Percutaneous coronary intervention (PCI) is safer than ever, yet coronary hematoma remains an underrecognized cause of early ischemic complications. In this episode, Host Mitsuaki Sawano, MD welcome Takunori Tsukui, MD and Akiko Maehara, MD to discuss their JACC: Cardiovascular Interventions study comparing 22 event-causing hematomas with 80 event-free hematomas identified from more than 3,000 IVUS-guided PCI procedures. The conversation explores how IVUS can distinguish high-risk from low-risk post-PCI hematomas, the imaging features associated with progression, and how these findings may help operators decide when additional stenting is necessary—and when careful observation may be the better strategy.

Pediatric heart transplantation is one of medicine's scarcest resources, where every allocation decision can mean the difference between life and death. But does the current system truly prioritize the children at greatest risk? Hosts Mitsuaki Sawano, MD, and Satoshi Shoji, MD welcome Kazunari Sasaki, MD (Stanford University) to discuss his JACC study, Status Exceptions and Misalignment of Medical Urgency in U.S. Pediatric Heart Transplantation. Using the national OPTN registry of more than 6,000 children awaiting heart transplantation, the study examines whether "status exceptions"—special requests to elevate transplant priority—accurately reflect medical urgency and whether the National Heart Review Board has improved the fairness of organ allocation. The episode explores why well-intentioned exception requests may unintentionally disadvantage the sickest children, how waiting-list mortality varies dramatically within the highest priority category, and why objective measures of medical urgency may be needed to improve equity in donor heart allocation. Dr. Sasaki also shares insights into the evolution of the U.S. transplant system, emerging innovations such as ex vivo heart perfusion, and how data-driven policy can shape the future of pediatric transplantation.

Premature atrial complexes (PACs) are among the most common arrhythmias encountered in daily practice and are often dismissed as benign. But are they truly harmless—or could some represent the earliest stage of atrial fibrillation (AF)? Hosts Mitsuaki Sawano, MD, and Hiroyuki Sato, MD welcome Satoshi Higuchi, MD (Tokyo Women's Medical University) to discuss his JACC: Clinical Electrophysiology study, Atrial Effective Refractory Periods in Patients With Frequent Premature Atrial Complexes: Implications for Atrial Fibrillation. Building on translational work from experimental models, the study compares atrial effective refractory periods (AERP) in patients with frequent PACs, paroxysmal AF, and persistent AF to better define the electrophysiologic substrate underlying these conditions. The episode explores how electrical remodeling differs between PACs and AF, why pulmonary vein AERP shortens before more diffuse atrial remodeling develops, and what these findings reveal about the progression from atrial ectopy to sustained arrhythmia. The discussion also examines the emerging concept of PAC-induced atrial cardiomyopathy, the challenge of distinguishing "benign" from potentially malignant PACs, and the future of risk stratification and preventive intervention before AF becomes established.

Patients with active cancer face a difficult balance: preventing recurrent venous thromboembolism while avoiding major bleeding during anticoagulation. But which patients are truly at highest bleeding risk? Hosts Mitsuaki Sawano, MD welcome Tomoyuki Nagai, MD (Kyoto Prefectural University of Medicine) and Naohiko Nakanishi, MD (Kyoto Prefectural University of Medicine) to discuss their JACC: CardioOncology study introducing the ONCO-DOAC BLEED Score. Using more than 1,100 patients from COMMAND VTE Registry-2 with external validation in two independent cohorts, the investigators identified eight readily available clinical factors that stratify bleeding risk during DOAC therapy in patients with cancer-associated VTE. The conversation explores why existing bleeding scores fall short in patients with active cancer, how cancer type and disease stage influence bleeding risk, the challenges of developing and validating a practical bedside risk score, and what clinicians should consider when balancing thrombosis prevention against bleeding in everyday practice.

Host Mitsuaki Sawano, MD, welcomes Kai Nogami, MD (Mayo Clinic), to discuss his JACC Brief Report, "Higher Prevalence of Coronary Microvascular Dysfunction in Patients With HFpEF Without Obesity." Why do some patients develop HFpEF despite not being obese? In this episode, Dr. Nogami explains how combining invasive coronary function testing with exercise hemodynamics revealed a remarkably high prevalence of coronary microvascular dysfunction (CMD) in patients with non-obese HFpEF. The discussion explores why CMD may be a key driver of this distinct HFpEF phenotype, what these findings could mean for Japanese and other Asian populations, and how Mayo Clinic's unique invasive physiology platform provided new insights into HFpEF pathophysiology. Dr. Nogami also shares lessons from transforming the work into a JACC Brief Report and reflects on the enduring legacy of his mentor, the late Dr. Amir Lerman.

Hosts Mitsuaki Sawano, MD, Kentaro Ejiri, MD, Hiroyuki Sato, MD, and Shun Kosaka, MD welcome Dr. Kosuke Nakasuka, MD, PhD to discuss his JACC study, Sudden Cardiac Death Due to Myocardial Infarction With Obstructive and Nonobstructive Coronary Arteries. Using one of the world's most comprehensive population-based autopsy cohorts, this study challenges a decades-old assumption that myocardial infarction accounts for nearly 80% of sudden cardiac death. The conversation explores why autopsy remains the gold standard for uncovering the true causes of sudden death, what these findings reveal about MINOCA and right coronary artery infarction, and how survivor bias may have shaped our current understanding of sudden cardiac death and ICD risk stratification.

Hosts Mitsuaki Sawano, MD, Nobuhiro Ikemura, MD, and Satoshi Shoji, MD welcome Takahito Doi, MD, PhD to discuss his JACC Brief Report, "Risk of Atherosclerotic Cardiovascular Disease in Familial Remnant Hyperlipidemia and Familial Hypercholesterolemia." Using prospective population cohorts from Copenhagen and the UK Biobank, this study examined whether familial remnant hyperlipidemia, historically known as type III hyperlipidemia or dysbetalipoproteinemia, is associated with higher ASCVD risk. The episode explores why remnant cholesterol matters beyond LDL-C and Lp(a), how genetically elevated remnant lipoproteins may identify an underrecognized high-risk group, and what this means as new triglyceride- and remnant-lowering therapies move closer to clinical practice.

Hosts Mitsuaki Sawano, MD, Kentaro Ejiri, MD, and Hiroyuki Sato, MD welcome Tomoya Iwawaki, MD and Satoshi Yanagisawa, MD to discuss their JACC: Clinical Electrophysiology study, "Optimal Timing for Oral Anticoagulant Discontinuation and Prognosis After Successful Catheter Ablation for Atrial Fibrillation." Using data from 2,448 patients undergoing first-time AF ablation, the investigators performed 537 sequential landmark analyses to identify when the balance between thromboembolic protection and bleeding risk most favors oral anticoagulant discontinuation. The episode explores how stroke and bleeding risks evolve after ablation, the concept of reverse net clinical benefit, why the first several months after discontinuation may be particularly vulnerable, and whether a data-driven approach can help guide one of the most common questions in contemporary AF management: when is it truly safe to stop anticoagulation after a successful ablation?