Long-Term Atrioventricular Block Following Valve Surgery: Electrocardiographic and Surgical Predictors.

BACKGROUND: Bradyarrhythmia requiring pacemaker implantation among patients undergoing valve surgery may occur even after several years, with unclear predictors. Our aim was to investigate the incidence of pacemaker implantation at different follow-up times and identify associated predictors. METHODS: We conducted a retrospective study evaluating 1046 consecutive patients who underwent valve surgery at the Cardiac Surgery Division of Bologna University Hospital from 2005 to 2010. RESULTS: During 10 ± 4 years of follow-up, 11.4% of these patients required pacemaker implantation. Interventions on both atrioventricular valves independently predicted long-term pacemaker implantation (SHR 2.1, 95% CI 1.2-3.8, p = 0.014). Preoperative atrioventricular conduction disease strongly predicted long-term atrioventricular block, with right bundle branch block as the major predictor (SHR 7.0, 95% CI 3.9-12.4, p < 0.001), followed by left bundle branch block (SHR 4.9, 95% CI 2.4-10.1, p < 0.001), and left anterior fascicular block (SHR 3.9, 95% CI 1.8-8.3, p < 0.001). CONCLUSION: Patients undergoing valvular surgery have a continuing risk of atrioventricular block late after surgery until the 12-month follow-up, which was clearly superior to the rate of atrioventricular block observed at long-term. Pre-operative atrioventricular conduction disease and combined surgery on both atrioventricular valves are strong predictors of atrioventricular block requiring pacemaker implantation.

Atrial fibrillation recurrences during the blanking period after catheter ablation with the laser balloon technique.

INTRODUCTION: Regardless of the catheter ablation (CA) for atrial fibrillation (AF) strategy, the role of early recurrences during the blanking period (BP) is still unclear. Our aim was to evaluate atrial tachyarrhythmias (ATAs) recurrences during the BP after CA with the laser-balloon (LB) technique. METHODS: Consecutive patients undergoing LBCA were enrolled. Primary outcome of the study was the overall crude ATA recurrence rate during the BP. ATA recurrences after the BP and in-hospital readmissions during the BP were deemed secondary outcomes. RESULTS: Two hundred and twenty-four patients underwent CA with the LB. Median age was 63.0 (55.5-69.5) years and 74.1% were males. 28.6% were persistent AF patients, and 34.8% of patients were followed up with a loop recorder. 15.6% of patients experienced at least an ATA recurrence during the BP. Male sex, chronic heart failure, persistent AF, and recurrences during the BP were found to be associated with long-term ATA recurrences. Recurrences during the BP remained associated with the outcome of interest at multivariate analysis (hazard ratio [HR] = 12.393, 95% confidence interval [95% CI] = 3.699-41.865, p < .001). An association over time was found between early and late recurrences, with 73.7%, 45.5%, and 10.8% of patients presenting with recurrences at 1-, 2-, and 3-month follow-up being free from recurrences after the BP, respectively. 8.0% of patients were readmitted during the BP: 4.5% for AF electrical cardioversion, and 1.8% for CA of other atrial arrhythmias; no redo CA was performed. CONCLUSION: After adjusting for confounders, ATA recurrences during the BP represent the most significant predictor of ATA recurrences after the BP, regardless of AF pattern.

Stereotactic Arrhythmia Radioablation (STAR): A Multidisciplinary Narrative Minireview of Preclinical Studies.

The aim of this narrative review of the literature was to collect and analyze the results of the published preclinical studies on stereotactic arrhythmia radioablation (STAR) in the treatment of refractory cardiac arrhythmias. A literature search was conducted on PubMed using the following terms: ("stereotactic" OR "SBRT" OR "SABR" OR "radioablation" OR "radiosurgery") AND ("arrhythmia" OR "tachycardia"). Preclinical and pathological reports published in English without time limit, comprising studies of STAR in animal models and histological analyzes of explanted animal and human hearts were included. The analyzed studies confirm that doses lower than 25 Gy seem to produce sub-optimal therapeutic results whereas doses >35 Gy are less safe in terms of radiation-induced toxicity. However, long-term results (>1 year) are still missing and reporting outcomes based on low dose irradiation (≤15 Gy). Finally, STAR proved to be an effective therapy in the analyzed studies despite the irradiation of rather different cardiac targets. Therefore, additional studies are needed to: 1) compare the outcomes of STAR at doses of 25 Gy versus 30 Gy; 2) evaluate the long-term results (>1 year) in animal models irradiated at doses similar to those used in the clinic; 3) define the optimal target.

Correction: Bertelli et al. Is Less Always More? A Prospective Two-Centre Study Addressing Clinical Outcomes in Leadless versus Transvenous Single-Chamber Pacemaker Recipients. J. Clin. Med. 2022, 11, 6071.

The authors wish to make the following corrections to this paper [...].

Voltage mapping of Koch's triangle in atrioventricular nodal reentrant tachycardia ablation : Results from an observational multicenter prospective registry.

BACKGROUND: The identification of a "low-voltage bridge" to guide ablation of atrioventricular nodal reentry tachycardia (AVNRT) has been described as a safe and effective strategy in children. We investigated the presence of a low-voltage bridge in adult patients undergoing AVNRT ablation, to evaluate its anatomical correspondence with the successful ablation site. We also investigated the possible correlations between Koch's triangle anatomy and patients' biometric characteristics. METHODS: This observational registry prospectively collected data from 200 patients undergoing AVNRT ablation, guided by 3D electroanatomical mapping system, in 6 electrophysiology centers. Koch's triangle voltage map was collected; then, the anatomical correspondence between the low-voltage bridge and the successful ablation site was evaluated. Koch's triangle anatomical dimensions were subsequently drawn from the mapping system and correlated to patients' gender, age, and weight. RESULTS: The low-voltage bridge was identified in 159 over 200 procedures (79.5%). When the low-voltage bridge was identified, its anatomical correspondence with the successful ablation site has been proved in 137 over 159 cases (86%), with a reduction of radiofrequency deployment time. No strict correlations were found, on the other side, between Koch's triangle anatomy and patients' biometric data. CONCLUSIONS: The identification of the low-voltage bridge has proved to be a helpful strategy to guide AVNRT ablation in a large cohort of adult patients. Targeting the low-voltage bridge during AVNRT ablation helps to reduce RF application time. Koch's triangle morphological characteristics cannot be predicted on the base of patients' biometric data.

Pocket histology at cardiac implantable electronic device replacement: What's new?

BACKGROUND: Repeated procedures involving the cardiac implantable electronic device (CIED) pocket increase the infection risk, and the extent of pocket adhesions may prolong the procedure time. Few data on pocket histology at the time of CIED replacement are available. OBJECTIVE: The purpose of this study was to describe CIED pocket histology in a cohort of patients undergoing CIED replacement or upgrade. METHODS: All consecutive patients undergoing CIED replacement or upgrade at our center between November 2019 and May 2020 were enrolled. Subclinical pocket infection was ruled out by physical inspection and laboratory parameters before the procedure. Pocket tissue specimens from the anterior and posterior pockets were obtained intraoperatively. A systematic histological analysis of capsular thickness, fibrous connective tissue, neovascularization, inflammation, and calcifications was performed. RESULTS: Thirty patients (6 women, 20%) were enrolled. The mean capsular thickness was 0.8 ± 0.3 mm in the anterior wall and 1.1 ± 0.4 mm in the posterior wall. Subcapsular fibrosis was mild and multifocal in the anterior wall and moderate and focal in the posterior wall. Neovascularization was focal in most cases, and vessel remodeling mainly involved the tunica media. Chronic inflammation was usually mild and nongranulomatous, and in a quarter of cases, subacute exudative fibrous inflammation was detected in the posterior pocket wall. CONCLUSION: The CIED pocket is a histopathologically dynamic environment, given the coexistence of both a subacute foreign body response and fibrous tissue growth, implying continuous remodeling due to an injury-repair mechanism. Strategies to interact with foreign body response might minimize inflammatory pocket activity, especially device encapsulation by tight fibrous tissue, and possibly complications related to repeated CIED procedures.

Prognostic value of renal failure in patients undergoing transvenous lead extraction: single centre experience and systematic review of the literature.

INTRODUCTION: Cardiac implantable electronic device infections (CIEDI) are challenging complications, associated with high mortality rate. Transvenous lead extraction (TLE) is the only curative treatment for CIEDI. Albeit continuous improvement in tools and techniques dramatically decreased TLE associated complications, survival after TLE for CIEDI is still poor. Renal failure (RF) is frequently reported in candidates to TLE, but due to variability in its definition, the real prevalence is not well defined. OBJECTIVE: Considering the impact of RF on mortality among patients affected by cardiovascular diseases, we aimed our research at defining the role of RF as a predictor of post-TLE mortality. METHOD AND RESULTS: We will provide the results of a systematic revision of literature on the impact of RF on mortality at different time points after TLE, according to the various definitions adopted for RF. Considering the high variability of literature in this field, we will provide the results of an explorative analysis comparing the different definitions of RF on clinical outcomes in a cohort of candidates to TLE for CIEDI in a high-volume referral center. CONCLUSION: We discuss the possible reasons of the negative impact of RF after TLE, providing new perspectives for future research.

Is Less Always More? A Prospective Two-Centre Study Addressing Clinical Outcomes in Leadless versus Transvenous Single-Chamber Pacemaker Recipients.

(1) Background: Leadless (LL) stimulation is perceived to lower surgical, vascular, and lead-related complications compared to transvenous (TV) pacemakers, yet controlled studies are lacking and real-life experience is non-conclusive. (2) Aim: To prospectively analyse survival and complication rates in leadless versus transvenous VVIR pacemakers. (3) Methods: Prospective analysis of mortality and complications in 344 consecutive VVIR TV and LL pacemaker recipients between June 2015 and May 2021. Indications for VVIR pacing were "slow" AF, atrio-ventricular block in AF or in sinus rhythm in bedridden cognitively impaired patients. LL indication was based on individualised clinical judgement. (4) Results: 72 patients received LL and 272 TV VVIR pacemakers. LL pacemaker indications included ongoing/expected chronic haemodialysis, superior venous access issues, active lifestyle with low pacing percentage expected, frailty causing high bleeding/infectious risk, previous valvular endocarditis, or device infection requiring extraction. No significant difference in the overall acute and long-term complication rate was observed between LL and TV cohorts, with greater mortality occurring in TV due to selection of older patients. (5) Conclusions: Given the low complication rate and life expectancy in this contemporary VVIR cohort, extending LL indications to all VVIR candidates is unlikely to provide clear-cut benefits. Considering the higher costs of LL technology, careful patient selection is mandatory for LL PMs to become advantageous, i.e., in the presence of vascular access issues, high bleeding/infectious risk, and long life expectancy, rendering lead-related issues and repeated surgery relevant in the long-term perspective.

Personalizing configuration for atrial fibrillation external electrical cardioversion to improve first shock efficacy.

BACKGROUND: Despite the common use of biphasic electrical cardioversion (ECV) to convert atrial fibrillation (AF), we lack definite recommendations on electrode configuration. METHODS: We adopted a quasi-experimental design enrolling all candidates to ECV for AF. In the first stage, two units were involved, one using antero-apical pads (AAP) and the second antero-posterior adhesive patches (APP). These data enabled the creation of a decision algorithm to personalize the ECV approach, which was subsequently validated during the second stage. RESULTS: A total of 492 patients were enrolled overall. In the first stage, APP and AAP presented similar conversion rates (87.4 vs. 86.9% at first attempt of a step-up protocol, P = 0.661). While body surface area (BSA) ≤2.12 m2 was an independent predictor in the overall population, the two components (height and weight) acted differently in the two configurations: being height ≤1.73 m2 a significant cut-off value in the AAP subgroup, and weight <83 kg in the APP subgroup. Considering these cut-offs, we developed a decision algorithm for electrode configuration. In the second stage, algorithm validation confirmed an improvement in the first shock efficacy with respect to the results of the first stage (93.2 vs. 87.2%, P = 0.025), with a significant reduction in shock impedance (70.8 ±â€Š15.3 vs. 81.8 ±â€Š15.6, P < 0.001). CONCLUSION: Patients with high BSA require high energy shocks for sinus rhythm restoration with ECV. Weight seems to affect more APP configuration, while height seems to impact more for the AAP. These findings have the potential to optimize ECV in clinical practice.

Bridging the future of cardiac stimulation: physiologic or leadless pacing?

Cardiac simulation has moved from early life-saving pacemakers meant only to prevent asystole to current devices capable of physiologic stimulation for the treatment of heart rhythm and heart failure, that are also intended for remote patient and disease-progression monitoring. The actual vision of contemporary pacing aims to correct the electrophysiologic roots of mechanical inefficiency regardless of underlying structural heart diseases. The awareness of the residual cardiac dyssynchrony related to customary cardiac pacing has changed the concept of what truly represents "physiologic pacing". On a different perspective, leadless stimulation to abolish CIED surgery and prevent lead-related complications is becoming a priority both for young device recipients and for frail, elderly patients. Careful clinical evaluation attempts to bridge decision-making to patient-tailored therapy.

Ten-year follow-up of cardiac resynchronization therapy patients with non-ischemic dilated cardiomyopathy assessed by radionuclide angiography: a single-center cohort study.

PURPOSE: Relatively few data are available on long-term survival and incidence of ventricular arrhythmias in cardiac resynchronization therapy (CRT) patients. We investigated long-term outcomes of CRT patients with non-ischemic dilated cardiomyopathy stratified as responders or non-responders according to radionuclide angiography. METHODS: Fifty patients with non-ischemic dilated cardiomyopathy undergoing CRT were assessed by equilibrium Tc99 radionuclide angiography with bicycle exercise at baseline and after 3 months. Intra- and interventricular dyssynchrony were derived by Fourier phase analysis. Patient clinical outcome was assessed after 10 years. RESULTS: At 3 months, 50% of patients were identified as CRT responders according to an increase in LV ejection fraction ≥ 5%. During a follow-up of 109 ± 48 months, 30% of patients died and 6% underwent heart transplantation. Age and history of paroxysmal atrial fibrillation were found to be predictors of all-cause mortality. CRT responders showed lower risk of death from cardiac causes than non-responders. At follow-up, 38% of patients presented at least one episode of sustained ventricular tachycardia, with a similar percentage between responders and non-responders. CONCLUSION: At long-term follow-up, non-ischemic CRT recipients identified as responders by radionuclide angiography were found to be at lower risk of worsening heart failure death than non-responders. Long-term risk for sustained ventricular arrhythmia was similar between CRT responders and non-responders.

Preoperative checklist to reduce the risk of cardiac implantable electronic device infections.

Cardiac implantable electronic device (CIED) infection represents a dramatic event with a high mortality rate (>3x) despite antibiotic therapy and device extraction; therefore, the real winning strategy in this situation could be represented by prevention. Antibiotic prophylaxis and antibiotic-releasing envelope are effective in improving patient outcome; however, healthcare costs related to CIED infections remain high over the years. In this review we would keep the attention on a pre-surgical checklist to reduce the risk of CIED infections. In fact, checklist is an effective instrument for medical care quality improvement mainly used in surgery, but not very commonly in cath-lab and electrophysiology procedures. All steps of this checklist are of proven effectiveness in reducing the risk of CIED infections but, up till now, they are not considered together in a pre-surgical approach.

Use of Diltiazem in Chronic Rate Control for Atrial Fibrillation: A Prospective Case-Control Study.

Atrial fibrillation (AF) is a multifaceted disease requiring personalised treatment. The aim of our study was to explore the prognostic impact of a patient-specific therapy (PT) for rate control, including the use of non-dihydropyridine calcium channel blockers (NDDC) in patients with heart failure (HF) or in combination with beta-blockers (BB), compared to standard rate control therapy (ST), as defined by previous ESC guidelines. This is a single-centre prospective observational registry on AF patients who were followed by our University Hospital. We included 1112 patients on an exclusive rate control treatment. The PT group consisted of 125 (11.2%) patients, 93/125 (74.4%) of whom were prescribed BB + NDCC (±digoxin), while 85/125 (68.0%) were HF patients who were prescribed NDCC, which was diltiazem in all cases. The patients treated with a PT showed no difference in one-year overall survival compared to those with an ST. Notably, the patients with HF in ST had a worse prognosis (p < 0.001). To better define this finding, we performed three sensitivity analyses by matching each patient in the PT subgroups with three subjects from the ST cohort, showing an improved one-year survival of the HF patients treated with PT (p = 0.039). Our results suggest a potential outcome benefit of NDCC for rate control in AF patients, either alone or in combination with BB and in selected patients with HF.

Single-photon cardiac imaging in patients with cardiac implantable electrical devices.

Nuclear imaging techniques like single-photon emission computed tomography (SPECT) and radionuclide angiography have wide applications in patients receiving a cardiac implantable electrical device (CIED), who cannot usually undergo cardiac magnetic resonance. Our aim was to provide an update of single-photon imaging clinical applications, with a specific focus on CIED recipients. SPECT imaging is commonly used in CIED patients to assess myocardial perfusion, but it can also be used to evaluate myocardial viability, which is an important predictor of LV function improvement by cardiac resynchronization therapy (CRT). Radionuclide angiography has shown higher temporal resolution and reproducibility than SPECT in the evaluation of cardiac function and dyssynchrony. Left ventricular dyssynchrony as assessed by radionuclide angiography with phase analysis may be reliably used for CRT patient selection and evaluation of CRT response. SPECT imaging with meta-iodo-benzyl-guanidine allows for cardiac sympathetic innervation examination, which may be used for prognostic stratification of heart failure patients and prediction of ventricular tachyarrhythmias. Finally, promising results in CIED infection diagnosis have been shown by SPECT with radiolabeled autologous white blood cells.

The Challenges of Diagnosis and Treatment of Arrhythmogenic Cardiomyopathy: Are We there yet?

Background: we sought to review the evolution in the diagnosis and treatment of Arrhythmogenic Cardiomyopathy (ACM), a clinically multifaceted entity beyond the observation of ventricular arrhythmias, and the outcome of therapies aiming at sudden death prevention in a single center experience. Methods: retrospective analysis of the data of consecutive patients with an implanted cardioverter-defibrillator (ICD) and a confirmed diagnosis of ACM according to the proposed Padua Criteria, who were referred to our center from January 1992 to October 2021. Results: we enrolled 72 patients (66% males, mean age at implant 46 ± 16 years), 63.9% implanted for primary prevention. At the time of ICD implant, 29 (40.3%) patients had a right ventricular involvement, 24 (33.3%) had a dominant LV involvement and 19 (26.4%) had a biventricular involvement. After a median follow-up of 6,1 years [IQR: 2.5-9.9], 34 patients (47.2%) had 919 sustained episodes of ventricular arrhythmias (VA). 27 patients (37.5%) had 314 episodes of life-threatening arrhythmias (LT-VA), defined as sustained ventricular tachycardia ≥ 200 beats/min. Considering only the patients with an ICD capable of delivering ATP, 80.4% of VA and 65% of LT-VA were successfully terminated with ATP. 16 (22.2%) patients had an inappropriate ICD activation, mostly caused by atrial fibrillation, while in 9 patients (12.5%) there was a complication needing reintervention (in 3 cases there was a loss of ventricular sensing dictating lead revision). During the follow-up 11 (15.3%) patients died, most of them due to heart failure, and 8 (11.1%) underwent heart transplantation. Conclusions: ACM is increasingly diagnosed owing to heightened suspicion at ECG examination and to improved imaging technology and availability, though the diagnostic workflow is particularly challenging in the earliest disease stages. ICD therapy is the cornerstone of sudden death prevention, albeit its efficacy is not based on controlled studies, and VT ablation/medical therapy are complementary to this strategy. The high burden of ATP-terminated VA makes shock-only devices debatable. The progressive nature of ACM leads to severe biventricular enlargement and refractory heart failure, which pose significant treatment issues when a predominant RV dysfunction occurs owing to the reduced possibility for mechanical circulatory assistance.

Mortality after cardioverter-defibrillator replacement: Results of the DECODE survival score index.

BACKGROUND: Device replacement is the ideal time to reassess health care goals regarding continuing implantable cardioverter-defibrillator (ICD) therapy. Only few data are available on the decision making at this time. OBJECTIVES: The goals of this study were to identify factors associated with poor prognosis at the time of ICD replacement and to develop a prognostic index able to stratify those patients at risk of dying early. METHODS: DEtect long-term COmplications after implantable cardioverter-DEfibrillator replacement (DECODE) was a prospective, single-arm, multicenter cohort study aimed at estimating long-term complications in a large population of patients who underwent ICD/cardiac resynchronization therapy - defibrillator replacement. Potential predictors of death were investigated, and all these factors were gathered into a survival score index (SUSCI). RESULTS: We included 983 consecutive patients (median age 71 years (63-78)); 750 (76%) were men, 537 (55%) had ischemic cardiomyopathy; 460 (47%) were implanted with cardiac resynchronization therapy - defibrillator. During a median follow-up period of 761 days (interquartile range 628-904 days), 114 patients (12%) died. In multivariate Cox regression analysis, New York Heart Association class III/IV, ischemic cardiomyopathy, body mass index < 26 kg/m2, insulin administration, age ≥ 75 years, history of atrial fibrillation, and hospitalization within 30 days before ICD replacement remained associated with death. The survival score index showed a good discriminatory power with a hazard ratio of 2.6 (95% confidence interval 2.2-3.1; P < .0001). The risk of death increased according to the severity of the risk profile ranging from 0% (low risk) to 47% (high risk). CONCLUSION: A simple score that includes a limited set of variables appears to be predictive of total mortality in an unselected real-world population undergoing ICD replacement. Evaluation of the patient's profile may assist in predicting vulnerability and should prompt individualized options, especially for high-risk patients.

The Complex Management of Atrial Fibrillation and Cancer in the COVID-19 Era: Drug Interactions, Thromboembolic Risk, and Proarrhythmia.

PURPOSE OF REVIEW: Cardiotoxicity by anticancer agents has emerged as a multifaceted issue and is expected to affect both mortality and morbidity. This review summarizes clinical challenges in the management of oncological patients requiring anticoagulants for atrial fibrillation (AF) also considering the current outbreak of the COVID-19 (coronavirus disease 2019) pandemic, since this infection can add challenges to the management of both conditions. Specifically, the aims are manyfold: (1) describe the evolving use of direct oral anticoagulants (DOACs) in AF patients with cancer; (2) critically appraise the risk of clinically important drug-drug interactions (DDIs) between DOACs and oral targeted anticancer agents; (3) address expected DDIs between DOACs and candidate anti-COVID drugs, with implications on management of the underlying thrombotic risk; and (4) characterize the proarrhythmic liability in cardio-oncology in the setting of COVID-19, focusing on QT prolongation. RECENT FINDINGS: AF in cardio-oncology poses diagnostic and management challenges, also due to the number of anticancer drugs recently associated with AF onset/worsening. Oral targeted drugs can potentially interact with DOACs, with increased bleeding risk mainly due to pharmacokinetic DDIs. Moreover, the vast majority of oral anticancer agents cause QT prolongation with direct and indirect mechanisms, potentially resulting in the occurrence of torsade de pointes, especially in susceptible patients with COVID-19 receiving additional drugs with QT liability. Oncologists and cardiologists must be aware of the increased bleeding risk and arrhythmic susceptibility of patients with AF and cancer due to DDIs. High-risk individuals with COVID-19 should be prioritized to target preventive strategies, including optimal antithrombotic management, medication review, and stringent monitoring.