Volume 04 · Issue 02 · 2024

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, significantly impacting patients’ quality of life and increasing the risk of death, stroke, heart failure, and dementia. Over the past 2 decades, there have been significant breakthroughs in AF risk prediction and screening, stroke prevention, rhythm control, catheter ablation, and integrated management. During this period, the scale, quality, and experience of AF management in China have greatly improved, providing a solid foundation for the development of guidelines for the diagnosis and management of AF. To further promote standardized AF management, and apply new technologies and concepts to clinical practice in a timely and comprehensive manner, the Chinese Society of Cardiology of the Chinese Medical Association and the Heart Rhythm Committee of the Chinese Society of Biomedical Engineering have jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial Fibrillation. The guidelines have comprehensively elaborated on various aspects of AF management and proposed the CHA₂DS₂-VASc-60 stroke risk score based on the characteristics of AF in the Asian population. The guidelines have also reevaluated the clinical application of AF screening, emphasized the significance of early rhythm control, and highlighted the central role of catheter ablation in rhythm control.

Patients with untreated severe aortic regurgitation (AR) have a high risk of mortality. Transfemoral transcatheter aortic valve replacement (TF-TAVR) is a treatment option for AR; however, the safety and efficacy of this technique have not been sufficiently established. This study aimed to evaluate the clinical and anatomical variables correlating with device success of TF-TAVR using a self-expanding valve system for pure AR.

Patients with pure native severe AR who underwent TF-TAVR using a self-expanding valve system were registered at 5 Chinese centers. The primary endpoint was device success at 1 month after TAVR. The secondary endpoint was the composite of major adverse cardiovascular events (MACE) at 6 months, including all-cause death, ischemic stroke, emergency conversion to cardiac surgery, and permanent pacemaker implantation. Echocardiography was used to analyze the left ventricular function before the TAVR procedure and during follow-up. Multivariable logistic regression and Cox regression analyses were performed to find relevant independent risk factors.

Between September 2019 and February 2022, 79 patients with AR were enrolled in the study. At 1 month, device success was achieved in 60 (75.9%) patients. By 6 months, 29 (36.7%) patients had MACE. Echocardiography revealed improved left ventricular function after TAVR. Multivariate regression analysis demonstrated that the Society of Thoracic Surgeons risk score (odds ratio 0.760, 95% confidence interval (CI): 0.584-0.989; P = 0.041) and annulus perimeter (odds ratio 0.888, 95% CI: 0.796-0.992; P = 0.035) were 2 predictors of device success. Moreover, annulus perimeter (<80.2 mm), but not Society of Thoracic Surgeons risk score, was associated with a significant reduction in MACE at 6 months (hazard ratio 2.223, 95% CI: 1.060-4.659; P = 0.028).

TF-TAVR using a self-expanding valve system appears to be a safe and feasible treatment for patients with pure native severe AR, particularly those with a less enlarged annulus.

The aim of this multicenter, prospective, single-arm pilot study (ClinicalTrials.gov number: NCT05040074) was to observe the procedural and 30-day results of the novel transcatheter mitral valve repair system, SQ-Kyrin^®-M Clip (Shenqi Medical, Shanghai, China), in patients with severe mitral regurgitation (MR).

The heart team considered patients from 5 centers in China with clinically significant functional mitral regurgitation ≥3+ despite optimal medical therapy or degenerative mitral regurgitation ≥3+ with high surgical risk as candidates for transcatheter repair. All patients received transcatheter edge-to-edge mitral valve repair under general anesthesia. The primary outcome was technical success, which included all of the following measured at the exit from the catheterization laboratory: (1) absence of procedural mortality; (2) successful access, delivery, and retrieval of the device delivery system; (3) successful deployment and correct positioning of the first intended device; and (4) no emergency surgery or reintervention related to the device or access procedure. The secondary outcomes included all-cause mortality, serious adverse events, device success, and procedural success 30 d after the intervention.

From June 2021 to December 2021, 18 patients were enrolled in this study with age (75.7 ± 7.4) years. Fifteen patients had MR 4+, while 3 had MR 3+. Technical success was achieved in all patients, including 6 degenerative mitral regurgitation and 12 functional mitral regurgitation patients. There was no all-cause mortality at 30 d. One patient had single leaflet device attachment within 30 d, which was regarded as a serious adverse event, and the patient was successfully treated with reintervention by implanting another clip. Another patient’s transmitral gradient was 6 mmHg (>5 mmHg), with an effective orifice area of 2.57 cm² after the procedure. Sixteen patients had device success and procedural success at 30 d postoperation. Fourteen patients had MR 1+, 3 had MR 2+, and only 1 patient had MR 3 + 30 d after the procedure.

The results of this feasibility study showed the efficacy and safety of the SQ-Kyrin^®-M device in the Chinese population with severe MR, laying a solid foundation for a subsequent large-scale confirmatory study.

To evaluate the feasibility, safety, and effectiveness of a novel edge-to-edge mitral valve repair system (the NovoClasp system) in patients with severe mitral regurgitation.

In this prospective, single-arm, first-in-human study conducted at Beijing Anzhen Hospital, data were collected from patients undergoing transcatheter edge-to-edge repair using the NovoClasp system. The study candidates were patients exhibiting a mitral regurgitation severity of 3+ or more and were at high-risk or contraindicated for surgical intervention. Technical success and device success according to the Mitral Valve Academic Research Consortium definitions were used as primary outcomes. Other safety and efficacy outcomes were prospectively assessed at device implantation, discharge, and 30 d, 6 months, and 12 months post-procedure.

Between October 1, 2021, and January 31, 2022, 11 patients were treated for moderate-to-severe (grade 3+) or severe (grade 4+) mitral regurgitation using the NovoClasp system. All patients had a baseline New York Heart Association functional class of III-IV, with 7/11 exhibiting complex mitral valve disease. All patients achieved the primary endpoints of technical and device success, with a post-operative 30-d mitral regurgitation grade reduction to 2+ or lower, which was maintained at 12 months. One patient had minor bleeding and hematoma at the access site before discharge, and 2 patients were readmitted due to fast atrial fibrillation within 12 months post-discharge. No additional cases of death, adverse cerebral or cardiovascular events, or device-related complications was observed during the follow-up.

This study suggested the potential feasibility and safety of the NovoClasp system, showing a promising technical and device success rate, along with a decrease in mitral regurgitation severity. A further pivotal study is needed to assess the procedural and long-term outcomes.

Severe tricuspid regurgitation frequently leads to increased mortality and a poor prognosis. Transcatheter edge-to-edge repair (TEER) for tricuspid valve regurgitation has been reported as a safe alternative to traditional open-heart surgery. This study endeavors to assess the efficacy and safety of a newly designed Neoblazar TEER system in this high-risk population.

This investigation was structured as a prospective, single-arm, first-in-man trial in China (ClinicalTrials.gov number: NCT05497141). From August 2022 to October 2022, patients with severe tricuspid regurgitation were enrolled from 3 centers (Xiamen Cardiovascular Hospital, Fuwai Yunnan Cardiovascular Hospital, and Wuhan Union Hospital). The primary endpoint was achieving a minimum 1-grade reduction in tricuspid regurgitation at the 6-month post-TEER intervention, in addition to the pertinent New York Heart Association class. Scheduled echocardiographic evaluations were conducted at the following distinct intervals: baseline, discharge, 1 month, and 6 months post-TEER intervention.

A total of 10 patients were enrolled in the study. Immediately after the TEER procedure with the Neoblazar system, massive tricuspid regurgitation (grade 5+) at baseline decreased to moderate-severe tricuspid regurgitation (grade 3+) in 2 patients and the optimal tricuspid regurgitation reduction (severe tricuspid regurgitation (grade 4+) to mild tricuspid regurgitation (grade 1+)) were achieved in 6 patients. After 6 months of follow-up, tricuspid regurgitation reduction was found to be durable in all enrolled patients, among whom at least 1 grade of tricuspid regurgitation reduction was sustained, even without reintervention. Consistently, the New York Heart Association class among these subjects significantly improved, with the percentage of patients categorized as class I-II increasing from 0/10 at baseline to 5/10 after 1 month (P = 0.015) and 8/10 after 6 months (P < 0.001).

Tricuspid TEER with the newly designed Neoblazar system appears to be a feasible and safe alternative in treating patients with severe tricuspid regurgitation. However, the implementation of larger and more robust randomized trials is still necessary for further verification of the potential benefits.

To investigate the predictive value of carotid-femoral pulse wave velocity (cf-PWV) for assessing major adverse cardiovascular events (MACE) and all-cause mortality in different age groups of a Chinese community.

This is an observational study which enrolled 1,325 individuals from a community in Beijing from September 2007 to October 2018. They were classified based on age into <65-year-old (n = 572) and ≥65-year-old (n = 753) groups, and on cf-PWV into cf-PWV <12 m/s (n = 501) and cf-PWV≥12 m/s (n = 824) group. The incidence rates of MACE and all-cause mortality were recorded for both the groups during the follow-up period of 9.5 years. The predictive value of cf-PWV for MACE and all-cause mortality in the 2 age groups was estimated using the Cox proportional hazards regression models.

The baseline cf-PWV showed positive correlation with age (r = 0.462, P < 0.001). During the follow-up period, 191 MACE and 84 all-cause mortality cases were recorded in the study population. The incidence rates of MACE (χ² = 27.196, P < 0.001) and all-cause mortality (χ² = 9.473, P = 0.002) were significantly higher in subjects with cf-PWV ≥12 m/s than in subjects with cf-PWV <12 m/s. Cox proportional hazards regression model analyses demonstrated that cf-PWV was an independent risk factor in the <65-year-old group for MACE (hazard ratio: 1.310; 95% confidence interval: 1.007-1.560; P = 0.038) and all-cause mortality (hazard ratio: 1.412; 95% confidence interval: 1.133-1.936; P = 0.005) after adjusting for several risk factors. However, both univariate and multivariate analyses demonstrated that cf-PWV was not an independent risk factor for MACE or all-cause mortality in the ≥65-year-old group (P > 0.05).

cf-PWV, a measure of arterial stiffness, emerged as an independent risk factor for MACE and all-cause mortality in subjects below 65 years of age.

The long QT syndrome type 2 is caused by the loss-of-function mutations in the KCNH2 gene, which encodes hERG1, the voltage-gated potassium channel. The hERG1 channels conduct rapid delayed rectifier K⁺ currents (I_Kr) in the human cardiac tissue. KCNH2 encodes 2 main isoforms—hERG1a and hERG1b, which assemble to form the homomeric or heteromeric hERG1 channels. However, the functional characteristics of the heteromeric hERG1 channels in long QT syndrome type 2 are not clear. In this study, a novel mutation in the N-terminus of hERG1a (F129I) was identified in a proband of long QT syndrome type 2. The purpose of this study was to identify the electrophysiological change of homomeric and heteromeric hERG1 channels with the F129I-hERG1a.

Candidate genes were screened by direct sequencing. F129I-hERG1a was cloned in the pcDNA3.1 vector by site-directed mutagenesis. Then, the wild-type (WT) hERG1a and/or F129I-hERG1a were transiently expressed in the HEK293 cells with or without hERG1b co-expression. The expression levels of the transgenes, cellular distribution of hERG1a and hERG1b, and the electrophysiological features of the homomeric and the heteromeric hERG1 channels with the WT-hERG1a or F129I-hERG1a were analyzed using whole-cell patch-clamp electrophysiology, western blotting, and immunofluorescence techniques.

The proband was clinically diagnosed with long QT syndrome type 2 and carried a heterozygous mutation c.385T>A (F129I) in the KCNH2 gene. Electrophysiology study proved that the F129I substitution in hERG1a significantly decreased I_Kr in both the homomeric and heteromeric hERG1channels by 86% and 70%, respectively (WT-hERG1a (54.88 ± 18.74) pA/pF vs. F129I-hERG1a (7.34 ± 1.90) pA/pF, P < 0.001; WT-hERG1a/hERG1b (89.92 ± 24.51) pA/pF vs. F129I-hERG1a/hERG1b (26.54 ± 9.83) pA/pF, P < 0.001). The voltage dependence of I_Kr activation (V_½ and k) was not affected by the mutation in both the homomeric and heteromeric hERG1 channels. The peak current densities and the kinetic characteristics of I_Kr were comparable for both WT/F129I-hERG1a and WT-hERG1a. The channel inactivation and deactivation analysis showed that F129I substitution did not affect deactivation of the homomeric hERG1a channel, but significantly accelerated the deactivation and recovery from inactivation of the heteromeric hERG1a/hERG1b channel based on the time constants of fast and slow recovery from deactivation F129I-hERG1a/hERG1b vs. WT-hERG1a/hERG1b (P < 0.05). Western blotting and immunofluorescence labeling experiments showed that maturation and intracellular trafficking of the F129I-hERG1a protein was impaired and potentially increased the ratio of hERG1b to hERG1a in the F129I-hERG1a/hERG1b tetramer channel, thereby resulting in electrophysiological changes characteristic of the long QT syndrome type 2 pathology.

I_Kr was significantly reduced in the homomeric and heteromeric hERG1 channels with F129I-hERG1a. The F129I mutation significantly accelerated the deactivation and recovery from inactivation of the heteromeric F129I-hERG1a/hERG1b channel. F129I-hERG1a exhibited impaired maturation and intracellular trafficking, thereby potentially increasing the ratio of the hERG1b to hERG1a stoichiometry in the hERG1 tetrameric channel. These changes demonstrated the importance of the heteromeric hERG1 channel in long QT syndrome type 2 pathophysiology.

This case report described a 61-year-old woman who presented with dizziness, headache, muscle ache, diplopia, and vomiting who lost consciousness. Upon hospital admission, the levels of high-sensitivity cardiac troponin I and partial pressure of carbon dioxide were increased markedly. Loss of consciousness occurred twice after removal of invasive ventilator support. Coronary angiography demonstrated no stenosis in coronary arteries. Ultrasonography revealed inactivity of respiratory muscles. Oculomotor disturbance and autonomic-nerve dysfunctions were observed. Serum antibody against glutamic acid decarboxylase was positive. The rare phenotypes of persistent stiffness of muscles in the neck, face, bilateral upper and lower limbs were observed. The patient was diagnosed with fulminant myocarditis complicated by Stiff-person syndrome. Immunomodulatory treatment (glucocorticoids and immunoglobulins) elicited satisfactory therapeutic effects. In this case report, it was found that fulminant myocarditis and Stiff-person syndrome shared a common pathogenesis: "cytokine storm". Such patients may benefit from early treatment with immunomodulatory agents.