Implantable loop recorders in patients with Brugada syndrome: the BruLoop study.

BACKGROUND AND AIMS: Available data on continuous rhythm monitoring by implantable loop recorders (ILRs) in patients with Brugada syndrome (BrS) are scarce. The aim of this multi-centre study was to evaluate the diagnostic yield and clinical implication of a continuous rhythm monitoring strategy by ILRs in a large cohort of BrS patients and to assess the precise arrhythmic cause of syncopal episodes. METHODS: A total of 370 patients with BrS and ILRs (mean age 43.5 ± 15.9, 33.8% female, 74.1% symptomatic) from 18 international centers were included. Patients were followed with continuous rhythm monitoring for a median follow-up of 3 years. RESULTS: During follow-up, an arrhythmic event was recorded in 30.7% of symptomatic patients [18.6% atrial arrhythmias (AAs), 10.2% bradyarrhythmias (BAs), and 7.3% ventricular arrhythmias (VAs)]. In patients with recurrent syncope, the aetiology was arrhythmic in 22.4% (59.3% BAs, 25.0% VAs, and 15.6% AAs). The ILR led to drug therapy initiation in 11.4%, ablation procedure in 10.9%, implantation of a pacemaker in 2.5%, and a cardioverter-defibrillator in 8%. At multivariate analysis, the presence of symptoms [hazard ratio (HR) 2.5, P = .001] and age >50 years (HR 1.7, P = .016) were independent predictors of arrhythmic events, while inducibility of ventricular fibrillation at the electrophysiological study (HR 9.0, P < .001) was a predictor of VAs. CONCLUSIONS: ILR detects arrhythmic events in nearly 30% of symptomatic BrS patients, leading to appropriate therapy in 70% of them. The most commonly detected arrhythmias are AAs and BAs, while VAs are detected only in 7% of cases. Symptom status can be used to guide ILR implantation.

The interventricular conduction delays guide best cardiac resynchronization therapy: A tailored-patient approach to perform a CRT through Conduction System Pacing.

Evaluation of conduction intervals to predict success of resynchronization in biventricular pacing(BiVP) or Conduction System Pacing(CSP) is not spread in clinical practice. A right ventricle-to-left ventricle intrinsic conduction interval (RVs-LVs) > 70 ms or prolonged RVpaced - LVs(RVp-LVs)interval can predict Cardiac Resynchronization Therapy (CRT)response.This paper describes a case of cardiac resynchronization guided by spontaneous and paced interventricular conduction delays (IVCD) obtained in BiVP that led to changing intraoperative approach. A strategy for cardiac resynchronization based on the CSP/BiVP approach according to the IVCD could represent a viable and reliable solution to obtain a narrow paced QRS and to improve the CRT response.

Cardiac resynchronization therapy with conduction system pacing in a long-term heart transplant recipient: A case report.

We performed cardiac resynchronization therapy by means of conduction system pacing in a heart transplant patient suffering from heart failure with reduced ejection fraction and atrial fibrillation with conduction disturbance (bifascicular block and QRS >160 ms). ECG monitoring showed paroxysmal atrioventricular block. Biventricular pacing was not feasible due to the absence of a suitable coronary sinus branch for pacing. His bundle pacing was performed, and an implantable cardioverter-defibrillator was implanted due to severe left ventricular dysfunction. Cardiac allograft vasculopathy was excluded. During follow-up, the patient's left ventricular function improved, and symptoms alleviated with a high percentage of ventricular stimulation.

Implantable defibrillator-detected heart failure status predicts ventricular tachyarrhythmias.

INTRODUCTION: The prediction of ventricular tachyarrhythmias among patients with implantable cardioverter defibrillators is difficult with available clinical tools. We sought to assess whether in patients with heart failure (HF) and reduced ejection fraction with defibrillators, physiological sensor-based HF status, as summarized by the HeartLogic index, could predict appropriate device therapies. METHODS: Five hundred and sixty-eight consecutive HF patients with defibrillators (n = 158, 28%) or cardiac resynchronization therapy-defibrillators (n = 410, 72%) were included in this prospective observational multicenter analysis. The association of both HeartLogic index and its physiological components with defibrillator shocks and overall appropriate therapies was assessed in regression and time-dependent Cox models. RESULTS: Over a follow-up of 25 (15-35) months, 122 (21%) patients received an appropriate device therapy (shock, n = 74, 13%), while the HeartLogic index crossed the threshold value (alert, HeartLogic ≥ 16) 1200 times (0.71 alerts/patient-year) in 370 (65%) subjects. The occurrence of ≥1 HeartLogic alert was significantly associated with both appropriate shocks (Hazard ratios [HR]: 2.44, 95% confidence interval [CI]: 1.49-3.97, p = .003), and any appropriate defibrillator therapies. In multivariable time-dependent Cox models, weekly IN-alert state was the strongest predictor of appropriate defibrillator shocks (HR: 2.94, 95% CI: 1.73-5.01, p < .001) and overall therapies. Compared with stable patients, patients with appropriate shocks had significantly higher values of HeartLogic index, third heart sound amplitude, and resting heart rate 30-60 days before device therapy. CONCLUSION: The HeartLogic index is an independent dynamic predictor of appropriate defibrillator therapies. The combined index and its individual physiological components change before the arrhythmic event occurs.

Combination of an implantable defibrillator multi-sensor heart failure index and an apnea index for the prediction of atrial high-rate events.

AIMS: Patients with atrial fibrillation frequently experience sleep disorder breathing, and both conditions are highly prevalent in presence of heart failure (HF). We explored the association between the combination of an HF and a sleep apnoea (SA) index and the incidence of atrial high-rate events (AHRE) in patients with implantable defibrillators (ICDs). METHODS AND RESULTS: Data were prospectively collected from 411 consecutive HF patients with ICD. The IN-alert HF state was measured by the multi-sensor HeartLogic Index (>16), and the ICD-measured Respiratory Disturbance Index (RDI) was computed to identify severe SA. The endpoints were as follows: daily AHRE burden of ≥5 min, ≥6 h, and ≥23 h. During a median follow-up of 26 months, the time IN-alert HF state was 13% of the total observation period. The RDI value was ≥30 episodes/h (severe SA) during 58% of the observation period. An AHRE burden of ≥5 min/day was documented in 139 (34%) patients, ≥6 h/day in 89 (22%) patients, and ≥23 h/day in 68 (17%) patients. The IN-alert HF state was independently associated with AHRE regardless of the daily burden threshold: hazard ratios from 2.17 for ≥5 min/day to 3.43 for ≥23 h/day (P < 0.01). An RDI ≥ 30 episodes/h was associated only with AHRE burden ≥5 min/day [hazard ratio 1.55 (95% confidence interval: 1.11-2.16), P = 0.001]. The combination of IN-alert HF state and RDI ≥ 30 episodes/h accounted for only 6% of the follow-up period and was associated with high rates of AHRE occurrence (from 28 events/100 patient-years for AHRE burden ≥5 min/day to 22 events/100 patient-years for AHRE burden ≥23 h/day). CONCLUSIONS: In HF patients, the occurrence of AHRE is independently associated with the ICD-measured IN-alert HF state and RDI ≥ 30 episodes/h. The coexistence of these two conditions occurs rarely but is associated with a very high rate of AHRE occurrence. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Performance of a multi-sensor implantable defibrillator algorithm for heart failure monitoring in the presence of atrial fibrillation.

AIMS: The HeartLogic Index combines data from multiple implantable cardioverter defibrillators (ICDs) sensors and has been shown to accurately stratify patients at risk of heart failure (HF) events. We evaluated and compared the performance of this algorithm during sinus rhythm and during long-lasting atrial fibrillation (AF). METHODS AND RESULTS: HeartLogic was activated in 568 ICD patients from 26 centres. We found periods of ≥30 consecutive days with an atrial high-rate episode (AHRE) burden <1 h/day and periods with an AHRE burden ≥20 h/day. We then identified patients who met both criteria during the follow-up (AHRE group, n = 53), to allow pairwise comparison of periods. For control purposes, we identified patients with an AHRE burden <1 h throughout their follow-up and implemented 2:1 propensity score matching vs. the AHRE group (matched non-AHRE group, n = 106). In the AHRE group, the rate of alerts was 1.2 [95% confidence interval (CI): 1.0-1.5]/patient-year during periods with an AHRE burden <1 h/day and 2.0 (95% CI: 1.5-2.6)/patient-year during periods with an AHRE-burden ≥20 h/day (P = 0.004). The rate of HF hospitalizations was 0.34 (95% CI: 0.15-0.69)/patient-year during IN-alert periods and 0.06 (95% CI: 0.02-0.14)/patient-year during OUT-of-alert periods (P < 0.001). The IN/OUT-of-alert state incidence rate ratio of HF hospitalizations was 8.59 (95% CI: 1.67-55.31) during periods with an AHRE burden <1 h/day and 2.70 (95% CI: 1.01-28.33) during periods with an AHRE burden ≥20 h/day. In the matched non-AHRE group, the rate of HF hospitalizations was 0.29 (95% CI: 0.12-0.60)/patient-year during IN-alert periods and 0.04 (95% CI: 0.02-0.08)/patient-year during OUT-of-alert periods (P < 0.001). The incidence rate ratio was 7.11 (95% CI: 2.19-22.44). CONCLUSION: Patients received more alerts during periods of AF. The ability of the algorithm to identify increased risk of HF events was confirmed during AF, despite a lower IN/OUT-of-alert incidence rate ratio in comparison with non-AF periods and non-AF patients. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/Identifier: NCT02275637.

Prognostic value of right ventricular refractory period heterogeneity in Type-1 Brugada electrocardiographic pattern.

AIMS: To investigate the prognostic significance of heterogeneity in the refractoriness of right ventricular (RV) outflow tract (RVOT) and RV apex at the electrophysiological study (EPS) in Brugada syndrome (BrS). METHODS AND RESULTS: A cohort of BrS patients (primary prevention) from five Italian centres was retrospectively analysed. Patients with spontaneous or drug-induced Type-1 electrocardiogram (ECG) + symptoms were offered an EPS for prognostic stratification. The primary endpoint was a composite of sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate intervention by the implantable cardioverter-defibrillator (ICD). Three hundred and seventy-two patients with BrS were evaluated (44 ± 15 years, 69% males, 23% with ICD): 4 SCDs and 17 ICD interventions occurred at follow-up (median 48, interquartile range: 36-60 months). Family history of SCD, syncope, and a spontaneous Type-1 ECG pattern were univariate predictors of the primary endpoint in the whole population. In patients undergoing EPS (n = 198, 53%, 44 ± 12 years, 71% males, 39% with ICD), 3 SCD and 15 ICD interventions occurred at follow-up. In this subset, the primary endpoint was not only predicted by ventricular tachycardia/fibrillation inducibility but also by a difference in the refractory period between RVOT and RV apex (ΔRPRVOT-apex) >60 ms. ΔRPRVOT-apex > 60 ms remained an independent predictor of SCD/ICD shock at bivariate analysis, even when adjusted for the other univariate predictors, showing the highest predictive power at C-statistic analysis (0.75, 95% confidence interval 0.63-0.86). CONCLUSIONS: Heterogeneity of RV refractory periods is a strong, independent predictor of life-threatening arrhythmias in BrS patients, beyond VT/VF inducibility at EPS and common clinical predictors.

Ventricular tachycardia ablation guided or aided by scar characterization with cardiac magnetic resonance: rationale and design of VOYAGE study.

BACKGROUND: Radiofrequency ablation has been shown to be a safe and effective treatment for scar-related ventricular arrhythmias (VA). Recent preliminary studies have shown that real time integration of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images with electroanatomical map (EAM) data may lead to increased procedure efficacy, efficiency, and safety. METHODS: VOYAGE is a prospective, randomized, multicenter controlled open label study designed to compare in terms of efficacy, efficiency, and safety a CMR aided/guided workflow to standard EAM-guided ventricular tachycardia (VT) ablation. Patients with an ICD or with ICD implantation expected within 1 month, with scar related VT, suitable for CMR and multidetector computed tomography (MDCT) will be randomized to a CMR-guided or CMR-aided approach, whereas subjects unsuitable for imaging or with image quality deemed not sufficient for postprocessing will be allocated to standard of care ablation. Primary endpoint is defined as VT recurrences (sustained or requiring appropriate ICD intervention) during 12 months follow-up, excluding the first month of blanking period. Secondary endpoints will include procedural efficiency, safety, impact on quality of life and comparison between CMR-guided and CMR-aided approaches. Patients will be evaluated at 1, 6 and 12 months. DISCUSSION: The clinical impact of real time CMR-guided/aided ablation approaches has not been thoroughly assessed yet. This study aims at defining whether such workflow results in more effective, efficient, and safer procedures. If proven to be of benefit, results from this study could be applied in large scale interventional practice. Trial registrationClinicalTrials.gov, NCT04694079, registered on January 1, 2021.

Safety, efficacy, and reproducibility of cavotricuspid isthmus ablation guided by the ablation index: acute results of the FLAI study.

AIMS: Ablation index (AI) is a marker of lesion quality during catheter ablation that incorporates contact force, time, and power in a weighted formula. This index was originally developed for pulmonary vein isolation as well as other left atrial procedures. The aim of our study is to evaluate the feasibility and efficacy of the AI for the ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical atrial flutter (AFL). METHODS AND RESULTS: This prospective multicentre non-randomized study enrolled 412 consecutive patients with typical AFL undergoing AI-guided cavotricuspid isthmus ablation. The procedure was performed targeting an AI of 500 and an inter-lesion distance measurement of ≤6 mm. The primary endpoints were CTI 'first-pass' block and persistent block after a 20-min waiting time. Secondary endpoints included procedural and radiofrequency duration and fluoroscopic time. A total of 412 consecutive patients were enrolled in 31 centres (mean age 64.9 ± 9.8; 72.1% males and 27.7% with structural heart disease). The CTI bidirectional 'first-pass' block was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting time was achieved in 405 patients (98.3%). Mean procedural, radiofrequency, and fluoroscopic time were 56.5 ± 28.1, 7.8 ± 4.8, and 1.9 ± 4.8 min, respectively. There were no major procedural complications. There was no significant inter-operator variability in the ability to achieve any of the primary endpoints. CONCLUSION: AI-guided ablation with an inter-lesion distance ≤6 mm represents an effective, safe, and highly reproducible strategy to achieve bidirectional block in the treatment of typical AFL.

Detection of oesophageal course during left atrial catheter ablation.

BACKGROUND: Oesophageal changes and injuries were recorded after atrial fibrillation(AF) ablation procedures. The reduction of power in the posterior left atrial(LA) wall(closest to the oesophagus) and the monitoring of temperature in the oesophagus(OE) reduced oesophageal injuries. The intracardiac-echocardiography(ICE) with a Cartosound module provides two-dimensional imaging (2D) to assess detailed cardiac anatomy and its relationship with the OE. The aim of this study was to highlight the safety and feasibility of 3D-reconstruction of the oesophageal course in left atrial catheter ablation(CA) procedures without OE temperature probe or quadripolar catheter to guide ICE OE reconstruction. METHODS: 180 patients(PT) underwent left atrial ablation. AF ablation were 125(69.5%); incisional left atrial tachycardias(IAFL) were 37(20.6%); left atrial tachycardias(LAT) were 19(10.6%). The LA and pulmonary vein anatomies were rendered by traditional electroanatomic mapping(EAM) and merged with an ICE anatomic map. In 109 PT ICE imaging was used to create a geometry of the OE(group A). A quadripolar catheter was used in 71 PT to show OE course associated to ICE(group B). RESULTS: Ablation energy delivery was performed outside the broadest OE anatomy borders. The duration of procedures was longer in group B vs group A Fluoroscopy time was lower in Group A than Group B(Group A 7 ± 3.2 vs 19.2 ± 2.4 min; p < 0.01). CONCLUSIONS: OE monitoring with ICE is safe and feasible. Oesophageal anatomy is complex and variable. Many PT will have a broad oesophageal boundary, which increases the risk of untoward thermal injury during posterior LA ablation. ICE with 3D construction of the OE enhances border detection of the OE, and as such, should decrease the risk of oesophageal injury by improving avoidance strategies without intra-oesophageal catheter visualization.

From near-zero to zero fluoroscopy catheter ablation procedures.

AIMS: The use of electroanatomical mapping (EAM) systems can reduce radiation exposure (RX) and it can also completely eliminate the use of RX. Radiation exposure related to conventional radiofrequency ablation procedures can have a stochastic and deterministic effect on health. The main aim of this study was to evaluate the safety and feasibility of an entirely nonfluoroscopic approach to catheter ablation (CA) using EAM CARTO3. METHODS: In 2011 we started an RX-minimization programme in all procedures using the CARTO system with the deliberate intention to not resort to the aid of RX unless strictly necessary. We divided procedures into two groups (group 1: from 2011 to 2013; group 2: from 2014 to 2017). The only exclusion criteria were the need for transseptal puncture, and nonidiopathic ventricular tachycardia (VT). RESULTS: From a total of 525 procedures, we performed CA entirely without RX in 78.5% of cases. From 2011 to 2013, we performed CA without RX in 38.5% of cases; from 2014 to 2017, we performed 96.2% of cases with zero RX. The use of RX was significantly reduced in group 2 (group 2: 1.4 ± 19.6 seconds vs group 1: 556.92 ± 520.76 seconds; P < .001). These differences were irrespective of arrhythmia treatment. There were no differences between the two groups in acute success, complications, or duration of procedures. CONCLUSION: CA of supraventricular tachycardia and VT entirely without RX, guided by the CARTO system, is safe, feasible, and effective. After an adequate learning curve, CA can be performed entirely without RX.

Left ventricular strain modifications after maximal exercise in athletes: a speckle tracking study.

PURPOSE: The increase in systolic indexes from rest (R) to exercise is achieved by combination of enhanced heart rate (HR) and stroke volume (SV). Aim of this study was to evaluate left ventricular (LV) longitudinal, circumferential, and torsional components immediately after a maximal intensity exercise (ME) by speckle tracking echocardiography (STE). METHODS: Twenty-seven male water polo players performed an ME that consisted of 6 repeats of 100 m freestyle swim sets. An echocardiographic examination was performed before and after ME. STE was performed to obtain the analysis of LV myocardial deformation. RESULTS: There were no differences between R and ME regarding LV longitudinal strains (PVLS). Apical circumferential LV strain (AVCS) and LV longitudinal strain rate (SR) increased at ME with respect to R (R: -23.1 ± 4.9%; ME: -28.4 ± 7.6%, P < 0.05; R: -1.1 ± 0.1/sec, ME: -1.5 ± 0.2/sec, P < 0.01). LV twisting (LVT) and untwisting (UTW) increased at ME (R: 7.9 ± 2.4°, ME: 14.2 ± 3.2°, P < 0.001; R: -107.2 ± 47.4; ME: -158.5 ± 61.5 °/sec; P < 0.01). At ME, apical rotation (Arot) had higher values than R values (5.4 ± 3.0°; 10.0 ± 6.0°; P < 0.01) and time-to-peak (TTP) of apical segments are earlier than all TTP. SV was related to LVT (r = 0.56, P = 0.01), AVCS (r = -0.59, P = 0.005) and Arot (r = 0.46, P = 0.04). At multivariate analysis, AVCS was the independent predictor of SV (ß = -0.58; P < 0.05). CONCLUSIONS: Apical fibers and LVT give the main contribution to systolic components at ME. The storage of energy during LVT, released during early diastole, seems to be a fundamental mechanism to support diastolic filling during maximal exercise.

Left ventricular twisting modifications in patients with left ventricular concentric hypertrophy at increasing after-load conditions.

AIMS: Left ventricular hypertrophy (LVH) develops as a result of several clinical conditions, such as intensive training, hypertension, aortic valve stenosis. Aim of this study was to analyze the left ventricular twist (LVT) modifications in LVH patients with increasing after-load conditions. METHODS: A total of 131 patients were enrolled: 17 healthy sedentary people (Hg), without concentric LVH; 45 water polo players (ATg); 22 patients with hypertensive cardiopathy (HPg); 47 patients with different degrees of aortic stenosis (ASg); all patients had concentric LVH, ejection fraction (EF) >54%, and were age-matched. The left ventricular end-systolic wall stress (LV-ESWS) was used as index of after-load. RESULTS: Left ventricular twist value showed a progressive increase from ATg to ASg, according to increasing after-load. Longitudinal left ventricular function by tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) was reduced in HPg and ASg. There was a negative correlation between LVT and longitudinal systolic function at TDI and STE (r = -0.4; P < 0.001; -0.23; P < 0.05). E/A ratio was lower in HPg and ASg than ATg and Hg. LVT was linearly related to LV-ESWS (r = 0.36; P < 0.01), E/A ratio (r = -0.59; P < 0.001), E/E' ratio (r = 0.43; P < 0.001), age (r = 0.5; P < 0.001), relative wall thickness (RWT) (r = 0.38; P < 0.01), heart rate (HR) (r = 0.3; P < 0.05), maximum (G. max), and mean transvalvular gradient (G. mean) in ASg (r = 0.37; P < 0.01, r = 0.4; P < 0.01). RWT, E/A ratio, and HR were independent predictor of LVT (ß = 0.23; P = 0.007; -0.44; P = 0.001; 0.17; P = 0.049). Only in ASg, G. mean was independent predictor of LVT (ß = 0.44; P = 0.01). CONCLUSION: Left ventricular twist showed a linear trend at increasing after-load values to compensate the reduction in systolic longitudinal function in pathological LVH patients.

Multimodality Imaging for Selecting Candidates for CRT: Do We Have a Single Alley to Increase Responders?

Cardiac resynchronization therapy has evolved in recent years to provide a reduction of morbidity and mortality for many patients with heart failure. Its application and optimization is an evolving field and its use requires a multidisciplinary approach for patient and device selection, technical preprocedural planning, and optimization. While echocardiography has always been considered the first line for the evaluation of patients, additional imaging techniques have gained increasing evidence in recent years. Today different details about heart anatomy, function, dissynchrony can be investigated by magnetic resonance, cardiac computed tomography, nuclear imaging, and more, with the aim of obtaining clues to reach a maximal response from the electrical therapy. The purpose of this review is to provide a practical analysis of the single and combined use of different imaging techniques in the preoperative and perioperative phases of cardiac resynchronization therapy, underlining their main advantages, limitations, and information provided.

Left Ventricular Lead Placement for Biventricular Pacing in a Left Lateral Vein in a Patient with Congenital Atresia of the Coronary Sinus Ostium.

Coronary sinus ostial atresia (CSOA) is a rare kind of congenital heart anomaly. This creates a new drainage pathway for the cardiac venous flow, with the most common being a persistent left superior vena cava (PLSVC). During the implantation of a cardiac resynchronization therapy defibrillator, we discovered a case of CSOA in a patient who underwent aortic valve and ascending aorta replacement. CSOA led to the research and subsequent identification of a PLSVC, which drained in the CS. The left ventricular pacing lead was appropriately placed in a left lateral vein. This case report highlights the technical aspects and procedural difficulties that characterize this specific anatomical variant.

Moderator Band and Ventricular Tachycardia: Structural or Functional Substrate?

The moderator band (MB) is an intracavitary structure of the right ventricle composed of muscular fibers encompassing specialized Purkinje fibers, separated each other by collagen and adipose tissue. In the last decades, premature ventricular complexes originating within the Purkinje network have been implicated in the genesis of life-threatening arrhythmias. However, right Purkinje network arrhythmias have been much less reported in the literature compared to the left counterpart. The MB has unique anatomical and electrophysiological properties, which may account for its arrhythmogenicity and may be responsible for a significant portion of idiopathic ventricular fibrillation. MB embodies autonomic nervous system cells, with important implications in arrhythmogenesis. Some idiopathic ventricular arrhythmias, defined as the absence of any identifiable structural heart disorder, can begin from this site. Due to these complex structural and functional peculiarities strictly interplayed each other, it is arduous to determine the precise mechanism underlying MB arrhythmias. MB-related arrhythmias should be differentiated from other right Purkinje fibers arrhythmias because of the opportunity for intervention and the unusual site for the ablation poorly described in the literature. In the current paper, we report the characteristics and electrical properties of the MB, their involvement in arrhythmogenesis, clinical and electrophysiological peculiarities of MB-related arrhythmias, and current treatment options.

Biventricular or Conduction System Pacing for Cardiac Resynchronization Therapy: A Strategy for Cardiac Resynchronization Based on a Hybrid Approach.

BACKGROUND: Cardiac resynchronization therapy (CRT) is usually performed with biventricular pacing (BiVP), but recently, conduction system pacing (CSP) has been proposed as an alternative in case of BiVP failure. The aim of this study is to define an algorithm to choose between BiVP and CSP resynchronization using the interventricular conduction delays (IVCD) as a guide. METHODS: Consecutive patients from January 2018 to December 2020 with an indication for CRT were prospectively enrolled in the study group (delays-guided resynchronization group, DRG). A treatment algorithm based on IVCD was used to decide whether to leave the left ventricular (LV) lead to perform BiVP or pull it out and perform CSP. Outcomes from the DRG group were compared to a historical cohort of CRT patients who underwent CRT procedures between January 2016 and December 2017 (resynchronization standard guide group, SRG). The primary endpoint was a composite of cardiovascular mortality, heart failure (HF) hospitalization, or HF event at 1 year after the date of intervention. RESULTS: The study population consisted of 292 patients, of which 160 (54.8%) were in the DRG and 132 (45.2%) in the SRG. In the DRG, 41 of 160 patients underwent CSP based on the treatment algorithm (25.6%). The primary endpoint was significantly higher in the SRG (48/132, 36.4%) compared to the DRG (35/160, 21.8%) (hazard ratio (HR): 1.72; 95% confidence interval (CI): 1.12-2.65; p = 0.013). CONCLUSIONS: A treatment algorithm based on IVCD shifted one patient out of every four from BiVP to CSP, with consequent reduction in the primary endpoint after implantation. Therefore, its application could be useful to determine whether to perform BiVP or CSP.

Integration of a Smartphone HF-Dedicated App in the Remote Monitoring of Heart Failure Patients with Cardiac Implantable Electronic Devices: Patient Access, Acceptance, and Adherence to Use.

(200 w) Introduction. Remote monitoring (RM) of cardiac implantable electronic device (CIED) diagnostics helps to identify patients potentially at risk of worsening heart failure (HF). Additionally, knowledge of patient HF-related symptoms is crucial for decision making. Patient smartphone applications may represent an ideal option to remotely collect this information. PURPOSE: To assess real-world HF patient access, acceptance, and adherence to use of an HF-dedicated smartphone application (HF app). METHODS: In this study, 10 Italian hospitals administered a survey on smartphone/app use to HF patients with CIED. The subgroup who accepted it downloaded the HF app. Mean 1-year adherence of the HF app use was evaluated. RESULTS: A total of 495 patients (67 ± 13 years, 79% males, 26% NYHA III-IV) completed the survey, of which 84% had access to smartphones and 85% were willing to use the HF app. In total, 311/495 (63%) downloaded the HF app. Patients who downloaded the HF app were younger and had higher school qualification. Patients who were ≥60 years old had higher mean 1-year adherence (54.1%) than their younger counterparts (42.7%; p < 0.001). Hospitals with RM-dedicated staff had higher mean 1-year patient adherence (64.0% vs. 33.5%; p < 0.001). Adherence to HF app decreased from 63.3% (weeks_1-13) to 42.2% (weeks_40-52, p < 0.001). CONCLUSIONS: High access and acceptance of smartphones/apps by HF patients with CIED allow HF app use for RM of patient signs/symptoms. Younger patients with higher school qualifications are more likely to accept HF app; however, older patients have higher long-term adherence.

Anti-Ro/SSA Antibodies Blocking Calcium Channels as a Potentially Reversible Cause of Atrioventricular Block in Adults.

BACKGROUND: In ∼50% of severe atrioventricular blocks (AVBs) occurring in adults <50 years, the underlying etiology remains unknown. Preliminary evidence from case reports suggests that autoimmunity, specifically the presence of circulating anti-Ro/SSA antibodies in the patient (acquired form), in the patient's mother (late-progressive congenital form), or in both (mixed form), could be involved in a fraction of idiopathic AVBs in adults by possibly targeting the L-type calcium channel (Cav1.2) and inhibiting the related current (ICaL). OBJECTIVES: The purpose of this study was to evaluate whether anti-Ro/SSA antibodies are causally implicated in the development of isolated AVBs in adults. METHODS: Thirty-four consecutive patients with isolated AVB of unknown origin and 17 available mothers were prospectively enrolled in a cross-sectional study. Anti-Ro/SSA antibodies were assessed by fluoroenzyme-immunoassay, immuno-Western blotting, and line-blot immunoassay. Purified immunoglobulin-G (IgG) from anti-Ro/SSA-positive and anti-Ro/SSA-negative subjects were tested on ICaL and Cav1.2 expression using tSA201 and HEK293 cells, respectively. Moreover, in 13 AVB patients, the impact of a short course of steroid therapy on AV conduction was evaluated. RESULTS: Anti-Ro/SSA antibodies, particularly anti-Ro/SSA-52kD, were found in 53% of AVB-patients and/or in their mothers, most commonly an acquired or mixed form (two-thirds of cases) without history of autoimmune diseases. Purified IgG from anti-Ro/SSA-positive but not anti-Ro/SSA-negative AVB patients acutely inhibited ICaL and chronically down-regulated Cav1.2 expression. Moreover, anti-Ro/SSA-positive sera showed high reactivity with peptides corresponding to the Cav1.2 channel pore-forming region. Finally, steroid therapy rapidly improved AV conduction in AVB-patients with circulating anti-Ro/SSA antibodies but not in those without. CONCLUSIONS: Our study points to anti-Ro/SSA antibodies as a novel, epidemiologically relevant and potentially reversible cause of isolated AVB in adults, via an autoimmune-mediated functional interference with the L-type calcium channels. These findings have significant impact on antiarrhythmic therapies by avoiding or delaying pacemaker implantation.

Predicting all-cause mortality by means of a multisensor implantable defibrillator algorithm for heart failure monitoring.

BACKGROUND: The HeartLogic algorithm (Boston Scientific) has proved to be a sensitive and timely predictor of impending heart failure (HF) decompensation. OBJECTIVE: The purpose of this study was to determine whether remotely monitored data from this algorithm could be used to identify patients at high risk for mortality. METHODS: The algorithm combines implantable cardioverter-defibrillator (ICD)-measured accelerometer-based heart sounds, intrathoracic impedance, respiration rate, ratio of respiration rate to tidal volume, night heart rate, and patient activity into a single index. An alert is issued when the index crosses a programmable threshold. The feature was activated in 568 ICD patients from 26 centers. RESULTS: During median follow-up of 26 months [25th-75th percentile 16-37], 1200 alerts were recorded in 370 patients (65%). Overall, the time IN-alert state was 13% of the total observation period (151/1159 years) and 20% of the follow-up period of the 370 patients with alerts. During follow-up, 55 patients died (46 in the group with alerts). The rate of death was 0.25 per patient-year (95% confidence interval [CI] 0.17-0.34) IN-alert state and 0.02 per patient-year (95% CI 0.01-0.03) OUT of the alert state, with an incidence rate ratio of 13.72 (95% CI 7.62-25.60; P <.001). After multivariate correction for baseline confounders (age, ischemic cardiomyopathy, kidney disease, atrial fibrillation), the IN-alert state remained significantly associated with the occurrence of death (hazard ratio 9.18; 95% CI 5.27-15.99; P <.001). CONCLUSION: The HeartLogic algorithm provides an index that can be used to identify patients at higher risk for all-cause mortality. The index state identifies periods of significantly increased risk of death.