bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of clinical audits on patient radiation exposure for device procedures
Authors: Sazgary L , Theano Samara E , Stuessi A , Guckenberger M , Ruschitzka F , Wolber T , Molitor N , Fu G , Suna G , Hofer D , Breitenstein A , Brunckhorst C B , Duru F , Saguner A
Published: May 2024

Background

Clinical audits aim to ensure ideal use of ionizing radiation in clinical practice. Since it became mandatory by Swiss law in 2018, such an audit also took place in our Cardiac Pacing and Electrophysiology Division at the University Heart Center.

Purpose

To establish local diagnostic reference levels (DRLs) for specific procedures and to examine if patient radiation exposure was reduced after the clinical audit.

Methods

Retrospective cohort study including patients from October 2018 to October 2020 who underwent device implantation, including pacemakers, implantable cardioverter defibrillators (ICD), cardiac resynchronization therapy (CRT), or lead extraction / device explantation. Main measures to reduce radiation exposure after the audit were lower pulsed fluoroscopy frame rates and dose characteristics at baseline. Patient radiation exposure was evaluated with the dose-area product (DAP), cumulative dose, fluoroscopy time, and the number of cine acquisitions. Secondary endpoints included the effective dose, the acute procedural success rate and 30-day complications. Data were collected from a dose management system and cross-checked for accuracy with the patient information system. The third quartiles were set as local DRLs. Data before and after the clinical audit were compared.

Results

A total of 541 patients (45.7 % before the audit, 54.3% after the audit) were included. 28.3% had a conventional pacemaker, 22.0% a leadless pacemaker, 21.1% an ICD, and 17.2% a CRT implantation. Lead extraction / device explantation was undergone by 11.5% of patients. The local DRLs (including all procedures before and after the audit) for the DAP were significantly lower as compared to national DRLs (6.2 dGy.cm2 versus 300 dGy.cm2 for conventional pacemakers; 7.6 dGy.cm2 versus 200 dGy.cm2 for ICDs, 203 dGy.cm2 versus 570 dGy.cm2 for CRTs). After the audit, DAP (Figure 1), cumulative dose, effective dose and the number of cine acquisition significantly decreased for conventional pacemakers (p-value ≤ 0.04), whereas no significant differences were observed for the other procedures. The acute procedural success rate (98.4 vs 98.9%) and the 30-day complications (4.0 vs 7.8%) were not significantly different before and after the audit.

Conclusions

The clinical audit in our institution led to a significant reduction of radiation exposure for patients during pacemaker implantations. Regarding DRLs, local values were far below national DRLs, which suggests that national DRLs need to be updated more regularly. Our study highlights the importance of clinical audits and the need for more research in this field.
Prognostic impact of permanent pacemaker implantation after cardiac surgery
Authors: David A D , Taha A T , Thorleifsson S T , Jeppsson A J , Martinsson A M
Published: May 2024

Introduction

Brady-arrhythmias with subsequent need for permanent pacemaker implantation is after cardiac surgery. It is not known whether the need of a permanent pacemaker influences long-term prognosis after cardiac surgery.

Methods

This large, nationwide study included all patients who underwent cardiac surgery in Sweden 2006-2020. Data was obtained from the Swedish Cardiac Surgery Registry, The Swedish ICD and Pacemaker Registry, The Swedish National Patient Register, and the Swedish Cause of Death Register. Patients who received a permanent pacemaker within 30 days were compared to those who did not. Exclusion criteria were previous pacemaker or implantable cardioverter defibrillator implantation and death within 30 days. Missing data were handled by multiple imputation. Cox regressions models were used to obtain hazard ratios (HR) with 95% confidence intervals (95%CI). The model was adjusted for age at operation, sex, left ventricular ejection fraction (EF), type of surgery, previous myocardial infarction, diabetes, peripheral artery disease, chronic respiratory disease, hypertension and atrial fibrillation.

Results

In total, 74 606 patients were included out of which 2 150 (2.9%) received a pacemaker within the first 30 days after cardiac surgery. Those who had a pacemaker implanted were older, more often female, had lower EF and significantly more often atrial fibrillation and peripheral artery disease. These patients were less likely to have diabetes, hypertension and previous myocardial infarction. Pacemaker implantation was associated with a higher risk of all-cause mortality (adjusted HR: 1.09 (95%CI=1.00-1.19), p=0.035, Figure 1) and heart failure hospitalization (adjusted HR: 1.45 (95%CI=1.30-1.62), p<0.001). Cardiovascular mortality had similar estimates but did not reach statistical significance (HR: 1.09 (95%CI=0.99-1.24), p=0.15).

Conclusions

The presence of brady-arrhythmias requiring permanent pacemaker implantation after cardiac surgery is associated with a higher risk of mortality and heart failure hospitalization. Measures should be taken to minimize the risk of injury to the conduction system leading to brady-arrhythmias during cardiac surgery.
Permanent pacemaker at the time of coronary artery bypass grafting and long-term outcome: a nationwide study from the SWEDEHEART registry
Authors: Taha A , David A , Bene O , Jeppsson A , Martinsson A
Published: May 2024

Introduction

A permanent pacemaker is not rare in patients who undergo coronary artery bypass grafting (CABG). It is unknown if the presence of a pacemaker influences the long-term prognosis after surgery.

Purpose

To investigate if patients with permanent pacemaker have a higher risk for severe complications after CABG.

Methods

All patients who underwent CABG in Sweden 2006-2020 were included in a nationwide observational study based on prospectively collected data. Exclusion criteria were implantation of a cardioverter defibrillator at any time (prior to or after surgery) and death within 30 days. Individual patient data was merged from SWEDEHEART, The Swedish ICD- and pacemaker registry, the Cause of Death Register and the National Patient Register. Multivariable Cox regressions models were used to obtain hazard ratios (HR) with 95% confidence intervals (95%CI). The model was adjusted for age at operation, sex, left ventricular ejection fraction, heart failure, previous myocardial infarction, diabetes, peripheral artery disease, chronic respiratory disease, hypertension and atrial fibrillation.

Results

In total 41,722 patients underwent CABG during the study period, 555 (1.3%) of these had a previously implanted permanent pacemaker. Patients with a previous pacemaker were older, more often male, and had more often reduced left ventricular ejection fraction heart failure, atrial fibrillation, diabetes, hypertension and peripheral artery disease. Permanent pacemaker was not associated with higher risk for all-cause mortality (adjusted HR (aHR) 1.09 (95%CI=0.96-1.26), p=0.30, Figure 1), myocardial infarction (aHR: 1.01 (95%CI=0.73-1.41), p=0.94), or cardiovascular mortality (HR: 1.19 (95%CI=0.98-1.44), p=0.082). However, permanent pacemaker implantation was associated with increased risk for heart failure hospitalization (HR: 2.16 (95%CI=1.84-2.53), p<0.001).

Conclusions

A permanent pacemaker before CABG is not associated with increased mortality, cardiovascular mortality nor new myocardial infarction, but an increased risk for heart failure hospitalization after CABG. These patients could benefit from increased surveillance for heart failure symptoms after surgery to prevent hospitalizations.
An incremental energy stimulation test to predict success in left bundle branch capture
Authors: Chavez Ortiz I , Vangrieken J , Sanchez Vallejo C , Martinez Gomez E , Bello E , Goni Blanco L , Calvao J , Salgado Aranda R , Canadas Godoy V , Gonzalez Ferrer J J , Filgueiras Rama D , Perez Castellano N , Perez Villacastin J , Calvo D
Published: May 2024

Introduction

Left bundle branch (LBB) stimulation is guided by fluoroscopic projections and electrocardiographic criteria limited by positional variations.

Purpose

To evaluate an incremental energy stimulation test (IEST) to optimize success.

Methods

Prospective, non-randomized experimental study for proof-of-concept analysis (N=23), consisting on: (i) stimulation at three locations at the high, middle and low right mid-ventricular septum (right oblique 30o); and (ii) continuous unipolar stimulation (lumenless fixed helix electrode) at each location with increasing outputs (2 volt x 0.5 ms up to 10 vol x 1.5 ms). The final position for lead penetration was made by the operator blinded to the results of the IEST.

Results

IEST shortened the S-LVAT (δ-S-LVAT) up to 6.4±5 ms (range 0 to 18 ms), 8±8 ms (range 0 to 36 ms) and 5.5±5 ms (range 0 to 20 ms) respectively for high, mid, and low sites (Figure, panel A and B). There was not observed any paired correlation between the magnitude of the δ-S-LVAT at the three different positions (Pearson 0.36, 0.12 and 0.22; p= 0.1, 0.6 and 0.4 respectively), suggesting that the δ-S-LVAT is site specific. The final position for lead penetration was medium in 17 cases vs low in 6 cases. The low-output S-LVAT interval at the final position before lead penetration was positively correlated with the final S-LVAT achieved after lead penetration (Pearson 0.44; p=0.04), but the magnitude of the correlation increased with the high-output S-LVAT interval (Pearson 0.57; p=0.006) suggesting a better prediction performance (Figure, panel C). A complex relationship was observed where higher δ-S-LVAT values were associated with shorter S-LVAT after penetration and final position of the lead. In fact, for cases with low-output S-LVAT interval > 100 ms, the δ-S-LVAT significantly correlated with S-LVAT after penetration and final position of the lead (Pearson -0.61; p=0.026).

Conclusions

IEST lead to a site-specific shortening of the S-LVAT, pointing to optimized positions for LBB pacing. The technique provides with additional diagnostic criteria to determine the better site for lead penetration.
Conduction system pacing: procedural success and failures over the years
Authors: Marcantoni L , Deluca F , Valenza S , Pastore G , Bejko A , Diaferio A , Porcelli G , Follesa A , Zanon F
Published: May 2024

Background

Conduction system pacing (CSP) ensures physiological ventricular activation and avoids the dyssynchrony. New tools (sheaths and leads) can better assist the implant thus increasing procedural successes.

Objective

Retrospective analysis of CSP implants from the last 4 years, analyzing procedural success and failures.

Methods

From 2019 to 2022, 820 CSP implant were performed, being 66% of the overall implants (excluding SR and DR ICDs). 89% were PMs and 11% were ICDs. 32.6% were styled-driven leads while 67.4% were lumenless. Pacing indications were standard with prevalence of AV block (53.6%); AF with slow ventricular rate 14.8%; sinus node disease 12.9%; ablate&pace 3.7%; heart failure 12.8%, re-interventions after malfunction of a previous implant 2.2%. Mean age was 78±9 years; 61.8% were males.

Results

From 2019 to 2022, CSP was successfully achieved in 756 cases (92.2%) considering all indications. In 64 (7.8%) cases, CSP lead implant failed (17 lumenless leads; 47 stylet driven leads) and the lead was then implanted in RV septum or coronary sinus. Reasons for failure were: 2.7% suboptimal electrical parameters (mainly high threshold); 1.1% uncorrected BBB; 0.9% intraprocedural lead dislodgement; 1.4% impossibility to penetrate the septum; 1.4% severe right atrial enlargement; 0.3% unavailable venous access. Heart failure and left ventricular dysfunction (EF<45%) were found more frequently in the failed implant subgroup. Procedural failures were more frequently associated with more than 1 sheath and more than 1 lead utilization during the procedure. Interestingly, in 12.8 % of successful procedures the sheath was changed intraprocedurally; and in the 5.4% of successful procedures the lead was changed (from lumenless to styled-driven or viceversa). No predictors of procedural failure were found in the logistic regression analysis. IInterestingly, failed implants have not decreased over the years.

Conclusions

conduction system pacing is feasible in daily clinical practice. Both lumenless and stylet-driven lead can be utilized. Different sheaths allow to customize the procedure based on the anatomy. During a 4-year experience, the overall procedural success rate was 92.2% while 7.8% of the procedures failed. Interestingly the failure rate has not decreased over the years, likely being related to increasingly complex cardiac conditions where CSP has been attempted.CSP implant success and failures
Near-zero fluoroscopy technique for cardiac electronic device implantation: long-term outcomes
Authors: Creta A , Finlay M , Providencia R , Schilling R J , Monkhouse C , Dhinoja M
Published: May 2024

Introduction

Radiation hazards are a major concern for both patients and staff. We have previously described a near-zero fluoroscopy technique for cardiac electronic device implantation. In this study, we aimed to investigate the long-term safety of this technique and compare outcomes and procedural metrics with a conventional approach in a larger population.

Methods

Low-dose fluoroscopy technique.

Radiation exposure during fluoroscopy is directly proportional to the time the unit is activated. Typically, the pedal switch is depressed for at least a few seconds per imaging sequence in order to visualize "live" movements of either the leads during their positioning or the needle during a fluoroscopy-guided puncture of the subclavian vein. Our technique consists of setting a low frame rate per second (0.5-3.75fps) and momentarily triggering the foot pedal switch only to obtain screenshots of the position of the leads/needle. Use of live electrograms to assist spatial awareness of lead position (e.g. Atrial, Coronary Sinus, Ventricular signals) acts as an adjunct to guidance.

Study design

We included consecutive patients undergoing permanent pacemaker (PPM) or cardiac defibrillator (ICD) implant at our center from July 2018 to December 2022 using the near-zero fluoroscopy technique. Procedures were performed by three operators (AC, MD, MF). Cumulative radiation dose was measured using dose-area product (DAP). We assessed procedure success and complication rate during long-term follow-up. We compared the procedural metrics and outcomes with a cohort of patients with PPM or ICD implanted in our centre by senior operators, using a traditional fluoroscopic approach. Propensity score was adopted to match baseline characteristics between the study and control group.

Results

The total population consisted of 412 patients (74.2±13.9 years, 60.9% male). We included 206 who underwent PPM or ICD implantation using the low-dose fluoroscopy technique, and 206 matched-control. A PPM or ICD was successfully implanted in all patients. Fluoroscopy time and DAP were significantly lower in the low-dose fluoroscopy group, mean 2.3±2.0 seconds versus 258.4±252.1 seconds (P<0.001) and 3.4±3.5 µGym2 versus 29.8±55.4 µGym2 (P<0.001), respectively. Mean procedure time was 49.0±20.8 minutes in the low fluoroscopy group and 65.7±26.8 minutes in the control group (P<0.001). Median frame per second setting was 0.5 in the low-dose cohort. After a mean follow-up of 441±470 days, the rate of complications was identical across groups (2.4%, p = 1.0).

Conclusion

This near-zero dose fluoroscopy technique is effective and safe, enabling a 10x reduction in radiation exposure during device implant. Modification of traditional implant and imaging techniques can provide material reductions in fluoroscopy dose to even below that for a standard PA chest radiograph.
Comparison of long-term risk of device-related complications between left bundle branch area pacing and biventricular pacing in candidates for resynchronization therapy
Authors: Coluccia G , Ziacchi M , Dell'era G , Donateo P , Ammendola E , Aspromonte V , Guido A , Ghiglieno C , Parlavecchio A , Nigro G , Senes J , Patti G , Biffi M , Accogli M , Palmisano P
Published: May 2024

Introduction

Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is a well established therapy in patients with reduced left ventricular ejection fraction (LVEF), heart failure, and wide QRS. Left bundle branch area pacing (LBBAP) has recently been shown to be a feasible and effective alternative to BVP. Comparative data on the risk of complications between LBBAP and BVP among CRT candidates are lacking.

Purpose

The aim of this study was to compare the long-term risk of device-related complications between LBBAP and BVP in a cohort of patients undergoing CRT.

Methods

Prospective, multicenter, observational study enrolling 668 consecutive patients (71.2±10.0 years, 52.2% male, 59.4% NYHA class >II), with LVEF ≤35% (mean 33.4±4.3%) who underwent BVP (n=560) or LBBAP (n=108) for the first time for Class I or II indications for CRT from January 2020 to June 2023 at 6 Italian centers. Propensity matching for baseline characteristics yielded 90 matched pairs. Rate and nature of device-related complications occurring during follow-up were prospectively collected and compared between the two groups.

Results

During a mean follow-up of 18 months, device-related complications were observed in 14 patients: 11 in BVP (12.2%), and in 3 in LBBAP (3.3%) (p=0.026). Compared to BVP patients, LBBAP patients showed a higher cumulative survival free from first device–related complication (Figure). Complications related to coronary sinus lead were most frequently observed in BVP patients (36.4% of all complications). The rate of overall lead-related complications was 6.7 and 2.2% in BVP and LBBAP patients, respectively (p=0.149).

Conclusion

LBBAP was associated with a lower long-term risk of device-related complications compared with BVP in patients with CRT indications.
Left ventricule remodeling with improvement of mitral regurgitation after resynchronization therapy
Authors: Carias M , Almeida A , Paralta M , Viana R , Bento A , Trinca M
Published: May 2024

Introduction

Moderate or severe mitral regurgitation is common in patients with dilated cardiomyopathy who are candidates for resynchronization therapy (CRT). In many patients there is no improvement in mitral regurgitation (MR), and this factor may be associated with a lower response to CRT and worse prognosis.

Purpose

This study seeks to evaluate the association between MR reduction with left ventricular remodeling (LVR), left ventricular ejection fraction (LVEF) and mortality after CRT implantation.

Methods

This is a 4-year retrospective observational study. Patients who had CRT implantation according to the indications in the guidelines with moderate or severe MR were selected. A pre-implantation transthoracic echocardiogram and another at 12-month follow-up were performed. The LVEF, the left ventricle end-systolic volume (LVESV) and the severity of MR were evaluated, which was categorized into without, mild, moderate or severe, according to vena contracta and quantitative method of proximal isovelocity surface area. Patients with a reduction greater or equal to 15% in LVESV or an increase greater or equal to 5% in LVEF were considered responders to CRT.

Results

86 patients had moderate or severe MR pre-CRT, with a mean age of 71.9±9.8 years and 62.2% were female. In 51.2% of the patients there was a reduction in the severity of the MR to without or mild. LVEF recovery was significantly greater in patients with MR reduction (13.1% vs 6.3%, p=0.01). Although not statistically significant, reverse remodeling was more frequent among patients with MR reduction (DLVESV 13.1% vs 6.3%, p=0.119) and mortality was also lower in patients with MR reduction (56% vs 44%, p=0.395).

Conclusion

Improvement in RM severity after CRT implantation appears to be associated with better response to this therapy and better prognosis at 1-year follow-up.
QRS length/left ventricular mass index: a novel predictive factor of response to cardiac resynchronization therapy
Authors: Sanhueza S , Velasquez L , Flores P , Paredes A , Castillo J , Vergara I , Bittner A
Published: May 2024

Introduction

The length of QRS interval is an extensively studied predictor of response to CRT. There is little evidence of the probability of response in patients with QRS between 130 and 150 ms and its relationship with LV mass. (1,2)

Objective

Evaluation of the QRS length/LV mass index (QRS/LVMi) as a "relative dyssynchrony" marker and its correlation to response after CRT implantation.

Methods

Retrospective study that included patients over 18 years of age with HFrEF (LVEF ≤ 35%) and CRT implantation between years 2018 – 2022 (n = 92). QRS length (ms) was measured with CardioLab 3.0 Software and divided by LV mass (g), according to Deveraux equation using echocardiography measurements. Primary outcome was response to CRT defined by: Improvement of at least 1-point in NYHA functional class + (i) increase of at least 5% in LVEF or (ii) decrease of at least 15% in LVESD.

Results

QRS/LVMi value ≥ 0.6 was associated with a higher frequency of response to CRT than values < 0.6 (83% responders vs 17% non responders; OR 5.1; CI 2.7–12.1, p < 0.05). There was no difference in response to CRT between QRS > 150 ms and 130 – 150 ms in patients with QRS/LVMi ≥ 0.6 (80% vs 82% of responders, p = 0.8). A multivariate analysis showed a significantly higher probability of response to CRT in patients with QRS/LVMi ≥ 0.6 compared to other known predictive factors (OR 4.1; CI 1.2–12, p < 0.05).

Conclusions

The use of QRS/LVMi was associated with a better prediction of response to CRT than other traditional factors. There was no difference in response between QRS > 150 ms and 130 - 150 ms in patients with QRS/LVMi ≥ 0.6, suggesting the efficacy of CRT in patients with shorter QRS interval length and less LV mass, highlighting the importance of the concept of relative dyssynchrony.Total Response according QRS/LMViMultivariate analysis
Early vs. late lead extraction in CIED infections: evaluating the interplay of infection type, timing, and comorbidities
Authors: Tamborrino P P , Segreti L , Barletta V , Fiorentini F , Torre M , Di Cori A , De Lucia R , Viani S M , Paperini L , Grifoni G , Soldati E , Parollo M , Bongiorni M G , Zucchelli G
Published: May 2024

Background

Cardiovascular Implantable Electronic Devices (CIEDs) may be associated with peri- and post-procedural complications like device-related infection, one of the most serious challenge of CIEDs therapy associated with significant morbidity, mortality, and financial healthcare burden. Despite a routine use of antibiotics, recent studies reported an increase in CIEDs infections, with or without systemic involvement, that often require surgical interventions like transvenous lead extraction.

Purpose

This study evaluates the outcomes of transvenous lead extraction in patients with infected CIEDs, focusing on the impact of early versus delayed extraction timing on patient outcomes.

Methods

A retrospective analysis of 165 patients who underwent transvenous lead extraction for CIED infections between 2019 and 2022 was conducted. Patients were categorized into systemic (n=64) or local (n=101) infection groups and further into early (within 7 days from admission, n=102) or delayed (after 7 days, n=63) extraction groups. Post-procedural outcomes, including septic shock, complications, and mortality rates were described.

Results

The majority of patients were male (75%) with a median age of 73 (IQR 64-80) years. In the early extraction group, the 1-year mortality rate was significantly lower at 6.4%, compared to 25% in the delayed group. Patients with systemic infections had higher 1-month and 1-year mortality rates compared to those with local infections. The success rates of complete device removal were similar across groups. However, the delayed extraction group exhibited higher rates of comorbidities like anemia, chronic kidney disease, and elevated C-reactive protein levels, which were prevalent in 70% of these patients, compared to 45% in the early extraction group.

Conclusions

Timely management of CIED infections is crucial for improving patient outcomes. Early extraction within 7 days from hospital admission is associated with significantly lower mortality, regardless of local or systemic infection. Patients undergoing delayed extraction often present with greater comorbidity, which may contribute to their higher mortality rates. This underscores the importance of considering patient comorbidities and prompt intervention in managing CIED infections.
Incidence and prognosis of subclinical cardiac perforation after leadless pacemaker implantation
Authors: Lee Y , Uhm J S , Kim M H , Park J W , Kim D , Yu H T , Kim T H , J B , Pak H N , Lee M H
Published: May 2024

Introduction

Subclinical cardiac perforation, a known complication of cardiac implantable electronic device leads, occurs in 6–20% of cases. While leadless pacemakers are advised to be placed in the septum to mitigate perforation risk, limited studies exist on lead positioning and perforation incidence.

Objectives

This retrospective observational study aimed to assess leadless pacemaker lead positions, determine the incidence of subclinical cardiac perforation, and evaluate associated prognoses through computed tomography (CT) in post-implantation patients.

Methods

Thirty-one patients underwent CT after leadless pacemaker implantation. Two cardiologists and a radiologist analyzed CT scans to categorize lead positions (septum, free wall, or septum-free wall junction) and identify subclinical perforation (defined as tine transversal beyond the outer myocardial contour without symptoms, hemodynamic instability, or pacemaker issues).

Results

Mean age at implantation was 70.5 ± 12.7 years; 35.5% were male, and 41.9% had atrial fibrillation. Twenty patients (64.5%) were on anticoagulants or antiplatelet agents. Twenty-four patients (77.4%) were positioned at the septum-free wall junction. Subclinical perforation occurred in 12 patients (38.7%), with a higher proportion in patients on non-vitamin K antagonist oral anticoagulants. Two patients had moderate amount of pericardial effusion; the remaining ten with subclinical perforation were stable during follow-up.

Conclusions

The most common leadless pacemaker implantation site was the septum-free wall junction with 38.7% of subclinical perforation.
Electrophysiological characteristics of tachyarrhythmia and effects of catheter ablation in patients with Fontan circulation
Authors: Uhm J S
Published: May 2024

Introduction

Incidence of arrhythmia in complex congenital heart disease is higher than general population. Characteristics of arrhythmia in patients with functional single ventricle is not known.

Methods

Total 18 patients (age, 22.1 8.5 years, 9 men) with Fontan circulation who had undergone catheter ablation for tachyarrhythmia were retrospectively consecutively included. Characteristics of congenital heart disease, mechanisms of tachyarrhythmia, and efficacy and safety of catheter ablation were analyzed.

Results

Congenital heart diseases of the patients were as follows: double outlet right ventricle, 9; common atrioventricular septal defect, 5; and pulmonary atresia, 4. Fontan types were as follows: lateral tunnel Fontan, 9; extracardiac conduit Fontan 9. Fontan conduit puncture was successful in all patients. Mechanisms of tachyarrhythmia were as follows: intraatrial macroreentrant tachycardia, 8; focal atrial tachycardia, 4; atrioventricular nodal reentrant tachycardia, 3; twin atrioventricular nodal reciprocating tachycardia, 2; unknown, 2. Success rate of catheter ablation, recurrence rate, and complication rate were 16 of 18 patients, 2 of 18 patients, and 0 of 18 patients, respectively.

Conclusion

Intraatrial macroreentrant tachycardia is the most common tachycardia mechanism in patients with Fontan circulation. Catheter ablation for tachyarrhythmia is effective and safe in these population.
Phenotypes and outcomes in patients with atrial fibrillation: a global unsupervised cluster analysis from Phase II/III of the GLORIA-AF registry
Authors: Bisson A , Fawzy A M , Calvert P , Romiti G F , Proietti M , Angoulvant D , El-Bouri W , Fauchier L , Lip G Y H
Published: May 2024

Background

Atrial fibrillation (AF) patients are characterized by a great clinical heterogeneity and complexity across the world. Usual classifications may not adequately characterize this population. Data-driven cluster analysis reveals different possible classifications of patients.

Purpose

To identify different clusters of AF patients who share similar clinical phenotypes and evaluate the association between identified clusters and clinical outcomes using cluster analysis.

Methods

An agglomerative hierarchical cluster analysis was performed in patients from phase II/III of the GLORIA-AF registry. Associations between clusters and a composite outcome composed of all-cause death, stroke and major bleeding were evaluated using Cox regression analyses.

Results

The study included 26,045 AF patients (mean±SD age 70.1±10; 44.8% female) with a median [IQR] follow-up of 3 years [2.3-3.1]. Five clusters were identified: Cluster 1 was composed of young males from North America with morbid obesity and cardiovascular (CV) risk factors; Cluster 2 included older Asian patients with lower body mass index (BMI), fewer CV risk factors, lower anticoagulation rate but the highest AF ablation rate; Cluster 3 identified European males with CV comorbidities and behavioral disorders (smoking, alcohol abuse); Cluster 4 was characterized by patients with the highest rate of permanent AF, cancer, anticoagulant therapy prescription ; Cluster 5 included older women from Europe with high CHA2DS2-VASc and HAS-BLED scores, the highest heart rate, lower BMI and high rate of previous stroke and transient ischemic attack. The incidence of the composite outcome increased a stepwise fashion among clusters from 3.2% patient-years (95% confidence interval (CI): 2.4-4.1) for Cluster 1 to 6% patient-years (95% CI: 5.6-6.4) for Cluster 5 (p<0.0001): Cluster 1 versus 2 hazard ratio (HR): 0.85 (95% CI 0.65–1.11); 2 versus 3 HR: 0.84 (95% CI 0.76–0.93); 3 versus 4 HR: 0.9 (95% CI 0.82–0.99) and 4 versus 5 HR: 0.82 (95% CI 0.74–0.91).

Conclusion

Cluster analysis identified five statistically-driven groups of AF patients, with distinct phenotype characteristics and associated with different risks for major clinical adverse events.Baseline characteristics.Dendrogram and Kaplan Meier-curves.
Predicting left atrial appendage thrombus in patients with persistent atrial fibrillation or flutter and no oral anticoagulation using machine-learning models
Authors: Pieszko K , Makowski B , Bansal M , Hiczkiewicz J , Lojewska K , Musielak B , Uzieblo-Zyczkowska B , Krzesinski P , Kowalik E , Kwiecinski J , Gawalko M , Budnik M , Slomka P , Kaplon-Cieslicka A
Published: May 2024

Background

Atrial fibrillation and flutter (AF/AFL) increase the risk of thromboembolic events by promoting the formation of a left atrial appendage thrombus (LAT). We previously developed artificial intelligence (AI) models to predict LAT based on data from the multicentre, prospective LATTEE registry (Left Atrial Thrombus on Transoesophageal Echocardiography, n= 2489) establishing the utility of AI for identifying the presence of LAT. While our model is now available as an online calculator to date there is no data regarding the utility of our AI in guiding cardioversion in haemodynamically stable patients with persistent arrhythmia and no prior oral anticoagulation (OAC).

Purpose

To assess the performance of AI decision support to perform TOE or readmit the patient after at least 3 weeks of OAC.

Methods

In this study, we applied the LAT-AI model (based on 39 features) and the LAT-AI reduced model (based on 8 features) to patients with no or insufficient prior OAC, who underwent TOE before direct current cardioversion or catheter ablation (n=311). We excluded patients with paroxysmal arrhythmia, resulting in a final cohort of 150 patients originating from four sites. We investigated the sensitivity and specificity of the respective models to predict LAT based on the score thresholds established in previous studies (0.37 for the LAT-AI and 0.34 for the LAT-AI reduced).

Results

The median age in the external cohort was 66 (interquartile range 56-73), 59% were male, and 7.3% had AFL. LAT was found in 17 patients (11%). The LAT-AI model achieved 100% sensitivity (confidence interval [CI]: 40-100) and 12% specificity (95% CI: 7-18). The LAT-AI reduced model achieved 100% sensitivity (95% CI: 87-100) and 14% specificity (95% CI: 8-21). By applying the score threshold which has been derived in our prior studies for the the LAT-AI reduced model, the TOE-first approach would be chosen in 18% and no LAT would be found in this group, while the remaining 82% would be recommended for 3 weeks of OAC before TOE. Such approach could be used to identify patients at low risk of LAT to undergo TOE despite the lack of prior OAC, while the remaining patients at higher risk of LAT could potentially avoid repeated TOE thanks to the 3-week course of OAC before the first TOE.

Conclusion

AI scores allow high sensitivity for prediction of the presence of LAT in patients with AF/AFL irrespective of OAC treatment and have the potential to optimise the management of patients with indications for elective cardioversion and no prior or ineffective OAC.Simulated AI-supported decisionScreenshot of the online app
Development and validation of a machine learning-based prediction model for sudden cardiac death in the general population: insights from the community cardiovascular cohort
Authors: Chen Y Y , Lin Y L , Lee C L , Chien K L , Hsieh Y C , Lip G Y H , Chen S A
Published: May 2024

Background/Introduction

Accurately predicting and managing the risk of sudden cardiac death (SCD) in the general population is a formidable challenge.

Purpose

This study aimed to develop and validate a machine learning (ML)-based prediction model for SCD using data from the Community Cardiovascular Cohort (CCCC) in Taiwan.

Methods

A community-based cohort study was used for model construction . Four ML algorithms, including extreme gradient boosting (XGBoost), random forests (RF), logistic regression, and deep neural network (DNN), underwent meticulous evaluation. Performance assessment encompassed receiver operating characteristic (ROC) curves, area under the curves (AUC), and accuracy metrics. Significant risk factors were identified through feature importance analysis.

Results

We employed a random partitioning strategy, allocating 1744 participants (55%) to the training dataset, 952 participants (30%) to the test dataset, and 476 participants (15%) to the validation dataset. In the data training stage, the XGBoost algorithm demonstrated outstanding prediction performance for SCD (AUC: 1.000); In the validation stage, the XGBoost algorithm demonstrated good prediction performance for SCD prediction (AUC: 0.791, 95%CI: 0.617-0.964; Accuracy: 0.971). Using XGBoost-generated predicted probabilities (P(XGB)), we identified individuals with P(XGB) ≥ 0.5 (Group 1) who displayed significantly higher SCD risk (HR 32.0; 95% CI: 9.29-109.9) compared to those with P(XGB) < 0.5 (Group 0).

Conclusions

Our study demonstrates the effectiveness of ML algorithms, particularly XGBoost, in predicting event of SCD in the general population. The identification of these pivotal risk factors holds profound implications, empowering the identification of high-risk individuals and facilitating the implementation of precisely tailored preventive strategies.Figure 1:KM sruvival curveFigure 2:Feature importance analysis
Same-day discharge strategy in a heart rhythm management clinic - what about patients' reported experience?
Authors: Zeriouh S , Sousonis V , Albenque J P , Jacob S , Mene R , Cardin C , Voglimacci-Stepganopoli Q , Combes N , Combes S , Deharo J C , Boveda S
Published: May 2024

Background and aims

Same-day discharge (SDD) has been adopted for many interventional cardiology procedures, however data on patients’ experience are scarce. The aim of this study was to investigate patient-reported experience of a SDD strategy following electrophysiology procedures (EP) in a Heart Rhythm Management Department.

Methods

Consecutive patients undergoing EP procedures in our centre, who fulfilled pre-defined eligibility criteria for SDD, were asked to complete the study questionnaire, right before hospital discharge. Procedures suitable for SDD ranged from non-invasive (electric cardioversion, tilt test) to invasive ones (EP studies, device replacement, rhythm recorders implantation, ablation of supraventricular tachycardias including atrial fibrillation). The questionnaire aimed to assess patients’ experience before and during the procedure, their satisfaction with the quality of the provided information and their comprehension of the given instructions regarding the post-discharge period and their medication.

Results

The study questionnaire was completed by 501 patients. The majority of participants described SDD as a good or a quite good experience (n=440, 87,8%), while 94,6% of them (n=474) would not hesitate to undergo a second SDD procedure, if necessary. A direct interview with a healthcare team member was viewed as the preferred method of obtaining information on the procedure. At discharge, 1 out of 10 patients were still unsure of the instructions given by the healthcare team, including their anticoagulation treatment. Patient reported satisfaction rates did not differ between invasive and non-invasive procedures. However, after an invasive procedure, patients seemed to significantly have a better understanding of post-discharge instructions.

Conclusion

Patients reported a high level of satisfaction with SDD EP procedures. However, significant efforts need to be made in order to ensure their understanding of post-discharge instructions.Figure : Patients' reported experience
PKP2 gene therapy reduces ventricular arrhythmias, reverses ventricular remodeling, improves heart function, and reduces mortality in a mouse model of arrhythmogenic right ventricular cardiomyopathy
Authors: Yang Z H J , Wu I , Zeng A , Greer-Short A , Aycinena J A , Tefera A E , Shenwai R , Farshidfar F , Van Pell M , Xu E , Reid C , Rodriguez N , Lim B , Chung T W , Dee-Hoskins C
Published: May 2024

Introduction

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy associated with ventricular arrhythmias and an increased risk of sudden cardiac death. Currently, there are no approved treatments that address the underlying genetic cause of this disease, representing a significant unmet need.

Purpose

Mutations in desmosome gene Plakophilin-2 (PKP2) account for approximately 40% of ARVC cases and result in reduced gene expression. Our goal is to examine the feasibility and the efficacy of restoration of PKP2 expression in a cardiac specific knock-out mouse model of Pkp2.

Methods

Adeno-associated virus 9 (AAV9) was used to deliver a wild-type copy of PKP2 gene that is driven by a cardiac-selective promoter and expressed selectively in cardiomyocytes.

Results

We demonstrated that a single-dose AAV9-mediated PKP2 gene therapy effectively prevented disease onset before overt cardiomyopathy and attenuated disease progression after overt cardiomyopathy. Restoration of PKP2 expression led to a significant extension of lifespan by restoring cellular structures of desmosomes and gap junctions, preventing or halting decline in left ventricular ejection fraction, preventing or reversing dilation of the right ventricle, attenuating ventricular arrhythmia event frequency and severity, and preventing adverse fibrotic remodeling. Additional RNA sequencing analyses showed that durable restoration of PKP2 expression led to highly coordinated and durable correction of PKP2-associated transcriptional networks beyond desmosomes, revealing a broad spectrum of biological perturbances behind ARVC disease etiology.

Conclusion

These results indicate that a cardiac-selective AAV9-mediated PKP2 gene therapy may be a promising one-time treatment for ARVC patients with PKP2 mutations.
Circadian rhythm in pro-arrhythmic activity of pulmonary vein cardiomyocytes
Authors: Pannell L M K , Carpenter A , Segers F , Koh Y Z , Harmer S C , Piggins H D , Hancox J C , James A F
Published: May 2024

Introduction

Cardiomyocytes in the pulmonary vein (PV) sleeves are a major source of ectopic activity driving atrial fibrillation (AF) and episodes of AF in patients are more prevalent at night. While it is known that circadian clocks within the heart regionally control 24-hour variation in pacemaking and ventricular repolarisation, the mechanisms underlying the nighttime preponderance in AF are unknown.

Purpose

This study addresses the hypothesis that circadian rhythms exist in the pro-arrhythmic activity of PV cardiomyocytes.

Methods

Male Wistar rats maintained in a 24-hour cycle of 12-hr light/dark (lights-on at Zeitgeber time, ZT=0; lights-off, ZT12) were subject to terminal general anaesthesia (140 mg/kg Na pentobarbital i.p.) at ZT=0, 6, 12 or 18 hr and the hearts removed. RNA was extracted from left atrial (LA) appendage (LAA) and proximal PV at the LA/PV junction (3 rats per ZT) and RNA sequencing conducted. Reads were mapped to the rat genome, counts normalised and models in which ZT was or was not included as a factor compared (Likelihood Ratio Test, adjusted-P<0.01). Whole-cell current clamp recordings were made from cardiomyocytes isolated from the proximal PV (n=308) and the LAA (n=264) (N=74 rats). The effects of noradrenaline (NA, 1 µM) and acetylcholine (ACh, 1 µM) were examined. Data were plotted against the ZT of the time of recording and fitted to a sine wave to establish circadian rhythmicity (P<0.05, extra-sum-of-squares F-test). The effect of ≥24 hr constant dark in the period immediately before experiment was examined. Data are reported as mean ± standard error.

Results

The expression of 1368 genes varied significantly with ZT, including circadian clock components (e.g. Bmal1, Per1). PV cells were larger than LAA cells (73±1.6 pF vs 53±1.3 pF, P<0.0001) and had more depolarised resting membrane potential (-69±0.2 mV vs -72±0.1 mV, P<0.0001). Both cell types showed circadian variation in action potential duration at 90% repolarisation (APD90) and frequency of pro-arrhythmic activity. Pro-arrhythmic activity was greatest in PV cells and the frequency was greater during the rest phase (ZT0-12) in both cell types. In contrast, the circadian rhythm in APD90 differed between cell type, with the longest APD­­90 recorded during the active phase in PV cells (ZT12-24) but during the rest phase in LAA cells. Pro-arrhythmic activity was increased by NA and decreased by ACh in both cell types with maximal effect during the rest phase.

Conclusion

Circadian variation in APD90 and proarrhythmic-activity has been demonstrated in isolated proximal PV and LAA cardiomyocytes, with differences in rhythm between the two cell types. RNA sequencing suggests the presence of peripheral clocks in LAA and PV cardiomyocytes. Understanding these mechanisms is important in development of future therapeutic options for AF.
Oxidative stress and mitochondrial function among various types of atrial fibrillation
Authors: Nantsupawat T , Apaijai N , Prommintikul A , Prasertwitayakij N , Chattipakorn S , Chattipakorn N , Wongcharoen W
Published: May 2024

Introduction

Mitochondrial dysfunction has been shown to be associated with atrial fibrillation (AF) in previous studies.

Purpose

We aimed to determine mitochondrial function in various AF types and AF burden to further delineate whether mitochondrial function has graded or quantal response relationship with AF.

Methods

This is a cross-sectional study in patients with atrial high-rate episode (AHRE) or AF who have dual-chamber cardiovascular implantable electronic device (CIED). Patients were categorized into clinical AF and subclinical AF. AF burden was measured as AHRE via CIED interrogations. Oxidative stress and mitochondrial function were determined in peripheral blood mononuclear cells (PBMCs).

Results

There was a total of 54 CIED patients. Mean age was 69.9+12.8 years. There were 9 (16.7%) patients with diabetes mellitus and 36 (66.7%) patients with history of clinical AF. After adjusting with multiple linear regression for age, left ventricular ejection fraction, glomerular filtration rate, history of AF, and diabetes mellitus, we found that clinical AF, as compared to subclinical AF, was independently associated with lower non-mitochondrial respiration (20.8, 6.5-35.6 vs. 48.0, 14.0-60.9 pMol/min, p=0.021) (median, IQR); lower basal respiration (72.1, 47.4-94.4 vs.97.2, 52.1-152.6 pMol/min, p=0.020); and lower ATP production (57.3, 24.7-73.2 vs. 78.6, 45.7-112.0 pMol/min, p=0.014) (Table 1). However, AF burden was not associated with alterations in oxidative stress and mitochondrial function.

Conclusions

Mitochondrial function from PBMC was significantly lower in patients with clinical AF compared to those with subclinical AF. However, there was no association between AF burden and the change in mitochondrial function. The study revealed a quantal response relationship between PBMC’s mitochondrial function and AF.
Unraveling the links between genetics and electrophysiological phenotype of sustained monomorphic ventricular tachycardias in left and biventricular arrhythmogenic cardiomyopathy
Authors: Cabrera Borrego E , Bermudez-Jimenez F J , Gasparetti A , Macias-Ruiz R , Jimenez-Jaimez J
Published: May 2024

Background and objective

Arrhythmogenic cardiomyopathy (ACM) is an inherited disease with a high arrhythmogenic potential. Despite previous research efforts, a comprehensive electrophysiological characterization of sustained monomorphic ventricular tachycardias (SMVT) by genotype has not yet been achieved.

Purpose

Establishing a correlation between the electrophysiological SMVT substrate and the causative genotype of left and biventricular ACM.

Methods

Observational and retrospective multicenter study of a serie of 71 patients from 18 European and American centers with left/biventricular ACM, carriers of pathogenic genetic variants, in whom an electrophysiological study (EPS) was performed for SMVT ablation. Localization of SMVT-circuit in the EPS was performed by activation mapping, pacemapping and substrate characterization by voltage and decremental-conduction functional analysis.

Results

The cohort had a median age of 49,65 IQR 19,06 years, with the majority being male (54, 76.1%). Significant differences, according to genotype, were found in the anatomical localization of SMVT critical isthmus (p 0.001), figure 1. Patients with mutations in desmoplakin showed biventricular involvement and SMVTs with positive QRS in V1. Substrate could be located in endocardium and epicardium of left ventricle (LV) inferolateral segments. Patients with filamin-C variants had exclusive LV impairment, although the morphology and origin of SMVTs were identical to those observed in desmoplakin. In the case of mutations in lamin-A, the substrate was found mainly in LV septal endocardium. Patients with variants in plakoglobin-2, desmoglein-2 and TMEM43 showed biventricular involvement with negative QRS in V1 SMVTs and right ventricular origin (in the free wall in the case of plakoglobin-2 and in the outflow tract in the case of desmoglein-2 and TMEM43). During clinical follow-up, 26,03 IQR 54,47 months, approximately one third of patients (19, 26,8%) experienced recurrence of clinical SMVT, with significant differences between genotypes (log-rank 0,001), figure 2.

Conclusions

The analysis of these data provides discriminatory SMVT localization patterns between the different genotypes and evaluates the effectiveness of EPS as a therapeutic tool in this group of patients.