Cardiac conduction disorders in young adults: Clinical characteristics and genetic background of an underestimated population

BACKGROUND

Cardiac conduction disorder (CCD) in patients <50 years old is a rare and mostly unknown condition.

OBJECTIVE

We aimed to assess clinical characteristics and genetic background of patients <50 years old with CCD of unknown origin.

METHODS

We retrospectively reviewed a consecutive series of patients with a diagnosis of CCD before the age of 50 years referred to our center between January 2019 and December 2021. Patients underwent complete clinical examination and genetic evaluation.

RESULTS

We enrolled 39 patients with a median age of 40 years (28-47 years) at the onset of symptoms. A cardiac implantable electronic device was implanted in 69% of the patients. In 15 of 39 CCD index patients (38%), we found a total of 13 different gene variations (3 pathogenic, 6 likely pathogenic, and 4 variants of uncertain significance), mostly in 3 genes (SCN5A, TRPM4, and LMNA). In our cohort, genetic testing led to the decision to implant an implantable cardioverter-defibrillator in 2 patients for the increased risk of sudden cardiac death.

CONCLUSION

Patients with the occurrence of CCD before the age of 50 years present with a high rate of pathologic gene variations, mostly in 3 genes (SCN5A, TRPM4, and LMNA). The presence of pathogenic variations may add information about the prognosis and lead to an individualized therapeutic approach.

Comparative Study of Lesions Obtained through Radiofrequency between the Irrigated Ablation Catheter with a Flexible Tip and the Non-Irrigated Catheter in Ex Vivo Porcine Hearts

BACKGROUND

At the same conditions of delivered power and contact force, open-irrigated radiofrequency ablation catheters are believed to create deeper lesions, while non-irrigated ones produce shallower lesions. This ex vivo study aims to directly compare the lesion dimensions and characteristics of an irrigated ablation catheter with a flexible tip and a non-irrigated solid-tip catheter.

METHODS

Radiofrequency lesions were induced on porcine myocardial slabs using both open-tip irrigated and non-irrigated standard 4 mm catheters at three power settings (20 W, 30 W, and 40 W), maintaining a fixed contact force of 10 gr. A lesion assessment was conducted including the lesion depth, depth at the maximum diameter, and lesion surface diameters, with the subsequent calculation of the lesion volume and area being undertaken.

RESULTS

Irrigated catheters produced lesions with significantly higher superficial widths at all power levels (3.8 vs. 4.4 mm at 20 W; 3.9 mm vs. 4.4 mm at 30 W; 3.8 mm vs. 4.5 mm at 40 W; p = 0.001, p = 0.019, p = 0.003, respectively). Non-irrigated catheters resulted in significantly higher superficial areas at all power levels (23 mm2 vs. 18 mm2 at 20 W; 25 mm2 vs. 19 mm2 at 30 W; 26 mm2 vs. 19 mm2 at 40 W; p = 0.001, p = 0.005, p = 0.001, respectively). Irrigated catheters showed significantly higher values of lesion maximum depth at 40 W (4.6 mm vs. 5.5 mm; p = 0.007), while non-irrigated catheters had a significantly higher calculated volume at 20 W (202 µL vs. 134 µL; p = 0.002).

CONCLUSIONS

Radiofrequency ablation using an irrigated catheter with a flexible tip has the potential to generate smaller superficial lesion areas compared with those obtained using a non-irrigated catheter.

Trends in atrial fibrillation-related mortality in Europe, 2008-2019

AIMS

Update data regarding the atrial fibrillation (AF)-related mortality trend in Europe remains scant. We assess the age- and sex- specific trends in AF-related mortality in the European states between the years 2008 and 2019.

METHODS AND RESULTS

Data on cause-specific deaths and population numbers by sex for European countries were retrieved through the publicly available World Health Organization (WHO) mortality dataset for the years 2008 to 2019. AF-related deaths were ascertained when the ICD-10 code I48 was listed as the underlying cause of death in the medical death certificate. To calculate annual trends, we assessed the average (AAPC) annual % change with relative 95% confidence intervals (CIs) using Joinpoint regression. During the study period, 773 750 AF-related deaths (202 552 males and 571 198 females) occurred in Europe. The age-adjusted mortality rate (AAMR) linearly increased from 12.3 (95% CI: 11.2 to 12.9) per 100 000 population in 2008 to 15.3 (95% CI: 14.7 to 15.7) per 100 000 population in 2019 [AAPC: +2.0% (95% CI: 1.6 to 3.5), p < 0.001] with a more pronounced increased among men [AAPC: +2.7% (95% CI: 1.9 to 3.5), p < 0.001] compared to women [AAPC: +1.7% (95% CI: 1.1 to 2.3), p < 0.001] (p for parallelism 0.01). The higher AAMR increased was observed in some eastern European countries such as Latvia, Lithuania and Poland while the lower were mainly clustered in the central Europe.

CONCLUSIONS

Over the last decade, the age-adjusted AF-related mortality has increased in Europe especially among males. Disparities still exist between western and eastern European countries.

Ultrasound-Guided Venous Axillary Access Versus Standard Fluoroscopic Technique for Cardiac Lead Implantation: ZEROFLUOROAXI Randomized Trial

BACKGROUND

Axillary vein puncture (AVP) and cephalic vein surgical cutdown are recommended in international guidelines because of their low risk of pneumothorax and chronic lead complications. Directly visualizing and puncturing the axillary vein under ultrasound guidance reduces radiation exposure, provides direct needle visualization, and lowers periprocedural complications. Our hypothesis is that ultrasound-guided axillary access is safer and more feasible than the standard fluoroscopic technique.

OBJECTIVES

The purpose of this study was to assess the efficacy and safety of ultrasound-guided axillary venous access during cardiac lead implantation for pacemakers (PMs) and implantable cardioverter-defibrillator (ICD) implantations.

METHODS

Patients were randomized in a 1:1 fashion to either axillary venous access under fluoroscopic guidance or ultrasound-guided axillary venous access. The composite outcome, including pneumothorax, hemothorax, inadvertent arterial puncture, pocket hematoma, pocket infection, lead dislodgement, and death, was evaluated 30 days after implantation.

RESULTS

We randomized 270 patients into 2 groups: the standard group for fluoroguided AVP (n = 134) and the experimental group for ultrasound-guided AVP (n = 136). No disparities in baseline characteristics were observed between the groups. The median age of the patients was 81 years, with women comprising 41% of the population. The majority of patients received single- and dual-chamber PMs (87% vs 88%; P = 1.00), and slightly over 10% in both groups received ICDs (13% vs 12%; P = 0.85). In total, we placed 357 leads in PMs and 48 leads in ICDs. Among these, 295 leads were inserted via axillary vein access and 110 via cephalic vein access. Notably, the subclavian vein was never used as a vascular access. The composite outcome was lower in the ultrasound group according to intention-to-treat analysis (OR: 0.55; 95% CI: 0.31-0.99; P = 0.034). The main difference within the composite outcome was the lower incidence of inadvertent axillary arterial puncture in the experimental group (17% vs 6%; P = 0.004). The ultrasound group also exhibited lower total procedural x-ray exposure (10,344 μGy × cm2 vs 7,119 μGy × cm2; P = 0.002) while achieving the same rate of success at the first attempt (61% vs 69%; P = 0.375).

CONCLUSIONS

Ultrasound-guided AVP is safer than the fluoroscopy-guided approach because it achieves the same rate of acute success while maintaining low total procedural radiation exposure. Ultrasound AVP should be considered the optimal venous access method for cardiac lead implantation. (Ultrasound Guided Axillary Access vs Standard Fluoroscopic Technique for Cardiac Lead Implantation [ZEROFLUOROAXI]; NCT05101720).

SCN5A mutation is associated with a higher Shanghai Score in patients with type 1 Brugada ECG pattern

AIMS

Brugada syndrome (BrS) is an inherited arrhythmic disease characterized by a coved ST-segment elevation in the right precordial electrocardiogram leads (type 1 ECG pattern) and is associated with a risk of malignant ventricular arrhythmias and sudden cardiac death. In order to assess the predictive value of the Shanghai Score System for the presence of a SCN5A mutation in clinical practice, we studied a cohort of 125 patients with spontaneous or fever/drug-induced BrS type 1 ECG pattern, variably associated with symptoms and a positive family history.

METHODS

The Shanghai Score System items were collected for each patient and PR and QRS complex intervals were measured. Patients were genotyped through a next-generation sequencing (NGS) custom panel for the presence of SCN5A mutations and the common SCN5A polymorphism (H558R).

RESULTS

The total Shanghai Score was higher in SCN5A+ patients than in SCN5A- patients. The 81% of SCN5A+ patients and the 100% of patients with a SCN5A truncating variant exhibit a spontaneous type 1 ECG pattern. A significant increase in PR (P = 0.006) and QRS (P = 0.02) was detected in the SCN5A+ group. The presence of the common H558R polymorphism did not significantly correlate with any of the items of the Shanghai Score, nor with the total score of the system.

CONCLUSION

Data from our study suggest the usefulness of Shanghai Score collection in clinical practice in order to maximize genetic test appropriateness. Our data further highlight SCN5A mutations as a cause of conduction impairment in BrS patients.

A Comparative Assessment of Myocardial Work Performance during Spontaneous Rhythm, His Bundle Pacing, and Left Bundle Branch Area Pacing: Insights from the EMPATHY Study

BACKGROUND

Physiological pacing has gained significant interest due to its potential to achieve optimal hemodynamic response. This study aimed to assess left ventricular performance in terms of electrical parameters, specifically QRS duration and mechanical performance, evaluated as myocardial work. We compared His Bundle Pacing (HBP) and Left Bundle Branch Area Pacing (LBBAP) to evaluate their effects.

METHODS

Twenty-four patients with class I or IIa indications for pacing were enrolled in this study, with twelve patients undergoing HBP implantation and another twelve undergoing LBBAP implantation. A comprehensive analysis of myocardial work was conducted.

RESULTS

Our findings indicate that there were no major differences in terms of spontaneous and HBP activation in myocardial work, except for global wasted work (217 mmHg% vs. 283 mmHg%; p 0.016) and global work efficiency (87 mmHg% vs. 82 mmHg%; p 0.049). No significant differences were observed in myocardial work between spontaneous activation and LBBAP. Similarly, no significant differences in myocardial work were found between HBP and LBBAP.

CONCLUSIONS

Both pacing modalities provide physiological ventricular activation without significant differences when compared to each other. Moreover, there were no significant differences in QRS duration between HBP and LBBAP. However, LBBAP demonstrated advantages in terms of feasibility, as it achieved better lead electrical parameters compared to HBP (threshold@0.4 ms 0.6 V vs. 1 V; p = 0.045-sensing 9.4 mV vs. 2.4 mV; p < 0.001). Additionally, LBBAP required less fluoroscopy time (6 min vs. 13 min; p = 0.010) and procedural time (81 min vs. 125 min; p = 0.004) compared to HBP.

Trends in age- and sex-specific atrial fibrillation/flutter mortality in Italy between 2003 and 2017

AIMS

We sought to assess the atrial fibrillation/flutter (AF/AFL) mortality rates and relative trends among the Italian population between 2003 and 2017.

METHODS

Data regarding the cause-specific mortality and population size by sex in 5-year age groups were extracted from the World Health Organization (WHO) global mortality database. Decedents reporting the codes I48 were extracted accordingly to the International Classification of Disease-10 (ICD-10) coding system. The age-adjusted mortality rates (AAMRs), with relative 95% confidence intervals (CIs), also stratified by sex, were determined using the direct method. Joinpoint regression analyses were used to identify periods with statistically distinct log linear trends in AF/AFL-related death rates. To calculate nationwide annual trends in AF/AFL-related mortality, we assessed the average annual percentage change (AAPC) and relative 95% CIs.

RESULTS

Over the study period, 90 623 (57 109 females) AF-related deaths were recorded. The AF/AFL AAMR increased from 8.1 (95% CI: 7.8-8.2) deaths per 100 000 to 18.7 (16.9-20.0) deaths per 100 000 population. Joinpoint regression analysis revealed a linear increase in age-standardized AF/AFL-related mortality [AAPC: +3.6 (95% CI: 3.0-4.3, P  < 0.0001)] in the entire Italian population. Moreover, the mortality rate increased with age, showing a seemingly exponential distribution with a similar trend between males and females. Although the increase was more pronounced among women [AAPC: +3.7 (95% CI: 3.1-4.3, P  < 0.0001)] compared with men [AAPC: +3.4 (95% CI: 2.8-4.0, P  < 0.0001)], the difference did not reach statistical significance ( P  = 0.16).

CONCLUSIONS

In Italy, the AF/AFL-related mortality rates linearly increased from 2003 to 2017.

[Epicardial adipose tissue: a novel cardiovascular risk factor]

Epicardial adipose tissue (EAT) has various metabolic functions aiming at heart protection. When abnormal, it is related to atherosclerotic plaque development and adverse cardiovascular outcome. Additionally, in recent years, several studies have demonstrated its role in other settings such as atrial fibrillation and heart failure with preserved ejection fraction. Future studies should aim to assess diagnostic role of EAT and the effect of medical therapy on EAT volume and attenuation.

Structural Abnormalities in Brugada Syndrome and Non-Invasive Cardiac Imaging: A Systematic Review

The aim of this review is to identify possible structural abnormalities of BrS and their potential association with symptoms, risk stratification, and prognosis. (1) Background: BrS has always been considered a purely electrical disease and imaging techniques do not currently play a specific role in the diagnosis of this arrhythmic syndrome. Some authors have recently hypothesized the presence of structural and functional abnormalities. Therefore, several studies investigated the presence of pathological features in echocardiography and cardiac magnetic resonance imaging (MRI) in patients with BrS, but results were controversial. (2) Methods: We performed a systematic review of the literature on the spectrum of features detected by echocardiography and cardiac MRI. Articles were searched in Pubmed, Cochrane Library, and Biomed Central. Only papers published in English and in peer-reviewed journals up to November 2021 were selected. After an initial evaluation, 596 records were screened; the literature search identified 19 relevant articles. (3) Results: The imaging findings associated with BrS were as follows: right ventricular dilation, right ventricular wall motion abnormalities, delayed right ventricular contraction, speckle and feature tracking abnormalities, late gadolinium enhancement, and fat infiltration in the right ventricle. Furthermore, these features emerged more frequently in patients carrying the genetic mutation on the sodium voltage-gated channel α-subunit 5 (SCN5A) gene. (4) Conclusions: Specific imaging features detected by echocardiography and cardiac magnetic resonance are associated with BrS. However, this population appears to be heterogeneous and imaging anomalies emerged to be more frequent in patients carrying genetic mutations of SCN5A. Future studies with an evaluation of BrS patients are needed to identify the specific association linking the Brugada pattern, imaging abnormalities and their possible correlation with prognosis.

651 ZERO FLUOROSCOPY CARDIAC ABLATION: A NOVEL WORKFLOW FOR ATRIAL FIBRILLATION

Background and Rationale

A fluoroscopy-based approach to an electrophysiological procedure is widely validated and has been recognized as the gold standard for a long time. The use of fluoroscopy exposes both the healthcare staff and the patient to a non-negligible dose of radiation. To minimize the risks associated with the use of fluoroscopy, it would be reasonable to perform ablation procedures with zero fluoroscopy. This approach is widely used in simple ablation procedures, but not in complex procedures. In atrial fibrillation (AF) ablation procedures, fluoroscopy remains the main technology used, particularly to guide the transseptal puncture.

Main results and Implications

We present a workflow to perform a complete zero-fluoroscopy ablation for AF ablation procedures using a 3D electro-anatomical mapping system, intracardiac echocardiography and a novel steerable guiding sheath that can be visualized on the mapping system. We present two AF ablation procedures, one performed on a patient with paroxysmal AF (Fig.1) and one with persistent AF (Fig. 2, Fig 3) during which we applied this novel workflow, achieving a successful pulmonary vein isolation without complications and complete zero-fluoroscopy exposure.

304 CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY FOR THE ASSESSMENT OF SIROLIMUS-ELUTING RESORBABLE MAGNESIUM SCAFFOLD

Background

Coronary computed tomography angiography (CCTA) is an established technique for non-invasive evaluation of the coronary arteries. Whereas artifacts limit the assessment of the stented vessels, studies supported its performance in vessels treated with first generation bioresorbable scaffold (BRS). Anatomical findings can be integrated with non-invasive fractional flow reserve (FFR-CT) to discriminate the presence or not of flow-limiting disease. After the failure of the first BRS generation, alternative platforms have been developed, including the second-generation resorbable magnesium scaffold (RMS). Ongoing studies investigate the long-term safety and effectiveness of RMS, but few evidence describes their performance with CCTA.

Aims

The present investigation aims to report the luminal measurement, FFR-CT assessment, and clinical outcomes, in the first patients treated with RMS in the Scaffold Implantation in Emilia-Romagna Plus Multi Absorbable Gears Intra Coronary (SHERPA-MAGIC) study.

Methods

As prespecified sub-study, patients underwent CCTA 18 months after RMS implantation. Three-dimensional models were reconstructed for simulation of coronary flow and pressure. FFR-CT analysis was performed using the DeepVessel FFR software (Keya Medical, Seattle, WA, USA).

Results

From December 2017 to July 2018, 34 patients underwent RMS implantation. After exclusion of 7 patients due to additional drug eluting stent (DES) implantation, poor CCTA quality and CCTA refusal, the population included 26 patients. Overall, 29 vessels were treated with 35 RMS. Median stent length was 25 [20-25] mm, with a median diameter of 3 [3-3.5] mm. Three-year follow-up was available for all patients. One patient received revascularization of the target vessel after 18-month CCTA. Another patient was admitted for atypical chest pain 12 months after index procedure. Quantitative analysis was feasible in all vessels (n=29). Complete RMS reabsorption was observed in 27 cases. Median minimal lumen diameter (MLD) and area (MLA) of the scaffolded segments were 2.5 [2.1-2.8] mm and 6.4 [4.4-8.4] mm2, respectively. Non-invasive FFR analysis was feasible in 23 vessels (80%). The causes for missing computation were artifacts and the incomplete documentation of the entire coronary artery. Median FFR-CT in the target vessels was 0.88 [0.81-0.91]. Ttwo target vessels showed a flow-limiting FFR-CT value. In the first case, the patient underwent coronary artery angiography. Invasive FFR confirmed a flow-limiting stenosis (FFR value 0.74), and a new PCI was performed. In the second case, the patient was asymptomatic in optimal medical therapy, and mid-distal LAD was involved (FFR-CT value 0.79).

Conclusions

In a highly selected population of patients undergoing RMS implantation with a standardized technique, CCTA is feasible and allows to discriminate long-term anatomical and functional performance of scaffolded segments.

Antibiotic prophylaxis based on individual infective risk stratification in cardiac implantable electronic device: the PRACTICE study

Aims

In patients undergoing cardiac implantable electronic device (CIED) intervention, routine pre-procedure antibiotic prophylaxis is recommended. A more powerful antibiotic protocol has been suggested in patients at high risk of infection. Stratification of individual infective risk could guide the prophylaxis before CIED procedure.

Methods and results

Patients undergoing CIED surgery were stratified according to the Shariff score in low and high infective risk. Patients in the ‘low-risk’ group were treated with only two antibiotic administrations while patients in the ‘high-risk’ group were treated with a prolonged 9-day protocol, according to renal function and allergies. We followed-up patients for 250 days with clinical outpatient visit and electronic control of the CIED. As primary endpoint, we evaluated CIED-related infections. A total of 937 consecutive patients were enrolled, of whom 735 were stratified in the ‘low-risk’ group and 202 in the ‘high-risk’ group. Despite different risk profiles, CIED-related infection rate at 250 days was similar in the two groups (8/735 in ‘low risk’ vs. 4/202 in ‘high risk’, P = 0.32). At multivariate analysis, active neoplasia, haematoma, and reintervention were independently associated with CIED-related infection (HR 5.54, 10.77, and 12.15, respectively).

Conclusion

In a large cohort of patients undergoing CIED procedure, an antibiotic prophylaxis based on individual stratification of infective risk resulted in similar rate of infection between groups at high and low risk of CIED-related infection.