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Welcome to EP Edge Journal Watch, where cardiac electrophysiology meets evidence, precision, and perspective.
Hosted by Dr. Niraj Sharma, this weekly podcast distills high-impact cardiovascular and Cardiac Electrophysiology and arrhythmia research into clear, clinically meaningful insights. Each episode goes beyond headlines and abstracts to uncover what new studies actually mean for patient care, decision-making, and the future of electrophysiology.
What EP Edge Journal Watch stands for:
Evidence-based practice
Precision electrophysiology, arrhythmias analysis
A forward-thinking, edge-driven approach to how we interpret and apply data in real-world clinical settings.
Whether you’re an electrophysiologist, cardiologist, researcher, trainee, or allied health professional, EP Edge Journal Watch brings you the signal not the noise. Expect sharp summaries, thoughtful commentary, and practical takeaways designed for the busy clinician who wants to stay ahead of the curve
This program is for educational purposes only and reflects independent editorial commentary. It is not medical advice and should not replace clinical judgment or review of primary sources and guidelines. The views expressed are those of the host and contributors.
Niraj Sharma:Hello and welcome to epedge Journal Watch. This is Doctor. Sharma. Thank you for joining us for Issue 39, October 2026. Every week brings another substantial collection of electrophysiology research.
Niraj Sharma:Across The United States and Europe, our reading includes Circulation, Arrhythmia and Electrophysiology Clinical Electrophysiology Heart Rhythm UroPACE Pacing and Clinical Electrophysiology, The Journal of Cardiovascular Electrophysiology, and The Journal of Interventional Cardiac Electrophysiology. To illustrate the volume, suppose these seven journals average 10 relevant research articles each per month (seventy papers), assuming another two electrophysiology articles per issue Circulation Journal of American Medical Association Cardiology and the European Heart Journal adds approximately 25 more each month. This illustrative estimate approaches 100 before other international cardiology and internal medicine journals. These are different types of research articles, not all randomized trials. With that volume we have to prioritize.
Niraj Sharma:We generally favor randomized trials, meta analyses, informative observational studies, and thought provoking research that challenges our understanding. Whether that ranking is entirely fair is debatable. It reflects our editorial judgment, and reasonable readers may choose differently. Quality and clinical relevance matter alongside design. Case reports are usually excluded and brief communications are generally included only when particularly interesting or clinically important.
Niraj Sharma:Preparing Journal Watch takes an exceptional amount of time and sustained effort. Selecting papers is only the beginning. We examine methods, results, tables, figures, statistics, and limitations and incorporate accompanying editorials into the relevant discussion. Our aim is for us to understand what the evidence establishes, where uncertainty remains, and whether a finding should influence practice. Our newsletter covers 24 articles.
Niraj Sharma:For this podcast, we'll examine four in-depth: PIFPAF PFA, pulmonary vein isolation durability across pulsed field systems, the durability of atrial linear lesion sets, and a defibrillator lead placed in the left bundle branch area. We'll finish with brief takeaways from the remaining articles, grouping related topics to keep the episode within twenty five minutes. Let's begin with Lauren Roten et al. In JAMA, August 2026. The title is Pulmonary Using Pulsed Field Ablation with versus without posterior wall isolation in patients with symptomatic persistent atrial fibrillation the PIFPAF PFA randomized clinical trial.
Niraj Sharma:We'll call it PIFPAF. The clinical question is familiar: if pulsed field ablation makes posterior wall isolation relatively straightforward, should we add it routinely during first ablation for persistent atrial fibrillation? Six Swiss centers randomized two zero six patients, one hundred and two to pulmonary vein plus posterior wall isolation, and one hundred and four to pulmonary vein isolation alone. Treatment was open label but endpoint adjudication was blinded. Every patient received an implantable cardiac monitor, an important strength when recurrence can be asymptomatic.
Niraj Sharma:The primary endpoint was an atrial tachyarrhythmia lasting at least thirty seconds between days ninety one and three sixty five. Antiarrhythmic drugs were intended to stop after thirty days. Cardioversion, repeat ablation, and subsequent drug treatment still matter when interpreting the final clinical result. Recurrence occurred in fifty one versus sixty three patients. The Kaplan Meier recurrence estimates were fifty point six percent with posterior wall isolation and sixty point six percent with pulmonary vein isolation alone.
Niraj Sharma:These are time to event estimates, not simply the event counts divided by the randomized totals. The reported rate ratio was zero point seven five, with a 95% confidence interval from 0.51 to 1.09. The p value was 0.13. That estimates a twenty five percent lower recurrence rate, but the interval includes anything from a forty nine percent reduction to a nine percent increase. The study did not establish superiority.
Niraj Sharma:It also did not establish equivalence. Two zero six participants in a trial powered for a 20 percentage point difference cannot reliably exclude a smaller benefit. A p value of 0.13 is not a 13% probability that the treatments are identical. It describes how incompatible the data are with the no difference hypothesis under the statistical model. Here the uncertainty remains clinically consequential.
Niraj Sharma:PIFPAF becomes more interesting when we look beyond the first thirty second recurrence. Mean arrhythmia burden was six point nine percent versus eleven percent. The modeled absolute difference was 4.1 percentage points less time in arrhythmia, with a confidence interval from 0.2 to eight points less. The p value was 0.04. Episodes lasting at least a day occurred in ten versus twenty five patients.
Niraj Sharma:However, the six hour and seven day thresholds were not significant, and twenty two of twenty nine secondary endpoints were non significant. There was no correction for multiple comparisons. These findings generate a hypothesis about prolonged episodes. They don't reverse the neutral primary result. Repeat ablation occurred in ten versus twelve patients, cardioversion in eleven patients in each group, and antiarrhythmic drug use in seven in each group.
Niraj Sharma:The quality of life comparison also failed to establish an advantage. Less measured arrhythmia time therefore did not translate into a clearly demonstrated reduction in these other clinical outcomes. The additional lesion set added about eight minutes. Two vascular complications occurred in that group, including one followed by stroke after anticoagulation interruption. Through one year, stroke or transient ischemic attack occurred in one patient per group.
Niraj Sharma:These small numbers cannot exclude uncommon harm. Systematic surveillance for hemolysis was not performed. Kistler and Chieng's accompanying editorial distinguishes empirical anatomical ablation from targeting demonstrated abnormal substrate. That's a useful distinction, but findings from another selected population cannot establish superiority over the strategy tested here. Low voltage mapping itself depends on rhythm, wavefront contact, and electrode configuration.
Niraj Sharma:Our EP EDGE take is that routine empirical posterior wall isolation remains unproven for this setting. A short recurrence and a day of symptomatic atrial fibrillation are not clinically interchangeable, but the endpoint that matters must be specified before examining the results. A larger study should test burden, symptoms, repeat intervention, and safety together with attention to atrial substrate and background treatment. For now, the ease of adding applications is not sufficient reason to add a lesion set. Our next paper is by Kakarla Sanders et al.
Niraj Sharma:In the October 2026 issue of Durability of Pulmonary Does the Pulsed Field Ablation System Matter? The study compared a pentaspline system with a balloon in basket system. These technologies differ in geometry, waveform, contact, and application strategy. Acute isolation does not tell us whether their chronic lesions are identical. This retrospective two center cohort included 132 index procedures, 86 with the pentaspline system and 46 with the balloon and basket system.
Niraj Sharma:The latter patients came through trials and had more intensive rhythm surveillance. Baseline heart failure, ventricular function, and diabetes also differed. All pulmonary veins were isolated acutely. Clinical recurrence occurred in nine patients in each group, ten point five percent versus nineteen point six percent, with a p value of 0.12. Among 34 propensity matched pairs, recurrence occurred in six versus seven patients.
Niraj Sharma:The striking result came from only seventeen patients who returned for repeat ablation, eight after pentaspline treatment, and nine after balloon and basket treatment. Reconnection involved nine of 32 veins versus one of 35 veins or 28.1 versus two point nine percent. The p value was point zero zero three. All veins remained isolated in three of eight patients versus eight of nine, with a p value of point zero four nine. Those numbers deserve attention, but we must keep the denominator in view.
Niraj Sharma:Sixty seven veins in seventeen patients are not sixty seven independent patients. Veins within a patient share anatomy, operator technique, and exposure. At the patient level, changing one outcome moves the group percentage by approximately 11 to 13 points. The clinical cohort was propensity matched. The separate redo sample was not thereby made representative or randomized.
Niraj Sharma:Returning for ablation selects patients according to symptoms, recurrence, referral, and treatment choices. Different monitoring and posterior wall treatment further complicate comparison. No randomized odds ratio or hazard ratio establishes platform superiority here. Likewise, non significant clinical recurrence results do not prove equivalence. The matched analysis contains only 13 recurrences.
Niraj Sharma:Procedure times were similar. Application counts differed markedly. But one application from one system is not a standardized energy dose interchangeable with another. No major procedural complication was recorded. This small cohort cannot settle comparative safety.
Niraj Sharma:Our take is that this is a valuable durability signal requiring prospective confirmation. It should guide questions about lesion formation, not establish a platform ranking. Systematic remapping, standardized surveillance, and patient level analysis are needed. At redo, map the patient's actual mechanism, pulmonary vein reconnection, another trigger, or an organized atrial tachycardia. Our third featured paper by Nies et al.
Niraj Sharma:Also appears in Heart Rhythm, October 2026. Its title is Durability of Atrial Linear Lesion Sets Using a Dual Energy Latest Tip Catheter data from invasive remapping. An additional atrial line carries an obligation. It needs a clear purpose and a reliable electrical endpoint. A gap can permit macro reentry, so an apparently complete line at the first procedure may become clinically important later.
Niraj Sharma:Investigators remapped thirty nine of two fifty two treated patients, approximately sixteen percent. Fourteen returned with recurrent arrhythmia, twenty five returned for appendage occlusion after previous appendage isolation. Most had persistent atrial fibrillation and prior ablation. The overall median remapping interval was forty six days, although intervals differed substantially by lesion location. Seventy one lesion sets were examined: 18 pulmonary vein encirclements and 53 additional lines.
Niraj Sharma:Fifty four of the 71 sets remained blocked, approximately seventy six percent. Separately, thirty one of 36 individual pulmonary veins remained isolated. That denominator matters. Seventy one refers to all remapped sets, not seventy one additional linear lesions. Roof lines remained blocked in six of six cases, posterior boxes in ten of ten, and CTI lines in seven of seven.
Niraj Sharma:In contrast, only nine of 17 anterior lines and seven of 13 mitral lines remained blocked, approximately fifty three and fifty four percent. These are descriptive proportions, not comparative odds ratios. Six of six does not establish universal durability. Nine of seventeen is a meaningful warning, but it doesn't identify why reconnection occurred. Energy and anatomy varied together.
Niraj Sharma:Posterior targets generally received pulsed field ablation, anterior and mitral lines often received mixed energy, and CTI lines received radiofrequency. Median remapping intervals range from thirty five days for mitral lines to five sixty four days for roof lines. These are not controlled comparisons of energy sources over equal follow-up. Selection also cuts in different directions. Recurrence enriches for failure, while planned appendage occlusion selects a different treatment population.
Niraj Sharma:Multiple lesions within one patient remain correlated. The report also contains differing remapping intervals for the recurrent subgroup, which prevents a clean reconstruction of one uniform cohort. Our practical concern is the limited anterior and mitral durability. When a line is necessary, confirm bidirectional block and have a strategy for completion. Visual continuity is insufficient.
Niraj Sharma:Avoid adding lines without a defensible clinical objective. The posterior findings are promising, but durable electrical block is still a surrogate. We need systematic remapping and clinical follow-up to determine whether a particular lesion strategy improves symptoms and reduces repeat procedures without creating new tachycardias. Our fourth featured paper is by Vijayraman et al, Safety and Performance of a Novel Defibrillation, Lead for Left Bundle Branch Area Placement, primary results of the Leader Left Bundle Branch Area Pacing Clinical Trial. It appears in Heart Rhythm's October 2026 issue, following online publication in 2025.
Niraj Sharma:We're discussing newly selected coverage, not newly generated 2026 evidence. Combining defibrillation and left bundle area pacing in one lead could simplify some device configurations, but that concept contains separate questions. Can the lead reliably defibrillate? Can it pace and sense safely? Does its position provide effective conduction system capture and resynchronization?
Niraj Sharma:This prospective single arm study enrolled three twenty three patients at 24 centers. Implantation was attempted in 03/2007 and succeeded in two ninety three or ninety five point four percent. Mean follow-up in this interim report was only two point six months. All one hundred and sixty two patients who completed protocol defibrillation testing met the acute efficacy endpoint. The ninety five percent confidence interval for success was 97.7-one 100%, exceeding a pre specified 88% performance benchmark.
Niraj Sharma:Among one hundred and fifty nine patients succeeding at the first induction, one hundred and thirty four converted at 18 joules, and twenty five demonstrated the required 10 joule safety margin. Three additional patients succeeded after troubleshooting or repositioning. Twenty one patients unable to begin or complete protocol testing were outside the one hundred and sixty two patient efficacy denominator. One hundred percent is encouraging, but it applies to those tested patients under that protocol. It does not mean every attempted implant was successful, or that future spontaneous arrhythmias will always terminate.
Niraj Sharma:The confidence interval expresses sampling uncertainty. It does not remove selection introduced by incomplete testing. This was comparison with a historical performance benchmark, not randomized comparison with another defibrillation lead. No comparative hazard ratio establishes superiority. Implantation success, defibrillation success, and freedom from complications have different denominators and answer different questions.
Niraj Sharma:The pacing threshold averaged 0.6 volts at zero 0.4 and remained stable. Sensed ventricular amplitudes were also reassuring over this short observation period. These are useful early electrical measurements but chronic lead performance must be demonstrated over years. The lead study's safety findings need the same careful reading. Five lead related major complications required revision with a non study lead, two dislodgements, a connection problem, threshold elevation and undersensing.
Niraj Sharma:Four occurred within ninety days. Kaplan Meier freedom from major lead complications was ninety seven point nine percent at three months, with a confidence interval from ninety five point eight to one hundred percent. That estimate accounts for differing follow-up and censoring. It isn't simply one minus five divided by the number implanted Only forty two patients remained at risk at six months, making the later estimate particularly uncertain. Seven deaths were considered unrelated to the lead.
Niraj Sharma:Four inappropriate shocks in three patients were attributed to atrial tachycardia or atrial fibrillation. No inappropriate shock from P wave or T wave over sensing was observed, but the follow-up is too short to establish durable protection from sensing problems or mechanical failure. Approximately half the patients received a resynchronization defibrillator with an additional left ventricular lead. Consequently, this study does not show that the septal defibrillation lead alone can replace conventional resynchronization. Left bundle area placement also did not uniformly establish unequivocal conduction system.
Niraj Sharma:The manufacturer sponsored the study, and sponsor employees were among the authors. That's relevant context for independent replication and long term surveillance, rather than a reason to dismiss the observed performance. Our epedge take is encouraging technical feasibility with unresolved chronic questions. We need longer follow-up for defibrillation reliability, sensing, lead integrity, capture, interaction with other leads, and eventual extraction. Any proposed reduction in lead count must preserve the pacing physiology and clinical benefit that the individual patient needs.
Niraj Sharma:Across our four featured papers, the distinction is consistent. PIFPAF PFA did not establish routine posterior wall benefit. The platform comparison offers a selected remapping signal. The linear lesion study warns that acute block may not persist, especially anteriorly and at the mitral isthmus. The defibrillation lead study demonstrates promising early performance with long term reliability and resynchronization still to be established.
Niraj Sharma:Let's turn briefly to the other 20 articles in the newsletter. Two additional ablation papers complement that discussion. Bax and colleagues' review of pulsed field dosing found no universal application count balancing durability and safety. Dosing must remain specific to the system and lesion strategy. In Oates et al.
Niraj Sharma:SAFE ablation registry, strokes occurred with the original radiofrequency workflow, followed by no observed strokes after a bundle of energy and workflow changes, an important safety signal that cannot identify one protective component. For pacing, Vinther et al, his alternative two trial randomized one hundred and fifty patients and met its prespecified non inferiority criterion for ventricular remodeling (six months). Crossovers and complications, including delayed septal perforation with ventricular fibrillation, mean remodeling non inferiority should not be translated into proven survival or safety equivalents. The Caracasys and Chauhan meta analyses offer complementary perspectives. One found lower odds of the combined endpoint of death or heart failure hospitalization in randomized trials, while the other showed stronger benefits when observational evidence was added.
Niraj Sharma:Neither establishes a mortality advantage from randomized evidence. The integrated editorial and viewpoint reinforce the importance of capture verification and study design. The three anticoagulation reports asked different questions. Kim et al. Randomized single AF trial found a one percentage point absolute reduction in the two year composite outcome among intermediate risk patients, based on only 17 events.
Niraj Sharma:It was not a trial of stopping treatment after successful ablation. Kawaji et al. Observational STOP oral anticoagulants study found less bleeding after clinicians selected withdrawal, but its stroke hazard ratio of 1.01 had a confidence interval from 0.21 to 4.99, too wide to reassure us that stroke risk is unchanged. Peng et al. Target trial emulation also left thromboembolic uncertainty, with detected atrial recurrence approaching forty six percent by four years despite favorable selection at six months.
Niraj Sharma:Together these papers inform individualized discussion. They do not establish a general rule that apparently successful ablation permits anticoagulation withdrawal in high risk patients. The metabolic studies also need to stay distinct. Deshmuk et al. Small META AF trial found freedom from recurrent atrial arrhythmia in approximately seventy eight percent with metformin versus fifty eight percent with usual care after ablation, but early termination, post randomization exclusions, and treatment discontinuation limit a practice changing conclusion.
Niraj Sharma:Palmisano et al. Found an association between glucagon like peptide-one treatment and lower incident atrial fibrillation, including analyses accounting for weight change. Observational mediation cannot prove a weight independent drug mechanism. Mansouri et al. Tirzepatide meta analysis found no established atrial fibrillation prevention benefit, with sparse adverse event data and a possible broader arrhythmia signal.
Niraj Sharma:Abhaknesha et al. Omega-three meta analysis found higher AFib odds with higher doses in cardiovascular high risk populations, an odds ratio of one point four three and an absolute excess of approximately zero point eight percentage points. That's forty three percent higher odds, not a forty three percentage point increase in risk. It is not a finding about dietary FISH. Thacker et al.
Niraj Sharma:Persistent Atrial Fibrillation Review estimated progression at sixteen point four events per 100 person years, but the studies differed profoundly in what progression meant, Its study level association between more previous ablation and less progression does not prove that ablation prevents permanent atrial fibrillation in an individual patient. Bordeaux et al. Linked device detected atrial high rate episodes with cardiovascular events, particularly heart failure hospitalization, while the stroke estimate remained uncertain. A confirmed episode should prompt review of the electrogram, ventricular function, congestion, and treatment rather than automatic anticoagulation based on six minutes alone. Wynn et al.
Niraj Sharma:Randomized cardioversion trial found similar first shock success with the two tested waveform and energy protocols (approximately eighty three versus eighty four percent). A non significant difference does not establish equivalence, and immediate conversion says little about how long sinus rhythm persists. Granfeldt et al. Randomized bicarbonate trial did not improve sustained return of circulation during in hospital cardiac arrest (approximately thirty nine versus thirty seven percent ), with an adjusted risk ratio of one point zero five. The confidence interval included benefit and harm, and the result does not answer the excluded situations of hyperkalemia or certain poisonings.
Niraj Sharma:Rainier et al. Warning symptom study combined symptoms and clinical history to explore imminent arrest triage. High case proportions in an enriched case control sample are not real world probabilities for an emergency caller and the model requires prospective validation. Demidova et al. Review of ventricular arrhythmias during acute myocardial ischemia emphasizes rhythm phenotype, residual ischemia, reperfusion, ventricular function, and timing together.
Niraj Sharma:Early ventricular fibrillation carries substantial immediate risk, but it does not uniformly predict the same long term risk as monomorphic ventricular tachycardia after reperfusion. Treatment must address the mechanism and hemodynamic setting. Goldenberg et al. Associated later menarche with more recurrent cardiac events in women with congenital long QT syndrome, while beta blocker use was associated with substantial protection. Reproductive history may add context, but these observational findings do not justify hormonal manipulation or a new isolated treatment threshold.
Niraj Sharma:Finally, Gupta et al. Study of intravascular lithotripsy during extraction of long dwell leads did not establish improved success or reduced extraction tool requirements and serious venous injuries occurred. Technical feasibility must be considered alongside anatomical selection, complications, and the need for experienced teams with rescue capability. The full 24 article newsletter provides the detailed methods, statistics, limitations, and integrated editorial discussions. Please visit epedge on LinkedIn and epedge.substack.com for the complete analyses and references and our accompanying graphics where available, and look out for the arrival of our website, epedge.org and our app later this month.
Niraj Sharma:For questions, suggestions or concerns can be emailed to epedge. Castgmail dot com. Thank you for listening, reading and sharing EP Edge Journal Watch. We look forward to continuing the discussion. This is Doctor.
Niraj Sharma:Sharma. Until next time, take care.