Epicardial adipose tissue volume assessed by cardiac CT as a predictor of atrial fibrillation recurrence following catheter ablation.

INTRODUCTION: In patients with atrial fibrillation (AF), up to one third have recurrence after a first catheter ablation (CA). Epicardial adipose tissue (EAT) has been considered to be closely related to AF, with a potential role in its recurrence. We aimed to evaluate the association between the volume of EAT measured by cardiac computed tomography (CT) and AF recurrence after CA. METHODS: Consecutive AF patients underwent a standardized cardiac CT protocol for quantification of EAT, thoracic adipose volume (TAV) and left atrium (LA) volume before CA. An appropriate cut-off of EAT was determined and risk recurrence was estimated. RESULTS: 305 patients (63.6 % male, mean age 57.5 years, 28.2 % persistent AF) were followed for 24 months; 23 % had AF recurrence at 2-year mark, which was associated with higher EAT (p = 0.037) and LAV (p < 0.001). Persistent AF was associated with higher EAT volumes (p = 0.010), TAV (p = 0.003) and LA volumes (p < 0.001). EAT was predictive of AF recurrence (p = 0.044). After determining a cut-off of 92 cm3, survival analysis revealed that EAT volumes > 92 cm3 showed higher recurrence rates at earlier time points after the index ablation procedure (p = 0.006), with a HR of 1.95 (p = 0.008) of AF recurrence at 2-year. After multivariate adjustment, EAT > 92 cm3 remained predictive of AF recurrence (p = 0.028). CONCLUSION: The volume of EAT measured by cardiac CT can predict recurrence of AF after ablation, with a volume above 92 cm3 yielding almost twice the risk of arrhythmia recurrence in the first two years following CA. Higher EAT and TAV are also associated with persistent AF.

Very-early detection of atrial fibrillation after ablation evaluated by a wearable ECG-patch predicts late blanking period recurrence: Preliminary data from a prospective registry.

Introduction: Atrial fibrillation (AF) ablation represents a safe and effective procedure to restore sinus rhythm. The idea that post-procedural AF episodes - during the blanking period - are not considered treatment failure has been increasingly challenged. The E-Patch, a single-use adhesive electrode, facilitates extended continuous ECG monitoring for 120 h. This pilot study aims to assess the effectiveness of this ambulatory monitoring device and investigate whether very-early AF recurrence correlates with delayed blanking period ablation outcomes. Methods: We conducted a single-center, prospective, longitudinal study, including consecutive post-ablation patients monitored with the E-patch. The ability of the device to continuously record was analyzed, as well as the occurrence of AF episodes during external 7-day loop-recorder in the 2nd-month post-ablation. Results: We included 40 patients, median age 62 years (IQR 56-70). E-Patch monitoring was obtained for a median of 118 h (IQR 112-120), with no discomfort nor interpretation artefacts. Very-early AF recurrence was detected in 11 (27.5 %) patients, with a median AF burden of 7 % (IQR 6 %-33 %). Late-blanking period AF was detected in 13 (33 %) of the external 7-day loop recordings. Of the 11 patients that had very-early AF recurrence, 10 (91 %) had late-blanking AF. Very-early AF detection showed 77 % (95 % CI 64 %-90 %) sensitivity and 96 % (95 % CI 90-100 %) specificity in predicting late-blanking AF, with a non-parametric ROC curve AUC of 0.903 (95 % 0.797--1.0). Conclusion: The E-Patch was able to detect very-early AF during an extended period. Very-early AF detection emerges as a predictor of AF recurrence during the late blanking period post-ablation.

A simplified single transseptal puncture approach using high-density 3D voltage mapping for atrial fibrillation ablation: acute complications and long-term results.

Background: An ablation catheter and a circular mapping catheter requiring a double transeptal puncture (TSP) for left atrial access have been conventionally used for atrial fibrillation (AF) ablation. Recently, different operators have combined a single transseptal puncture technique with 3D high-density mapping catheters for pulmonary vein isolation (PVI). Objective: This study aims to compare two strategies, single vs. double TSP, regarding the duration of the procedure, radiation time, complication rates, and outcomes. Methods: Retrospective analysis of a large cohort of consecutive patients that underwent first PVI with radiofrequency energy (RF), using a point-by-point strategy, with a 3D mapping system, either with single or double TSP, according to the operator's choice. Results: 285 patients with a mean age of 59.5 ± 11.6 years (36.5% female, 67.7% paroxysmal AF) underwent a point-by-point catheter ablation with RF between July 2015 and March 2020. The mean CHA2DS2-VASc score was 1.7 ± 1.3. Single TSP was performed in 115 (40.3%) patients and double TSP in 170 (59.6%). The operator's experience (≥5 years of AF ablation procedures) was equally distributed among the two groups. The average procedure time (133 ± 31.7 min vs. 123 ± 35.5 min, for single and double TSP, respectively) did reach a statistical difference between both groups (p = 0.008), but there was a substantial advantage regarding fluoroscopy time (13 ± 6.3 min vs. 19 ± 9.1 min, for single and double TSP, respectively; p < 0.001). Acute major complications present similar rates in both groups (2.6% vs. 2.3%, p = 0.799). At the 2-year follow-up, both groups had a similar sinus rhythm maintenance rate (76.5% vs. 78.8%, p = 0.646). Conclusion: A simplified single-TSP technique using high-density multi-electrode 3D mapping is a safe and highly successful option for AF ablation. This approach yields a substantial reduction in fluoroscopy time, with the potential to avoid acute complications, compared to a conventional double-TSP strategy.

Validation of a Heart Failure Risk Score in a Cohort of Cardiac Resynchronization Therapy Patients Under Remote Monitoring: Results from the TriageHF™ Algorithm.

The heart failure risk status (HFRS) is a validated dynamic tool for risk score prediction, based on the TriageHF™ algorithm (Medtronic, Minneapolis, MN, USA), for the occurrence of a heart failure (HF) event in the 30 days following a remote monitoring (RM) transmission. The aim of this study was to evaluate the accuracy of the HFRS in predicting an unplanned hospital admission due to HF decompensation in a real-world cohort of patients submitted to cardiac resynchronization therapy (CRT). We conducted a single-center review of a cohort of 40 consecutive HF patients, under RM, with CRT devices using the HFRS of the TriageHF™ algorithm. The correlation of the HFRS with hospital admissions was analyzed. During a mean follow-up of 36 months, a stepwise increase in the HFRS was significantly associated with a higher risk of HF admission (odds ratio, 12.7; 95% confidence interval, 3.2-51.5; P < .001), and the HFRS was demonstrated to have good discrimination for HF hospitalization, with an area under the receiver-operating characteristic curve of 0.812. The TriageHF™ algorithm effectively predicted HF-related hospitalization in a cohort of CRT patients during long-term RM follow-up, providing a novel clinical pathway to optimize the clinical management of this complex population.

Dilated Cardiomyopathy: A Comprehensive Approach to Diagnosis and Risk Stratification.

Dilated cardiomyopathy (DCM) represents one of the most common causes of non-ischemic heart failure, characterised by ventricular dilation alongside systolic dysfunction. Despite advances in therapy, DCM mortality rates remain high, and it is one of the leading causes of heart transplantation. It was recently recognised that many patients present minor structural cardiac abnormalities and express different arrhythmogenic phenotypes before overt heart-failure symptoms. This has raised several diagnostic and management challenges, including the differential diagnosis with other phenotypically similar conditions, the identification of patients at increased risk of malignant arrhythmias, and of those who will have a worse response to medical therapy. Recent developments in complementary diagnostic procedures, namely cardiac magnetic resonance and genetic testing, have shed new light on DCM understanding and management. The present review proposes a comprehensive and systematic approach to evaluating DCM, focusing on an improved diagnostic pathway and a structured stratification of arrhythmic risk that incorporates novel imaging modalities and genetic test results, which are critical for guiding clinical decision-making and improving outcomes.

Apical or Septal Right Ventricular Location in Patients Receiving Defibrillation Leads: A Systematic Review and Meta-Analysis.

This study reviews the published data comparing the efficacy and safety of apical and septal right ventricle defibrillator lead positioning at 1-year follow-up. Systemic research on Medline (PubMed), ClinicalTrials.gov, and Embase was performed using the keywords "septal defibrillation," "apical defibrillation," "site defibrillation," and "defibrillation lead placement," including implantable cardioverter-defibrillator and cardiac resynchronization therapy devices. Comparisons between apical and septal position were performed regarding R-wave amplitude, pacing threshold at a pulse width of 0.5 ms, pacing and shock lead impedance, suboptimal lead performance, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, readmissions due to heart failure and mortality rates. A total of 5 studies comprising 1438 patients were included in the analysis. Mean age was 64.5 years, 76.9% were male, with a median LVEF of 27.8%, ischemic etiology in 51.1%, and a mean follow-up period of 26.5 months. The apical lead placement was performed in 743 patients and septal lead placement in 690 patients. Comparing the 2 placement sites, no significant differences were found regarding R-wave amplitude, lead impedance, suboptimal lead performance, LVEF, left ventricular end-diastolic diameter, and mortality rate at 1-year follow-up. Pacing threshold values favored septal defibrillator lead placement (P = 0.003), as well as shock impedance (P = 0.009) and readmissions due to heart failure (P = 0.02). Among patients receiving a defibrillator lead, only pacing threshold, shock lead impedance, and readmission due to heart failure showed results favoring septal lead placement. Therefore, generally, the right ventricle lead placement does not appear to be of major importance.

The atrial fibrillation burden during the blanking period is predictive of time to recurrence after catheter ablation.

Objective: This study aimed to assess whether atrial fibrillation (AF) occurrence or its corresponding daily mean burden (in minutes/day) during the mid to late blanking period after pulmonary vein isolation (PVI), predicts AF recurrence. Methods: Analysis of consecutive first PVI ablation patients undergoing prolonged electrocardiogram (ECG) monitoring during the second and third months after PVI. The clinical variables, total AF burden, and their relationship with time to recurrence were studied. Results: 477 patients with a mean age of 56.9 (SD = 12.3) years (63.7 % male; 71.7 % paroxysmal AF), from which 317 (66.5 %) had an external event recorder between 30 and 90 days after ablation. Median follow-up of 16.0 (P 25:12.0: P 75:33.0) months, 177 (37 %) patients had an AF recurrence, with 106 (22.2 %) having the first episode after 12 months of follow-up. In the group of patients with an event recorder, 80 (25.2 %) had AF documented during the blanking period. Multivariable analysis showed that AF during the blanking period was associated with a 4-fold higher risk of recurrence (HR: 3.98; 95 %CI: 2.95-5.37), and, compared to patients in sinus rhythm, those with an AF burden ≥ 23 min/day had an approximately 7-fold higher risk of recurrence (HR estimate: 6.79; 95 %CI: 4.56-10.10). Conclusions: The probability of experiencing AF recurrence can be predicted by atrial tachyarrhythmia episodes during the second and third months after PVI. Atrial arrhythmias burden > 23 min/day has a high predictive ability for recurrence.

Long-term outcomes of non-contact multi-electrode balloon catheter mapping-guided ablation of ventricular arrhythmias originating from the outflow tract.

INTRODUCTION: The outflow tract (OT) regions of the ventricles are a common location of origin for idiopathic ventricular arrhythmias (VA). Non-contact mapping (NCM) with a multi-electrode balloon catheter Ensite-Array enables three-dimensional reconstruction of the geometry of the cardiac chambers and accurate mapping of the propagation map, based on a single beat analysis, facilitating the ablation and contributing procedure success. OBJECTIVE: Assessment of the feasibility and long-term outcomes following NCM-guided OT VA ablation. METHODS: Single center retrospective analysis of patients admitted for symptomatic OT VA ablation. Demographic and clinical characteristics of patients, procedure data and long-term outcomes were assessed. RESULTS: Fifty-eight patients (79.3% female, age 43.9±17.6 years) were considered, 89.7% without structural heart disease. In 85.7% of the cases left ventricle ejection fraction (LVEF) was preserved (LVEF≥50%), 8.6% had mild systolic dysfunction (LVEF 40%-49%) and 5.7% had moderate systolic dysfunction (LVEF 30%-39%). Twenty-four-hour Holter recording documented sustained VA episodes in 12.1% of the patients, non-sustained VA in 31.0%, and >10 000 premature ventricular complex (PVC)/24 h in 56.9%, with an ECG suggesting right ventricular OT origin in 84.5%. There was total elimination of PVC in 87.9% cases and a significant reduction in 3.4%. During a mean follow-up of 5.5 years, 87.9% patients remained asymptomatic without medication, 12.1% underwent re-ablation due to symptomatic PVC recurrence, and two cases underwent a third successful intervention. CONCLUSION: Non-contact mapping-guided multi-electrode balloon catheter VA ablation is a highly effective and safe procedure, with a low rate of long-term recurrence.

Impact of substrate-based ablation for ventricular tachycardia in patients with frequent appropriate implantable cardioverter-defibrillator therapy and dilated cardiomyopathy: Long-term experience with high-density mapping.

INTRODUCTION: Recurrent ventricular tachycardia (VT) episodes have a negative impact on the clinical outcome of implantable cardioverter-defibrillator (ICD) patients. Modification of the arrhythmogenic substrate has been used as a promising approach for treating recurrent VTs. However, there are limited data on long-term follow-up. AIM: To analyze long-term results of VT substrate-based ablation using high-density mapping in patients with severe left ventricular (LV) dysfunction and recurrent appropriate ICD therapy. METHODS: We analyzed 20 patients (15 men, 55% with non-ischemic cardiomyopathy, age 58±15 years, LV ejection fraction 32±5%) and repeated appropriate shocks or arrhythmic storm (>2 shocks/24 h) despite antiarrhythmic drug therapy and optimal heart failure medication. All patients underwent ventricular programmed stimulation (600 ms/S3) to document VT. A sinus rhythm (SR) voltage map was created with a three-dimensional electroanatomic mapping system (CARTO, Biosense Webster, CA) using a PentaRay® high-density mapping catheter (Biosense Webster, CA) to delineate areas of scarred myocardium (ventricular bipolar voltage ≤0.5 mV - dense scar; 0.5-1.5 mV - border zone; ≥1.5 mV - healthy tissue) and to provide high-resolution electrophysiological mapping. Substrate modification included elimination of local abnormal ventricular activities (LAVAs) during SR (fractionated, split, low-amplitude/long-lasting, late potentials, pre-systolic), and linear ablation to obtain scar homogenization and dechanneling. Pace-mapping techniques were used when capture was possible. The LV approach was retrograde in nine cases, transseptal in five and epi-endocardial in four. In two patients ablation was performed inside the right ventricle. RESULTS: LAVAs and scar areas were modified in all patients. Mean procedure duration was 149 min (105-220 min), with radiofrequency ranging from 18 to 70 min (mean 33 min) and mean fluoroscopy time of 15 min. Non-inducibility was achieved in 75% of cases (in four patients with hemodynamic deterioration and an LV assist device, VT inducibility was not performed). There were two cases of pericardial tamponade, drained successfully. During a follow-up of 50±24 months, 65% had no VT recurrences. Among the seven patients with recurrences, three underwent redo ablation and four, with fewer VT episodes, received appropriate ICD therapy. There were five hospital readmissions due to heart failure decompensation, one patient died in the first week after unsuccessful ablation of a VT storm and three died (stroke and pneumonia) >1 year after ablation. CONCLUSION: Catheter ablation based on substrate modification is feasible and safe in patients with frequent VTs and severe LV dysfunction. This approach may be of clinical relevance, with potential long-term benefits in reducing VT burden.

Atrial fibrosis and decreased connexin 43 in rat hearts after exposure to high-intensity infrasound.

BACKGROUND: Noise is an important environmental risk factor. Industrial environments are rich in high-intensity infrasound (hi-IFS), which we have found to induce myocardial and coronary perivascular fibrosis in rats. The effects of exposure to IFS on the ventricles have been studied, but not on the atria. We hypothesized that rats exposed to hi-IFS develop atrial remodeling involving fibrosis and connexin 43, which we sought to evaluate. MATERIAL AND METHODS: Seventy-two Wistar rats, half exposed to hi-IFS (120 dB, <20 Hz) during a maximum period of 12 weeks and half age-matched controls, were studied. Atrial fibrosis was analyzed by Chromotrope-aniline blue staining. The immunohistochemical evaluation of Cx43 was performed using the polyclonal antibody connexin-43 m diluted 1:1000 at 4 °C overnight. Digitized images were obtained with an optical microscope using 400× magnifications. The measurements were performed using image J software. A two-way ANOVA model was used to compare the groups. RESULTS: The mean values of the ratio "atrial fibrosis / cardiomyocytes" increased to a maximum of 0.1095 ± 0,04 and 0.5408 ± 0,01, and of the ratio "CX43 / cardiomyocytes" decreased to 0.0834 ± 0,03 and 0.0966 ± 0,03, respectively in IFS-exposed rats and controls. IFS-exposed rats exhibited a significantly higher ratio of fibrosis (p < .001) and lower ratio of Cx43 (p = .009). CONCLUSION: High-intensity infrasound exposure leads to an increase in atrial interstitial fibrosis and a decrease in connexin 43 in rat hearts. This finding reinforces the need for further experimental and clinical studies concerning the effects of exposure to infrasound.

An inappropriate shock after reprogramming tachycardia zones.

A patient with an implantable cardioverter-defibrillator (ICD) (Abbott®) had episodes of slow monomorphic ventricular tachycardia (VT) and his ICD was programmed with three tachycardia zones. During the follow-up, he received an inappropriate shock. Upon interrogation (of the device), trigeminal pattern binned as ventricular sensing (VS)-VS-ventricular fibrillation (VF) was detected. VF was assumed according to binning system. When VF is present, discrimination algorithms are not available and five consecutive sinus beats are necessary to reset binning system. Catheter ablation was performed to treat VT in order to reprogram tachycardia zones.

Long-term follow-up of adult patients with congenital heart disease and an implantable cardioverter defibrillator.

OBJECTIVE: Sudden cardiac death is common in the adult congenital heart disease (ACHD) population. Knowledge and experience about the use of implantable cardioverter defibrillators (ICD) in ACHD patients is very limited. We aimed to characterize a cohort of patients with ACHD and ICDs. DESIGN: Thirty consecutive ACHD patients submitted to an ICD implantation in a single tertiary center were evaluated. Data on baseline clinical features, heart defect, indication for ICD, type of device, appropriate therapies, ICD-related complication, and mortality during follow-up were collected. RESULTS: Of the 30 patients, 56.7% received appropriate therapies due to ventricular tachycardia (VT) or ventricular fibrillation (VF). The rate of inappropriate therapies and device-related complications was 33.3%. Secondary prevention and primary prevention patients with class I indications for ICD had more appropriate therapies than complication, but this relationship was reversed for patients with class II indications. Remote monitoring played an important role in diagnosing new atrial arrhythmias before scheduled visits in 46.2% of patients, leading to a change in medication. VT/VF episodes were associated with a composite of death, cardiac transplantation, and hospital admission (OR 13.0; 95% CI: 2.1-81.5). CONCLUSION: ICDs are not only useful in preventing SCD, but also have a major role in diagnosing atrial tachyarrhythmias ahead of scheduled visits. Although improvements in ICD technology might reduce complications and inappropriate therapies, adequate selection of candidates for primary prevention still remains difficult because of the lack of clear indications.

Importance of monitoring zones in the detection of arrhythmias in patients with implantable cardioverter-defibrillators under remote monitoring.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) monitoring zones (MZ) provide passive features that do not interfere with the functioning of active treatment zones. However, it is not known for certain whether programming an MZ affects arrhythmia detection by the ICD. The aim of the present study is to assess the clinical relevance of MZ in a population of patients with ICDs. METHODS: In this retrospective analysis of patients with ICDs, with or without cardiac resynchronization therapy, for primary prevention under remote monitoring, the MZ was analyzed and recorded arrhythmias were assessed in detail. RESULTS: A total of 221 patients were studied (77% men; age 64±12 years). Mean ejection fraction was 30±12%. The mean follow-up was 63±35 months. One hundred and seventy-four MZ events were documented in 139 patients (62.9%): 74 of non-sustained ventricular tachycardia (NSVT), 42 of supraventricular tachycardia, 44 of atrial fibrillation/atrial flutter, and five cases of noise. Among the 137 patients who presented with arrhythmias in the MZ (excluding two cases with noise detection only), 22 (16.1%) received appropriate shocks and/or antitachycardia pacing (ATP), while of the other 84 patients, 15.5% received appropriate ICD treatment (p=NS). In patients who presented with NSVT in the MZ, 15 (20.5%) received appropriate shocks and/or ATP. In accordance with the MZ findings, physicians decided to change outpatient medication in 41.7% of all patients in whom arrhythmic events were reported. CONCLUSION: Ventricular and supraventricular arrhythmias are common findings in the MZ of ICD patients. Programming an MZ is valuable in the diagnosis of arrhythmias and may be a useful tool in clinical practice.

Impact on long-term cardiovascular outcomes of different cardiac resynchronization therapy response criteria.

INTRODUCTION: There is a lack of consensus on the definition of response to cardiac resynchronization therapy (CRT), and it is not clear which response criteria have most influence on cardiac event-free survival. OBJECTIVES: To assess the predictive value of various response criteria in patients undergoing CRT and the agreement between them. METHODS: We performed a secondary analysis of the BETTER-HF trial. Patient response was classified at six months after CRT according to eleven criteria used in previous trials. The predictive value of response criteria for survival free from mortality, cardiac transplantation and heart failure hospitalization was assessed by Cox regression analysis. Agreement between the different response criteria was assessed using Cohen's kappa (κ). RESULTS: A total of 115 patients were followed for a mean of 25 months. During follow-up, 15 deaths occurred (13%) and 29 patients had at least one adverse cardiac event (25%). Only five of the eleven response criteria were predictors of event-free survival. The most powerful isolated clinical and echocardiographic predictors were a reduction of ≥1 NYHA functional class (HR 0.39 for responders; 95% CI 0.18-0.83, p=0.014) and an increase of at least 15% in left ventricular ejection fraction (HR 0.43, 95% CI 0.20-0.90, p=0.024), respectively. Agreement between the different response criteria was poor. CONCLUSIONS: Most currently used response criteria do not predict clinical outcomes and have poor agreement. It is essential to establish a consensus on the definition of CRT response in order to standardize studies.

Infrasound induces coronary perivascular fibrosis in rats.

BACKGROUND: Chronic exposure to industrial noise is known to affect biological systems, namely, by inducing fibrosis in the absence of inflammatory cells. In rat hearts exposed to this environmental hazard, we have previously found myocardial and perivascular fibrosis. The acoustic spectrum of industrial environments is particularly rich in high-intensity infrasound (<20 Hz), whose effects on the heart are unknown. We evaluated the morphological changes induced by IFS in rat coronaries in the presence and absence of dexamethasone. METHODS: Adult Wistar rats were divided into three groups: group A (GA)-IFS (<20 Hz, 120 dB)-exposed rats for 28 days treated with dexamethasone; group B (GB)-IFS-exposed rats; group C (GC)-age-matched controls. The midventricle was prepared for observation with an optical microscope using 100× magnification. Thirty-one arterial vessels were selected (GA 8, GB 10, GC 13). The vessel caliber, thickness of the wall, and perivascular dimensions were quantified using image J software. Mann-Whitney and Kruskal-Wallis tests were used to compare the groups for lumen-to-vessel wall (L/W) and vessel wall-to-perivascular tissue (W/P) ratios. RESULTS: IFS-exposed rats exhibited a prominent perivascular tissue. The median L/W and median W/P ratios were 0.54 and 0.48, 0.66 and 0.49, and 0.71 and 0.68, respectively, in GA, GB, and GC. The W/P ratio was significantly higher in GC compared with IFS-exposed animals (P=.001). The difference was significant between GC and GB (P=.008) but not between GC and GA. CONCLUSION: IFS induces coronary perivascular fibrosis that differs under treatment with corticosteroid.

A link to better care: The effect of remote monitoring on long-term adverse cardiac events in a propensity score-matched cohort.

AIMS: There are conflicting data regarding the clinical benefits of device-based remote monitoring (RM). We sought to assess the effect of device-based RM on long-term clinical outcomes in recipients of implantable cardioverter-defibrillators (ICDs). METHODS: We assessed the incidence of adverse cardiac events, overall mortality and device therapy efficacy and safety in a propensity score-matched cohort of patients under RM compared to patients under conventional follow-up. Data on hospitalizations, mortality and cause of death were systematically assessed using a nationwide healthcare platform. The primary outcome was time to a composite outcome of first hospital admission for heart failure or cardiovascular death. RESULTS: Of a total of 923 implantable device recipients, 164 matched patients were identified (84 under RM, 84 under conventional follow-up). The mean follow-up was 44 months (range 1-123). There were no significant differences regarding baseline characteristics in the matched cohorts. Patients under RM had a significantly lower incidence of the primary outcome (hazard ratio [HR] 0.42, confidence interval [CI] 0.20-0.88, p=0.022); there was a non-significant trend towards lower overall mortality (HR 0.53, CI 0.27-1.04, p=0.066). No significant differences between cohorts were found regarding appropriate therapies (RM vs. conventional follow-up, 8.1 vs. 8.2%, p=NS) or inappropriate therapies (6.8 vs. 5.0%, p=NS). CONCLUSION: In a propensity score-matched cohort of ICD recipients with long-term follow-up, RM was associated with a lower rate of a combined endpoint of hospital admission for heart failure or cardiovascular death.