Diagnostic and Prognostic Value of Right Ventricular Fat Quantification from Computed Tomography in Arrhythmogenic Right Ventricular Cardiomyopathy.

Background: In arrhythmogenic right ventricular cardiomyopathy (ARVC) non-invasive scar evaluation is not included among the diagnostic criteria or the predictors of ventricular arrhythmias (VA) and sudden death (SD). Computed tomography (CT) has excellent spatial resolution and allows a clear distinction between myocardium and fat; thus, it has great potential for the evaluation of myocardial scar in ARVC. Objective: The objective of this study is to evaluate the feasibility, and the diagnostic and prognostic value of semi-automated quantification of right ventricular (RV) fat replacement from CT images. Methods: An observational case-control study was carried out including 23 patients with a definite (19) or borderline (4) ARVC diagnosis and 23 age- and sex-matched controls without structural heart disease. All patients underwent contrast-enhanced cardiac CT. RV images were semi-automatically reconstructed with the ADAS-3D software (ADAS3D Medical, Barcelona, Spain). A fibrofatty scar was defined as values of Hounsfield Units (HU) <-10. Within the scar, a border zone (between -10 HU and -50 HU) and dense scar (<-50 HU) were distinguished. Results: All ARVC patients had an RV scar and all scar-related measurements were significantly higher in ARVC cases than in controls (p < 0.001). The total scar area and dense scar area showed no overlapping values between cases and controls, achieving perfect diagnostic performance (sensitivity and specificity of 100%). Among ARVC patients, 16 (70%) had experienced sustained VA or aborted SD. Among all clinical, ECG and imaging parameters, the dense scar area was the only one with a statistically significant association with VA and SD (p = 0.003). Conclusions: In ARVC, RV myocardial fat quantification from CT is feasible and may have considerable diagnostic and prognostic value.

Variations in the threshold's values for border zone and dense scar produce significant changes in the scar parameters obtained by ADAS-3D.

BACKGROUND: ADAS-3D software elaborates Cardiac Magnetic Resonance (CMR) images to obtain a quantitative evaluation of dense scar and border zone (BZ), including BZ channels, which can be useful for ventricular tachycardia ablation and for risk-stratification. However, most prior reports with ADAS-3D used flexible thresholds (60%±5% and 40%±5% of maximum pixel signal intensity -PSI) to define dense scar and BZ. It is unknown which is the impact of such variations of the thresholds values on the measurements obtained with ADAS-3D. OBJECTIVE: To quantify the degree of change in ADAS-3D measurements when different thresholds for dense scar and BZ are employed. METHODS: Single-center retrospective observational cohort study including 87 consecutive patients with previous myocardial infarction who underwent CMR. ADAS-3D software semi-automatically processed CMR sequences. We compared the scar measurements obtained using the 9 possible combinations of thresholds (55%/60%/65% and 35%/40%/45% of maximum PSI). RESULTS: The overall comparison between thresholds showed highly significant differences (p<0.001) in all scar parameters. Not a single patient maintained the same number of BZ channels with all the thresholds settings. A percentage difference of up to 200% in BZ channels numbers and channels mass was observed in all 36 comparisons. An absolute difference of up to 10 channels was also recorded. Of note, the highest median channel mass (obtained with the thresholds 35-65) was 59-fold higher as compared to the lowest one (obtained with the 45-55 cut-offs). CONCLUSIONS: Variations in threshold values result in statistically significant and high-magnitude changes in the quantification of scar parameters by ADAS-3D.

Predictive value of a comprehensive atrial assessment with cardiac magnetic resonance in non-ischemic cardiomyopathy: keep it simple.

Cardiac magnetic resonance (CMR) can provide a multi-parametric evaluation of left atrial (LA) size and function. A complete CMR-based LA assessment might improve the risk stratification of patients with non-ischemic dilated cardiomyopathy (DCM). We performed a comprehensive CMR-based evaluation of LA size and function, in order to assess the prognostic impact of specific LA parameters in DCM. Secondary analysis of a prospective registry (UHSM-CMR study, NCT02326324) including 648 consecutive patients with DCM and CMR evaluation of LA area and LA length. Of these, 456 had complete LA assessment covering reservoir, conduit and booster pump function and including LA reservoir strain evaluated with feature tracking. The heart failure (HF) endpoint included HF hospitalizations, HF death and heart transplant. The arrhythmic endpoint included ventricular arrhythmias (VA) (sustained or treated by implantable defibrillator) and sudden death (SD). At median follow-up of 23 months, 34 patients reached the HF endpoint; in a multivariable model including NYHA class and LVEF, LA length had incremental predictive value. LA length ≥ 69 mm was the best cut-off to predict HF events (adjusted HR 2.3, p = 0.03). Among the 456 patients with comprehensive LA assessment, only LA length was independently associated with the HF endpoint after adjusting for LVEF and NYHA class. By contrast, no LA parameter independently predicted the arrhythmic risk. In DCM patients, LA length is an independent predictor of HF events, showing stronger association than other more complex parameters of LA function. No atrial parameter predicts the risk of VA and SD.

Impact of Cardiac Magnetic Resonance to Arrhythmic Risk Stratification in Nonischemic Cardiomyopathy.

Left ventricular ejection fraction-based arrhythmic risk stratification in nonischemic cardiomyopathy (NICM) is insufficient and has led to the failure of primary prevention implantable cardioverter defibrillator trials, mainly due to the inability of selecting patients at high risk for sudden cardiac death (SCD). Cardiac magnetic resonance offers unique opportunities for tissue characterization and has gained a central role in arrhythmic risk stratification in NICM. The presence of myocardial scar, denoted by late gadolinium enhancement, is a significant, independent, and strong predictor of ventricular arrhythmias and SCD with high negative predictive value. T1 maps and extracellular volume fraction, which are able to quantify diffuse fibrosis, hold promise as complementary tools but need confirmatory results from large studies.

Ventricular Electrograms Duration Map to Detect Ventricular Arrhythmia Substrate: the VEDUM Project Study.

BACKGROUND: The analysis of the wave-front activation patterns is crucial for the comprehension and treatment of ventricular tachycardia (VT). The ventricular electrograms duration map (VEDUM) is a potential method to identify areas (VEDUM area) with slow and inhomogeneous activation. There is no available data on the characteristics and the arrhythmogenic role of VEDUM areas identified during sinus/paced rhythm. METHODS: Patients referred for VT ablation were enrolled at 3 different centers. VEDUM maps during sinus/paced rhythm as well as substrate and functional maps were created; activation mapping was performed for all hemodynamically tolerated VT. RESULTS: Thirty-two patients (mean age:70.1±9.4 years; males 93.8%) were enrolled. The VEDUM approach was achieved in all patients and the mean size of the VEDUM area was 12.1±6.9 cm2 (interquartile range, 7.8-14.9 cm2). A significative difference was observed between the electrogram duration in the VEDUM area and the normal tissue (163.7 ms [interquartile range, 142.3-199.2 ms]; versus 65.5 ms [interquartile range, 59.5-76.2 ms]; P<0.001). The VEDUM area was visualized in a dense scar (<0.5 mV) in 19 (59.4%) patients. A deceleration zone and late potentials were recorded inside the VEDUM area in 56.3% and 81.3%, respectively. When a complete VT activation mapping was available, the isthmus projected in the VEDUM area in 93.5% of patients; 8 of them had multiple VTs mapped and in the 87.5% all VT isthmuses were included in the VEDUM area. CONCLUSIONS: VEDUM maps allow the identification of discrete areas of inhomogeneous and slow conduction. They represent a potential target for VT ablation, including patients with multiple morphologies.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole.

AIMS: To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD. METHODS AND RESULTS: In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF. CONCLUSION: A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Late gadolinium enhancement and the risk of ventricular arrhythmias and sudden death in NYHA class I patients with non-ischaemic cardiomyopathy.

AIM: To compare the risk of ventricular arrhythmias (VA) and sudden death (SD) between New York Heart Association (NYHA) class I and NYHA class II-III patients with non-ischaemic cardiomyopathy (NICM). METHODS AND RESULTS: Observational retrospective cohort study including patients with NICM who underwent cardiac magnetic resonance at two hospitals. The primary endpoint included appropriate implantable cardioverter defibrillator (ICD) therapies, sustained ventricular tachycardia, resuscitated cardiac arrest and SD. The secondary endpoint included heart failure (HF) hospitalizations, heart transplant, left ventricular assist device implant or HF death. Overall, 698 patients were included, 33% in NYHA class I. During a median follow-up of 31 months, the primary endpoint occurred in 57 patients (8%), with no differences between NYHA class I and NYHA class II-III cases (7% vs. 9%, p = 0.62). Late gadolinium enhancement (LGE) was the only independent predictor of the primary outcome both in NYHA class I and NYHA class II-III patients. LGE+ NYHA class I patients had a similar cumulative incidence of the primary endpoint as compared to LGE+ NYHA class II-III (p = 0.92) and a significantly higher risk as compared to LGE- NYHA class II-III cases (p < 0.001). The risk of the secondary endpoint was significantly higher in patients in NYHA class II-III as compared to those in NYHA class I (hazard ratio 3.2, p = 0.001). CONCLUSIONS: Patients with NICM in NYHA class I are not necessarily at low risk of VA and SD. Actually, LGE+ NYHA class I patients have a high risk. NYHA class I patients with high-risk factors, such as LGE, could benefit from primary prevention ICD at least as much as those in NYHA class II-III with the same risk factors.

Prognostic impact of late gadolinium enhancement at the right ventricular insertion points in non-ischaemic dilated cardiomyopathy.

AIMS: To evaluate the baseline characteristics and the prognostic implications associated with late gadolinium enhancement limited to the right ventricular insertion points (IP-LGE) or present at both the right ventricular insertion points and the left ventricle (IP&LV-LGE) in non-ischaemic dilated cardiomyopathy (DCM). METHODS AND RESULTS: This is a retrospective observational multicentre cohort study including 1165 consecutive patients with DCM evaluated by cardiac magnetic resonance. The primary endpoint included appropriate defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest, or sudden death. The secondary outcome encompassed heart failure hospitalizations, heart transplant, left ventricular assist device implantation, and end-stage heart failure death. IP-LGE was found in 72 patients (6%), who had clinical characteristics closer to LGE- than to LGE+ patients. During follow-up (median 36 months), none of the IP-LGE patients experienced the primary endpoint. The cumulative incidence of the primary endpoint was similar between IP-LGE and LGE- patients (P = 1), while IP-LGE had significantly lower cumulative incidence when compared with LGE+ patients (P < 0.001). When compared with IP-LGE patients, the cumulative incidence of the secondary endpoint was similar in LGE- cases (P = 0.86) but tended to be higher in LGE+ patients (P = 0.06). Both clinical characteristics and outcomes were similar between IP&LV-LGE patients and the rest of LGE+ cases. CONCLUSIONS: In a large cohort of DCM patients, IP-LGE was associated with similar outcome when compared with LGE- patients and with significant lower risk of ventricular arrhythmias and sudden death when compared with LGE+ cases. Patients with IP&LV-LGE had clinical characteristics and outcomes similar to the rest of LGE+ cases.

Extracellular volume fraction improves risk-stratification for ventricular arrhythmias and sudden death in non-ischaemic cardiomyopathy.

AIMS: To evaluate whether cardiac magnetic resonance (CMR)-based parametric mapping and strain analysis can improve the risk-stratification for ventricular arrhythmias (VA) and sudden death (SD) in non-ischaemic cardiomyopathy (NICM). METHODS AND RESULTS: Secondary analysis of a prospective single-centre-registry (NCT02326324), including 703 consecutive NICM patients, 618 with extracellular volume (ECV) available. The combined primary endpoint included appropriate implantable cardioverter defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest and SD. During a median follow-up of 21 months, 14 patients (2%) experienced the primary endpoint. Native T1 was not associated with the primary endpoint. Left ventricular global longitudinal strain lost its significant association after adjustment for left ventricular ejection fraction (LVEF). Among patients with ECV available, 11 (2%) reached the primary endpoint. Mean ECV was significantly associated with the primary endpoint and the best cut-off was 30%. ECV ≥ 30% was the strongest independent predictor of the primary endpoint (hazard ratio 14.1, P = 0.01) after adjustment for late gadolinium enhancement (LGE) and LVEF. ECV ≥ 30% discriminated the arrhythmic risk among LGE+ cases and among those with LVEF ≤ 35%. A simple clinical risk-stratification model, based on LGE, LVEF ≤ 35% and ECV ≥ 30%, achieved an excellent predictive ability (Harrell's C 0.82) and reclassified the risk of 32% of the study population as compared to LVEF ≤ 35% alone. CONCLUSIONS: Comprehensive CMR evaluation in NICM showed that ECV was the only parameter with an independent and strong predictive value for VA/SD, on top of LGE and LVEF. A risk-stratification model based on LGE, LVEF ≤ 35% and ECV ≥ 30% achieved an excellent predictive ability for VA/SD. CLINICAL TRIAL REGISTRATION: UHSM CMR study (NCT02326324) https://clinicaltrials.gov/ct2/show/NCT02326324.

Registro español de ablación con catéter. XXI informe oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2021) / Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)

Introducción y objetivos: Se describen los resultados del Registro español de ablación con catéter correspondientes al año 2021, marcado por la recuperación de la actividad tras la pandemia de SARS-CoV-2. Métodos: La recogida de datos fue restrospectiva mediante la cumplimentación y el envío de un formulario específico por los centros participantes. Resultados: Se analizaron los datos de 93 centros (65 públicos, 28 privados). Se comunicaron 17.941 procedimientos de ablación con una media de 193±133 y mediana de 171. La recuperación de la actividad tras el cierre por la pandemia de SARS-CoV-2ha supuesto un marcado aumento de procedimientos (+2.772 casos, +18%) a pesar de un ligero descenso en el número de centros participantes (4 menos que en 2020). La ablación de la fibrilación auricular sigue siendo el procedimiento más frecuente, a distancia del resto de sustratos (5.848; 32,6%). Junto con la ablación del istmo cavotricuspídeo (3.766; 21%) y la taquicardia por reentrada intranodular (3.132; 17,5%), constituye los 3 sustratos abordados con más frecuencia. Las tasas comunicadas de éxito (94%), complicaciones (2%) y mortalidad (0,07%) son similares a las de años previos. Se realizaron 401 procedimientos en pacientes pediátricos (el 3,8% del total). Conclusiones: El Registro español de ablación con catéter recoge de manera sistemática e ininterrumpida la actividad nacional, y este año se ha observado una marcada recuperación de la actividad a pesar del persistente efecto de la pandemia de SARS-CoV-2. La tasa de éxito sigue manteniéndose elevada, con una baja tasa de complicaciones.(AU)

Introduction and objectives: The results of the 2021 Spanish catheter ablation registry are presented. Methods: Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers. Results: Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193±133 clases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%). Conclusions: The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.(AU)

Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021).

INTRODUCTION AND OBJECTIVES: The results of the 2021 Spanish catheter ablation registry are presented. METHODS: Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers. RESULTS: Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 cases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%). CONCLUSIONS: The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

[Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)]. / Registro español de ablación con catéter. XXI informe oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2021).

Introduction and objectives: The results of the 2021 Spanish catheter ablation registry are presented. Methods: Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers. Results: Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 clases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%). Conclusions: The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

Distinct spectral dynamics of implanted cardiac defibrillator signals in spontaneous termination of polymorphic ventricular tachycardia and fibrillation in patients with electrical and structural diseases.

AIMS: To determine the spectral dynamics of early spontaneous polymorphic ventricular tachycardia and ventricular fibrillation (PVT/VF) in humans. METHODS AND RESULTS: Fifty-eight self-terminated and 173 shock-terminated episodes of spontaneously initiated PVT/VF recorded by Medtronic implanted cardiac defibrillators (ICDs) in 87 patients with various cardiac pathologies were analyzed by short fast Fourier transform of shifting segments to determine the dynamics of dominant frequency (DF) and regularity index (RI). The progression in the intensity of DF and RI accumulations further quantified the time course of spectral characteristics of the episodes. Episodes of self-terminated PVT/VF lasted 8.6 s [95% confidence interval (CI): 8.1-9.1] and shock-terminated lasted 13.9 s (13.6-14.3) (P < 0.001). Recordings from patients with primarily electrical pathologies displayed higher DF and RI values than those from patients with primarily structural pathologies (P < 0.05) independently of ventricular function or antiarrhythmic drug therapy. Regardless of the underlying pathology, the average DF and RI intensities were lower in self-terminated than shock-terminated episodes [DF: 3.67 (4.04-4.58) vs. 4.32 (3.46-3.93) Hz, P < 0.001; RI: 0.53 (0.48-0.56) vs. 0.63 (0.60-0.65), P < 0.001]. In a multivariate analysis controlled by the type of pathology and clinical variables, regularity remained an independent predictor of self-termination [hazard ratio: 0.954 (0.928-0.980)]. Receiver operating characteristic (ROC) curve analysis of DF and RI intensities demonstrated increased predictability for self-termination in time with 95% CI above the 0.5 cut-off limit at about t = 8.6 s and t = 6.95 s, respectively. CONCLUSION: Consistent with the notion that fast organized sources maintain PVT/VF in humans, reduction of frequency and regularity correlates with early self-termination. Our findings might help generate ICD methods aiming to reduce inappropriate shock deliveries.