First-in-Human Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy.

BACKGROUND: To simplify surgical septal reduction therapy for hypertrophic obstructive cardiomyopathy (HOCM), we developed a novel transapical beating-heart septal myectomy (TA-BSM) procedure. OBJECTIVES: In this study, we sought to evaluate the clinical utility of TA-BSM in a first-in-human trial. METHODS: Patients with HOCM were enrolled if they presented with drug-refractory disabling symptoms. TA-BSM was performed via minithoracotomy with the use of our beating-heart myectomy device under echocardiographic guidance, without the use of cardiopulmonary bypass. Repeated resections were performed to tailor the extent of the septal myectomy for sufficient abolishment of left ventricular outflow tract (LVOT) obstruction and mitral regurgitation (MR). The primary outcome measure was procedural success, defined by resting/provoked LVOT gradient <30/50 mm Hg and residual MR grade ≤1+ (of 4+) at 3-month follow-up. RESULTS: A total of 47 patients aged 12 to 77 years were enrolled. Of the 46 patients who were followed for 3 months, 42 achieved procedural success. The maximal LVOT gradient decreased from 86 mm Hg (IQR: 67-114 mm Hg) at baseline to 19 mm Hg (IQR: 14-28 mm Hg) at 3 months. MR grade was ≤1+ in 3 patients at baseline and in 45 patients at 3 months. One patient died on postoperative day 10 owing to device-unrelated reasons. Other major adverse events included 1 delayed ventricular septal perforation and 1 intraoperative left ventricular apical tear. CONCLUSIONS: TA-BSM is a safe and efficient minimally invasive procedure for septal reduction of heterogeneous HOCM. Compared with conventional septal myectomy, TA-BSM provides real-time evaluation to guide resection while reducing surgical trauma. (Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy; NCT05332691).

Lineage-specific regulatory changes in hypertrophic cardiomyopathy unraveled by single-nucleus RNA-seq and spatial transcriptomics.

Hypertrophic cardiomyopathy (HCM) is the most common cardiac genetic disorder characterized by cardiomyocyte hypertrophy and cardiac fibrosis. Pathological cardiac remodeling in the myocardium of HCM patients may progress to heart failure. An in-depth elucidation of the lineage-specific changes in pathological cardiac remodeling of HCM is pivotal for the development of therapies to mitigate the progression. Here, we performed single-nucleus RNA-seq of the cardiac tissues from HCM patients or healthy donors and conducted spatial transcriptomic assays on tissue sections from patients. Unbiased clustering of 55,122 nuclei from HCM and healthy conditions revealed 9 cell lineages and 28 clusters. Lineage-specific changes in gene expression, subpopulation composition, and intercellular communication in HCM were discovered through comparative analyses. According to the results of pseudotime ordering, differential expression analysis, and differential regulatory network analysis, potential key genes during the transition towards a failing state of cardiomyocytes such as FGF12, IL31RA, and CREB5 were identified. Transcriptomic dynamics underlying cardiac fibroblast activation were also uncovered, and potential key genes involved in cardiac fibrosis were obtained such as AEBP1, RUNX1, MEOX1, LEF1, and NRXN3. Using the spatial transcriptomic data, spatial activity patterns of the candidate genes, pathways, and subpopulations were confirmed on patient tissue sections. Moreover, we showed experimental evidence that in vitro knockdown of AEBP1 could promote the activation of human cardiac fibroblasts, and overexpression of AEBP1 could attenuate the TGFß-induced activation. Our study provided a comprehensive analysis of the lineage-specific regulatory changes in HCM, which laid the foundation for targeted drug development in HCM.

Sex differences in atrial remodeling and its relationship with myocardial fibrosis in hypertrophic obstructive cardiomyopathy.

Background: This study aimed to explore the effect of sex on left atrial (LA) remodeling and its relationship with myocardial fibrosis in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods and results: A total of 85 patients with HOCM were enrolled. Myocardial fibrosis was quantified by the collagen volume fraction (CVF) in myocardial samples. The early atrial peak of emptying rate (PER-E) was assessed by LA volume/time (V/t) curves derived from cardiac magnetic resonance (CMR) imaging analysis. The PER-E index was PER-E normalized by left ventricular (LV) filling volume. Patients with HOCM showed a lower PER-E index than healthy controls (P = 0.027). Compared with men, the PER-E (P < 0.001) and the PER-E indexes (P = 0.012) in women were lower. In CVF-stratified subgroups, a sex difference in the PER-E index was eliminated (P > 0.05). The CVF was correlated with the PER-E and PER-E indexes in both sexes (all P-values were <0.05). In multivariate regression analysis, sex (P = 0.007) and CVF (P < 0.001) were independently correlated with PER-E (all P-values were <0.05). Conclusion: Patients with HOCM presented LA reverse remodeling. Impaired LA function was more common in female patients with HOCM due to their susceptibility to myocardial fibrosis.

Long-term outcome prediction for chronic thromboembolic pulmonary hypertension after pulmonary endarterectomy.

BACKGROUND: The definitive treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA), which has good long-term outcomes. However, after surgery, a quarter of the patients still have residual pulmonary hypertension (RPH). In pulmonary hemodynamics, there are no unified criteria for RPH, even though the level may affect long-term survival. METHODS: Between March 1997 and December 2021, 253 CTEPH patients were treated at our center with PEA. Patients were evaluated retrospectively and classified into early (1997-2014) and late (2015-2021) groups. The clinical characteristics and perioperative outcomes of the two groups were compared, and risk factor analysis for RPH and long-term survival for all cases was performed. RESULTS: There was no statistically significant difference in demographics between the two groups. However, the Early Group had a significantly higher rate of perioperative death (9.8% vs. 1.2%, p = .001), RPH (48.8% vs. 14.0%, p < .001), and reperfusion pulmonary edema (18.3% vs. 2.9%, p < .001). The median follow-up time was 66.0 months, and overall survival rates at 5, 10, 15, and 18 years after PEA were 91.2%, 83.9%, 64.5%, and 46.0%, respectively. Age and postoperative systolic pulmonary artery pressure (sPAP) were independently related to long-term outcomes in the multivariate Cox analyses. Patients with postoperative sPAP less than 46 mm Hg had a higher chance of survival. CONCLUSIONS: PEA improved CTEPH hemodynamics immediately and had a positive effect on long-term survival. Patients with postoperative sPAP ≥ 46 mm Hg indicate clinically significant RPH and have a lower long-term survival rate.

Bioprosthetic mitral valve stenosis secondary to hypereosinophilic syndrome.

Herein we present a case of hypereosinophilic syndrome (HES) with recurrent involvement of mitral valve. The patient developed mitral regurgitation secondary to HES. Surgical mitral valve replacement was performed successfully. The prosthetic valve dysfunction occurred 3 years later and echocardiography showed severe mitral valve stenosis. Extensive mural thrombi were discovered on both sides of the stenotic valve with eosinophilic infiltration. The patient underwent a repeated mechanical prosthesis replacement and recovered uneventfully.

Validation of existing risk scores for mortality prediction after a heart transplant in a Chinese population.

OBJECTIVES: The objectives of this study were to validate 3 existing heart transplant risk scores with a single-centre cohort in China and evaluate the efficacy of the 3 systems in predicting mortality. METHODS: We retrospectively studied 428 patients from a single centre who underwent heart transplants from January 2015 to December 2019. All patients were scored using the Index for Mortality Prediction After Cardiac Transplantation (IMPACT) and the United Network for Organ Sharing (UNOS) and risk stratification scores (RSSs). We assessed the efficacy of the risk scores by comparing the observed and the predicted 1-year mortality. Binary logistic regression was used to evaluate the predictive accuracy of the 3 risk scores. Model discrimination was assessed by measuring the area under the receiver operating curves. Kaplan-Meier survival analyses were performed after the patients were divided into different risk groups. RESULTS: Based on our cohort, the observed mortality was 6.54%, whereas the predicted mortality of the IMPACT and UNOS scores and the RSSs was 10.59%, 10.74% and 12.89%, respectively. Logistic regression analysis showed that the IMPACT [odds ratio (OR), 1.25; 95% confidence interval (CI), 1.15-1.36; P < 0.001], UNOS (OR, 1.68; 95% CI, 1.37-2.07; P < 0.001) and risk stratification (OR, 1.61; 95% CI, 1.30-2.00; P < 0.001) scores were predictive of 1-year mortality. The discriminative power was numerically higher for the IMPACT score [area under the curve (AUC) of 0.691)] than for the UNOS score (AUC 0.685) and the RSS (AUC 0.648). CONCLUSIONS: We validated the IMPACT and UNOS scores and the RSSs as predictors of 1-year mortality after a heart transplant, but all 3 risk scores had unsatisfactory discriminative powers that overestimated the observed mortality for the Chinese cohort.

Changes in left atrial function, left ventricle remodeling, and fibrosis after septal myectomy for obstructive hypertrophic cardiomyopathy.

BACKGROUND: This study aimed to investigate the impact of septal myectomy on left atrial function, left ventricle remodeling, and fibrosis in patients with obstructive hypertrophic cardiomyopathy. METHOD: From May 2012 to September 2016, preoperative cardiac magnetic resonance imaging of 507 adult patients who underwent septal myectomy at Fuwai Hospital was retrospectively collected. Until October 2019, 57 patients were followed up with postoperative cardiac magnetic resonance imaging at 11.9 months (interquartile range, 6.4-25.3). Preoperative and postoperative left atrium and left ventricle changes, as well as late gadolinium enhancement as a surrogate of myocardial fibrosis, were analyzed. RESULTS: Patients with hypertrophic cardiomyopathy requiring myectomy showed increased left atrium volume, stroke volume, left ventricular ejection fraction, and left ventricle mass, as well as decreased left ventricle end-systolic volume. Echocardiography demonstrated that myectomy decreased the left ventricle outflow tract gradient, left atrium diameter, left ventricular ejection fraction, and posterior wall thickness. Postoperative cardiac magnetic resonance imaging showed that the minimal left atrium volume (P < .001), stroke volume (P = .009), left ventricle ejection fraction (P < .001), and left ventricle mass (166.9 [interquartile range, 135.8] vs 149.3 [interquartile range, 100.5] g, P < .001) decreased, whereas the left ventricle end-systolic volume (P = .001) and left atrium ejection fraction (37.9% ± 14.6% vs 47.8% ± 14%, P < .001) increased. However, left ventricle myocardial fibrosis, as detected by late gadolinium enhancement, still progressed after myectomy in patients with obstructive hypertrophic cardiomyopathy (15.2% ± 9.6% vs 18.6% [interquartile range, 21.6], P = .009). CONCLUSIONS: Septal myectomy alleviated left ventricle hypertrophy and reversed left atrium and left ventricle remodeling in patients with obstructive hypertrophic cardiomyopathy. Late gadolinium enhancement in the left ventricle increased despite myectomy in patients with obstructive hypertrophic cardiomyopathy.

No-Touch Versus Conventional Vein Harvesting Techniques at 12 Months After Coronary Artery Bypass Grafting Surgery: Multicenter Randomized, Controlled Trial.

BACKGROUND: Vein graft occlusion is deemed a major challenge in coronary artery bypass grafting. Previous studies implied that the no-touch technique for vein graft harvesting could reduce occlusion rate compared with the conventional approach; however, evidence on the clinical benefit and generalizability of the no-touch technique is scare. METHODS: From April 2017 to June 2019, we randomly assigned 2655 patients undergoing coronary artery bypass grafting at 7 hospitals in a 1:1 ratio to receive no-touch technique or conventional approach for vein harvesting. The primary outcome was vein graft occlusion on computed tomography angiography at 3 months and the secondary outcomes included 12-month vein graft occlusion, recurrence of angina, and major adverse cardiac and cerebrovascular events. The generalized estimate equation model was used to account for the cluster effect of grafts from the same patient. RESULTS: During the follow-up, 2533 (96.0%) participants received computed tomography angiography at 3 months after coronary artery bypass grafting and 2434 (92.2%) received it at 12 months. The no-touch group had significantly lower rates of vein graft occlusion than the conventional group both at 3 months (2.8% versus 4.8%; odds ratio, 0.57 [95% CI, 0.41-0.80]; P<0.001) and 12 months (3.7% versus 6.5%; odds ratio, 0.56 [95% CI, 0.41-0.76]; P<0.001). Recurrence of angina was also less common in the no-touch group at 12 months (2.3% versus 4.1%; odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). Rates of major adverse cardiac and cerebrovascular events were of no significant difference between the 2 groups. The no-touch technique was associated with higher rates of leg wound surgical interventions at 3-month follow-up (10.3% versus 4.3%; odds ratio, 2.55 [95% CI, 1.85-3.52]; P<0.001). CONCLUSIONS: Compared with the conventional vein harvesting approach in coronary artery bypass grafting, the no-touch technique significantly reduced the risk of vein graft occlusion and improved patient prognosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03126409.

Coronary Evaluation Before Heart Valvular Surgery by Using Coronary Computed Tomographic Angiography Versus Invasive Coronary Angiography.

Background Coronary computed tomography angiography (CCTA) is a noninvasive, less expensive, low-radiation alternative to invasive coronary angiography (ICA). ICA is recommended for coronary evaluation before heart valvular surgery, and the supporting evidence for CCTA is insufficient. Our study is a single-center, prospective cohort study designed to evaluate the feasibility of CCTA instead of ICA in detection of coronary artery disease before surgery. Methods and Results Heart valvular surgery candidates were consecutively enrolled between April 2017 and December 2018. Nine hundred fifty-eight patients in the CCTA group underwent CCTA primarily, and those with ≥50% coronary stenosis or uncertain diagnosis underwent subsequent ICA. One thousand five hundred twenty-five patients in the ICA group underwent ICA directly before surgery. Coronary artery bypass grafting decision was made by surgeons according to CCTA or ICA results. Most of the patients (78.8%) in the CCTA group avoided invasive angiography. Thirty-day mortality (0.7% versus 0.9%, P=0.821), myocardial infarction (6.4% versus 6.9%, P=0.680 ), and low cardiac output syndrome (4.2% versus 2.8%, P=0.085) were similar in the CCTA and ICA groups. Median duration of follow-up was 19.3 months (interquartile range, 14.2-30.0 months), cumulative rates of mortality (2.6% versus 2.6%, P=0.882) and major adverse cardiac events (9.6% versus 9.0%, P=0.607) showed no difference between the 2 groups. Coronary evaluation expense was lower in the CCTA group ($149.6 versus $636.0, P<0.001). Conclusions The strategy of using CCTA as a doorkeeper in coronary evaluation before heart valvular surgery showed noninferiority in identification of candidates for coronary artery bypass grafting and postoperative safety.

Clinical predictors of the presence of obstructive sleep apnea in patients with hypertrophic cardiomyopathy.

Obstructive sleep apnea (OSA) is much common and associated with worse clinical outcomes in patients with hypertrophic cardiomyopathy (HCM), however, the diagnosis of OSA in HCM is still insufficient. We aim to investigate the clinical predictors of OSA in a large series of patients with HCM. A total of 589 patients with HCM who underwent sleep evaluations were retrospectively enrolled. Data from clinical characteristics and polysomnography studies were recorded. OSA was present in 346 patients (58.7%). Patients who had OSA were older, more likely to be male and had more clinical comorbidities such as hypertension, atrial fibrillation and cardiac remodeling. Multivariate logistic analyses showed that male, age, body mass index, hypertension and left ventricular outflow tract obstruction were significant factors associated with OSA. The area under the ROC curve (AUC) was 0.78 (95% CI 0.74-0.82; P < 0.001). These factors were also able to identify moderate to severe OSA with an AUC of 0.77 (95% CI 0.73-0.81; P < 0.001). These findings suggest that identifying HCM patients with high risk for OSA is feasible using characteristics from clinical practices and clinicians should have no hesitate to conduct sleep test in these patients.

Dual Antiplatelet Therapy with Clopidogrel and Aspirin Versus Aspirin Monotherapy in Patients Undergoing Coronary Artery Bypass Graft Surgery.

Background The optimal antiplatelet therapy after coronary artery bypass grafting remains unclear. We evaluated the association of dual antiplatelet therapy (DAPT) with clopidogrel plus aspirin and clinical outcomes among patients undergoing coronary artery bypass grafting. Methods and Results A total of 18 069 consecutive patients who underwent primary isolated coronary artery bypass grafting between 2013 and 2017 were identified from a contemporary registry, and 10 854 (60.1%) received DAPT with clopidogrel plus aspirin as determined by claimed prescriptions after surgery. Cox regression models with inverse probability of treatment weighting were used to examine the associations between DAPT and outcomes. Patients who received DAPT, compared with those who received aspirin monotherapy, had a lower incidence of a composite of all-cause death, myocardial infarction, stroke, or repeat revascularization at 6 months (2.9% versus 4.2%; inverse probability of treatment weighting-adjusted hazard ratio [HR], 0.65; 95% CI, 0.55-0.77; P<0.001) as well as death (HR, 0.61; 95% CI, 0.41-0.90), myocardial infarction (HR, 0.55; 95% CI, 0.40-0.74), and stroke (HR, 0.58; 95% CI, 0.46-0.74). The incidence of major bleeding did not differ significantly between the 2 groups (HR, 1.11; 95% CI, 0.69-1.78). Similar results were noted across multiple subgroups as well as when using different analytic methods. Conclusions Among patients undergoing coronary artery bypass grafting, DAPT with clopidogrel plus aspirin as secondary prevention was associated with reduced risk of major adverse cardiovascular and cerebrovascular events within 6 months as compared with aspirin monotherapy, and there was no significant increase in major bleeding.

Cardiac paraganglioma with sulfur subunit B gene mutation: a case report.

BACKGROUND: Pheochromocytoma and paraganglioma is a rare disease with a prevalence of 0.2-0.6% in hypertensive patients from outpatient. CASE SUMMARY: A 21-year-old man complained of blood pressure elevation over one year and persistent hyperhidrosis near 5 years. In local hospital, a mass in the pericardial space with abundant blood flow was observed via echocardiography and confirmed under minimally invasive thoracotomy. With suspicion of malignant cardiac mass, the patient was recommended to transfer for further diagnosis and treatment. Combining evaluation for blood and urinary catecholamine levels, somatostatin receptor imaging, and iodine-131 metaiodobenzylguanidine scintigraphy, he was confirmed with the diagnosis of cardiac paraganglioma with blood supply from the right coronary artery identified via angiography. The cardiac tumour was then surgically resected and confirmed with a pathological diagnosis of paraganglioma. Subsequent genetic test suggested succinate dehydrogenase complex iron sulfur subunit B (SDHB) gene mutation. At 5-month follow-up, the patient was recovered with normal levels of blood catecholamines and catecholamine metabolites. DISCUSSION: Cardiac paraganglioma should be considered and evaluated in hypertensive patients with cardiac mass, even in non-typical population. Given a potential risk of developing malignancies, close follow-up is significant in patients with SDHB gene mutations.

Surgical septal myectomy outcome for obstructive hypertrophic cardiomyopathy after alcohol septal ablation.

BACKGROUND: Although surgical treatment of residual obstruction after alcohol septal ablation (ASA) is often challenging in patients with obstructive hypertrophic cardiomyopathy (OHCM) there are very few relevant clinical reports. Thus, outcomes of surgical septal myectomy (SSM) in this subgroup of patients remain to be determined. Therefore, this study aimed to determine the surgical and follow-up outcomes in patients with OHCM exhibiting residual obstruction after ASA. METHODS: We collected case data for 62 patients with OHCM and residual obstruction after ASA who underwent SSM at Fuwai Hospital between January 2002 and June 2019. Propensity score matching with patients having had a myectomy as the only invasive procedure-was conducted in a 1:2 ratio. Echocardiography parameters, surgery results, and follow-up outcomes were compared between the groups. RESULTS: The prior ASA group had a higher incidence of complete atrioventricular block (AVB) and subsequently postoperative permanent pacemaker (PPM) implantation than the primary myectomy group (9.7% vs. 1.6%, P=0.01). Two patients died within 30 days after surgery in the prior ASA group, and one patient died in the primary myectomy group, with an operative mortality rate of 3.2% and 0.8%, respectively (P=0.2). The 5-year event-free survival rate was 86.0% in the prior ASA group (median follow-up period: 3.2 years; mean: 3.9±2.6 years; maximum, 10.6 years) and 88.5% in the primary myectomy group (median follow-up period: 2.4 years; mean 2.8±1.7 years; maximum, 9.1 years) (P=0.2). During follow-up, four of 62 (6.5%) patients in the prior ASA group and one of 124 (0.8%) patients in the primary myectomy group progressed to advanced heart failure (P=0.025). CONCLUSIONS: Patients with OHCM following ASA are at an increased risk of developing AVB after SSM. Their surgical outcomes, and long-term survival rate were satisfactory and, osimilar to those for patients having had a myectomy as the only invasive procedure. In addition, they had an increased risk of advanced heart failure after SSM in the present study.

Influence of operator volume on early outcomes of septal myectomy for isolated hypertrophic obstructive cardiomyopathy.

BACKGROUND: Guidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) recommend that septal myectomy be performed by experienced operators. However, the impact of operator volume on surgical treatment outcomes for isolated HCM has been poorly investigated. METHODS: From 2002 to 2014, 435 consecutive patients with isolated HCM undergoing myectomy at the Fuwai Hospital were retrospectively enrolled. All 29 surgeons were divided into beginner surgeons (operator volume ≤20) and experienced surgeons (operator volume >20) according to the guidelines for the diagnosis and treatment of HCM. Propensity score matching of patients in the two groups was performed. RESULTS: Baseline differences included advanced New York Heart Association classification and older age in the experienced surgeon group. After matching, in the beginner surgeon group (107 cases), residual obstruction (18.7% vs. 0.9%, P<0.001) was more common, and the postoperative left ventricular outflow tract pressure gradient (20.7±15.1 vs. 14.3±7.4 mmHg, P<0.001) was higher than that of the experienced surgeon group. In the experienced surgeon group (107 cases), the incidence of mitral valve replacement (1.9% vs. 11.2%, P<0.001) and permanent pacemaker implantation (1.9% vs. 3.7%, P<0.001) was significantly lower than that in the beginner surgeon group. However, there was no difference in procedural mortality (1.9% vs. 1.9%) between the two groups. CONCLUSIONS: Operator volume is an important factor in achieving better obstruction obliteration after septal myectomy in patients with isolated HCM.

Surgical treatment of pulmonary artery sarcoma: a report of 17 cases.

Pulmonary artery sarcoma (PAS) is a rare and devastating disease. The diagnosis is often delayed, and optimal treatment remains unclear. The aim of this study is to report our experience in the surgical management of this disease. Between 2000 and 2018, 17 patients underwent operations for PAS at our center. The medical records were retrospectively reviewed to evaluate the clinical characteristics, operative findings, the postoperative outcomes, and the long-term results. The mean age at operation was 46.0 ± 12.4 years (range, 26-79 years), and eight (47.1%) patients were male. Six patients underwent tumor resection alone, whereas the other 11 patients received pulmonary endarterectomy (PEA). There were two perioperative deaths. Follow-up was completed for all patients with a mean duration of 23.5 ± 17.6 months (1-52 months). For all 17 patients, the median postoperative survival was 36 months, and estimated cumulative survival rates at 1, 2, 3, and 4 years were 60.0%, 51.4%, 42.9%, and 21.4%, respectively. The mean survival was 37.0 months after PEA and 14.6 months after tumor resection only (p = 0.046). Patients who had no pulmonary hypertension (PH) postoperatively were associated with improved median survival (48 vs. 5 months, p = 0.023). In conclusion, PAS is often mistaken for chronic pulmonary thromboembolism. The prognosis of this very infrequent disease remains poor. Early detection is essential for prompt and best surgical approach, superior to tumor resection alone, and PEA surgery with PH relieved can provide better chance of survival.

Comparisons of simulation results between passive and active fluid structure interaction models for left ventricle in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Patient-specific active fluid-structure interactions (FSI) model is a useful approach to non-invasively investigate the hemodynamics in the heart. However, it takes a lot of effort to obtain the proper external force boundary conditions for active models, which heavily restrained the time-sensitive clinical applications of active computational models. METHODS: The simulation results of 12 passive FSI models based on 6 patients' pre-operative and post-operative CT images were compared with corresponding active models to investigate the differences in hemodynamics and cardiac mechanics between these models. RESULTS: In comparing the passive and active models, it was found that there was no significant difference in pressure difference and shear stress on mitral valve leaflet (MVL) at the pre-SAM time point, but a significant difference was found in wall stress on the inner boundary of left ventricle (endocardium). It was also found that pressure difference on the coapted MVL and the shear stress on MVL were significantly decreased after successful surgery in both active and passive models. CONCLUSION: Our results suggested that the passive models may provide good approximated hemodynamic results at 5% RR interval, which is crucial for analyzing the initiation of systolic anterior motion (SAM). Comparing to active models, the passive models decrease the complexity of the modeling construction and the difficulty of convergence significantly. These findings suggest that, with proper boundary conditions and sufficient clinical data, the passive computational model may be a good substitution model for the active model to perform hemodynamic analysis of the initiation of SAM.

Collagen Cross-Linking Is Associated With Cardiac Remodeling in Hypertrophic Obstructive Cardiomyopathy.

Background Collagen cross-linking is covalent bonds among collagen fibers from catalysis of lysyl oxidase (LOX) and advanced glycation end products (AGEs). We aimed to evaluate the formation of enzymatic and nonenzymatic collagen cross-linking and its clinical significance in patients with hypertrophic obstructive cardiomyopathy. Methods and Results Forty-four patients with hypertrophic obstructive cardiomyopathy who underwent surgical myectomy were consecutively enrolled. Cardiovascular magnetic resonance parameters of left atrial/left ventricular function were measured, including peak filling rate (PFR) and early peak emptying rate (PER-E). Total collagen was the sum of soluble and insoluble collagen, which were assessed by collagen assay. The myocardial LOX and AGEs expression were measured by molecular and biochemical methods. Compared with patients without atrial fibrillation, insoluble collagen (P=0.018), insoluble collagen fraction (P=0.017), and AGEs (P=0.039) were higher in patients with atrial fibrillation, whereas LOX expression was similar (P=0.494). The insoluble collagen fraction was correlated with PFR index (PFR normalized by left ventricular filling volume) (r=-0.44, P=0.005), left atrial diameters (r=0.36, P=0.021) and PER-E index (PER-E normalized by left ventricular filling volume) (r=-0.49, P=0.001).Myocardial LOX was positively correlated with total collagen (r=0.37, P=0.025) and insoluble collagen fraction (r=0.53, P < 0.001), but inversely correlated with PFR index (r=-0.43, P=0.006) and PER-E index (r=-0.35, P=0.027). In multiple regression analysis, myocardial LOX was independently associated with PFR, while insoluble collagen fraction showed independent correlation with PER-E after adjustment for clinical confounders. Conclusions Collagen cross-linking plays an important role on heart remodeling in hypertrophic obstructive cardiomyopathy. Myocardial LOX expression is independently correlated with left ventricular stiffness, while accumulation of AGEs cross-links might be associated with the occurrence of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy.

Matrix Metalloproteinases Increase Because of Hypoperfusion in Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND: Myocardial fibrosis (MF) is considered a result of microvascular dysfunction in patients with hypertrophic cardiomyopathy. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), capable of degrading collagen, directly participate in the development of MF. First we investigated the relationships among MF, microvascular rarefaction, and MMPs. Then we assessed the prognostic value of MF-related circulating biomarkers. METHODS: Fifty-five obstructive hypertrophic cardiomyopathy (HOCM) patients were enrolled after surgical myectomy. Myocardial samples were performed with Masson's trichrome staining and immunohistochemical procedures for collagen volume fraction and microvascular density, respectively. Enzyme-linked immunosorbent assays were used to assess myocardial and plasma of MMP-2, MMP-9, and TIMP-1 and plasma C-terminal propeptide of procollagen type Ⅰ (PICP) and C-terminal telopeptide of type Ⅰ collagen (ICTP) levels. The composite cardiovascular endpoint consisted of new-onset atrial fibrillation, heart failure requiring hospitalization, and all-cause death. RESULTS: In HOCM patients microvascular density was associated with the myocardial MMP-2/TIMP-1 ratio (r = -0.348, P = .009), whereas no correlation was found between collagen volume fraction and myocardial MMPs. During the 44-month follow-up 6 patients experienced a cardiovascular endpoint. The plasma PICP/ICTP ratio and MMP-2/TIMP-1 ratio were the 2 strongest prognostic makers. In multivariable analyses high PICP/ICTP and MMP-2/TIMP-1 ratios remained independent predictors of cardiovascular outcomes after adjusting for clinical confounders (hazard ratios, 12.683 [P = .021] and 17.037 [P = .027], respectively). CONCLUSIONS: In HOCM patients the myocardial MMP-2/TIMP-1 ratio was elevated because of microvascular rarefaction but may not be responsible for MF. High plasma PICP/ICTP and MMP-2/TIMP-1 ratios are independent predictors of adverse outcomes in HOCM patients.

Preoperative Statin Use Is Associated With Less Postoperative Atrial Fibrillation After Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy.

The present study aims to investigate whether preoperative statin use is associated with less postoperative atrial fibrillation occurrence after septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM). Clinical data of consecutive patients with HOCM who underwent septal myectomy between February 2009 and May 2019 at our institution was retrospectively reviewed. The cohort was divided into 2 groups according to the status of preoperative statin use (statin group vs no statin group). Logistic regression was used to explore associations of clinical variables with postoperative atrial fibrillation occurrence. A total of 1307 patients with HOCM underdoing septal myectomy were included in the present study, with 109 patients in the statin group and 1198 in the no statin group. Among 322 patients (24.6%) developing postoperative atrial fibrillation, 21 cases (19.3%) occurred in the statin group, while 301 cases (25.1%) were in the no statin group (P = 0.202). After propensity score matching with confounding variables at baseline, 91 paired patients were included in the matched cohort. Postoperative atrial fibrillation developed in 17 (18.7%) and 38 (41.8%) in the statin and no statin groups, respectively (P = 0.001). Preoperative statin use was associated with less postoperative atrial fibrillation occurrence (odds ratio 0.220, 95% confidence interval 0.083-0.588, P<0.003). The present study suggested that preoperative statin use was associated with less postoperative atrial fibrillation occurrence after septal myectomy in patients with HOCM. This finding may provide clues for subsequent prospective study to investigate this clinical issue.

Resection of Cardiac Pheochromocytoma With Cardiopulmonary Bypass.

We report a case of a 21-year-old man with a cardiac pheochromocytoma involving the right atrium and extending to the right ventricular inflow tract, which was diagnosed by somatostatin receptor scintigraphy. For the preoperative evaluation, we chose multiple methods of imaging to accurately describe the anatomic extent and location of the tumor and its surrounding tissues, which showed that no major coronary artery ran through the tumor. The tumor was resected with disease-free margins effectively and safely with the use of cardiopulmonary bypass and with cardiac arrest. The patient remained asymptomatic at the 3-month follow-up.