[Single center experience of transcatheter aortic valve replacement with a simplified operative protocol]

Objective: To summarize the single center experience of transcatheter aortic valve replacement (TAVR) with a simplified operative protocol. Methods: Consecutive patients who underwent transfemoral TAVR (TF-TAVR) from July 2020 to December 2020 in Fuwai Hospital were retrospectively analyzed. We compared the baseline characteristic, procedure information, 30-day follow-up outcomes of the patients who underwent TF-TAVR without the simplified operative protocol (routine group) or with the simplified operative protocol (simplified protocol group). Results: 93 patients were collected, 42 patients belonging to routine group, 51 patients belonging to simplified protocol group. In simplified protocol group, there were 51 patients planned to use ultrasound-guided femoral access puncture, procedure was successful in all 51 patients (100%). There were 49 patients planned to use the radial artery as the secondary access, procedure was successful in 45 patients (92%). There were 48 patients planned to use the strategy of avoidance of urinary catheter, this strategy was achieved in 35 patients (73%). There were 12 patients planned to use the left ventricular guidewire to pace, procedure was successful in 11 patients (92%). There were no differences in baseline characteristics, major clinical endpoints and 30-day follow-up outcomes between the two groups. Meanwhile, the procedure time ((62.5±17.9)min vs. (78.3±16.7)min, P<0.001), operation room time ((133.7±25.1)min vs. (159.2±42.6)min, P<0.001), X-ray exposure time ((17.2±6.5)min vs. (20.2±7.7)min, P=0.027) were significantly shorten in simplified protocol group compared with the routine group. Conclusion: Our study results indicate that the simplified operative protocol of TF-TAVR is as effective and safe as the routine operative protocol, meanwhile using the simplified operative protocol can significantly increase the operative efficiency of TF-TAVR.

[Left ventricular guidewire pacing during transcatheter aortic valve replacement]

Objective: To investigate the safety and efficacy of left ventricular guidewire pacing during transcatheter aortic valve replacement (TAVR). Methods: This is a retrospective study. Thirteen patients, who underwent TAVR with left ventricular guidewire pacing from October 2019 to December 2019 in Fuwai Hospital, were included. Clinical data and operational procedure data of the patients were collected. Changes in blood pressure and electrocardiogram were observed during operations. Ascending aorta angiography was performed to evaluate the regurgitation of aortic valve after valve implantion. The incidence of major adverse cardiac events during hospitalization and at 3-months after discharge was recorded. Results: There were 7 male and 6 female patients in this cohort,and age was (73.8±8.3) years old. Among the 13 patients, 9 were tricuspid aortic valves, 3 were bicuspid aortic valves, and 1 was degenerated bioprosthetic surgical aortic valve. TAVR were successfully performed in all of the 13 cases using pacing through the left ventricular guidewire. During balloon dilation, the blood pressure decreased to below 60 mmHg (1 mmHg=0.133 kPa) after 180 beats/min pacing, and the valve release process was smooth and the position was stable. The results of aortography showed that there was no regurgitation in 7 cases, mild regurgitation in 5 cases and moderate regurgitation in 1 case. Three patients required temporary pacing during the procedure due to complete heart block, among whom 1 patient was implanted with permanent pacemaker during hospitalization, and the other 2 patients recovered within 24 hours after operation. In another case, there was no significant change of electrocardiogram during the operation, and complete heart block occurred 10 days after the operation, and treated with permanent pacemaker. The other 10 patients began to carry out bedside activities and rehabilitation training 24 hours after operation. There was no death, myocardial infarction, stroke and other major adverse cardiac events during hospitalization and at 3-month follow-up after discharge. Conclusion: Left ventricular guidewire pacing is a safe and effective strategy for TAVR.

[Feasibility of single-stage stent implantation following rotational atherectomy combined with TAVR]

Objective: To explore the feasibility of the single-stage stent implantation following rotational atherectomy combined with transcatheter aortic valve replacement (TAVR) in treating patients with severe aortic stenosis(AS) and severe calcified coronary artery stenosis. Methods: Three patients who received single-stage stent implantation following rotational atherectomy combined with TAVR in Fuwai hospital from April to October 2019 were included in this retrospective analysis. Clinical and anatomical features (including echocardiography and aortic CT) of the patients were collected, efficacy and safety of this operation strategy were observed and 6 months follow up results were summarized. Results: Three patients (2 females, 66-80 years old) were included. The mean Society of Thoracic Surgeons (STS) risk score was 7.8%. The mean maximum velocity of aortic valve was 4.4 m/s, the mean transvalvular pressure gradient was 53.2 mmHg (1 mmHg=0.133 kPa), mean left ventricular ejection fraction (LVEF) was 48.6%. All three patients had severe calcified coronary artery stenosis: left anterior descending artery (LAD, n=2) and left main coronary artery (LM, n=1), requiring rotary grinding. The mean SYNTAX score was 20. All the procedures were performed through transfemoral access. After aortic valve crossing, all coronary lesions were successfully treated with stent implantation following rotational atherectomy, transfemoral TAVR was then immediately performed with a self-expandable Venus-A valve. One patient underwent"valve-in-valve"implantation due to the high-implantation position of the first valve. The procedures were completed without complications in all the three patients. The immediate effect was satisfactory. Echocardiography results showed that the mean maximum velocity of aortic valve was 2.1 m/s, mean gradient was 9.3 mmHg, and mean LVEF was 59% after the procedure. There was no death and revascularization during the 6 months follow-up. Conclusion: In patients with severe calcified coronary artery and severe AS with high risk of cardiac surgery, the single-stage stent implantation following rotational atherectomy combined with TAVR is feasible and results are satisfactory in this patient cohort.

Cross-sectional study of retroperitoneal hematoma after invasive intervention in a Chinese population: Prevalence, characteristics, management and outcomes

The present study aimed to explore the clinical characteristics and management of retroperitoneal hematoma (RPH) after invasive intervention during a 12-year period in China. A retrospective review of patients with RPH after various invasive interventions was conducted at the China National Center for Cardiovascular Diseases. A total of 42 patients with a mean age of 63.1±2.5 years were continuously recruited in the study between January 2007 and September 2018. The incidence, manifestations and management of RPH were analyzed. A total of 20 patients had punctures in the femoral arterial access under the inguinal ligament and 5 patients had punctures above the inguinal ligament. The majority of RPH occurred within 24 h after intervention, while some occurred after postoperative 24 h. Pain was the most common symptom in patients with RPH. All patients who underwent intervention presented a reduction in hemoglobin (HB) concentration. The overall incidence of nosocomial infection was 38.1% and mortality was 7.1%. The findings demonstrated that RPH is a rare complication after invasive intervention of cardiovascular diseases with non-specific clinical manifestations. The reduction of HB concentration was a vital manifestation for RPH. Most RPH cases could be treated by conservative treatment and blood transfusion. A puncture in the femoral arterial access under the inguinal ligament may result in RPH.

Gender differences in treatment strategies among patients ≥80 years old with non-ST-segment elevation myocardial infarction

Background

This study aims to investigate the gender differences in treatment strategies among non-ST-segment elevation myocardial infarction (NSTEMI) patients ≥80 years old in China.

Methods

A total of 190 consecutive NSTEMI patients ≥80 years old in Fuwai Hospital were included from 2014 to 2017. These patients were grouped by gender, and sub-grouped by conservative treatment or invasive treatment. The clinical characteristics, medical history, discharge drug used, and prognosis were collected and compared between these two treatment strategies.

Results

There were significant differences between these two treatment strategies in terms of GRACE grade, history of myocardial infarction (MI), after coronary artery bypass grafting (CABG), III grade, renal dysfunction, anemia, and use of diuretic (P<0.05). In addition, the age, creatinine and Killip class of female patients, and the death and good prognosis of male patients were found to be significantly different between these two treatment strategies (P<0.05). The multivariate logistic regression analysis revealed that the death of males was significantly associated with treatment strategies in the multivariable logistic regression analysis (P<0.05). In addition, the Kaplan-Meier survival analyses revealed that the survival rates of invasive strategy were significantly higher, when compared to that of conservative strategy in males (P=0.001) and females (P=0.015).

Conclusions

There were gender differences in treatment strategies among NSTEMI patients ≥80 years old. The difference in treatment strategies in males was more pronounced than in females, in terms of long-term survival rate.

A retrospective study of an invasive versus conservative strategy in patients aged ≥80 years with acute ST-segment elevation myocardial infarction

Objective

To investigate what is the most appropriate strategy for patients with ST-segment elevation myocardial infarction (STEMI) aged ≥80 years in China.

Methods

This cohort study retrospectively enrolled patients with STEMI aged ≥80 years old and grouped them according to the treatment strategy that was used: a conservative treatment strategy or an invasive treatment strategy. Factors associated with whether to perform an invasive intervention, in-hospital death and a good prognosis were investigated using logistic regression analyses.

Results

A total of 232 patients were enrolled: conservative treatment group ( n = 93) and invasive treatment group ( n = 139). Patients in the invasive treatment group had a better prognosis and lower incidence of adverse events compared with the conservative treatment group. Advanced age, creatinine level and a higher Killip class were inversely correlated with whether to perform an invasive intervention, while the use of beta-receptor-blocking agents was a favourable factor for invasive treatment. Hypertension and a higher Killip class were risk factors for in-hospital death, while the use of beta-receptor-blocking agents and diuretics decreased the risk of in-hospital death.

Conclusions

An invasive treatment strategy was superior to a conservative treatment strategy in patients with STEMI aged ≥80 years.

[Impact of aortic root morphology on the implantation depth of aortic valve prosthesis during trans-catheter aortic valve replacement in patients with native bicuspid aortic valve stenosis]

Objective: To investigate the impact of aortic root morphology on the implantation depth of aortic valve prosthesis during trans-catheter aortic valve replacement (TAVR) in bicuspid aortic valve patients. Methods: Clinical data of 40 patients with native bicuspid aortic valve stenosis who underwent TAVR using the self-expandable prosthesis (the Venus A-valve) from 2014 to 2017 in Fuwai Hospital was retrospectively analyzed. The patients were divided into non-deep implantation group (implant depth ≤10 mm by instant angiogram after implantation,29 cases) and deep implantation group (implant depth> 10 mm by instant angiogram after implantation,11 cases).Pre-procedural aortic root characteristics (e.g. calcification, angle and dimensions) were assessed by CT. The impact of aortic root morphology on the implantation depth and clinical outcomes were also evaluated. Results: The age was (75.1±5.9) years with equal representation from the raphe-type and non-raphe type (52.5%(21/40) and 47.5%(19/40)).The bigger aorta angle ((56.5±4.5)° vs. (47.4±9.4)°, P=0.004),more frequent mild-calcification (HU850, <200 mm(3)) or severe-calcification(HU850, >1 000 mm(3)) of aortic leaflets (7/11 vs. 4/29, P=0.006), as well as higher ratio of left ventricular outflow tract perimeter to annulus perimeter ((109.2±7.5)% vs. (101.5±6.5)%, P=0.004) were found in the deep implantation group compared to the non-deep implantation group. The new in-hospital onset of bundle-branchheart-block or atrioventricular block conduction disturbance rate was higher in the deep implantation group than in the non-deep implantation group (6/11 vs. 2/29, P=0.030).Left ventricular ejection fraction was similar between deep implantation group and non-deep implantation group at baseline((49.9±8.9)% vs. (55.8±10.4)%, P=0.117), and was significantly lower in the deep implantation group than in the non-deep implantation group at 30 days after implantation ((51.6±12.8)% vs. (60.9±8.1)%, P=0.020). Conclusion: Aortic root morphology of bicuspid aortic valve patients is associated with implantation depth of the prosthesis during TAVR, which affects the conduction system and left ventricular function during and post TAVR.

[Safety and feasibility of sheathless transfemoral aortic valve implantation]

Objective: To investigate the safety and feasibility of sheathless transfemoral aortic valve replacement (TAVR). Methods: In this prospective study, we enrolled 23 patients with severe aortic stenosis (AS) who were inoperable or at high-risk for surgical aortic valve replacement operation in Fuwai hospital From September 2012 to June 2015. Multislice spiral CT and angiography of femoral artery showed that all patients had minimal femoral artery diameters (<6.5 mm) and severe calcification which was not suitable for transfemoral TAVR through sheath. We attempted to apply the sheathless transfemoral TAVR using Venus-A prosthesis without sheath insertion, and procedure related complication during the procedure and hospital stay were observed. Results: The 6 mm×30 mm balloon was used for femoral artery predilation in 1 patient with iliofemoral artery stenosis before delivery system was transported. In the other 22 patients, the delivery system was transported directly. A total of 21 patients finished TAVR with transfemoral sheathless technique. In 2 patients, prosthesis was unable to fully expand after release due to severe valve calcification, and patients received urgent surgical aortic valve replacement. One patient had valve dislocation into the ascending aorta that was not related to the sheathless replacement technique, and delivery system and Venus-A valve were removed after femoral artery was opened surgically, and repeated sheathless TAVR implantation was performed and was successful. Moderate aortic regurgitation occurred in 2 patients immediately after procedure, and trace or mild aortic regurgitation was detected in rest of the patients. One patient had puncture site rupture and bleeding after procedure, and was successfully treated by balloon compression without blood transfusion. Complete atrioventricular block occurred in 3 patients within 24 hours after procedure and lasted after 48-72 hours, permanent pacemakers were implanted in these patients. Conclusion: The sheathless transfemoral technique in TAVR is safe and feasible in severe aortic stenosis patients with small access vessel diameter.

Clinical and angiographic correlates of left ventricular dysfunction in patients with three vessel coronary disease

BACKGROUND

Among patients with advanced multivessel coronary disease, left ventricular (LV) function is widely variable, and clinical and angiographic correlates of ventricular dysfunction remain to be defined.

METHODS

Among 73 339 patients undergoing diagnostic cardiac catheterization at a single center in China, patients with left ventriculographic assessment were identified with three-vessel coronary disease with or without left main involvement. Clinical and angiographic characteristics were examined among patients with normal or varying extent of LV dysfunction, and predictors of LV impairment (ejection fraction (EF): < 25%, 25% - 40% or > 40%) were determined.

RESULTS

Among 11 950 patients identified with three-vessel coronary disease, the sample distribution of LVEF was > 40%, n = 10 776; 25% - 40%, n = 948; < 25%, n = 226. Patients with reduced LV function (< 40%) more commonly were male and had a history of myocardial infarction (MI), diabetes or unstable angina. Hypertension was more frequent in those with LVEF ≥ 40%. In a multivariate Logistic regression analysis, prior MI (odds ratio (OR), 3.37; 95% confidence interval (CI), 2.96 - 3.84) was most predictive of LVEF < 40%, followed by male gender, diabetes, and presentation with unstable angina. For LVEF < 25%, only prior MI was identified as a significant correlate of severe LV dysfunction (OR 4.06, 95%CI 3.06 - 5.39). Following exclusion of patients with previous MI (n = 7416), male gender and diabetes were predictive of LVEF < 40%, yet presentation with unstable angina was the only factor significantly associated with LVEF < 25%.

CONCLUSION

Among individuals identified with three-vessel coronary disease with or without left main involvement, previous MI was the most significant risk factor of LV dysfunction.

Novel compound heterozygous mutations T2C and 1149insT in the KCNQ1 gene cause Jervell and Lange-Nielsen syndrome

Mutations in the KCNQ1 gene account for more than 90% of the individuals with Jervell and Lange-Nielsen syndrome (JLNS). In this study, we identified and characterized two novel KCNQ1 mutations that caused JLNS. A 6-year-old deaf girl suffering from recurrent syncope had a documented electrocardiogram with polymorphic ventricular fibrillation since the age of 4 years. The baseline electrocardiogram showed a significantly prolonged corrected QT interval (524 msec). Genetic analysis revealed that the proband carried two heterozygous mutations of T2C and 1149insT in the KCNQ1 gene on separate alleles. Patch-clamp analysis demonstrated that the T2C mutation resulted in significant reduction in the slowly activated delayed rectifier current (IKs). Furthermore, western blot analysis and confocal imaging revealed that the T2C mutation produced a truncated protein with trafficking defects. In contrast, the 1149insT mutation failed to generate any measurable current, consistent with no protein expression in both the cell membrane and cytoplasm. Moreover, co-expression of the T2C and 1149insT mutations significantly reduced the peak tail current density to 8.27% of the wild-type (WT) current value, while co-transfected WT channels with either T2C or 1149insT mutant channels produced comparable current and channel kinetics to that of WT channels. Our study demonstrates that the compound heterozygous mutations T2C and 1149insT cause the 'loss-of-function' of the IKs that may account for the clinical phenotype of the proband. Multiple mechanisms have been involved in the pathogenesis of 'loss-of-function' of IKs.

[Readthrough of nonsense mutation W822X in the SCN5A gene can effectively restore expression of cardiac Na+ channels W822X]

OBJECTIVE

In this study we investigated the functional restoration of nonsense mutations in the SCN5A gene.

METHODS

The readthrough-enhancing reagents were introduced to HEK293 cells to suppress one nonsense mutation W822X in the SCN5A gene. Patch-clamp was used to record the whole-cell current and dynamics. Western blot and immunofluorescence staining were used to certify the expression and the location of the sodium channel.

RESULTS

In transfected HEK293 cells, the nonsense mutation in SCN5A inhibited the expression level of full-length protein, and the sodium currents from the mutant channels were less than 3% of the wild-type level. Readthrough enhancement by decreasing translation termination efficiency with a siRNA targeting eukaryotic release factor eRF3a (a GTPase that binds eRF1), the sodium current from the mutant cDNAs was restored to as much as 30% of the wild-type. After the treatment by the readthrough-enhancing reagents, the channels from cDNA carrying W822X remained the features of wild-type phenotype, and Western blot and immunochemical staining also showed the expression of full-length channel proteins.

CONCLUSION

Readthrough-enhancing reagents could effectively suppress nonsense mutations in SCN5A and partially restore the function of sodium channel and the expression of full-length channels.

Paracrine activation of extracellular signal-regulated kinase in a simple in vitro model of wounded osteoblasts

The immediate signal-transduction response of osteoblasts to acute trauma is poorly characterized. We have developed a simple in vitro model for osteoblast trauma to investigate aspects of the molecular mechanisms of wound healing in bone. Herein we report the specific, rapid, and transient phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2 in osteoblasts as a response to disruption ("wounding") of a confluent monolayer. The mitogen-activated protein kinase (MAPK) cascades of p38 and stress-activated protein kinase/c-jun N-terminal kinase (SAPK/JNK) were not activated by this perturbation. The response to wounding was equivalent to the activation of ERK by the addition of exogenous growth factors, and the perturbation-dependent phosphorylation of ERK can be suppressed by an inhibitor of heparin-binding growth factors. Conditioned media from wounded monolayers can induce the phosphorylation of ERK in unperturbed monolayers. Using immunohistochemistry, it was demonstrated that the cells with increased levels of phosphorylated ERK were not localized to the wound edges. These results indicate that ERK activation is the result of an autocrine/paracrine response by osteoblasts to trauma. We speculate that osteoblasts respond to trauma with the release of soluble factors as part of an autocrine/paracrine modulation of the wound-healing process in bone.

[Determination of contents of glycosaminoglycans in temporomandibular joint discs in dogs]

Glycosaminoglycans (GAGs) are one of the important components of articular cartilage. The present study had determined the contents of uronic acid, galactomine, glucosamine, and hexosamine of temporomandibular joint discs in 10 dogs by Bitter's carbozole reaction method and derivative spectrophotometry. The data indicated that the contents of these components in different bands of the disc are not significantly different and that the discs of dogs contained averagely 0.6%, 0.987%, 0.4% and 1.4% of uronic acid, galactomine, glucosamine, and hexosamine respectively. The data also suggested that the discs contained keratan sulfate and chondroitin sulfate in some degree. This study is significant for analysing TMJ disc functions and its biomechanical properties in the future.