Bailout Deep Septal LV Pacing to Treat Inadvertent Complete AV Block During Complex Ablation Procedure.

We present a case of persistent complete atrioventricular block that occurred during the diagnostic portion of a premature ventricular contractions' radiofrequency ablation in a complex heart failure patient. The case was managed by bailout deep left ventricular septal pacing after bipolar radiofrequency elimination of premature ventricular contractions.

Pulsed Field Ablation Index-Guided Ablation for Lesion Formation: Impact of Contact Force and Number of Applications in the Ventricular Model.

BACKGROUND: The effect of contact force (CF) on lesion formation is not clear during pulsed field ablation (PFA). The aim of this study was to evaluate the impact of CF, PFA, and their interplay through the PFA index (PF index) formula on the ventricular lesion size in swine. METHODS: PFA was delivered through the CF-sensing OMNYPULSE catheter. Predefined PFA applications (×3, ×6, ×9, and ×12) were delivered maintaining low (5-25 g), high (26-50 g), and very high (51-80 g) CFs. First, PFA lesions were evaluated on necropsy in 11 swine to investigate the impact of CF/PFA-and their integration in the PF index equation-on lesion size (study characterization). Then, 3 different PF index thresholds-300, 450, and 600-were tested in 6 swine to appraise the PF index accuracy to predict the ventricular lesion depth (study validation). RESULTS: In the study characterization data set, 111 PFA lesions were analyzed. CF was 32±17 g. The average lesion depth and width were 3.5±1.2 and 12.0±3.5 mm, respectively. More than CF and PFA dose alone, it was their combined effect to impact lesion depth through an asymptotically increasing relationship. Likewise, not only was the PF index related to lesion depth in the study validation data set (r2=0.66; P<0.001) but it also provided a prediction accuracy of the observed depth of ±2 mm in 69/73 lesions (95%). CONCLUSIONS: CF and PFA applications play a key role in lesion formation during PFA. Further studies are required to evaluate the best PFA ablation settings to achieve transmural lesions.

Acute Kidney Injury Resulting From Hemoglobinuria After Pulsed-Field Ablation in Atrial Fibrillation: Is it Preventable?

BACKGROUND: High-voltage pulses can cause hemolysis. OBJECTIVES: The authors evaluated the occurrence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF). METHODS: A consecutive series of patients with AF undergoing PFA were included in this analysis. The initial patients who did not receive postablation hydration immediately after the procedure were classified as group 1 (n = 28), and the rest of the study patients who received planned fluid infusion (0.9% sodium chloride ≥2 L) after the procedure were categorized as group 2 (n = 75). RESULTS: Of the 28 patients in group 1, 21 (75%) experienced hemoglobinuria during the 24 hours after catheter ablation. The mean postablation serum creatinine (S-Cr) was significantly higher than the baseline value in those 21 patients (1.46 ± 0.28 mg/dL vs 0.86 ± 0.24 mg/dL, P < 0.001). Of those 21 patients, 4 (19%) had S-Cr. >2.5 mg/dL (mean: 2.95 ± 0.21 mg/dL). The mean number of PF applications was significantly higher in those 4 patients than in the other 17 patients experiencing hemoglobinuria (94.63 ± 3.20 vs 46.75 ± 9.10, P < 0.001). In group 2 patients, no significant changes in S-Cr were noted. The group 2 patients received significantly higher amounts of fluid infusion after catheter ablation than did those in group 1 (2,082.50 ± 258.08 mL vs 494.01 ± 71.65 mL, P < 0.001). In multivariable analysis, both hydration (R2 = 0.63, P < 0.01) and number of PFA applications (R2 = 0.33, P < 0.01) were independent predictors of postprocedure acute kidney injury. CONCLUSIONS: On the basis of our findings, both the number of PFA applications and postablation hydration were independent predictors of renal insult that could be prevented using planned fluid infusion immediately after the procedure.

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review.

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Lower rate of major bleeding in very high risk patients undergoing left atrial appendage occlusion: A propensity score-matched comparison with direct oral anticoagulation.

BACKGROUND: Long-term oral anticoagulation is the mainstay therapy for thromboembolic (TE) prevention in patients with atrial fibrillation. However, left atrial appendage occlusion (LAAO) could be a safe alternative to direct oral anticoagulants (DOACs) in patients with a very high TE risk profile. OBJECTIVE: The purpose of this study was to compare the safety and efficacy of LAAO vs DOACs in patients with atrial fibrillation at very high stroke risk (CHA2DS2-VASc [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category] score ≥ 5). METHODS: Data from patients with CHA2DS2-VASc score ≥ 5 were extracted from a prospective multicenter database. To attenuate the imbalance in covariates between groups, propensity score matching was used (covariates: CHA2DS2-VASc and HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] scores), which resulted in a matched population of 277 patients per group. The primary end point was a composite of cardiovascular death, TE events, and clinically relevant bleeding during follow-up. RESULTS: Of 2381 patients, 554 very high risk patients were included in the study (mean age 79 ± 7 years; CHA2DS2-VASc score 5.8 ± 0.9; HAS-BLED score 3.0 ± 0.9). The mean follow-up duration was 25 ± 11 months. A higher incidence of the composite end point was documented with DOACs compared with LAAO (14.9 events per 100 patient-years in the DOAC group vs 9.4 events per 100 patient-years in the LAAO group; P = .03). The annualized clinically relevant bleeding risk was higher with DOACs (6.3% vs 3.2%; P = .04), while the risk of TE events was not different between groups (4.1% vs 3.2%; P = .63). CONCLUSION: In high-risk patients, LAAO had a similar stroke prevention efficacy but a significantly lower risk of clinically relevant bleeding when compared with DOACs. The clinical benefit of LAAO became significant after 18 months of follow-up.

Safety and feasibility of same-day discharge following uncomplicated transvenous lead extraction.

INTRODUCTION: Transvenous lead extraction (TLE), while mostly a safe procedure, has risk of serious periprocedural complications. As such, overnight hospitalization remains a routine practice. In our center, we routinely discharge patients on the same day following an uncomplicated TLE. METHODS: This is a retrospective study of 265 consecutive patients who underwent uncomplicated TLE in our center between 2019 and 2021. Same-day discharge (SDD) patients are compared with those who stayed at least overnight for observation after the TLE procedure (non-SDD group). To assess the safety of an SDD strategy after uncomplicated TLE, the main study endpoint was to compare the rate of major procedure-related complications at 1-, 7-, and 30-days. To identify the factors influencing the operator's decision to discharge the patient on the same day, the secondary endpoint was to analyze clinical and procedural predictors of SDD. RESULTS: A total of 153 patients were discharged the same day after uncomplicated TLE (SDD), while 112 stayed at least overnight after the procedure (non-SDD). There was no significant difference in major procedure-related complications at 1-day (SDD 0% vs. non-SDD 1.8%, p value = ns), while patients in the SDD group had a lower rate of 7- and 30-day complications when compared with those in the non-SDD group (2.1% vs. 8.2%, p value = .0308; and 3.5% vs. 16%, p value = .0049, respectively). Noninfectious indication for TLE (OR 16.1, 95% confidence interval [CI] 4.29-77.6) and procedure end time before 12:00 (OR 2.82, 95% CI 1.11-7.27) were the only independent predictors of SDD. CONCLUSION: SDD discharge following uncomplicated TLE in selected patients (i.e., those without device infection and when the TLE procedure is completed in the morning) is feasible and safe.

Pulsed-Field Ablation Does Not Worsen Baseline Pulmonary Hypertension Following Prior Radiofrequency Ablations.

BACKGROUND: Studies have reported development of pulmonary hypertension (PH) secondary to reduced LA compliance following AF ablation. OBJECTIVES: We aimed to compare the risk of worsening of baseline PH between non-paroxysmal AF patients undergoing pulsed-field ablation (PFA) and standard radiofrequency ablation (RFA). METHODS: This multicenter study included 28 nonparoxysmal AF patients with PH undergoing a PFA-based ablation procedure after >1 failed RFA. A cohort of 28 AF patients with PH, scheduled for repeat RFA, 1:1 propensity-score matched using a multivariable logistic model, were used as the comparator group. Right heart catheterization and echocardiography were performed before and after the procedure to assess the pulmonary artery pressure (PAP). PH was defined as resting mean PAP of >20 mm Hg. RESULTS: The baseline characteristics of the PFA and propensity-matched RFA groups were comparable. The mean PAP assessments at baseline, follow-up, and change from baseline were analyzed. The groups had comparable baseline mean pulmonary artery pressures (mPAP) (P = 0.177). After adjustment for baseline mPAP in an analysis of covariance model, the least-squares means change at 3 months after ablation was -1.71 ± 1.03 mm Hg and 19.67 ± 1.03 mm Hg in PFA and RFA, respectively (P <0.001). CONCLUSIONS: In this propensity-matched population, no worsening of mPAP was detected following pulsed-field ablation in patients with pre-existing PH undergoing a repeat procedure for recurrence.

Point-by-Point Pulsed Field Ablation Using a Multimodality Generator and a Contact Force-Sensing Ablation Catheter: Comparison With Radiofrequency Ablation in a Remapped Chronic Swine Heart.

BACKGROUND: Pulsed field ablation (PFA) has emerged as an alternative to radiofrequency ablation. However, data on focal point-by-point PFA are scarce. The aim of this study was to compare lesion durability and collateral damage between focally delivered unipolar/biphasic PFA versus radiofrequency in swine. METHODS: Eighteen swine were randomized to low-dose PFA, high-dose PFA, and radiofrequency using a multimodality generator. Radiofrequency delivered by market-available generator served as control group. A contact force-sensing catheter was used to focally deliver PFA/radiofrequency at the pulmonary veins and other predefined sites in the atria. Animals were remapped postprocedurally and 28 days postablation to test lesion durability followed by gross necroscopy and histology. RESULTS: All targeted sites were successfully ablated (contact force value, 13.9±4.1 g). Follow-up remapping showed persistent pulmonary vein isolation in all animals (100%) with lesion durability at nonpulmonary vein sites proven in most (98%). Regardless of the energy source used, the lesion size was similar across the study groups. Transmurality was achieved in 95% of targeted sites and 100% at pulmonary veins. On histology, PFA animals showed more mature scar formation than their radiofrequency counterpart without myocardial necrosis or inflammation. Finally, no sign of collateral damage was observed in any of the groups. CONCLUSIONS: In a randomized preclinical study, focally delivered unipolar/biphasic PFA guided by contact force values was associated with durable lesions on chronic remapping and with mature scar formation on histology without signs of collateral injury on necroscopy. Further studies are needed to investigate the long-term feasibility of this new approach to atrial fibrillation treatment.

Prognostic value of chronic kidney disease in patients undergoing left atrial appendage occlusion.

AIMS: Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist and share an increased risk of thrombo-embolism (TE). CKD concomitantly predisposes towards a pro-haemorrhagic state. Our aim was to evaluate the prognostic value of CKD in patients undergoing percutaneous left atrial appendage occlusion (LAAO). METHODS AND RESULTS: A total of 2124 consecutive AF patients undergoing LAAO were categorized into CKD stage 1+2 (n = 1089), CKD stage 3 (n = 796), CKD stage 4 (n = 170), and CKD stage 5 (n = 69) based on the estimated glomerular filtration rate at baseline. The primary endpoint included cardiovascular (CV) mortality, TE, and major bleeding. The expected annual TE and major bleeding risks were estimated based on the CHA2DS2-VASc and HAS-BLED scores. A non-significant higher incidence of major peri-procedural adverse events (1.7 vs. 2.3 vs. 4.1 vs. 4.3) was observed with worsening CKD (P = 0.14). The mean follow-up period was 13 ± 7 months (2226 patient-years). In comparison to CKD stage 1+2 as a reference, the incidence of the primary endpoint was significantly higher in CKD stage 3 (log-rank P-value = 0.04), CKD stage 4 (log-rank P-value = 0.01), and CKD stage 5 (log-rank P-value = 0.001). Left atrial appendage occlusion led to a TE risk reduction (RR) of 72, 66, 62, and 41% in each group. The relative RR of major bleeding was 58, 44, 51, and 52%, respectively. CONCLUSION: Patients with moderate-to-severe CKD had a higher incidence of the primary composite endpoint. The relative RR in the incidence of TE and major bleeding was consistent across CKD groups.

Catheter ablation approach and outcome in HIV+ patients with recurrent atrial fibrillation.

INTRODUCTION: Earlier studies have shown a clear association between severity of human immunodeficiency virus (HIV) infection and incident atrial fibrillation (AF). We present the long-term outcome of catheter ablation (CA) and electrophysiological characteristics in HIV+ AF patients. METHODS: This study evaluated 1438 consecutive AF patients [31 (2.15%) with HIV and 1407 (97.8%) without HIV diagnosis] undergoing their first CA at our center. A total of 31 HIV patients and 31 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model. During first procedure, all received isolation of pulmonary vein (PV) + posterior wall and superior vena cava. Non-PV triggers, defined as ectopic triggers originating from sites other than PVs, were identified at the redo ablation with high-dose isoproterenol challenge. RESULTS: Clinical characteristics were not different between the groups. When compared to the control, by the end of 5 years after the first procedure, recurrence was significantly greater in HIV group [100% vs. 54%, p < .001]. Among patients that underwent redo ablation non-PV triggers were higher in HIV group [93.5% vs. 54%, p < .001], and most frequently originated from the coronary sinus [67.7% vs. 45.2%, p < .001] and left atrial appendage [41.9% vs. 25.8%, p < .001]. After focal ablation of non-PV trigger, no difference in arrhythmia recurrence between two groups [80.6% vs. 87.1%, p = .753] at 1-year follow up was found. CONCLUSION: Our findings suggest that non-PV triggers are highly prevalent in HIV+ AF patients resulting in higher rate of the mid- and long-term arrhythmia recurrence.

Feasibility of three-dimensional artificial intelligence algorithm integration with intracardiac echocardiography for left atrial imaging during atrial fibrillation catheter ablation.

AIMS: Intracardiac echocardiography (ICE) is a useful but operator-dependent tool for left atrial (LA) anatomical rendering during atrial fibrillation (AF) ablation. The CARTOSOUND FAM Module, a new deep learning (DL) imaging algorithm, has the potential to overcome this limitation. This study aims to evaluate feasibility of the algorithm compared to cardiac computed tomography (CT) in patients undergoing AF ablation. METHODS AND RESULTS: In 28 patients undergoing AF ablation, baseline patient information was recorded, and three-dimensional (3D) shells of LA body and anatomical structures [LA appendage/left superior pulmonary vein/left inferior pulmonary vein/right superior pulmonary vein/right inferior pulmonary vein (RIPV)] were reconstructed using the DL algorithm. The selected ultrasound frames were gated to end-expiration and max LA volume. Ostial diameters of these structures and carina-to-carina distance between left and right pulmonary veins were measured and compared with CT measurements. Anatomical accuracy of the DL algorithm was evaluated by three independent electrophysiologists using a three-anchor scale for LA anatomical structures and a five-anchor scale for LA body. Ablation-related characteristics were summarized. The algorithm generated 3D reconstruction of LA anatomies, and two-dimensional contours overlaid on ultrasound input frames. Average calculation time for LA reconstruction was 65 s. Mean ostial diameters and carina-to-carina distance were all comparable to CT without statistical significance. Ostial diameters and carina-to-carina distance also showed moderate to high correlation (r = 0.52-0.75) except for RIPV (r = 0.20). Qualitative ratings showed good agreement without between-rater differences. Average procedure time was 143.7 ± 43.7 min, with average radiofrequency time 31.6 ± 10.2 min. All patients achieved ablation success, and no immediate complications were observed. CONCLUSION: DL algorithm integration with ICE demonstrated considerable accuracy compared to CT and qualitative physician assessment. The feasibility of ICE with this algorithm can potentially further streamline AF ablation workflow.

Feasibility and Safety of Intravenous Sotalol Loading in Adult Patients With Atrial Fibrillation (DASH-AF).

BACKGROUND: Inpatient initiation of sotalol is recommended owing to its proarrhythmic effects. OBJECTIVES: The DASH-AF (Feasibility and Safety of Intravenous Sotalol Administered as a Loading Dose to Initiate Oral Sotalol Therapy in Adult Patients With Atrial Fibrillation) trial evaluates the safety and feasibility of intravenous (IV) sotalol, achieving a steady state with maximum QTc prolongation within 6 hours instead of the traditional 5-dose inpatient oral (PO) titration. METHODS: DASH-AF is a prospective, nonrandomized, multicenter, open-label trial consisting of patients who underwent IV sotalol loading dose to initiate rapid oral therapy for atrial arrhythmias. IV dose was calculated based on the target oral dose as indicated by baseline QTc and renal function. Patients' QTc (in sinus) was measured via electrocardiography at 15-minute intervals and after IV loading completion. Patients were discharged 4 hours after first oral dose. All patients were monitored via mobile cardiac outpatient telemetry for 72 hours. The control group was composed of patients admitted for the traditional 5 PO doses. Safety outcomes were assessed in both groups. RESULTS: A total of 120 patients from 3 centers were enrolled from 2021 to 2022 in the IV loading group (compared with type of AF- and renal function-matched patients in the conventional PO loading cohort). This study demonstrated no significant change in ΔQTc in both groups, with a significantly lower number of patients requiring dose adjustment in the IV arm compared with the PO arm (4.1% vs 16.6%; P = 0.003). This led to potential cost savings of up to $3,500.68 per admission. CONCLUSIONS: The DASH-AF trial shows that rapid IV sotalol loading in atrial fibrillation/flutter patients for rhythm control is feasible and safe compared with conventional oral loading with significant cost reduction. (Feasibility and Safety of Intravenous Sotalol Administered as a Loading Dose to Initiate Oral Sotalol Therapy in Adult Patients With Atrial Fibrillation [DASH-AF]; NCT04473807).

Impact of Colchicine Monotherapy on the Risk of Acute Pericarditis Following Atrial Fibrillation Ablation.

BACKGROUND: Acute pericarditis is a known complication of ablation procedures for atrial fibrillation (AF). OBJECTIVES: This study aimed to evaluate the benefits of colchicine monotherapy in terms of reducing the risk of pericarditis and related hospitalization rate in AF patients undergoing catheter ablation. METHODS: Consecutive AF patients undergoing first catheter ablation were classified into 3 groups based on their colchicine use: Group 1: no colchicine; group 2: colchicine from 7 days before to 1 month after ablation; and group 3: colchicine from the day of the procedure to 1 month after. Standard institutional protocol was used to follow all patients for 1 year. RESULTS: A total of 1,075 patients were classified into groups 1 (n = 607), 2 (n = 213), and 3 (n = 255). Symptoms of acute pericarditis were reported in 129 patients (12%): group 1: n = 106 (17.5%); group 2: n = 4 (1.9%); and group 3: n = 19 (7.5%); P < 0.001. Rate of mild-moderate as well as severe pericarditis were significantly lower in group 2. In the multivariable regression analysis, pre- and post-ablation colchicine use was seen to be associated with significantly lower risk of acute pericarditis and related hospitalization compared with the other 2 groups. In addition, at 1-year follow-up, arrhythmia-free survival rate was significantly higher in paroxysmal AF patients receiving colchicine compared with the no-colchicine population. CONCLUSIONS: Colchicine therapy starting 7 days before to 1 month after the ablation procedure was associated with significantly lower risk of acute pericarditis and related hospitalization. In addition, paroxysmal AF patients receiving colchicine had a higher arrhythmia-free survival rate compared with those not receiving colchicine.