Distinct Roles of Zmynd17 and PGC1α in Mitochondrial Quality Control and Biogenesis in Skeletal Muscle

Maintaining skeletal muscle mitochondrial quality is important not only for muscle activity but also for systemic metabolism. Exercise has long been recognized to have a positive impact on muscle mitochondrial quality. Although exercise triggers various changes in the mitochondrial dynamics, its molecular basis remains to be elucidated. We have previously reported that inactivation of the muscle-specific protein, zinc finger MYND domain-containing protein 17 (Zmynd17), results in mitochondrial abnormalities. To investigate the link between Zmynd17 activity and exercise-induced mitochondrial maintenance, we observed the effect of consecutive exercise on the mitochondrial quality in Zmynd17-deficient muscles. Zmynd17-deficient mice displayed abnormal mitochondrial morphology in limb muscles, which remarkably improved upon voluntary exercise. Interestingly, morphological abnormalities in mitochondria were even more apparent when PGC1α, a regulator of exercise-induced mitochondrial biogenesis, was overexpressed in Zmynd17-KO limb muscle. These abnormalities were also ameliorated by voluntary exercise. Our results show that neither the effect of consecutive exercise on mitochondrial quality nor PGC1α-induced mitochondrial biogenesis are mediated through Zmynd17 activity, thereby suggesting the existence of a complex mechanism of mitochondrial quality control in muscles

Development of a novel artificial intelligence algorithm to detect pulmonary nodules on chest radiography

Background: In this study, we aimed to develop a novel artificial intelligence (AI) algorithm to support pulmonary nodule detection, which will enable physicians to efficiently interpret chest radiographs for lung cancer diagnosis. Methods: We analyzed chest X-ray images obtained from a health examination center in Fukushima and the National Institutes of Health (NIH) Chest X-ray 14 dataset. We categorized these data into two types: type A included both Fukushima and NIH datasets, and type B included only the Fukushima dataset. We also demonstrated pulmonary nodules in the form of a heatmap display on each chest radiograph and calculated the positive probability score as an index value. Results: Our novel AI algorithms had a receiver operating characteristic (ROC) area under the curve (AUC) of 0.74, a sensitivity of 0.75, and a specificity of 0.60 for the type A dataset. For the type B dataset, the respective values were 0.79, 0.72, and 0.74. The algorithms in both the type A and B datasets were superior to the accuracy of radiologists and similar to previous studies. Conclusions: The proprietary AI algorithms had a similar accuracy for interpreting chest radiographs when compared with previous studies and radiologists. Especially, we could train a high quality AI algorithm, even with our small type B data set. However, further studies are needed to improve and further validate the accuracy of our AI algorithm

A comparison between hospital follow‐up and collaborative follow‐up in patients with acute heart failure

AIMS: There are no previous studies focusing on collaborative follow-ups between hospitals and clinics for patients discharged after acute heart failure (AHF) in Japan. The purpose of this study was to determine the status of collaboration between hospitals and clinics for patients with AHF in Japan and to compare patient characteristics and clinical outcomes using a large Japanese observational database. METHODS AND RESULTS: Of 4056 consecutive patients hospitalized for AHF in the Kyoto Congestive Heart Failure registry, we analysed 2862 patients discharged to go home, who were divided into 1674 patients (58.5%) followed up at hospitals with index hospitalization (hospital follow-up group) and 1188 (41.5%) followed up in a collaborative fashion with clinics or other general hospitals (collaborative follow-up group). The primary outcome was a composite of all-cause death or heart failure (HF) hospitalization within 1 year after discharge. Previous hospitalization for HF and length of hospital stay longer than 15 days were associated with hospital follow-up. Conversely, ≥80 years of age, hypertension, and cognitive dysfunction were associated with collaborative follow-up. The cumulative 1-year incidence of the primary outcome, all cause death, and cardiovascular death were similar between the hospital and collaborative follow-up groups (31.6% vs. 29.6%, P = 0.51, 13.1% vs, 13.9%, P = 0.35, 8.4% vs. 8.2%, P = 0.96). Even after adjusting for confounders, the difference in risk for patients in the hospital follow-up group relative to those in the collaborative follow-up group remained insignificant for the primary outcome, all-cause death, and cardiovascular death (HR: 1.11, 95% CI: 0.97-1.27, P = 0.14, HR: 1.10, 95% CI: 0.91-1.33, P = 0.33, HR: 0.96, 95% CI: 0.87-1.05, P = 0.33). The cumulative 1-year incidence of HF hospitalization was higher in the hospital follow-up group than in the collaborative follow-up group (25.5% vs. 21.3%, P = 0.02). The risk of HF hospitalization was higher in the hospital follow-up group than in the collaborative follow-up group (HR: 1.19, 95% CI: 1.01-1.39, P = 0.04). CONCLUSIONS: In patients hospitalized for AHF, 41.5% received collaborative follow-up after discharge. The risk of HF hospitalization was higher in the hospital follow-up group than in the collaborative follow-up, although risk of the primary outcome, all-cause death, and cardiovascular death were similar between groups

Prognostic value of reduction in left atrial size during a follow-up of heart failure: an observational study

OBJECTIVE: The association between sequential changes in left atrial diameter (LAD) and prognosis in heart failure (HF) remains to be elucidated. The present study aimed to investigate the link between reduction in LAD and clinical outcomes in patients with HF. DESIGN: A multicentre prospective cohort study. SETTING: This study was nested from the Kyoto Congestive Heart Failure registry including consecutive patients admitted for acute decompensated heart failure (ADHF) in 19 hospitals throughout Japan. PARTICIPANTS: The current study population included 673 patients with HF who underwent both baseline and 6-month follow-up echocardiography with available paired LAD data. We divided them into two groups: the reduction in the LAD group (change <0 mm) (n=398) and the no-reduction in the LAD group (change ≥0 mm) (n=275). PRIMARY AND SECONDARY OUTCOMES: The primary outcome measure was a composite of all-cause death or hospitalisation for HF during 180 days after 6-month follow-up echocardiography. The secondary outcome measures were defined as the individual components of the primary composite outcome measure and a composite of cardiovascular death or hospitalisation for HF. RESULTS: The cumulative 180-day incidence of the primary outcome measure was significantly lower in the reduction in the LAD group than in the no-reduction in the LAD group (13.3% vs 22.2%, p=0.002). Even after adjusting 15 confounders, the lower risk of reduction in LAD relative to no-reduction in LAD for the primary outcome measure remained significant (HR 0.59, 95% CI 0.36 to 0.97 p=0.04). CONCLUSION: Patients with reduction in LAD during follow-up after ADHF hospitalisation had a lower risk for a composite endpoint of all-cause death or HF hospitalisation, suggesting that the change of LAD might be a simple and useful echocardiographic marker during follow-up

Improved and new-onset anemia during follow-up in patients with acute decompensated heart failure

There was no previous report on the prognostic impact of new-onset or improved anemia after discharge from acute decompensated heart failure (ADHF).We analyzed 771 patients with ADHF and who were followed in multicenters in Japan was divided into 4 groups based on the hemoglobin values at discharge and 6-month index visit: 373 patients (48.4%) with persistent anemia, 87 patients (11.3%) with new-onset anemia, 91 patients (11.8%) with improved anemia, and 220 patients (28.5%) without anemia.The primary outcome measure was a composite of all-cause death or HF hospitalization after index visit. The cumulative 6-month incidences of the primary outcome measure were 25.2% for persistent anemia, 18.5% for new onset anemia, 9.0% for improved anemia, and 9.2% for no anemia (log-rank P < .001). Compared with the no anemia group, the excess risk for the primary outcome measure remained significant in the persistent anemia group [hazard ratio (HR) 2.70, 95% confidence interval (95% CI), 1.45-5.44, P = .001] and in the new-onset anemia group (HR 2.73, 95% CI 1.19-6.25, P = .02), while it was not significant in the improved anemia group (HR 1.69, 95% CI 0.68-4.03, P = .25).Persistent and new-onset anemia at 6-month visit were associated with a subsequent higher risk for all-cause death or HF hospitalization in patients with ADHF, suggesting the importance of detecting anemia during follow-up

Left atrial reverse remodeling improves risk stratification in patients with heart failure with recovered ejection fraction

We aimed to investigate the relationship between left atrial (LA) reverse remodeling and prognosis of heart failure (HF) with recovered ejection fraction (EF) (HFrecEF). Among 1, 246 patients with acute heart failure enrolled in the prospective longitudinal follow-up study, 397 patients with HF with mildly-reduced EF and with reduced EF at discharge were analyzed. Echocardiography was performed during the index hospitalization and at the 6-month follow-up after discharge. They were divided into non-HFrecEF (n = 227) and HFrecEF (n = 170) groups. The primary outcome measure was a composite of all-cause death or hospitalization for HF. The cumulative 180-day incidence of the primary outcome measure after follow-up echocardiography was significantly lower in the HFrecEF group than in the non-HFrecEF group (8.9% versus 23.4%, log-rank P = 0.0002). LA reverse remodeling was associated with a lower cumulative 6-month incidence of the primary outcome measure in the HFrecEF group (4.7% versus 18.0%; HR: 0.27, 95%CI: 0.09-0.79, P = 0.01), but not in the non-HFrecEF group (24.4% versus 22.6%; HR: 1.13, 95%CI: 0.65-1.96, P = 0.28) with a significant LA reverse remodeling-by-HFrecEF interaction (P for interaction = 0.02). Combination of left ventricular and atrial reverse remodeling may help in improving HF risk stratification

Serum cholinesterase as a prognostic biomarker for acute heart failure

[Aims]The association between serum cholinesterase and prognosis in acute heart failure (AHF) remains to be elucidated. We investigated the serum cholinesterase level at discharge from hospitalization for AHF and its association with clinical outcomes in patients with AHF. [Methods and results]Among 4056 patients enrolled in the Kyoto Congestive Heart Failure multicentre registry, we analysed 2228 patients with available serum cholinesterase data. The study population was classified into three groups according to serum cholinesterase level at discharge: low tertile (<180 U/L, N = 733), middle tertile (≥180 U/L and <240 U/L, N = 746), and high tertile (≥240 U/L, N = 749). Patients in the low tertile had higher tricuspid pressure gradient, greater inferior vena cava diameter, and higher brain natriuretic peptide (BNP) levels than those in the high tertile. The cumulative 1-year incidence of the primary outcome measure (a composite endpoint of all-cause death and hospitalization for HF) was higher in the low and middle tertiles than in the high tertile [46.5% (low tertile) and 31.4% (middle tertile) vs. 22.1% (high tertile), P < 0.0001]. After adjustment for 26 variables, the excess risk of the low tertile relative to the high tertile for the primary outcome measure remained significant (hazard ratio 1.37, 95% confidence interval 1.10–1.70, P = 0.006). Restricted cubic spline models below the median of cholinesterase demonstrated incrementally higher hazards at low cholinesterase levels. [Conclusions]Low serum cholinesterase levels are associated with congestive findings on echocardiography, higher BNP, and higher risks for a composite of all-cause death and HF hospitalization in patients with AHF