Advertise on podcast: JACC Global

Hosts Mitsuaki Sawano, MD, Satoshi Shoji, MD, and Kentaro Ejiri, MD, welcome Yoshito Kadoya, MD, PhD (University of British Columbia / St. Paul’s Hospital) to discuss his JACC: Cardiovascular Imaging study, “PET-Based Coronary Microvascular Dysfunction Phenotypes and Outcomes in Patients With Normal Myocardial Perfusion.” Among 3,317 patients with normal relative perfusion on cardiac PET, the study examined four phenotypes defined by myocardial flow reserve and stress myocardial blood flow. Both classical CMD and endogen CMD were associated with higher long-term cardiovascular risk, suggesting that reduced MFR may remain clinically meaningful even when stress myocardial blood flow is preserved. The episode explores how PET can phenotype coronary microvascular dysfunction, differences between invasive and noninvasive approaches to CMD, and Dr. Kadoya’s cardiac imaging training and career in Canada.

Host Mitsuaki Sawano, MD, welcomes Shuhei Nomura, PhD (Tohoku University), Lisa Yamasaki, MD (Harvard T.H. Chan School of Public Health), and Haruka Sakamoto, MD, PhD (St. Luke’s International Hospital) to discuss two policy reviews published in The Lancet Regional Health – Western Pacific. Fifteen years after the 2011 Lancet Japan Series, Japan faces population aging, rising long-term care needs, workforce shortages, financial pressures, and a rapidly changing global health environment. The episode explores how Japan can shift from hospital-centered care toward prevention and community-based care while also rethinking its role in global health. The guests discuss why domestic reform and international collaboration must increasingly move together, and what Japan can learn from its neighbors as it prepares for 2040.

Hosts Mitsuaki Sawano, MD, and Hiroyuki Sato, MD, welcome Kazutaka Nakasone, MD (Kobe University) to discuss his JACC: Clinical Electrophysiology study on atrial tachycardia (AT) after pulsed field ablation (PFA) for atrial fibrillation. In a 5-center European registry of 4,144 patients, 76 (1.8%) underwent repeat ablation for AT. Most ATs were left atrial macroreentrant tachycardias, with approximately 86% involving dual-loop circuits. The episode explores why comprehensive left atrial mapping may be key to selecting the optimal ablation line, the impact of PVI versus posterior wall isolation, and the potential role of 3D mapping. Dr. Nakasone also shares how the study grew from his fellowship in Brussels and his experience training in Belgium.

Hosts Mitsuaki Sawano, MD, and Satoshi Shoji, MD, welcome Misato Chimura, MD, PhD (University of Glasgow) to discuss her ESC SimPub paper in JACC, “Low-normal hemoglobin concentrations and clinical outcomes in heart failure.” Using individual participant-level data from 11 randomized trials including 42,213 patients across the full LVEF spectrum, the study examined the continuous relationship between hemoglobin and clinical outcomes. Risk was lowest around 14 g/dL in women and 15 g/dL in men, while even patients just above the WHO anemia threshold had higher event rates. The episode explores why “normal” may not always mean low risk in heart failure, the role of iron deficiency, how these findings should and should not influence clinical practice, and the research environment behind the study at the University of Glasgow.

Hosts Mitsuaki Sawano, MD, and Shun Kohsaka, MD, welcome Kazuma Ohyama, MD, PhD (Tohoku University) to discuss the BRIDGE trial, Protocol-Based Implementation of Early Intensive Lipid Management After Acute Coronary Syndrome. In this 10-center cluster-randomized trial, hospitals were assigned to either protocol-based or standard lipid management after emergency PCI for ACS. Rather than simply reminding clinicians to intensify therapy, the intervention specified what treatment to initiate, when to reassess LDL-C, when to escalate therapy, and who was responsible for each step. At 6 months, LDL-C 70 mg/dL was achieved in 86.4% of patients in the protocol-based group versus 73.7% with standard care, while LDL-C 55 mg/dL was achieved in 60.8% versus 34.5%. The episode explores why implementation gaps persist despite strong evidence for statins, ezetimibe, and PCSK9 inhibitors, how cluster randomization helps evaluate system-level interventions, the practical role of CRC support and standardized care pathways, and how Japan-specific statin dosing should be considered when interpreting the results. Dr. Ohyama also shares the intense SimPub process surrounding ESC 2026, including multiple major revisions within days, and why the key message of BRIDGE is not simply that stronger drugs lower LDL-C, but that a simple, clearly assigned protocol can help translate established evidence into actual clinical practice.

Hosts Mitsuaki Sawano, MD, Takeshi Kitai, MD, PhD, Kentaro Ejiri, MD, PhD, and Satoshi Shoji, MD, PhD, highlight three JACC papers presented at ESC 2026 and simultaneously published with the meeting. Dr. Kitai discusses new HELIOS-B insights on whether the benefits of vutrisiran in transthyretin amyloidosis with cardiomyopathy are maintained among patients already receiving tafamidis. Dr. Ejiri reviews a nationwide Swedish study of nearly 500,000 heart failure hospitalizations examining how cold spells, heat waves, and non-optimal temperatures influence short-term HF risk, including the different timing of risk after rising versus falling temperatures. Dr. Shoji explores how lepodisiran, an extended-duration siRNA targeting lipoprotein(a), markedly reduces oxidized phospholipids carried by Lp(a), providing further insight into the mechanisms linking Lp(a) with cardiovascular risk. The team discusses what these findings add to current evidence, how they may translate to clinical practice in Japan, and the key questions that remain.

Hosts Mitsuaki Sawano, MD, Shun Kohsaka, MD, Nobuhiro Ikemura, MD, and Satoshi Shoji, MD, welcome Yohei Sotomi, MD, PhD (The University of Osaka), and Ken Kozuma, MD, PhD (Teikyo University) for a special episode made possible through the JACC–Lancet partnership to discuss the OPTIMA-AF trial, published in The Lancet. In this investigator-initiated, multicenter randomized trial of 1,079 patients with atrial fibrillation undergoing PCI, 1 month of DOAC plus a P2Y12 inhibitor followed by DOAC monotherapy was compared with 12 months of dual antithrombotic therapy. The 1-month strategy met the prespecified noninferiority criterion for death or thromboembolic events and reduced major or clinically relevant non-major bleeding from 8.8% to 4.5%. The episode explores whether antithrombotic therapy after PCI can safely be shortened, how intracoronary imaging and contemporary PCI may influence this balance, and how the findings should be interpreted in clinical practice. Drs. Sotomi and Kozuma also take us behind the scenes of OPTIMA-AF, from an ambitious idea born through a research competition among Osaka University-affiliated hospitals, through COVID-related enrollment challenges and a prolonged recruitment period, to an initial rejection, appeal, extensive revision, and eventual publication in The Lancet.

Hosts Mitsuaki Sawano, MD, Nobuhiro Ikemura, MD, and Satoshi Shoji, MD welcome Shunichi Doi, MD (St. Marianna University School of Medicine) to discuss his JACC: Heart Failure study, Heart Failure Duration, Cardiac Remodeling, Dysfunction, and Hemodynamic Severity in HFpEF and HFmrEF: Insights From REDUCE LAP-HF II. In this prespecified subanalysis of the REDUCE LAP-HF II trial, 522 patients with HFpEF or HFmrEF were categorized by time since heart failure diagnosis (3 years). Longer disease duration was associated with progressive left and right ventricular dysfunction, biatrial remodeling, worsening resting and exercise hemodynamics, and higher rates of heart failure events. In contrast, patients with more recent diagnoses often had normal resting filling pressures with congestion evident only during exercise, suggesting that early HFpEF may be missed by conventional evaluation. The discussion explores whether HFpEF phenotypes represent distinct disease entities or sequential stages of progression, why exercise hemodynamic testing may be critical for early diagnosis, and how identifying HFpEF before advanced remodeling develops may open opportunities for earlier intervention.

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.