[Feasibility and safety of bridge therapy with active fixed electrodes connected to external permanent pacemakers for patients with infective endocarditis after lead removal and before permanent pacemaker implantation]

Objective: To analyze the feasibility and safety of bridge therapy with active fixed electrodes connected to external permanent pacemakers (AFLEP) for patients with infective endocarditis after lead removal and before permanent pacemaker implantation. Methods: A total of 44 pacemaker-dependent patients, who underwent lead removal due to infective endocarditis in our center from January 2015 to January 2020, were included. According to AFLEP or temporary pacemaker option during the transition period, patients were divided into AFLEP group or temporary pacemaker group. Information including age, sex, comorbidities, indications and types of cardial implantable electionic device (CIED) implantation, lead age, duration of temporary pacemaker or AFLEP use, and perioperative complications were collected through Haitai Medical Record System. The incidence of pacemaker perception, abnormal pacing function, lead perforation, lead dislocation, lead vegetation, cardiac tamponade, pulmonary embolism, death and newly infection of implanted pacemaker were compared between the two groups. Pneumothorax, hematoma and the incidence of deep vein thrombosis were also analyzed. Results: Among the 44 patients, 24 were in the AFLEP group and 20 in the temporary pacemaker group. Age was younger in the AFLEP group than in the temporary pacemaker group (57.5(45.5, 66.0) years vs. 67.0(57.3, 71.8) years, P=0.023). Male, prevalence of hypertension, diabetes mellitus, chronic renal dysfunction and old myocardial infarction were similar between the two groups (all P>0.05). Lead duration was 11.0(8.0,13.0) years in the AFLEP group and 8.5(7.0,13.0) years in the temporary pacemaker group(P=0.292). Lead vegetation diameter was (8.2±2.4)mm in the AFLEP group and (9.1±3.0)mm in the temporary pacemaker group. Lead removal was successful in all patients. The follow-up time in the AFLEP group was 23.0(20.5, 25.5) months, and the temporary pacemaker group was 17.0(14.5, 18.5) months. In the temporary pacemaker group, there were 2 cases (10.0%) of lead dislocation, 2 cases (10.0%) of sensory dysfunction, 2 cases (10.0%) of pacing dysfunction, and 2 cases (10.0%) of death. In the AFLEP group, there were 2 cases of abnormal pacing function, which improved after adjusting the output voltage of the pacemaker, there was no lead dislocation, abnormal perception and death. Femoral vein access was used in 8 patients (40.0%) in the temporary pacemaker group, and 4 patients developed lower extremity deep venous thrombosis. There was no deep venous thrombosis in the AFLEP group. The transition treatment time was significantly longer in the AFLEP group than in the temporary pacemaker group (19.5(16.0, 25.8) days vs. 14.0(12.0, 16.8) days, P=0.001). During the follow-up period, there were no reinfections with newly implanted pacemakers in the AFLEP group, and reinfection occurred in 2 patients (10.0%) in the temporary pacemaker group. Conclusions: Bridge therapy with AFLEP for patients with infective endocarditis after lead removal and before permanent pacemaker implantation is feasible and safe. Compared with temporary pacemaker, AFLEP is safer in the implantation process and more stable with lower lead dislocation rate, less sensory and pacing dysfunction.

[Safety and efficacy of high-power, short-duration superior vena cava isolation in combination with conventional radiofrequency ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial]

Objective: For patients with paroxysmal atrial fibrillation, superior vena cava isolation on the basis of pulmonary vein isolation may further improve the long-term success rate of radiofrequency ablation. We aimed to explore the efficacy and safety of superior vena cava isolation by high-power and short-duration (HPSD) ablation plus conventional radiofrequency ablation (RA) in patients with paroxysmal atrial fibrillation. Methods: It was a prospective randomized controlled study. From January 1, 2019 to June 1, 2020, 180 patients who underwent radiofrequency ablation for paroxysmal atrial fibrillation in our center were consecutively screened. Patients were eligible if there was a trigger potential and the muscle sleeve length was greater than 3 cm. A total of 60 eligible patients were finally included and randomly divided into HPSD group (HPSD plus RA) and common power and duration (CPD) group (CPD plus RA) by random number table method (n=30 in each group). Efficacy was evaluated by ablation points, isolation time and ablation time. Safety was evaluated by the incidence of POP, cardiac tamponade, phrenic nerve injury, sinoatrial node injury and all-cause. Results: Superior vena cava isolation was achieved by 14 (13, 15) points in the HPSD group, which was significantly less than that in the CPD group (20(18, 22), P<0.001). The superior vena cava isolation time was 8 (7, 9) minutes in the HPSD group, which was significantly shorter than in the CPD group (17(14, 20) minutes, P<0.001). The average ablation time significantly shorter in HPSD group than in CPD group (78.0(71.1, 80.0) s vs. 200(167.5, 212.5)s, P<0.001). The average impedance drop was more significant in the HPSD group than in the CPD group (20.00(18.75, 21.00)Ω (and the percentage of impedance drop was 15%) vs. 12.00(11.75, 13.25)Ω (the percentage of impedance decrease was 12%), P<0.001). There was 1 POP (3.3%) in the HPSD group, and 3 POPs (10.0%) in the CPD group (P>0.05). There was no cardiac tamponade, phrenic nerve injury, sinoatrial node injury and death in both groups. Conclusions: HPSD technique for the isolation of superior vena cava is safe and effective in patients with paroxysmal atrial fibrillation undergoing conventional radiofrequency ablation.

[Effect of Li's catheter in the cardiac resynchronization therapy implantation]

Objective: To evaluate the effect of Li's catheter in cardiac resynchronization therapy (CRT) implantation. Methods: This study was a retrospective cohort study. Patients with indications for CRT implantation who visited the Department of Cardiology, Peking University People's Hospital from January 1, 2016 to January 1, 2022 were enrolled. Patients were divided into Li's catheter group (CRT implantation with Li's catheter) and control group (CRT implantation with the traditional method). The general clinical data of the patients were obtained through the electronic medical record system. Li's catheter is a new type of coronary sinus angiography balloon catheter independently developed by Dr. Li Xuebin (patent number: 201320413174.1). The primary outcome was the success rate of CRT device implantation, and the secondary outcomes included efficacy and safety parameters. Efficacy indicators included operation time, coronary sinus angiography time, left ventricular lead implantation time, X-ray exposure time, left ventricular lead threshold, and diaphragm stimulation. Safety outcomes included incidence of coronary sinus dissection, cardiac tamponade, and pericardial effusion. Results: A total of 170 patients were enrolled in this study, including 90 in Li's catheter group and 80 in control group. Age, male proportion of patients, proportion of patients with ischemic cardiomyopathy, hypertension, diabetes mellitus, chronic renal insufficiency, New York Heart Association (NYHA) functional classification, left ventricular ejection fraction, left ventricular end-diastolic diameter, proportion of left bundle branch block, and preoperative QRS wave width were similar between the two groups (all P>0.05). In Li's catheter group, 34 cases (37.8%) implanted with CRT defibrillators, and 28 cases (35.0%) implanted with CRT defibrillators in control group, the difference was not statistically significant (P=0.710). The success rate of CRT device implantation in Li's catheter group was 100% (90/90), which was significantly higher than that in control group (93.8%, 75/80, P=0.023).The operation time was 57.0 (52.0, 62.3) minutes, the time to complete coronary sinus angiography was 8.0 (6.0, 9.0) minutes, and the time of left ventricular electrode implantation was 8.0 (7.0, 9.0) minutes in Li's catheter group, and was 91.3 (86.3, 97.0), 18.0 (16.0, 20.0), 25.0 (22.0, 27.7) minutes respectively in control group, all significantly shorter in Li's catheter group (all P<0.05). The exposure time of X-ray was 15.0 (14.0, 17.0) minutes in Li's catheter group, which was also significantly shorter than that in control group (32.5 (29.0, 36.0) minutes, P<0.001). There was no coronary sinus dissection and cardiac tamponade in Li's catheter group, and 1 patient (1.1%) had diaphragmatic stimulation in Li's catheter group. In control group, 6 patients (6.7%) had coronary sinus dissection, and 1 patient (1.1%) developed pericardial effusion, and 3 patients (3.3%) had diaphragmatic stimulation. The incidence of coronary sinus dissection in Li's catheter group was significantly lower than that in control group (P=0.011). The postoperative left ventricular thresholds in Li's catheter group and control group were similar (1.80 (1.60, 2.38) V/0.5 ms vs. 1.80 (1.60, 2.40) V/0.5 ms, P=0.120). Conclusions: Use of Li's catheter is associated with higher success rate of CRT implantation, short time of coronary sinus angiography and left ventricular electrode implantation, reduction of intraoperative X-ray exposure, and lower incidence of coronary vein dissection in this patient cohort.

[Value of D-dimer and left atrial size combined with CHA2DS2-VASc score in excluding left atrial thrombosis in patients with non-valvular atrial fibrillation]

Objective: To investigate the related factors of thrombosis in patients with non-valvular atrial fibrillation (NVAF), and whether the combination of D-dimer, left atrial anteroposterior diameter and CHA₂DS₂-VASc score can be used to exclude left atrial thrombosis. Methods: A total of 75 NVAF patients with left atrial thrombosis confirmed by transesophageal echocardiography in Peking University People's Hospital from January 1, 2015 to December 31, 2019 were enrolled as the thrombus group. From January 1 to October 31, 2019, 80 patients with NVAF without left atrial thrombosis were enrolled as the control group. The clinical data, CHA₂DS₂-VASc score, hematological biomarkers, ultrasound data of two groups were compared. The independent factors associated with left atrial thrombosis were screened by univariate analysis and multivariate logistic regression analysis. The positive predictive value and negative predictive value for the diagnosis of left atrial thrombosis were gained by the score calculated based on the independent related factors. Results: There were no significant differences in age, gender, proportion of persistent atrial fibrillation and duration of atrial fibrillation between the two groups. The CHA₂DS₂-VASc score [M (Q₁, Q₃)] of the thrombus group was higher than that of the control group [2.5 (1.0, 3.0) vs 1.8 (1.0, 3.0), P=0.012]. The prothrombin time activity [M (Q₁, Q₃)] of the thrombus group was 81.1 (72.0, 93.0)%, which was lower than that of the control group 88.8 (83.0,96.0)% (P=0.008). The activated partial thromboplastin time (APTT) of the thrombus group was longer than that of the control group [(32.1±4.8) s vs (30.2±3.7) s, P=0.006]. D-dimer [M (Q₁, Q₃)] of the thrombus group was 231.0 (71.5, 272.2) ng/ml, which was higher than that of the control group 121.7 (49.0, 140.0) ng/ml (P<0.001). The left atrial anteroposterior diameter in thrombus group was larger [(44.6±6.6) mm vs (38.9±5.3) mm, P<0.001], the proportion of mitral regurgitation was higher (58.1% vs 26.8%, P<0.001). The left ventricular ejection fraction [M (Q₁, Q₃)] of the thrombus group was 56.7% (45.8%, 66.3%), which was lower than that of the control group 63.3% (60.5%, 70.2%) (P=0.003). Multivariate logistic regression analysis showed that the factor related to left atrial thrombosis was left atrial anteroposterior diameter (OR=4.480, 95%CI: 1.616-12.423). The negative predictive value of the new scoring system combined with D-dimer, left atrial anteroposterior diameter and CHA₂DS₂-VASc score for left atrial thrombosis was 100%. Conclusions: In NVAF patients, the factor independently associating with left atrial thrombosis is left atrial anteroposterior diameter. The combination of D-dimer, left atrial anteroposterior diameter, and CHA₂DS₂-VASc score can help exclude left atrial thrombosis before ablation of NVAF.