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The motion of binary particles in three horizontal rotating drums with continuous rotational speed changes was studied based on the Discrete Element Method (DEM). Different simulation conditions were compared between two circular drums and an elliptical drum using the same number of physical properties for binary particles and drums, rotating at a speed series from 0.01 to 21.9 rad/s. By varying the rotational speed, four flow regimes were produced in the simulation. Flow regimes, velocity vectors, normal forces, and the number of contacts between 1 mm particles and 3 mm particles were comparatively analyzed, especially the particle velocity at transient changing rotational speeds. The results showed that four flow regimes were found at the same rotational speed for three different rotating drums, and normal forces were weakest for the cataracting regime; moreover, the three layers of particles were damaged when the rotational speed was suddenly decreased and the velocity direction of the particle motion was changed at the top of the particles' bed. The maximum number of contacts was found with the rolling regime, based on the simulation results. The number of contacts of the major axis circular drum was smaller than for the minor axis at the same rotational speed, and the number of contacts of the elliptical drum was the largest among the three rotating drums. [ABSTRACT FROM AUTHOR]

Background: Myocardial bridging (MB) is commonly treated in patients with hypertrophic cardiomyopathy. However, whether and how MB should be treated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remain unclear. Methods: A total of 823 adults with HOCM who underwent septal myectomy at the Fuwai Hospital from 2011 to 2017 were retrospectively studied. Results: Overall, 31 events occurred: 24 patients died and 7 had nonfatal myocardial infarction (MI). The 3‐year cumulative event‐free survival of all‐cause death (97.9% vs. 100% vs. 100% vs. 98.4%, p =.89) and cardiovascular death (98.3% vs. 100% vs. 100% vs. 98.4%, p =.63) were similar among the four groups (non‐MB, coronary artery bypass grafting [CABG], unroofing, untreated, respectively). However, the 3‐year cumulative event‐free survival of nonfatal MI (100% vs. 97.5% vs. 98.0% vs. 89.9%, p <.001) and combined endpoints (97.9% vs. 97.5% vs. 98.0% vs. 88.4%, p =.02) were significantly lowest in untreated MB (non‐MB, CABG, unroofing, untreated, respectively). Cox regression analysis indicated that untreated MB was a significant independent predictor of combined endpoints (hazard ratio: 4.06, 95% confidence interval: 1.60–10.32, p <.001). Moreover, 49 patients underwent coronary artery computed tomography 1 year after surgery. The patency rate of the saphenous vein graft was significantly higher than that of the left internal mammary artery (13.3% vs. 84.2%, p <.001). No MB was detected in the unroofing group. Conclusions: Surgical MB treatment could be beneficial and performed safely during septal myectomy. Myocardial unroofing is the recommended treatment for MB, and unroofing when technically possible may be preferable for long‐term outcomes. [ABSTRACT FROM AUTHOR]

Background: Postoperative atrial fibrillation (POAF) is a common complication in patients with obstructive hypertrophic cardiomyopathy (HOCM) who undergo surgical myectomy. POAF is associated with poor outcome. The role of plasma big endothelin-1 level in predicting atrial fibrillation after surgical septal myectomy in HOCM patients has not well been studied.Methods: A total of 118 patients with HOCM who underwent surgical septal myectomy were recruited in this study. Plasma big endothelin-1 level was measured. The heart rhythm was continuously monitored during hospital stay. Preoperative, intraoperative, and postoperative variables were collected.Results: POAF developed among 26 of the 118 patients (22%) in this study. Compared with those without POAF, patients with POAF were significantly older (53.5 ± 10.6 vs. 47.3 ± 13.6 years, P = 0.033), more likely to undergo mitral valve surgery (38.5% vs. 18.5%, P = 0.032), and had higher plasma big endothelin-1 levels (0.41 ± 0.19 vs. 0.27 ± 0.14 pmol/l, P = 0.001), longer hospital stay (9.1 ± 3.7 vs. 7.5 ± 2.8 days, P = 0.022), larger preoperative left atria (48.0 ± 5.2 vs. 44.1 ± 5.9 mm; P = 0.003). In the receiver operating characteristic curve analysis, the area under the curve for big endothelin-1 was 0.734 (95% CI, 0.634 to 0.834, P<0.001). In multivariate logistic regression analysis, preoperative big endothelin-1 level (OR 100.7, 95%CI: 5.0-2020.0, P = 0.003) and left atrial diameter (OR 1.106, 95%CI: 1.015-1.205, P = 0.022) were independent predictors of POAF.Conclusion: Elevated preoperative plasma big endothelin-1 level is an independent predictor of POAF in HOCM patients undergoing surgical septal myectomy. [ABSTRACT FROM AUTHOR]

Background and Objectives: The relationship between physical frailty, age-related conditions, and the incidence of degenerative valvular heart disease (VHD) remains unclear. This study aimed to investigate the potential association between physical frailty and the development of degenerative VHD., Research Design and Methods: Participants from the UK Biobank who were initially free of VHD and heart failure were categorized into 3 groups based on the frailty phenotype: non-frailty, pre-frailty, and frailty. The frailty phenotype was determined by evaluating the following 5 components: weight loss, exhaustion, reduced physical activity, slow gait speed, and low grip strength. The incidence of degenerative VHD, including mitral valve regurgitation (MR), aortic valve regurgitation (AR), and aortic valve stenosis (AS), was assessed using hospital admission or death registries., Results: Among the 331 642 participants, 11 885 (3.6%) exhibited frailty and 143 379 (43.2%) were categorized as pre-frailty. During a median follow-up of 13.8 years, there were 3 684 MR, 1 205 AR, and 3 166 AS events. Compared to non-frailty participants, those with pre-frailty and frailty showed significantly increased risks for MR (hazard ratio [HR], HR pre-frailty :1.19, 95% confidence interval [CI]: 1.11-1.28; HR frailty : 1.50, 95% CI: 1.30-1.74), AR (HR pre-frailty :1.19, 95% CI: 1.05-1.34; HR frailty : 1.58, 95% CI: 1.22-2.04), and AS (HR pre-frailty :1.19, 95% CI: 1.11-1.29; HR frailty : 1.74, 95% CI: 1.51-2.00). Among the 5 components, slow gait speed showed the strongest association with the risk of various types of VHD (HR MR : 1.50, 95% CI: 1.34-1.65; HR AR : 1.50, 95% CI: 1.24-1.80; HR AS : 1.46, 95% CI: 1.32-1.62), followed by exhaustion, low grip strength, and weight loss., Discussion and Implications: Pre-frailty and frailty were associated with a higher risk of all 3 types of degenerative VHD. Early detection and intervention for pre-frailty and frailty in middle-aged and older individuals may assist in preventing or delaying the onset of degenerative VHD., Competing Interests: All authors declare no conflict of interest. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Gerontological Society of America.)

Background Sarcomere gene mutation and myocardial fibrosis are both associated with poorer clinical outcomes in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to determine the relationship between sarcomere gene mutation and myocardial fibrosis measured by both histopathology and cardiac magnetic resonance (CMR). Methods and Results Two hundred twenty-seven patients with HCM who underwent surgical treatment, genetic testing, and CMR were enrolled. We retrospectively analyzed basic characteristics, sarcomere gene mutation, and myocardial fibrosis measured by CMR and histopathology. In our study, the mean age was 43 years, and 152 patients (67.0%) were men. A total of 107 patients (47.1%) carried a positive sarcomere gene mutation. The myocardial fibrosis ratio was significantly higher in the late gadolinium enhancement (LGE)+ group (LGE+ 14.3±7.5% versus LGE- 9.0±4.3%; P =0.001). Patients with HCM with SARC+ showed a high probability of fibrosis both in histopathology (myocardial fibrosis ratio 15.3±8.0% versus 12.4±6.5%; P =0.003) and CMR examination (LGE+ 98.1% versus 84.2%; P <0.001; LGE quantification 8.3% versus 5.8%; P <0.001). Linear regression analysis showed that sarcomere gene mutation (B=2.661; P =0.005) and left atrial diameter (B=0.240; P =0.001) were related factors for histopathological myocardial fibrosis. Also, the myocardial fibrosis ratio was significantly higher in the MYH7 (myosin heavy chain) group ( MYH7 18.1±9.6% versus MYBPC3 [myosin binding protein C] 13.1±5.2%; P =0.019). Conclusions Patients with HCM with positive sarcomere gene mutation had a higher myocardial fibrosis extent than patients without mutation, and a significant difference in myocardial fibrosis was also observed between the MYBPC3 and MYH7 groups. In addition, a high consistency was found between CMR-LGE and histopathological myocardial fibrosis in patients with HCM.

Background Obesity is an established cardiovascular risk factor in patients with hypertrophic cardiomyopathy. Postoperative atrial fibrillation (POAF) is one of the most common complications after surgery in patients with obstructive hypertrophic cardiomyopathy (OHCM). We aimed to determine the impact of body mass index (BMI) on the occurrence of POAF in patients with OHCM who underwent septal myectomy. Methods and Results In all, 712 OHCM patients without previous atrial fibrillation who underwent septal myectomy were identified. Patients were stratified into 3 groups based on BMI. Of these, 224 (31.5%) had normal weight (BMI<24 kg/m 2 ), 339 (47.6%) were overweight (BMI, 24 to <28 kg/m 2 ), and 149 (20.9%) were obese (BMI≥28 kg/m 2 ). Overweight and obese patients had increased levels of left atrial diameter ( P <0.001) and left ventricular end-diastolic diameter ( P <0.001), compared with patients with normal weight. Among 184 patients (25.8%) developing POAF, 32 cases (14.3%) occurred in the normal weight group, 100 cases (29.5%) occurred in the overweight group, and 52 cases (34.9%) occurred in the obese group ( P <0.001). Logistic regression analysis indicated that overweight (odds ratio [OR]: 2.161, 95% CI, 1.333-3.503; P =0.002) or obesity (OR, 2.803; 95% CI, 1.589-4.944; P <0.001), age (OR, 1.037; 95% CI, 1.018-1.057; P <0.001), and left atrial diameter (OR, 1.060; 95% CI, 1.027-1.095; P <0.001) were independently associated with the occurrence of POAF in patients with OHCM. Conclusions Overweight and obesity are strong predictors of POAF in patients with OHCM. Strategies aimed at lowering BMI may be a potential way to prevent POAF.

Background: Ventricular late potentials (VLPs) detected by signal-averaged electrocardiogram are considered as an indicator of electrical instability in diseased myocardium. Little information exists about the VLPs and their effects on clinical prognosis in patients with obstructive hypertrophic cardiomyopathy (OHCM) undergoing septal myectomy., Methods: Patients with OHCM who underwent septal myectomy from January 2019 to December 2019 were prospectively enrolled. All patients underwent signal-averaged electrocardiogram. Patients were subsequently divided into two groups based on the presence or absence of VLPs. All patients were followed up after surgery to obtain information of survival status and adverse events, including all-cause mortality, congestive heart failure requiring hospitalization, new-onset stroke, and unexplained syncope., Results: In total, 128 patients (47.5±12.8 years, 57.8% male) were enrolled. There were 21 (16.4%) individuals in the VLPs-positive group and 107 (83.6%) individuals in the VLPs-negative group. There were no statistically significant differences in non-sustained ventricular tachycardia and late gadolinium enhancement on cardiovascular magnetic resonance images between the two groups. Eight adverse events were reported at the 14.9±4.1 months follow-up. The rates of adverse events in groups of VLPs-positive and VLPs-negative were 23.8% (5/21) and 2.8% (3/107) of cases, respectively. These events included three patients hospitalized for heart failure, two who experienced ischemic strokes, and three with unexplained syncope, respectively. Patients in the VLPs-positive group had a higher risk of adverse events than those in the VLPs-negative group (P<0.001). The presence of positive VLPs (hazard ratio =9.095, 95% confidence intervals: 2.080-39.776, P=0.003) was a strong independent risk factor of adverse events by multivariate Cox regression analysis. Cardiac function Class III or IV, as defined by the New York Heart Association classification, was also an independent risk factor of adverse events (hazard ratio =13.756, 95% confidence intervals: 1.667-113.510, P=0.015)., Conclusions: VLPs may increase the risk of adverse events in patients with OHCM after septal myectomy, which may be used as a screening test for further risk stratification.

Background: Red blood cell distribution width (RDW) is associated with increased morbidity and mortality in several cardiovascular diseases. However, the prognostic significance of RDW in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remains unclear as no studies have been conducted on this topic. This study aimed to assess the prognostic significance of RDW in these patients., Methods: A total of 867 adults with HOCM who underwent septal myectomy at Fuwai Hospital from 2011 to 2017 were retrospectively studied. All patients were assessed comprehensively, including their medical history, echocardiograms, and blood test results., Results: The median age of patients was 47.9 [interquartile range (IQR), 37.0-56.0] years and 61.5% of patients were men. During a median follow-up period of 32 (IQR, 17-53) months, 26 patients died and 23 had a cardiovascular death during follow-up. Compared to patients in the lowest RDW quartile, those in the highest quartile had a significantly lower 5-year survival free from all-cause and cardiovascular death (95.9% vs. 87.6%, P<0.001; 95.9% vs. 89.9%, P<0.001). Compared with lower RDW, higher RDW was significantly associated with all-cause and cardiovascular death after adjustment for age, sex, body mass index, and relevant clinical risk factors [per RDW standard deviation (SD) hazard ratio (HR) increase =1.76, 95% confidence interval (CI): 1.54-2.05, P<0.001; per RDW SD HR =1.91, 95% CI: 1.63-2.22, P for trend <0.001]., Conclusions: Higher RDW is independently associated with all-cause and cardiovascular death in patients with HOCM after septal myectomy. Therefore, this readily available biomarker could be considered as an additive biomarker for risk stratification in these patients., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jtd-20-2528). The authors have no conflicts of interest to declare., (2021 Journal of Thoracic Disease. All rights reserved.)

There is limited information on long-term outcomes of mitral valve repair for mitral regurgitation (MR) caused by different degrees of myxomatous degeneration. The aim of this study was to compare the surgical results of patients with advanced and mild/moderate myxomatous mitral valve degeneration (MVD). We identified 130 patients (25 advanced and 105 mild/moderate MVD patients) who underwent mitral valve repair for MR and were pathologically diagnosed as myxomatous degeneration. Follow-up was 100% complete (mean length, 5.1 ± 1.8 years). Survival differed significantly between the advanced and mild/moderate MVD groups (76.0 ± 9.7% versus 95.0 ± 5.4% at 8 years, P < 0.001). The univariate predictors of mortality were advanced myxomatous degeneration, recurrent MR, and early series (surgeries before 2011). The mild/moderate MVD group had higher freedom from a moderate or severe MR rate compared with the advanced MVD group (77.4 ± 4.5% versus 50.5 ± 10.2% at 7 years, P = 0.003). Multivariable Cox analysis revealed advanced myxomatous degeneration and residual MR as independent predictors of recurrent moderate or severe MR. A total of 25 patients (19.2%) had persistent atrial fibrillation (AF) after repair. In multivariate analysis, advanced myxomatous degeneration was found to be an independent predictor of postoperative persistent AF.In conclusion, the long-term outcomes of mitral valve repair in patients with advanced MVD are poorer than in those with mild/moderate MVD. Advanced myxomatous degeneration is an independent predictor of recurrent moderate or severe MR and postoperative persistent AF in MVD patients performing repair, which deserves more attention before and after surgery.