Deshmukh, Abhishek

Background: Dofetilide, a commonly prescribed class III antiarrhythmic for atrial fibrillation (AF), currently requires a 3-month amiodarone washout period per FDA guidelines. We evaluated the safety of initiating dofetilide within this 3-month washout period. Methods: We performed a retrospective cohort study across all Mayo Clinic sites and identified patients using centralized datamart that were transitioned from amiodarone to dofetilide in less than 90 days. Patients were included and confirmed by manual chart review if they had been on amiodarone for ≥ 12 weeks and if available amiodarone level >0.3 mg/ml at the time of dofetilide initiation. Serial ECGs were assessed during the hospitalization for dofetilide initiation and at 3-, 6-, and 12-months follow-up to evaluate QT interval. Primary safety end point was torsade de pointes. Results: The final cohort included 66 patients with a mean age of 65 ±14 years; 71.0% were male; and the average BMI was 29.6 ±5.1 kg/m 2 . Of the 66 patients, 65 had a history of AF: 31.8% paroxysmal, 54.5% persistent, and 12.1% long-standing persistent. Permanent pacemakers and ICDs were present in 27.3% and 22.7% of patients. Patients received amiodarone for a median of 7.8 months at a mean daily dose of 187.1±48.3 mg (range: 100 – 400 mg), with a mean transition period of 44.2±20.3 days. Of 66 patients, 16 (24 %) transitioned within 30 days of stopping amiodarone—including 5 (8 %) within 14 days—while the remaining 50 (76 %) was between 30 and 90 days. A total of 24.2% (16/66) patients required dofetilide dose reduction due to QT prolongation and 10.6% of patients (7/66) required drug discontinuation. There was no difference in either discontinuation rate or dose reduction rate in patients with a transition period ≤30 days vs > 30 days [6.25% vs. 12% (p=0.85) and 12.5% vs. 28% (p=0.36), respectively]. No cases of torsades de pointes were observed during dofetilide initiation or follow up. Conclusion: In this cohort, dofetilide initiation less than 90 days after amiodarone discontinuation was not associated with increased torsades de pointes risk. These data challenge and support reconsideration of the blanket 3-month washout and suggest that a monitored, expedited rhythm-control transition is feasible and safe.

Background: Leadless pacemaker has emerged as a promising alternative to traditional transvenous pacemaker (PM) among elderly patients who are at high risk of complications. Objective: This study aims to assess and compare 5-year clinical outcomes of leadless PM versus transvenous single-chamber PM in elderly patients using a multi-national dataset. Methods: Using the TriNetX Analytics Research Network, we included patients aged ≥65 years who underwent leadless versus transvenous single-chamber PM implantation between 1/1/2014 and 1/1/2020. Propensity score matching (PSM) was performed by using patient’s demographic, LVEF, cardiac comorbidities, and medications. The study outcomes included all-cause mortality and adverse cardiovascular events over a 5-year follow-up period. Results: After PSM, 7,501 patients in each group were analyzed. Leadless PM was associated with a significantly lower odds of 5-year all-cause mortality (odds ratio [OR]: 0.534; 95% confidence interval [CI]: 0.497-0.575), heart failure exacerbation (OR: 0.779, 95% CI: 0.721-0.841), major bleeding (OR: 0.666, 95% CI: 0.604-0.734), cardiac arrest (OR: 0.747, 95% CI: 0.646-0.864) and stroke (OR: 0.825, 95% CI: 0.750-0.908) compared to transvenous single-chamber PM. No significant difference was observed between the two groups in all-cause hospitalization (OR: 1.006, 95%CI: 0.938-1.079), cardiac thrombus (OR: 1.077, 95%CI: 0.791-1.465) or venous thromboembolism (OR: 1.028, 95%CI: 0.916-1.153). Conclusion: Leadless PM was associated with significantly improved mortality and cardiovascular outcomes compared to transvenous single-chamber PM in elderly patients. These findings support the strong consideration of leadless pacing as a strategy to reduce mortality and improve clinical outcomes in this high-risk population.

ABSTRACT Background The efficacy and safety of PolarX cryoballoon for pulmonary vein isolation (PVI) among patients with atrial fibrillation (AF) is unclear. Methods PubMed, Embase, Cochrane Central, and ClinicalTrials.gov were systematically searched for studies comparing the PolarX vs. standard cryoballoon (CB‐2/CB‐4). Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (95% CIs) were computed for binary and continuous outcomes, respectively. Results This systematic review and meta‐analysis included 2 randomized controlled trials and 18 observational studies with a total of 7107 patients, of whom 3.188 (44.8%) underwent ablation with PolarX. When compared to standard cryoablation, PolarX had similar incidence of atrial arrhythmias recurrence (OR 1.04; 95% CI 0.82–1.32; p = 0.73), acute PVI success (OR 0.91; 95% CI 0.31–2.68; p = 0.98), and procedural duration (MD 3.41; 95% CI ‐2.89 to 9.71; p = 0.29). However, PolarX was associated with higher persistent phrenic nerve palsy (OR 2.17; 95% CI 1.26–3.74; p = 0.005) and a lower nadir temperature in all veins. Additionally, in a subgroup analysis of randomized trials and propensity score matching studies, similar findings were noted for recurrence of atrial arrhythmias. Conclusion In patients with AF undergoing PVI, PolarX had similar acute PVI success, procedural duration, and recurrence of atrial arrhythmias as compared with standard cryoballoon technology, however, was associated with a lower nadir temperature, and higher rates of persistent nerve palsy.

Abstract Aims The increasing adoption of transcatheter tricuspid valve replacement (TTVR) offers a promising therapeutic option for patients with severe tricuspid regurgitation. However, many of these patients have pre-existing cardiac implantable electronic devices (CIEDs), raising concerns about potential lead-related complications. Despite these concerns, limited data exist on the impact of TTVR on CIED integrity and function. This study aimed to evaluate the impact of TTVR on CIED lead function, including pacing thresholds, sensing, and impedance, in patients undergoing TTVR with the EVOQUE valve system. Methods and results A retrospective observational study was conducted at Mayo Clinic Rochester, including 32 consecutive patients who underwent TTVR with pre-existing CIEDs. A total of 32 patients were included, with a mean age of 79.2 ± 8.4 years; 59% were female. A total of 62.5% had a permanent pacemaker, 12.5% had an implantable cardioverter-defibrillator, 15.6% had a cardiac resynchronization therapy pacemaker, and 9.4% had a cardiac resynchronization therapy defibrillator. Following TTVR, 10 (31%) of patients developed lead function changes during a median device follow-up of 210 days (IQR: 43–307 days). The right ventricular lead was primarily affected, with only one case involving an atrial lead. Neither the Ottawa score nor the anatomical lead position reliably predicted lead abnormality (P = 0.86 and P = 0.53, respectively). R-wave sensing changes were the most common lead change observed, affecting 55% of cases. In 67% of these cases, R-wave sensing alterations occurred as an isolated finding, with no significant change in impedance or thresholds, and were managed conservatively without any need for device reprogramming. Four patients (13%) had findings concerning for a lead insulation breach, in which one (3%) required a lead revision. Among five patients with follow-up exceeding 600 days, two patients exhibited a statistically significant gradual decline in impedance without other lead dysfunction, suggesting potential subclinical lead degradation. Conclusion Transcatheter tricuspid valve replacement with the EVOQUE system in the setting of cardiac device leads is associated with lead function changes in 31%. The majority of lead-related changes were managed conservatively, but 13% of patients had findings concerning for an insulation breach. Future studies should focus on refining implantation techniques and defining optimal strategies for managing device-lead interactions in this population.

ABSTRACT Background Valve‐in‐valve transcatheter aortic valve replacement (ViV‐TAVR) is increasingly used to treat structural valve degeneration. Permanent pacemaker implantation (PPI) following TAVR is associated with increased morbidity and mortality, yet predictors specific to ViV‐TAVR remain poorly defined. Objective To identify clinical and procedural predictors of PPI in patients undergoing ViV‐TAVR. Methods We conducted a retrospective observational study of consecutive ViV‐TAVR cases at the Mayo Clinic from 2012 to 2022. Clinical, ECG, procedural data and fluoroscopic measurements were analyzed, and propensity score matching was used to adjust for confounding. Predictors of PPI were identified using multivariable logistic regression. Results Among 261 patients, 24 (9.2%) underwent PPI. Balloon‐expandable valves were used in 66.7% and self‐expanding valves in 33.3%. Predictors of PPI included Preprocedural bifascicular block (OR 12.15, 95% CI: 2.52–68.89, p = 0.003), greater septal implantation depth (OR 1.29, 95% CI: 1.04–1.65, p = 0.019), and post‐procedural new left (OR 23.56, 95% CI: 4.91–48.52, p = 0.0004) and right bundle branch blocks (OR 24.4, 95% CI: 3.82–30.51, p = 0.001). Aortic regurgitation as the mechanism of prosthetic valve failure was associated with reduced PPI odds (OR 0.28, 95% CI: 0.10–0.76, p = 0.014). Pacing requirement—defined as > 90% ventricular pacing—increased from 25% at 3 months to 56.25% at 12 months. At a median follow‐up of 962.5 days (IQR 481.5–1555.3), adjusted mortality was significantly higher in the PPI group (aOR 9.4, 95% CI: 1.9–60.4, p = 0.028). Conclusion Bifascicular block, greater septal depth, and new bundle branch blocks predict PPI post‐ViV‐TAVR, while aortic regurgitation appears protective. Risk stratification and procedural planning are critical.

Ventricular tachycardia (VT) is a life-threatening arrhythmia that requires both relatively rapid and accurate detection in intensive care units (ICUs). Continuous monitoring systems play a crucial role in detecting them. However, previous studies have reported that nearly 9 out of 10 arrhythmia alarms in ICUs tend to be false positives, which usually transpire to a well-documented phenomenon called “alarm fatigue” that leads to desensitization, delayed responses and increased cognitive burden on healthcare providers. We developed a deep learning based, one-dimensional convolutional neural network (1D-CNN) to classify VT alarms using multiple raw waveform inputs, including two electrocardiogram (ECG) leads, photoplethysmogram (PPG) and arterial blood pressure (ABP) signals. The model was trained using the publicly available VTaC Arrhythmia Benchmark Dataset. Ten-second waveform segments preceding each alarm were pre-processed and used to train the model to correctly classify the VT alarm. On the test set, the model achieved an area under the receiver operating characteristic curve (AUC-ROC) of 0.901, overall accuracy of 83.22%, F1-score of 73.3%, sensitivity of 77.53%, specificity of 85.63%, and positive predictive value (PPV) of 69.57%. The model successfully detected over three-quarters of them while significantly reducing false positive rates for the detection of VT. This study demonstrates that a deep learning based 1D-CNN model using short segments of raw waveform data can achieve robust performance in distinguishing true and false VT alarms.

ABSTRACT Background Ventricular tachycardia (VT) is a major contributor to sudden cardiac death among patients with ischemic heart disease (IHD). While catheter ablation reduces the arrhythmic burden, the impact on long‐term outcomes remains uncertain. We assess the efficacy of catheter ablation in patients with IHD. Methods We performed a meta‐analysis by systematically searching electronic databases from inception to April 2025. Pairwise, reconstructed time‐to‐event data meta‐analyses and Trial Sequential analyses were conducted. Results A total of seven studies (1192 participants) were included. Among patients with IHD with ICD, VT ablation was associated with a significant reduction in ICD shocks (RR = 0.50, 95% CI = [0.34–0.74]), a trend toward reduced VT storm (RR = 0.64, 95% CI = [0.40–1.04], p = 0.07), and lower rates of cardiovascular hospitalization (RR = 0.73, 95% CI = [0.53–1.01], p = 0.06) compared to ICD alone. However, no significant differences were observed when compared to patients receiving ICD plus antiarrhythmic drugs (AADs). VT ablation showed no significant impact on mortality or VT/VF recurrence compared to either ICD alone or ICD with AADs. Reconstructed Kaplan–Meier analysis for all‐cause mortality showed no significant difference between VT ablation and AAD + ICD. Trial Sequential Analysis provided conclusive evidence for VT/VF recurrence, while further data is required for other outcomes. Conclusion Among patients with IHD with ICD, VT ablation reduces ICD shocks, VT storm, and cardiovascular hospitalizations compared to ICD‐only therapy, but offers no significant advantage over ICD combined with AADs. VT ablation does not impact overall mortality or the recurrence of VT/VF. Trial sequential analysis confirmed conclusive evidence for VT/VF recurrence, while additional data is needed for other outcomes.

ImportancePatients with kidney failure (KF) receiving long-term dialysis have increased incidence of atrial fibrillation (AF). Patients with KF and AF have increased risk of stroke, death, and bleeding compared with age-matched cohorts. In KF, the use of oral anticoagulants (OACs) increases hemorrhage risk, offsetting potential benefits and making left atrial appendage occlusion (LAAO) a potentially promising solution for risk reduction in AF.ObjectivesTo compare the outcomes and safety of OACs and LAAO for risk reduction of AF in patients with KF.Design, Setting, and ParticipantsThis retrospective cohort study assessed patients with KF enrolled in the US Renal Data System registry between January 1, 2015, and December 31, 2018, who were diagnosed with AF after initiation of long-term dialysis. On average, patients met inclusion criteria for 22 months. Data analysis was completed in May 2024.ExposureMedicare claims were used to identify patients who received OACs and LAAO after AF diagnosis. A propensity-matched cohort was created based on the CHA2DS2-VASc score and year of treatment.Main Outcomes and MeasuresDeath, nonfatal bleeds, and nonfatal strokes.ResultsThe final cohort included 2344 patients with KF and a new AF diagnosis (median [IQR] age, 66.0 [57.0-73.0] years; 1341 [57.2%] male). Of these patients, 293 received LAAO and 2051 received OACs. A total of 2194 patients (93.6%) were receiving hemodialysis, with the remaining 150 (6.4%) receiving peritoneal dialysis. In the LAAO group, 79 deaths (27.0%) and 21 nonfatal strokes (7.2%) occurred, and 117 patients (39.9%) experienced 234 bleeding events. In the OAC group, 729 deaths (35.5%) and 163 strokes (8.0%) occurred, and 687 patients (33.5%) experienced 1114 bleeding events. After accounting for correlation between bleeds and death, the joint frailty model showed evidence of a treatment association of LAAO compared with OACs on recurrent bleeding events (hazard ratio [HR], 0.74; 95% CI, 0.56-0.98) and death (HR, 0.47; 95% CI, 0.30-0.72). There was a reduced risk of nonfatal stroke in the LAAO group (HR, 0.55; 95% CI, 0.32-0.94), but this finding was not significant after adjustment (HR, 1.18; 95% CI, 0.76-1.81).Conclusions and RelevanceIn this cohort study, LAAO compared with OACs was associated with improved survival and reduced bleeding risk in patients with KF and AF. These findings suggest that these data should be considered in shared decision-making in consideration of LAAO for patients with KF and AF.