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.

Evaluation of left atrial strain imaging and integrated backscatter as predictors of recurrence in patients with paroxysmal, persistent, and long-standing persistent atrial fibrillation undergoing catheter ablation.

BACKGROUND: Impaired left atrial (LA) strain predicts atrial fibrillation (AF) recurrence after catheter ablation (CA), but currently there is no cut-off to guide patient selection for CA. Integrated backscatter (IBS) is a promising tool for noninvasive quantification of myocardial fibrosis. The aim of this study was to compare LA strain and IBS between paroxysmal, persistent, and long-standing persistent AF and evaluate their association with AF recurrence after CA. METHODS: Analysis of consecutive patients with symptomatic paroxysmal and persistent AF who underwent CA. LA phasic strain, strain rate and IBS were assessed by two-dimensional speckle-tracking at baseline. RESULTS: We analyzed 78 patients, 31% with persistent AF (46% long-standing AF), 65% male, mean age 59 ± 14 years, who underwent CA and were followed-up for 12 months. AF recurrence occurred in 22 (28%) patients. LA phasic strain parameters were significantly impaired in patients with AF recurrence and were independent predictors of AF recurrence in a multivariable analysis. LA reservoir strain (LASr) < 18% predicted AF recurrence with 86% sensitivity and 71% specificity, with a higher predictive power compared to LA volume index (LAVI). LASr < 22% in paroxysmal AF and LASr < 12% in persistent AF correlated with AF recurrence. Increased IBS was a predictor of AF recurrence in patients with paroxysmal AF. CONCLUSION: LA phasic strain parameters were predictors of AF recurrence after CA, independently of LAVI and AF subtype. LASr < 18% showed a higher predictive power compared to LAVI. Further studies are needed to investigate the role of IBS as a predictor of AF recurrence.

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.

Intraventricular gradients-When we have to "exercise" our minds: A case report.

Increased intraventricular pressure gradients due to dynamic left ventricular outflow tract obstruction during exercise have long been known to cause different symptoms. Exercise stress echocardiography is fundamental in the diagnostic approach of symptoms presenting during exercise. We hypothesize on the possible pathophysiological mechanisms responsible for our patient's syncopal episodes.

Quadripolar left ventricle only single lead pacing in a patient with a tricuspid mechanical valve: A less invasive approach.

In the presence of prosthetic tricuspid valve, the inaccessibility to the right ventricle makes permanent pacing challenging. The placement of a left ventricle (LV) single lead in the coronary sinus (CS) is a well-accepted alternative, with some limitations regarding sensing and threshold. We describe a clinical case of a patient who had a previous LV only lead in the CS due to the presence of a prosthetic tricuspid valve and, after a surgical valvular intervention, presented with recurrent syncope episodes due to lead malfunction with lack of pacing capture and significant ventricular pauses. A quadripolar lead was chosen to be placed in the CS connected to a cardiac resynchronization therapy pacemaker device, programmed at biventricular VVI and using a specific manufacturer T-wave protection algorithm to prevent pacemaker-induced arrhythmias and to use the patient's own rhythm. This approach prevented a fourth surgical intervention to place an epicardial lead and resulted in reasonable LV sensing and pacing threshold. Learning objectives: This paper reports an alternative and atypical approach that could solve some of the limitations associated with ventricular pacing in patients with tricuspid prosthetic valves and multiple previous surgeries.

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.

Remote versus in-office monitoring for implantable cardioverter defibrillators: Results from a randomized pragmatic controlled study in Portugal.

INTRODUCTION: Remote monitoring (RM) is a safe and effective alternative to in-office conventional follow-up. OBJECTIVE: We aimed to evaluate patient satisfaction with RM and its impact on healthcare resources in a population with cardiac implantable electronic devices. METHODS: Randomized, pragmatic, open-label controlled trial, with adult wearers of implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy with ICD (CRT-D), eligible for the CareLink® system. Patients newly implanted or with previous conventional follow-up were randomized to RM or conventional follow-up (control), and followed for 12 months, according to the centers' practice. The number of in-office visits and adverse events were compared between groups. Patient and healthcare professionals' satisfaction with RM were described. RESULTS: Of the 134 randomized patients (69 RM; 65 control, aged 60±13 years), 80% were male, 23% employed, 72% ICD wearers and 54% newly implanted. Most patients (70%) reported travel costs less than 15€/visit, and 46% daily routine interference with in-office visits. Median physician/technician time with patient was 15 min/15 min, per in-office visit. Excluding baseline and final visits, control patients had more in-office visits in total: median 1 vs. 0, p<0.001. In 81% of the in-office visits, no clinical measures were taken. There were 10 adverse events, with no differences between groups. At the final visit, 95% of RM patients considered RM easy/very easy to use, and would all prefer to maintain RM and recommend it to others. All professionals found the CareLink website easy/very easy to use and were satisfied with transmission data. CONCLUSIONS: In a Portuguese population with ICD and CRT-D, RM safely reduced the burden of in-office visits, with high levels of satisfaction among patients and healthcare professionals.

The Atrium in Atrial Fibrillation - A Clinical Review on How to Manage Atrial Fibrotic Substrates.

Atrial fibrillation (AF) is the most common sustained arrhythmia in the population and is associated with a significant clinical and economic burden. Rigorous assessment of the presence and degree of an atrial arrhythmic substrate is essential for determining treatment options, predicting long-term success after catheter ablation, and as a substrate critical in the pathophysiology of atrial thrombogenesis. Catheter ablation of AF has developed into an essential rhythm-control strategy. Nowadays is one of the most common cardiac ablation procedures performed worldwide, with its success inversely related to the extent of atrial structural disease. Although atrial substrate evaluation remains complex, several diagnostic resources allow for a more comprehensive assessment and quantification of the extent of left atrial structural remodeling and the presence of atrial fibrosis. In this review, we summarize the current knowledge on the pathophysiology, etiology, and electrophysiological aspects of atrial substrates promoting the development of AF. We also describe the risk factors for its development and how to diagnose its presence using imaging, electrocardiograms, and electroanatomic voltage mapping. Finally, we discuss recent data regarding fibrosis biomarkers that could help diagnose atrial fibrotic substrates.

Lockdown measures for COVID-19 outbreak and variation in physical activity in patients with heart failure and cardiac implantable devices.

AIMS: The present study analysed the patterns of physical activity pre-, during and post-lockdown measures for COVID-19 pandemic in patients with chronic heart failure (CHF) and cardiac implantable electronic devices (CIED) under remote monitoring (RM), and assessed the physical activity patterns during these periods. METHODS: The raw data from 95 patients with CHF (age 67,7 ± 15,1 years, 71,5% male) corresponding to 2238 RM transmissions of the Medtronic Carelink™ network platform was obtained. The physical exercise profiles and the impact of the lockdown measures on the physical behaviour during and after the measures were analysed. According to the level of activity duration in the pre-lockdown, lockdown and post-lockdown periods, the patterns of behaviour were identified (non-recoverees, incomplete recoverees, recoverees and full-recoverees). CONCLUSION: RM of CHF patients with CIED using the Carelink™ network is useful for close follow-up and identification of heart failure risk status variations. After relieving the confinement measures there were two groups of patients that did not recover the previous physical activity levels. Physical inactivity in patients with CHF can have a significant impact on outcomes.

Prognostic effect and modulation of cardiac sympathetic function in heart failure patients treated with cardiac resynchronization therapy.

BACKGROUND: Cardiac autonomic dysfunction as assessed by 123I-metaiodobenzylguanidine (123I-mIBG) scintigraphy is associated with poor prognosis in heart failure (HF) patients. Although cardiac resynchronization therapy (CRT) has emerged as an effective therapy in improving outcomes on HF patients, its effect on cardiac sympathetic nervous function is still not fully understood. We aimed to study the value of pre-implantation 123I-mIBG late heart-to-mediastinum ratio (HMR) as a predictor of response and outcomes after CRT and to correlate modification in this parameter with CRT response and functional improvement. METHODS AND RESULTS: BETTER-HF (Benefit of exercise training therapy and cardiac resynchronization in HF patients) is a prospective randomized clinical trial including HF patients submitted CRT (mean LVEF 24 ± 8%, 74% NYHA class ≥ III) who underwent a clinical, echocardiographic, and scintigraphic assessment before and 6 months after CRT. One-hundred and twenty-one patients were included. Echocardiographic response was observed in 54% and composite outcome of cardiac mortality, cardiac transplant or heart failure hospitalization in 24% of patients. Baseline late HMR was an independent predictor of CRT response (regression coefficient 2.906, 95% CI 0.293-3.903, P .029) and outcomes (HR 0.066 95% CI 0.005-0.880, P .040). At follow-up, 123I-mIBG imaging showed positive changes in cardiac sympathetic nerve activity only in responders to CRT (1.36 ± 0.14 prior vs. 1.42 ± 0.16 after CRT, P .039). There was a significant correlation between improvement in late HMR and improvement in peak oxygen consumption (r 0.547, P < .001). CONCLUSION: In our study, baseline cardiac denervation predicted response and clinical outcomes after CRT implantation. Cardiac sympathetic function was improved only in patients who responded to CRT and these positive changes were correlated with improvement in functional capacity.

Response and outcomes of cardiac resynchronization therapy in patients with renal dysfunction.

PURPOSE: Renal dysfunction is often associated with chronic heart failure, leading to increased morbi-mortality. However, data regarding these patients after cardiac resynchronization therapy (CRT) is sparse. We sought to evaluate response and long-term mortality in patients with heart failure and renal dysfunction and assess renal improvement after CRT. METHODS: We analyzed 178 consecutive patients who underwent successful CRT device implantation (age 64 ± 11 years; 69% male; 92% in New York Heart Association (NYHA) functional class ≥ III; 34% with ischemic cardiomyopathy). Echocardiographic response was defined as ≥ 15% reduction in left ventricular end-systolic diameter and clinical response as a sustained improvement of at least one NYHA functional class. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2. RESULTS: Renal dysfunction was present in 34.7%. Renal dysfunction was not an independent predictor of echocardiographic response (OR 1.109, 95% CI 0.713-1.725, p 0.646) nor clinical response (OR 1.003; 95% CI 0.997-1.010; p 0.324). During follow-up (mean 55.2 ± 32 months), patients with eGFR < 60mL/min/1.73 m2 had higher overall mortality (HR 4.902, 95% CI 1.118-21.482, p 0.035). However, clinical response in patients with renal dysfunction was independently associated with better long-term survival (HR 0.236, 95% CI 0.073-0.767, p 0.016). Renal function was significantly improved in patients who respond to CRT (ΔeGFR + 5.5 mL/min/1.73 m2 at baseline vs. follow-up, p 0.049), while this was not evident in nonresponders. Improvements in eGFR of at least 10 mL/min/1.73 m2 were associated with improved survival in renal dysfunction patients (log-rank p 0.036). CONCLUSION: Renal dysfunction was associated with higher long-term mortality in CRT patients, though, it did not influence echocardiographic nor functional response. Despite worse overall prognosis, renal dysfunction patients who are responders showed long-term survival benefit and improvement in renal function following CRT.

What happens to non-responders in cardiac resynchronization therapy?

INTRODUCTION AND OBJECTIVES: Left ventricular reverse remodeling (LVRR) is strongly related to the long-term prognosis of patients undergoing cardiac resynchronization therapy (CRT). The aim of this study was to assess the long-term clinical outcome of patients without LVRR at six months after CRT implantation and to determine the prognostic impact of clinical response in this population. METHODS: We analyzed 178 consecutive patients who underwent successful CRT device implantation (age 64±11 years; 69% male; 89% in New York Heart Association [NYHA] functional class III; 35% with ischemic cardiomyopathy). Clinical status and echocardiographic parameters were determined before and six months after CRT implantation. We identified those without criteria for LVRR (≥10% increase in left ventricular ejection fraction with ≥15% reduction in left ventricular end-systolic diameter compared to baseline). Clinical responders were defined by a sustained improvement of at least one NYHA functional class. RESULTS: At six-month assessment after CRT, 109 (61%) patients showed LVRR. During a mean follow-up of 56±21 months, 47 (26%) patients died, with higher mortality in the group without LVRR (36% vs. 20%, p=0.023). Clinical response was greater in patients with LVRR (88% vs. 55%, p<0.001). In patients without LVRR, clinical response to CRT was the strongest independent predictor of survival (hazard ratio: 0.120; 95% confidence interval: 0.039-0.366; p<0.001). CONCLUSION: Although patients without LVRR six months after CRT implantation had a worse prognosis, with higher all-cause mortality, clinical response can be an independent predictor of survival in this population.

[Duration of Atrial Fibrillation Episodes and Implications for the Thromboembolic Risk]. / Duração dos Episódios de Fibrilhação Auricular e Implicações no Risco Tromboembólico.

INTRODUCTION: Atrial fibrillation is the most common chronic arrhythmia in clinical practice, which is associated with a well known increased thromboembolic risk. The use of oral anticoagulants in this context is well established. However, there are some gaps in information that warrant further studies, such as the duration of an atrial fibrillation event that is long enough to increase the risk of embolic phenomena. This may be of important clinical concern, particularly in patients with cardiac implanted devices, in which very short periods of asymptomatic atrial fibrillation are often detected. MATERIAL AND METHODS: We performed a critical review on the association of brief atrial fibrillation episodes and thromboembolic events, based on available literature indexed on PubMed. RESULTS: After initial selection of abstracts and checking of references a final pool of 8 papers were analysed; seven describing studies with cardiac implanted devices and one with Holter monitoring. Four of the studies addressed this issue with a 'daily burden' approach rather than single episode duration. The risk increases with the magnitude of atrial fibrillation burden, with 5 minutes of atrial fibrillation in one day being the shortest time shown to independently predict thromboembolic events. DISCUSSION: The formation of an intracardiac thrombus, and respective embolic potential, is a dynamic process resulting from the interaction of anatomical and functional variables. The individual risk will depend on these factors. The association between embolic events and short atrial fibrillation episodes is evident, although the mechanism is not obvious, given the time discrepancy that is frequently observed between atrial fibrillation episode and clinical event. CONCLUSIONS: An atrial fibrillation burden of 5 minutes in one day has been shown to be independently associated with a significantly increased risk, although the cause-effect mechanism is not clear. A standardized way to select patients with short-duration atrial fibrillation periods that will have a meaningful benefit of chronic oral anticoagulation is still to define. Therefore, decisions should be made in an individualized manner.

Introdução: A fibrilhação auricular é uma arritmia comum e com risco tromboembólico bem documentado, estando definidas nas recomendações internacionais indicações referentes ao uso de anticoagulantes orais. Existem, contudo, lacunas de informação nomeadamente no que se refere à duração dos episódios de fibrilhação auricular e sua relação com o risco de tromboembolismo. Esta questão tem particular interesse em doentes com dispositivos electrónicos cardíacos implantados com documentação contínua da duração de episódios de taquidisritmias auriculares, que são frequentemente curtos e assintomáticos. Material e Métodos: Foi feita uma análise crítica da evidência disponível sobre a relação da duração dos episódios de FA paroxística e a ocorrência de eventos embólicos, com base numa pesquisa na base de dados bibliográfica PubMed. Resultados: Foram selecionados oito artigos com abordagens diferentes no estudo deste tema; sete com recurso a monitorização cardíaca com dispositivos electrónicos cardíacos implantados (pacemakers, cardioversores-desfibilhadores implantáveis e ressincronizadores cardíacos) e um com base em registo de Holter. Metade destas publicações, correspondendo globalmente às maiores amostragens, aborda a questão do ponto de vista do somatório diário de episódios de fibrilhação auricular (carga diária) e não da duração de cada episódio. O risco tromboembólico aumenta gradualmente com a carga arrítmica, tendo sido demonstrado um aumento significativo do risco quando esta ultrapassa os cinco minutos num dia. Discussão: A formação de um trombo intracavitário, e consequente potencial embólico, é um processo din'mico que resulta da interacção de várias condicionantes anatómicas e funcionais. O risco individual dependerá da interacção destes factores. A associação entre fenómenos embólicos e curtos períodos de fibrilhação auricular é inequívoca, apesar do mecanismo não ser óbvio, tendo em conta a discrep'ncia frequentemente observada entre os períodos de fibrilhação auricular e os eventos clínicos. Conclusões: O risco de eventos tromboembólicos aumenta significativamente mesmo para períodos curtos de fibrilhação auricular (cinco minutos de fibrilhação auricular em um dia), apesar da relação causa-efeito não estar definida. A decisão final sobre o recurso à anticoagulação oral deve basear-se na avaliação clínica individualizada.

[Right atrial aneurysm after chest trauma: late presentation]. / Aneurisma da aurícula direita após traumatismo torácico: apresentação tardia.

We report the case of a 59-year-old patient, with a history of severe chest trauma with rib fractures at the age of 20 and recent onset of fatigue and palpitations, who was diagnosed with atrial tachycardia, which was converted pharmacologically. Cor triatriatum or Ebstein's anomaly were suspected on initial imaging studies (transthoracic echocardiography and MRI). Due to recurrence of arrhythmia, he subsequently underwent repeat echocardiographic evaluation, which established a diagnosis of right atrial aneurysm. The arrhythmia was converted electrically. The patient has remained asymptomatic during 18 months of follow-up, without arrhythmia recurrence, medicated with carvedilol (after an initial period with amiodarone) and warfarin.

[Incidence of ventricular arrhythmias in patients with severe left ventricular systolic dysfunction: is there a benefit after cardiac resynchronization therapy?]. / Incidência de arritmias ventriculares em doentes corn disfunção sistólica ventricular esquerda grave: existe benefício após terapêutica de ressincronização cardíaca.

BACKGROUND: Cardiac resynchronization therapy (CRT) has significant benefits in selected patients (P). The impact of this modality in the incidence of ventricular tachyarrhythmias remains controversial. We analysed the occurrence of appropriate therapies in P submitted to CRT combined with a cardioverter-defibrillator (ICD). METHODS: Study of 123 P with left ventricular ejection fraction (LVEF) < 35%, submitted to successful implantation of CRT-ICD or ICD alone (primary prevention). RESULTS: Mean age was 63 +/- 12 years, LVEF of 25 +/- 6%, median follow-up of 372 days. CRT-ICD implanted in 63P (group A) and ICD alone in 60P (group B). Group A has 86% of clinical responders, lower prevalence of ischemic cardiomyopathy (30% vs. 72%), and more P in class III of the NYHA before device implantation (90% vs. 7%) compared with ICD alone patients. There were no differences in the incidence of appropriate therapies (19% vs. 12%) or in the time for first therapy (305 days vs. 293 days). Total mortality was 11% in group A and 12% in group B. Kaplan-Meier curves for arrhythmic events in patients with CRT showed no significant differences (HR 3.02, 95% CI 0.82 - 11.09, p = NS) when compared to patients without CRT. CONCLUSIONS: In P submitted to CRT-ICD for primary prevention, despite a higher rate of responders, the incidence of appropriate therapies is not different from those with an ICD alone.