Background The term “takotsubo cardiomyopathy” is commonly used in clinical practice. learn more However, there is conceptual problem with the term “cardiomyopathy” in this context because “cardiomyopathy” implies a primary and chronic myocardial disease of unknown etiology. In this study we reviewed the literature related to takotsubo cardiomyopathy to investigate whether it is appropriate to use the term “cardiomyopathy” for this condition. Methods and Results A literature review revealed that this condition was originally described in 1990 in Japan as postischemic myocardial stunning with unique left ventricular apical ballooning and that it gradually gained global attention thereafter. Subsequently, the term “takotsubo cardiomyopathy” was introduced to describe this heart failure phenotype. However, this term has been called into question because several recent studies investigating the mechanism underlying this condition have provided evidence of myocardial ischemia possibly due to microvascular dysfunction. The term “takotsubo syndrome” was suggested to describe this microvascular acute coronary syndrome, which is in agreement with the original description of the condition as myocardial stunning following acute myocardial ischemia. Conclusions Based on the accumulating evidence of acute myocardial ischemia due to microvascular dysfunction as the mechanism underlying this condition, in addition to the fact that the term “cardiomyopathy” literally implies a primary and chronic myocardial disease, it is advisable that the term “takotsubo syndrome” is used until the etiology and underlying mechanism of this condition are fully clarified.Background Post hoc analysis was used to investigate the effects of renal function on the efficacy and safety of landiolol using data from the J-Land II study, which evaluated landiolol in patients with hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF) who were refractory to Class III antiarrhythmic drugs. Methods and Results Patient data from the J-Land II study (n=29) were stratified by renal function (estimated glomerular filtration rate [eGFR] less then 45 and ≥45 mL/min/1.73 m2) and analyzed. Continuous landiolol infusion (1 μg/kg/min, i.v.) was initiated after VT/VF was suppressed with electrical defibrillation; subsequent dose adjustments were made (1-40 μg/kg/min). The primary efficacy endpoint was the proportion of patients free from recurrent VT/VF during the assessment period. Safety endpoints were also assessed. In the eGFR less then 45 and ≥45 mL/min/1.73 m2 groups, the median doses of landiolol during the assessment period were 9.44 and 8.97 μg/kg/min, the proportions of patients free from recurrent VT/VF were 69.2% and 81.8%, and adverse events occurred in 9 and 10 of 13 patients in each group, respectively. There were no apparent differences in the efficacy or safety of landiolol between the 2 groups. Conclusions The data suggest that renal function may not affect the efficacy and safety of landiolol for hemodynamically unstable VT or VF.Background Sudden cardiac death (SCD) is a most devastating complication of hypertrophic cardiomyopathy (HCM). The aim of this study was to clarify the clinical features of HCM in patients who experienced SCD-relevant events in an aged Japanese community. Methods and Results In 2004, we established a cardiomyopathy registration network in Kochi Prefecture, and herein report on 293 patients with HCM who are followed as part of the registry. The mean (±SD) age at registration and diagnosis was 63±14 and 56±16 years, respectively. SCD-relevant events occurred in 19 patients during a mean follow-up period of 6.1±3.2 years (incidence rate 1.0%/year) sudden death in 9 patients, successful recovery from cardiopulmonary arrest in 4 patients, and appropriate implantable cardioverter-defibrillator discharge in 6 patients. At registration, 13 patients were in the dilated phase of HCM (D-HCM). During the follow-up period, HCM developed to D-HCM in 21 patients; thus, 34 patients in total had D-HCM. Multivariate analysis revealed that D-HCM at registration or during follow-up and detection of non-sustained ventricular tachycardia (NSVT) during follow-up were significant predictors of SCD-relevant events. Conclusions In this HCM population in an aged Japanese community, the annual rate of SCD-relevant events was 1.0%. HCM developed to D-HCM in a considerable number of patients, and D-HCM and NSVT were shown to be independently associated with an increased risk of SCD-relevant events.Background Monocarboxylate transporter 9 (MCT9), an orphan transporter member of the solute carrier family 16 (SLC16), possibly reabsorbs uric acid in the renal tubule and has been suggested by genome-wide association studies to be involved in the development of hyperuricemia and gout. In this study we investigated the mechanisms regulating the expression of human (h) MCT9, its degradation, and physiological functions. Methods and Results hMCT9-FLAG was stably expressed in HEK293 cells and its degradation, intracellular localization, and urate uptake activities were assessed by pulse-chase analysis, immunofluorescence, and [14C]-urate uptake experiments, respectively. hMCT9-FLAG was localized on the plasma membrane as well as in the endoplasmic reticulum and Golgi apparatus. The proteasome inhibitors MG132 and lactacystine increased levels of hMCT9-FLAG protein expression with enhanced ubiquitination, prolonged their half-life, and decreased [14C]-urate uptake. [14C]-urate uptake was increased by both heat shock (HS) and the HS protein inducer geranylgeranylacetone (GGA). Both HS and GGA restored the [14C]-urate uptake impaired by MG132. Conclusions hMCT9 does transport urate and is degraded by a proteasome, inhibition of which reduces hMCT9 expression on the cell membrane and urate uptake. HS enhanced urate uptake through hMCT9.Background Transthyretin amyloid cardiomyopathy is a progressive disease with a poor prognosis. There had been no specific treatment for transthyretin amyloid cardiomyopathy until tafamidis received expanded approval in March 2019 in Japan. However, the clinical efficacy of tafamidis remains unknown. Methods and Results We initiated tafamidis treatment in 9 patients (median age 78 years; 89% male) from May 2019 to April 2020. Within 6 months after initiation, 1 patient discontinued prematurely and 2 patients were hospitalized due to worsening heart failure, with 1 of these patients discontinuing therapy. There were no significant changes in plasma B-type natriuretic peptide and serum troponin I concentrations over the 6-month treatment period, but interventricular septum thickness increased in 3 of 6 patients. Conclusions Further evaluation of tafamidis therapy in a larger patient cohort with transthyretin amyloid cardiomyopathy is warranted to determine the optimal therapeutic strategy.