 12:00 AM and 5:59 AM in those with AM dialysis and a later peak between 6:00 AM and 11:59 AM in those with PM shifts. Limitations: Post hoc analysis, unable to account for unmeasured confounders. Conclusion: Clinically significant arrhythmias showed strong diurnal patterns with a maximal peak between 12:00 AM and 5:59 AM and noon. Although overall arrhythmia rates were similar, the peak rate occurred overnight in individuals without heart failure and during the morning in individuals with heart failure. Further exploration of the influence of circadian rhythm on arrhythmia in the setting of hemodialysis is needed.

Arrhythmias occur with a high frequency in individuals with kidney failure. We sought to understand whether there were diurnal patterns for common types of arrhythmias in individuals with kidney failure. We used continuous rhythm data from 66 individuals on dialysis with implantable loop recorders. We found that clinically significant arrhythmias including bradycardia primarily occur overnight and in the early morning, whereas atrial fibrillation is more evenly distributed during the day.

Can a best practice advisory improve anticoagulation prescribing to reduce stroke risk in patients with atrial fibrillation?

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac rhythm disorder and a risk factor for stroke. Randomized trials have demonstrated that anticoagulation can reduce strokes in AF patients. Yet, widespread underutilization of this therapy continues. To address this practice gap, we designed a study to implement and evaluate the effectiveness of a best practice advisory (BPA) for an Atrial Fibrillation Decision Support Tool (AFDST) embedded within our electronic health record. METHODS: Our intervention is provider-facing, focused on decision support. Clinical setting is ambulatory patients being seen by primary care physicians. We prospectively enrolled 608 patients in our health system who are currently receiving less than optimal anticoagulation therapy as determined by the AFDST and randomized them to one of two arms - 1) usual care, in which the AFDST is available for use; or 2) addition of a BPA to the AFDST notifying clinicians that their patient stands to gain significant benefit from a change in current therapy. Primary outcome was effectiveness of the BPA measured by change to "appropriate thromboprophylaxis" based on the AFDST recommendation at 3 months post-enrollment. Secondary endpoints included Reach and Adoption from the RE-AIM (Reach, Effectiveness, Adoption, Implementation, & Maintenance) framework for implementation studies. RESULTS: Among 562 patients with a minimum follow-up of 3 months, addition of a BPA to the AFDST resulted in significant improvement in anticoagulation therapy, 5 % (12/248) versus 11 % (33/314) p = 0.02, odds ratio 2.31 (95 % CI, 1.17-4.87). CONCLUSIONS: A BPA added to an AF decision support tool improved anticoagulation therapy among AF patients in a primary care academic health system setting.

50-W vs 40-W During High-Power Short-Duration Ablation for Paroxysmal Atrial Fibrillation: A Multicenter Prospective Study.

BACKGROUND: High-power short-duration (HPSD) radiofrequency ablation of atrial fibrillation (AF) increases first-pass pulmonary vein isolation (PVI) and freedom from atrial arrhythmias while decreasing procedural time. However, the optimal power setting in terms of safety and efficacy has not been determined. OBJECTIVES: This study compared the procedural characteristics and clinical outcomes of 50-W vs 40-W during HPSD ablation of paroxysmal AF. METHODS: Patients from the REAL-AF prospective multicenter registry (Real-World Experience of Catheter Ablation for Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation) undergoing HPSD ablation of paroxysmal AF, either using 50-W or 40-W, were included. The primary efficacy outcome was freedom from all-atrial arrhythmias. The primary safety outcome was the occurrence of any procedural complication at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and the occurrence of transient ischemic attack or stroke at 12 months. RESULTS: A total of 383 patients were included. Freedom from all-atrial arrhythmias at 12 months was 80.7% in the 50-W group and 77.3% in the 40-W group (Log-rank P = 0.387). The primary safety outcome occurred in 3.7% of patients in the 50-W group vs 2.8% in the 40-W group (P = 0.646). The 50-W group had a higher rate of first-pass PVI (82.3% vs 76.2%; P = 0.040) as well as shorter procedural (67 minutes [IQR: 54-87.5 minutes] vs 93 minutes [IQR: 80.5-111 minutes]; P < 0.001) and radiofrequency ablation times (15 minutes [IQR: 11.4-20 minutes] vs 27 minutes [IQR: 21.5-34.6 minutes]; P < 0.001) than the 40-W group. CONCLUSIONS: There was no significant difference in freedom from all-atrial arrhythmias or procedural safety outcomes between 50-W and 40-W during HPSD ablation of paroxysmal AF. The use of 50-W was associated with a higher rate of first-pass PVI as well as shorter procedural times.

High-Frequency Low-Tidal Volume Ventilation Improves Long-Term Outcomes in AF Ablation: A Multicenter Prospective Study.

BACKGROUND: High-frequency, low-tidal-volume (HFLTV) ventilation is a safe and simple strategy to improve catheter stability and first-pass isolation during pulmonary vein (PV) isolation. However, the impact of this technique on long-term clinical outcomes has not been determined. OBJECTIVES: This study sought to assess acute and long-term outcomes of HFLTV ventilation compared with standard ventilation (SV) during radiofrequency (RF) ablation of paroxysmal atrial fibrillation (PAF). METHODS: In this prospective multicenter registry (REAL-AF), patients undergoing PAF ablation using either HFLTV or SV were included. The primary outcome was freedom from all-atrial arrhythmia at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and hospitalizations at 12 months. RESULTS: A total of 661 patients were included. Compared with those in the SV group, patients in the HFLTV group had shorter procedural (66 [IQR: 51-88] minutes vs 80 [IQR: 61-110] minutes; P < 0.001), total RF (13.5 [IQR: 10-19] minutes vs 19.9 [IQR: 14.7-26.9] minutes; P < 0.001), and PV RF (11.1 [IQR: 8.8-14] minutes vs 15.3 [IQR: 12.4-20.4] minutes; P < 0.001) times. First-pass PV isolation was higher in the HFLTV group (66.6% vs 63.8%; P = 0.036). At 12 months, 185 of 216 (85.6%) in the HFLTV group were free from all-atrial arrhythmia, compared with 353 of 445 (79.3%) patients in the SV group (P = 0.041). HLTV was associated with a 6.3% absolute reduction in all-atrial arrhythmia recurrence, lower rate of AF-related symptoms (12.5% vs 18.9%; P = 0.046), and hospitalizations (1.4% vs 4.7%; P = 0.043). There was no significant difference in the rate of complications. CONCLUSIONS: HFLTV ventilation during catheter ablation of PAF improved freedom from all-atrial arrhythmia recurrence, AF-related symptoms, and AF-related hospitalizations with shorter procedural times.

Porous tip radiofrequency ablation catheter reduced heart failure-related complications and healthcare resource utilization in paroxysmal atrial fibrillation patients.

Introduction: A 56-hole porous tip radiofrequency catheter was developed to provide more uniform cooling with less fluid delivery than a prior 6-hole irrigated design. This study aimed to evaluate the impact of contact force (CF) ablation with the porous tip on complications (congestive heart failure [CHF] and non-CHF related), healthcare resource utilization, and procedural efficiency in patients undergoing de novo paroxysmal atrial fibrillation (PAF) ablations in a real-world setting. Methods: Consecutive de novo PAF ablations were performed between February 2014 and March 2019 by six operators at a single US academic center. The 6-hole design was used through December 2016 with the 56-hole porous tip adopted in October 2016. The outcomes of interest included symptomatic CHF presentation and CHF-related complications. Results: Of 174 patients who were included, mean age was 61.1 ± 10.8 years, 67.8% were male, and 25.3% had a history of CHF. Ablation with the porous tip catheter significantly decreased fluid delivery (1177 vs. 1912 mL with the 6-hole design; p < .0001). CHF-related complications within 7 days, particularly fluid overload, were substantially reduced with the porous tip (15.2% vs. 5.3% of patients; p = .0281) and the proportion of patients with symptomatic CHF presentation within 30 days postablation was significantly lower (14.7% vs. 32.5%; p = .0058). Conclusion: The 56-hole porous tip led to significantly reduced CHF-related complications and healthcare utilization in PAF patients undergoing CF catheter ablation when compared to the prior 6-hole design. This reduction likely results from the significant decrease in fluid delivery during the procedure.

Performance of the REAL-AF Same-Day Discharge Protocol in Patients Undergoing Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Same-day discharge (SDD) after catheter ablation of atrial fibrillation (AF) has been widely adopted. Nevertheless, planned SDD has been performed by using subjective criteria rather than standardized protocols. OBJECTIVES: The goal of this study was to determine the efficacy and safety of the previously described SDD protocol in a prospective multicenter study. METHODS: Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation) SDD protocol eligibility criteria (stable anticoagulation, no bleeding history, left ventricular ejection fraction >40%, no pulmonary disease, no procedures within 60 days, and body mass index <35 kg/m2), operators prospectively determined whether patients undergoing ablation of AF were candidates for SDD (SDD vs non-SDD groups). Successful SDD was achieved if the patient met the protocol discharge criteria. The primary efficacy endpoint was the success rate of SDD. The primary safety endpoints were readmission rates as well as acute and subacute complications. The secondary endpoints included procedural characteristics and freedom from all-atrial arrhythmias. RESULTS: A total of 2,332 patients were included. The REAL-AF SDD protocol identified 1,982 (85%) patients as potential candidates for SDD. The primary efficacy endpoint was achieved in 1,707 (86.1%) patients. The readmission rate for SDD vs non-SDD group was similar (0.8% vs 0.9%; P = 0.924). The SDD group had a lower acute complication rate than the non-SDD group (0.8% vs 2.9%; P < 0.001), and there was no difference in the subacute complication rate between groups (P = 0.513). Freedom from all-atrial arrhythmias was comparable between groups (P = 0.212). CONCLUSIONS: In this large, multicenter prospective registry, the use of a standardized protocol showed the safety of SDD after catheter ablation of paroxysmal and persistent AF. (Real-world Experience of Catheter Ablation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation [REAL-AF]; NCT04088071).

Dual Medical Therapy for Treatment of Arrhythmias in Cardiac Sarcoidosis.

Anti-arrhythmics can be useful for ventricular arrhythmias in cardiac sarcoidosis (CS) that are refractory to immunosuppression. However, there is conflicting evidence on the efficacy of immunosuppression for treating arrhythmias in CS patients and a lack of data to support using immunosuppression alone as an initial strategy. The objective of this study was to assess for differences in arrhythmia burden over time with currently used immunosuppression and anti-arrhythmic regimens. Patients with CS and implanted cardiac devices were identified from a single-center registry. Study participants were retrospectively classified based on the medication regimen as follows: control (no therapy), immunosuppression, anti-arrhythmics, or dual therapy. Device interrogations were reviewed for premature ventricular contractions (PVCs), non-sustained ventricular tachycardia (NSVT), and device firings over time. Interrogations for 42 patients were reviewed over a mean period of 31 months. Regression analysis showed a significant decrease in the frequencies of PVCs (slope, -1.47; P = .04) and NSVT (slope, -0.05; P = .01) for patients on dual therapy compared to an increase or no change in the other groups. Across all patients, there was no difference between groups in the percentage of patients experiencing device firings. In a subset analysis of patients with implantable cardioverter-defibrillators for primary prevention, 6% on dual therapy required device firings compared to 43% and 40% on single or no therapy, respectively (P = .049, χ2 = 6.02). In conclusion, patients on both immunosuppression and anti-arrhythmics had a reduction in PVCs and NSVT over time. Overall, there were no differences between groups in terms of device firings, except in a subset analysis of patients with no history of ventricular tachycardia.

Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study.

Background: Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain. Methods: The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of predialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours before an HD session. Associations with CSBA were analyzed with mixed-effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters and associations of peridialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next. Results: There were 551 CSBA that occurred in the last 12 hours of the interdialytic interval preceding 100 HD sessions in 12% of patients and 1475 CSBA events in 23% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 versus 8, P=0.04). Use of dialysate sodium concentrations ≤135 (versus 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next. Conclusions: Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.

Ventricular Tachycardia or Fibrillation Storm in Coronavirus Disease.

Ventricular tachycardia (VT) or ventricular fibrillation (VF) storm associated with severe acute respiratory syndrome coronavirus 2 infection is a potentially fatal complication; the correlation of these 2 disorders, however, has not been well studied. This retrospective case series examined outcomes of 2 patients who were admitted for repeated implantable cardioverter-defibrillator shocks with or without syncope and observed to have VT/VF storms with COVID-19. Mechanisms of VT/VF storms in COVID-19 are multifactorial including myocarditis, systemic inflammation, hyperadrenergic state, hemodynamic instability, hypoxia, acidosis, and proarrhythmic drugs. A higher incidence of VT/VF storm is observed in patients with comorbidities and those requiring critical care, with some studies reporting increased mortality. In our cohort, 1 of the 2 patients succumbed to the complications from COVID-19, and the other patient was discharged to home in stable condition. Monitoring of life-threatening arrhythmias in the setting of COVID-19 may need to be adopted to prevent morbidity and mortality.

Implantable Loop Recorder Monitoring and the Incidence of Previously Unrecognized Atrial Fibrillation in Patients on Hemodialysis.

INTRODUCTION: Atrial fibrillation (AF) is common in patients with kidney failure on hemodialysis (KF-HD). We determined both AF incidence and burden in patients with KF-HD using implantable loop recorder (ILR) monitoring. METHODS: Patients with KF-HD were enrolled and received an ILR. In 6 monitoring months, the incidence of AF events lasting ≥6 minutes was captured. Demographic, clinical, and dialysis characteristics were collected, and associations with incident AF were estimated using negative binomial regression models and expressed as incidence rate ratios and 95% CIs. RESULTS: We enrolled 66 patients with KF-HD (mean age = 56 years, 70% male); 59 (90%) were without previously diagnosed AF. AF lasting ≥6 minutes was detected in 18 of 59 subjects (31%) without previously diagnosed AF and in 5 of 7 subjects (71%) with a previous AF diagnosis. Among the 23 with detected AF, episodes were present on 16% of patient days. Although 14 of 23 patients (61%) had AF on <5% of monitored days, the average duration of AF episodes was <1 hour in 13 of 23 patients (52%). Among patients with AF ≥6 minutes, 19 of 23 (83%) had a CHA2DS2-VASc score ≥2. When investigating individual HD parameters, higher dialysate calcium (>2.5 vs. 2.5 mEq/l: incidence rate ratio = 0.62; 95% CI, 0.48-0.80) was associated with lower AF risk whereas higher dialysate bicarbonate concentrations (>35 vs. 35 mEq/l: incidence rate ratio = 3.18; 95% CI, 1.13-8.94) were associated with higher AF risk. CONCLUSION: New AF was detected in approximately one-third of patients with KF-HD. AF affects a substantial proportion of patient days and may be an underappreciated cause of stroke in KF-HD.

Electronic health record-embedded decision support to reduce stroke risk in patients with atrial fibrillation - Study protocol.

BACKGROUND: Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder and is a powerful common risk factor for stroke. Randomized trials have demonstrated that anticoagulation can reduce the risk of stroke in patients with AF. Yet, there continues to be widespread underutilization of this therapy. To address this practice gap locally and improve efforts to reduce the risk of stroke for patients with AF in our health system, we have designed a study to implement and evaluate the effectiveness of an Atrial Fibrillation Decision Support Tool (AFDST) embedded within our electronic health record. METHODS: Our intervention is provider-facing and focused on decision support. The clinical setting is ambulatory patients being seen by primary care physicians. Patients include those with both incident and prevalent AF. This randomized, prospective trial will enroll 800 patients in our University of Cincinnati Health System who are currently receiving less than optimal anticoagulation therapy as determined by the AFDST. Patients will be randomized to one of two arms - 1) usual care, in which the AFDST is available for use; 2) addition of a best practice advisory (BPA) to the AFDST notifying the clinician that their patient stands to gain a significant benefit from a change in their current thromboprophylactic therapy. RESULTS: The primary outcome is effectiveness of the BPA measured by change to "appropriate thromboprophylaxis" based on the AFDST recommendation at 3 months post randomization. Secondary endpoints include Reach and Adoption, from the RE-AIM framework for implementation studies. Sample size is based upon an improvement from inappropriate to appropriate anticoagulation therapy estimated at 4% in the usual care arm and ≥10% in the experimental arm. CONCLUSION: Our goal is to examine whether addition of a BPA to an AFDST focused on primary care physicians in an ambulatory care setting will improve "appropriate thromboprophylaxis" compared with usual care. Results will be examined at 3 months post randomization and at the end of the study to evaluate durability of changes. We expect to complete patient enrollment by the end of June 2022. TRIAL REGISTRATION: Clinicaltrials.gov NCT04099485.

Racial and sex differences in optimizing anticoagulation therapy for patients with atrial fibrillation.

Study objective: Atrial fibrillation (AF) is the most common cardiac rhythm disorder, responsible for 15 % of strokes in the United States. Studies continue to document underuse of anticoagulation therapy in minority populations and women. Our objective was to compare the proportion of AF patients by race and sex who were receiving non-optimal anticoagulation as determined by an Atrial Fibrillation Decision Support Tool (AFDST). Design setting and participants: Retrospective cohort study including 14,942 patients within University of Cincinnati Health Care system. Data were analyzed between November 18, 2020, and November 20, 2021. Main outcomes and measures: Discordance between current therapy and that recommended by the AFDST. Results: In our two-category analysis 6107 (41 %) received non-optimal anticoagulation therapy, defined as current treatment category ≠ AFDST-recommended treatment category. Non-optimal therapy was highest in Black (42 % [n = 712]) and women (42 % [n = 2668]) and lower in White (39 % [n = 4748]) and male (40 % [n = 3439]) patients. Compared with White patients, unadjusted and adjusted odds ratios of receiving non-optimal anticoagulant therapy for Black patients were 1.13; 95 % CI, 1.02-1.30, p = 0.02; and 1.17; 95%CI, 1.04-1.31, p = 0.01; respectively, and 1.10; 95 % CI 1.03-1.18, p = 0.005; and 1.36; 95 % CI, 1.25-1.47, p < 0.001; for females compared with males. Conclusions and relevance: In patients with atrial fibrillation in the University of Cincinnati Health system, Black race and female sex were independently associated with an increased odds of receiving non-optimal anticoagulant therapy.

Electrolyte Changes in Contemporary Hemodialysis: A Secondary Analysis of the Monitoring in Dialysis (MiD) Study.

BACKGROUND: There is a paucity of contemporary data examining electrolyte changes during and immediately after hemodialysis (HD), and their relationship with dialysate prescriptions. The present study examines these relationships. METHODS: We analyzed patient- (n=66) and HD session-level pre- and post-dialysis laboratory data (n=1,713) over a six-month period from the Monitoring in Dialysis Study. We fit mixed effects regression models to analyze electrolyte, blood urea nitrogen, creatinine, and albumin levels immediately post-HD, accounting for pre-HD and dialysate prescriptions. In a subset of US patients (n=40), 15-minute post-HD and 30-minute post-HD values were available at one session. Predictive models were fit to estimate electrolyte levels immediately post-HD, accounting for pre-HD concentrations and dialysate prescriptions. RESULTS: Serum bicarbonate, calcium, and albumin increased (mean increase 4.9±0.3 mEq/L, 0.7±0.1 mEq/L, and 0.4±0.03 g/dL, respectively), whereas potassium, magnesium, and phosphorus decreased immediately post-HD (mean -1.2±0.1 mEq/L, -0.3±0.03 mEq/L, and -3.0±0.2 mg/dL, respectively). Hypokalemia and hypophosphatemia were present in 40% of and 67% of immediate post-HD samples, respectively. Dynamic changes were observed in electrolyte concentrations at 15- and 30-minutes post-HD, compared to immediately post-HD. CONCLUSION: We describe the magnitude of post-dialytic changes in serum electrolytes with contemporary HD, reporting a high incidence of electrolyte abnormalities post-HD, and present predictive nomograms relating electrolyte changes immediately post-HD to dialysate prescriptions. Our results may be useful for clinical care and provide insights for future research on dialysate prescriptions.

A prospective multi-site registry of real-world experience of catheter ablation for treatment of symptomatic paroxysmal and persistent atrial fibrillation (Real-AF): design and objectives.

PURPOSE: Catheter ablation has become a mainstay therapy for atrial fibrillation (AF) with rapid innovation over the past decade. Variability in ablation techniques may impact efficiency, safety, and efficacy; and the ideal strategy is unknown. Real-world evidence assessing the impact of procedural variations across multiple operators may provide insight into these questions. The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal (PAF) and Persistent (PsAF) Atrial Fibrillation registry (Real-AF) is a multicenter prospective registry that will enroll patients at high volume centers, including academic institutions and private practices, with operators performing ablations primarily with low fluoroscopy when possible. The study will also evaluate the contribution of advent in technologies and workflows to real-world clinical outcomes. METHODS: Patients presenting at participating centers are screened for enrollment. Data are collected at the time of procedure, 10-12 weeks, and 12 months post procedure and include patient and detailed procedural characteristics, with short and long-term outcomes. Arrhythmia recurrences are monitored through standard of care practice which includes continuous rhythm monitoring at 6 and 12 months, event monitors as needed for routine care or symptoms suggestive of recurrence, EKG performed at every visit, and interrogation of implanted device or ILR when applicable. RESULTS: Enrollment began in January 2018 with a single site. Additional sites began enrollment in October 2019. Through May 2021, 1,243 patients underwent 1,269 procedures at 13 institutions. Our goal is to enroll 4000 patients. DISCUSSION: Real-AF's multiple data sources and detailed procedural information, emphasis on high volume operators, inclusion of low fluoroscopy operators, and use of rigorous standardized follow-up methodology allow systematic documentation of clinical outcomes associated with changes in ablation workflow and technologies over time. Timely data sharing may enable real-time quality improvements in patient care and delivery. Trial registration Clinicaltrials.gov: NCT04088071 (registration date: September 12, 2019).

Atrial fibrillation associated with heart failure treated by a 2-lead CRT-DX system (BIO-AffectDX): Study design and clinical protocol.

BACKGROUND: Evidence to support use of cardiac resynchronization therapy (CRT) among patients with both heart failure (HF) and atrial fibrillation (AF) is largely limited to retrospective or post hoc subanalyses. Data from a prospectively enrolled and contemporary cohort are needed. OBJECTIVE: We aim to better characterize the changes from baseline in HF patients with concomitant AF subsequently implanted with a 2-lead CRT-DX system capable of sensing in the atrium, aggregating diagnostics, and delivering CRT therapy. The primary objective of this study is to evaluate the percentage of all HF subjects with an improvement in a clinical composite score from pre-CRT implant to 12 months. METHODS: The study is a US-based, prospective, observational multicenter clinical trial conducted at up to 50 sites and enrolling approximately 400 subjects with a follow-up period of 1 year. Multiple subject assessments, atrial rhythm status, and device interrogation will be collected at follow-up visits occurring at 3, 6, and 12 months postimplant. RESULTS: A Clinical Events Committee will adjudicate subject HF events, arrhythmia events, death events, and all device-classified ventricular tachycardia and ventricular fibrillation episodes with treatment that are collected throughout the follow-up period. Their decisions are based on independent physician review of the data from sites and device interrogation. CONCLUSION: The BIO-AffectDX study aims to provide further insight into the expected outcomes from CRT treatment in patients with HF and AF.

Real-world outcomes comparison among adults with atrial fibrillation undergoing catheter ablation with a contact force porous tip catheter versus a second-generation cryoballoon catheter: a retrospective analysis of multihospital US database.

OBJECTIVE: To compare real-world clinical and economic outcomes among atrial fibrillation (AF) patients undergoing cardiac ablation with the contact force-sensing porous tip THERMOCOOL SMARTTOUCH SF (STSF) catheter versus the Arctic Front Advance Cryoballoon (AFA-CB) catheter. DESIGN: Retrospective, observational cohort study. SETTING: Premier Healthcare Database (PHD), between 1 September 2016 and 30 June 2018. PARTICIPANTS: Patients with AF (≥18 years) were included if they had an index ablation procedure performed using the STSF catheter or AFA-CB catheter at a US hospital that consistently provided inpatient and outpatient data to PHD in the 12-month preindex period. Using 1:1 propensity score matching, patient groups were matched on study covariates. PRIMARY AND SECONDARY OUTCOME MEASURES: Cost, length of stay (LOS), readmissions, direct current cardioversion (DCCV) and reablation outcomes were compared between matched cohorts of STSF and AFA-CB patients. RESULTS: A total of 3015 patients with AF met the study criteria, of which 1720 had ablation using the STSF catheter and 1295 had ablation using the AFA-CB catheter. In the propensity-matched sample, patients receiving ablation with the STSF catheter had ~17% lower total costs (US$23 096 vs US$27 682, p≤0.0001) and ~27% lower supply costs (US$10 208 vs US$13 816, p≤0.0001) versus patients receiving ablation with the AFA-CB catheter. A significantly lower likelihood of 4-month to 6-month cardiovascular-related readmission (OR 0.460, 95% CI 0.220 to 0.959) was associated with the STSF catheter versus the AFA-CB catheter. No significant differences in LOS, room and board cost, 4-month to 6-month all-cause and AF-related readmissions, DCCV and reablation were observed among technologies. Sensitivity analysis restricting patient sample by provider ablation volume demonstrated similar results. CONCLUSION: Lower index ablation total and supply costs were observed among patients with AF undergoing cardiac catheter ablation using the STSF catheter versus the AFA-CB catheter.

Intradialytic Hypotension and Cardiac Arrhythmias in Patients Undergoing Maintenance Hemodialysis: Results from the Monitoring in Dialysis Study.

BACKGROUND AND OBJECTIVES: Patients receiving maintenance hemodialysis (HD) have a high incidence of cardiac events, including arrhythmia and sudden death. Intradialytic hypotension (IDH) is a common complication of HD and is associated with development of reduced myocardial perfusion, a potential risk factor for arrhythmia. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We analyzed data from the Monitoring in Dialysis study, which used implantable loop recorders to detect and continuously monitor electrocardiographic data from patients on maintenance HD (n=66 from the United States and India) over a 6-month period (n=4720 sessions). Negative binomial mixed effects regression was used to test the association of IDH20 (decline in systolic BP >20 mm Hg from predialysis systolic BP) and IDH0-20 (decline in systolic BP 0-20 mm Hg from predialysis systolic BP) with clinically significant arrhythmia (bradycardia≤40 bpm for ≥6 seconds, asystole≥3 seconds, ventricular tachycardia ≥130 bpm for ≥30 seconds, or patient-marked events) during HD. RESULTS: The median age of participants was 58 (25th-75th percentile, 49-66) years; 70% were male; and 65% were from the United States. IDH occurred in 2251 (48%) of the 4720 HD sessions analyzed, whereas IDH0-20 occurred during 1773 sessions (38%). The number of sessions complicated by least one intradialytic clinically significant arrhythmia was 27 (1.2%) where IDH20 occurred and 15 (0.8%) where IDH0-20 occurred. Participants who experienced IDH20 (versus not) had a nine-fold greater rate of developing an intradialytic clinically significant arrhythmia (incidence rate ratio, 9.4; 95% confidence interval, 3.0 to 29.4), whereas IDH0-20 was associated with a seven-fold higher rate (incidence rate ratio, 7.2; 95% confidence interval, 2.1 to 25.4). CONCLUSIONS: IDH is common in patients on maintenance HD and is associated with a greater risk of developing intradialytic clinically significant arrhythmia.