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Welcome to EP Edge Journal Watch — where cardiac electrophysiology meets evidence, precision, and perspective.
Hosted by Dr. Niraj Sharma, this bi-weekly podcast distills high-impact cardiovascular and EP 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
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
Hello everyone and welcome to the very first episode of EP Edge Journal Watch, your bi weekly deep dive into the latest evidence shaping the future of cardiac electrophysiology. I'm Doctor. Niraj Sharma and in this series we're not just summarizing data, we're distilling the studies that actually change how we practice EP. Each issue will break down high impact articles, analyze their strengths and limitations, and talk about what they mean in the real world in our EP labs, clinics, and patient encounters. Today's episode features three studies that touch on very different but deeply interconnected areas of cardiovascular care.
Dr Niraj Sharma:One, de escalation of heart failure therapy after successful AF ablation. Two, a simple but powerful electrolyte intervention to reduce arrhythmia burden. Three, how pregnancy outcomes decades earlier can influence AF risk. Let's dive in. The first article, GDMT or Guideline Directed Medical Treatment Withdrawal After EF Recovery Post AF Ablation.
Dr Niraj Sharma:This is a study published in Open Heart 2025 by Al Adarous and colleagues. This is an elegant, multicenter, UK cohort study of eighty eight patients who presented with tachycardia induced cardiomyopathy due to atrial fibrillation, that familiar phenotype of reduced ejection fraction, dilated LV, but no significant structural disease. All patients underwent AF ablation and achieved EF recovery to fifty percent or higher. Here's the key question: Do these patients really need to stay on guideline directed medical therapy indefinitely once their LV function normalizes? Fifty seven percent continued GDMT.
Dr Niraj Sharma:Forty three percent withdrew at least half their HF meds. After about thirty two months, EF remained stable in both groups, fifty six point three percent versus fifty six point eight percent. Relapse was rare, just around two percent in each group. LV dimension stayed stable and sinus rhythm was well maintained in more than eighty percent of patients. That's a remarkable observation because what we often do in practice and what guidelines have long encouraged is indefinite continuation of GDMT, especially beta blockers and RAAS inhibitors, even when EF recovers.
Dr Niraj Sharma:But this study suggests that in carefully select patients with arrhythmia induced cardiomyopathy, durable rhythm control itself may be sufficient to maintain left ventricular recovery. My take: As electrophysiologists, we see this all the time. A patient with persistent AF undergoes ablation and six months later the EF is normal. The reflex is to keep the patient on beta blockers, ACE inhibitors, maybe an MRA because that's what we do in heart failure with reduced EF. But this population isn't the same as non ischemic or ischemic cardiomyopathy.
Dr Niraj Sharma:What this study does is start a conversation about de escalation. Not reckless withdrawal but personalized care. This trial has the following strengths: one. Real world multicenter design two. Robust imaging and follow-up three.
Dr Niraj Sharma:A uniquely focused population distinct from traditional heart failure cohorts like TRED HF. Before we move on, it's worth putting this into context with the TRED HF trial published in The Lancet Bank in 2019. Tread HF looked at patients with previously reduced ejection fraction who had fully recovered on guideline directed therapy. These were mostly non ischemic dilated cardiomyopathy patients. When GDMT was withdrawn, nearly half relapsed within six months, even though they initially felt well and had normal imaging and biomarkers.
Dr Niraj Sharma:That was a big turning point. It proved that recovered EF is not the same as cured heart failure. But here's the nuance: those patients still had an underlying cardiomyopathy substrate. In AF induced cardiomyopathy, once the arrhythmia is successfully treated, the substrate may be far less persistent. That's why the new study by Al Aderous and colleagues is so intriguing.
Dr Niraj Sharma:It suggests that tachycardia induced cardiomyopathy might behave differently from the Tred HF population and selective GDMT de escalation may actually be feasible in some of these patients. What are the limitations of this trial? One. Non randomized, so selection bias. Two.
Dr Niraj Sharma:Modest sample size (eighty eight patients) three. Predominantly male cohort, which may limit generalizability four. And while follow-up was over two years, late relapse could still occur. What are the clinical implications of this trial? This trial doesn't mean we should stop GDMT in every patient with recovered EF, but it does mean that tachycardia induced cardiomyopathy may not behave like other heart failure with reduced EF phenotypes.
Dr Niraj Sharma:It opens the door to structured withdrawal protocols, careful echo follow-up, and patient specific decision making. And perhaps most importantly, it reminds us that curing the trigger, in this case AF, can sometimes be more powerful than just treating the consequence. The second article, Targeting high normal potassium to reduce ventricular arrhythmias, published in the New England Journal of Medicine, 2025, authored by Jons et al. Also known as the POTCAST trial. Now this is one of those trials that makes you think why haven't we been doing this all along?
Dr Niraj Sharma:1,200 ICD recipients with baseline K at or below 4.3 mmolL were enrolled. Participants were randomized to either standard care or an active intervention that titrated potassium into the high normal range of 4.5 to five point zero mmolL. The intervention wasn't fancy. It involved potassium supplements, mineralocorticoid receptor antagonists or both, combined with dietary guidance. Simple scalable tools.
Dr Niraj Sharma:Median follow-up was about forty months. The primary endpoint, a composite of VT, appropriate ICD therapy, arrhythmia or heart failure hospitalization or death occurred in twenty two point seven percent of the high normal potassium group compared with twenty nine point two percent in standard care. That's a hazard ratio of zero point seven six and the number needed to treat was just twelve patients to prevent one major event. And here's the kicker: no excess hyperkalemia hospitalizations. So it's not just effective, it's safe.
Dr Niraj Sharma:This is my take as EPs. We fine tune antiarrhythmics, optimize device therapies and chase scar borders on mapping systems. But something as basic as potassium can sometimes make a bigger difference than another fancy algorithm. We've long known that both hypokalemia and low normal potassium increase arrhythmia risk. This trial provides hard prospective evidence that pushing potassium just a bit higher safely reduces real arrhythmic events.
Dr Niraj Sharma:Strengths of the trial include: one. Large randomized trial with clinically meaningful endpoints two. Pragmatic and scalable intervention three. ICD therapies as a surrogate for arrhythmia burden: a robust objective endpoint. One.
Dr Niraj Sharma:Open label design two. Not all patients reach the target K range three. Applicability to non ICD populations is still uncertain Clinical implication of the trial: This is the kind of intervention that can be implemented tomorrow in EP and HF clinic. It's low cost, evidence based, and directly tied to arrhythmia risk. In my view, potassium targeting should become a standard part of ICD follow-up protocols, particularly for patients with borderline K plus levels and high arrhythmic burden.
Dr Niraj Sharma:The third and final article Adverse pregnancy outcomes and long term AF risk. This study was published in JAMA Cardiology 2025 authored by Krump et al. This is a landmark population based cohort from Sweden over two point two million women with follow ups spanning up to forty six years. More than fifty one thousand developed atrial fibrillation with a median age at diagnosis of 63. Here's what they found: women with adverse pregnancy outcomes including preterm delivery, preeclampsia, hypertensive disorders, gestational diabetes, and large for gestational age infants had a significantly increased risk of AF later in life.
Dr Niraj Sharma:The hazard ratios ranged from 1.11 to 1.44. And importantly, these associations persisted for decades after delivery. And through co sibling analyses, the authors showed the findings were largely independent of genetic or familial confounding. This is my take. This is a powerful reminder that AF risk doesn't start at age 60.
Dr Niraj Sharma:For many women it may be programmed during or even before pregnancy. Pregnancy is essentially a physiologic stress test revealing latent cardiovascular risk. We should be integrating adverse pregnancy outcomes history into AF risk assessment and prevention strategies just like we consider hypertension, sleep apnea, or obesity. The strengths of the trial include: one. Massive cohort with decades long follow-up two.
Dr Niraj Sharma:High quality national registry data three. Co sibling analysis to reduce confounding. Limitations of the study are: one. Observational design two. Limited physiologic data to explain the mechanisms Third, AF ascertainment based on registry coding.
Dr Niraj Sharma:Clinical implications are extensive. This study expands how we think about AF risk in women. If a woman has a history of preeclampsia or preterm birth, we should be flagging her for early surveillance and lifestyle intervention long before the first AF episode. This issue of EP Edge Journal watch highlights are: one. Reassessing who really needs lifelong heart failure after AF ablation two.
Dr Niraj Sharma:Using potassium as an arrhythmia prevention tool not just a lab value three. Recognizing that AF risk begins long before we think, sometimes as early as pregnancy. If you'd like to dive deeper into these studies including trial links, references and figures, check out the EP EDGE newsletter on LinkedIn. And don't forget and this journal watch series is now available as a podcast so you can stay up to date even between cases and consults. Thank you for tuning in to this first episode of EP Edge Journal Watch.
Dr Niraj Sharma:Until next time, this is Doctor. Niraj Sharma. Bye for now.