Hosts Mitsuaki Sawano, MD, Shun Kohsaka, MD, and Nobuhiro Ikemura, MD, welcome Masashi Amano, MD, from the National Cerebral and Cardiovascular Center in Japan, to discuss his recent article titled "Validation of Guideline Recommendation on Sudden Cardiac Death Prevention in Hypertrophic Cardiomyopathy," published in JACC: Heart Failure.Drawing from the REVEAL-HCM registry of 3,611 patients across 21 Japanese centers, the study evaluated how well U.S. and European guidelines for ICD implantation apply to Japanese patients with HCM. The findings revealed poor outcomes in end-stage HCM (EF <50%) and favorable prognosis in apical HCM, a subtype more prevalent in Japan. Dr. Amano discusses the limitations of applying international risk stratification tools in a Japanese context and emphasizes the need for regional validation.