Incidental and anticipated arrhythmic diagnoses in patients with an implantable cardiac monitor

AIMS

In this study, we investigated a cohort of unselected patients with various indications for an implantable cardiac monitor (ICM). Our main objectives were to determine the incidence of arrhythmic diagnoses, both anticipated and incidental in relation to the ICM indication, and to assess their clinical relevance.

METHODS

We examined remote monitoring transmissions from patients with an ICM at four Italian sites to identify occurrences of cardiac arrhythmias. Concurrently, we collected data on medical actions taken in response to arrhythmic findings.

RESULTS

The study included 119 patients, with a median follow-up period of 371 days. ICM indications were syncope/presyncope (46.2%), atrial fibrillation management (31.1%), and cryptogenic stroke (22.7%). In the atrial fibrillation management group, atrial fibrillation was the most common finding, with an incidence of 36% [95% confidence interval (CI) 22-55%] at 18 months. Rates of atrial fibrillation were not significantly different between patients with cryptogenic stroke and syncope/presyncope [17% (95% CI 7-40%) vs. 8% (95% CI 3-19%), P = 0.229].For patients with cryptogenic stroke, the incidence of asystole and bradyarrhythmias at 18 months was 23% (95% CI 11-45%) and 42% (95% CI 24-65%), respectively, similar to estimates obtained for patients implanted for syncope/presyncope (P = 0.277 vs. P = 0.836).Overall, 30 patients (25.2%) required medical intervention following ICM-detected arrhythmias, predominantly involving atrial fibrillation ablation (10.9%) and medication therapy changes (10.1%).

CONCLUSION

In a real-life population with heterogeneous insertion indications, approximately 25% of patients received ICM-guided medical interventions within a short timeframe, including treatments for incidental findings. Common incidental arrhythmic diagnoses were bradyarrhythmias in patients with cryptogenic stroke and atrial fibrillation in patients with unexplained syncope.

Video-assisted thoracoscopic epicardial pacing: A contemporary overview

Video-assisted thoracoscopic surgery (VATS) has revolutionized the approach and management of pulmonary and cardiac diseases, and its applications have significantly expanded in the last two decades. Beyond its established role in thoracic procedures, VATS has also emerged as a valuable technique for various electrophysiological procedures, including pacemaker implantations, ablation procedures, and left atrial appendage exclusion. This paper presents a thorough review of the existing literature on pacing procedures performed using a VATS approach. By analyzing and synthesizing the available studies, we aim to provide an in-depth understanding of the current knowledge and advancements in VATS-based pacing procedures. A key focus of this review is the detailed description of implantation techniques via a VATS approach.

Subcutaneous Implantable Cardioverter Defibrillator: A Contemporary Overview

The difference between subcutaneous implantable cardioverter defibrillators (S-ICDs) and transvenous ICDs (TV-ICDs) concerns a whole extra thoracic implantation, including a defibrillator coil and pulse generator, without endovascular components. The improved safety profile has allowed the S-ICD to be rapidly taken up, especially among younger patients. Reports of its role in different cardiac diseases at high risk of SCD such as hypertrophic and arrhythmic cardiomyopathies, as well as channelopathies, is increasing. S-ICDs show comparable efficacy, reliability, and safety outcomes compared to TV-ICD. However, some technical issues (i.e., the inability to perform anti-bradycardia pacing) strongly limit the employment of S-ICDs. Therefore, it still remains only an alternative to the traditional ICD thus far. This review aims to provide a contemporary overview of the role of S-ICDs compared to TV-ICDs in clinical practice, including technical aspects regarding device manufacture and implantation techniques. Newer outlooks and future perspectives of S-ICDs are also brought up to date.

Economic analysis of remote monitoring in patients with implantable cardioverter defibrillators or cardiac resynchronization therapy defibrillators in the Trento area, Italy

Introduction

Remote monitoring (RM) technologies have the potential to improve patient care by increasing compliance, providing early indications of heart failure (HF), and potentially allowing for therapy optimization to prevent HF admissions. The aim of this retrospective study was to assess the clinical and economic consequences of RM vs. standard monitoring (SM) through in-office cardiology visits, in patients carrying a cardiac implantable electronic device (CIED).

Methods

Clinical and resource consumption data were extracted from the Electrophysiology Registry of the Trento Cardiology Unit, which has been systemically collecting patient information from January 2011 to February 2022. From a clinical standpoint, survival analysis was conducted, and incidence of cardiovascular (CV) related hospitalizations was measured. From an economic standpoint, direct costs of RM and SM were collected to compare the cost per treated patient over a 2-year time horizon. Propensity score matching (PSM) was used to reduce the effect of confounding biases and the unbalance of patient characteristics at baseline.

Results

In the enrollment period, N = 402 CIED patients met the inclusion criteria and were included in the analysis (N = 189 patients followed through SM; N = 213 patients followed through RM). After PSM, comparison was limited to N = 191 patients in each arm. After 2-years follow-up since CIED implantation, mortality rate for any cause was 1.6% in the RM group and 19.9% in the SM group (log-rank test, p < 0.0001). Also, a lower proportion of patients in the RM group (25.1%) were hospitalized for CV-related reasons, compared to the SM group (51.3%; p < 0.0001, two-sample test for proportions). Overall, the implementation of the RM program in the Trento territory was cost-saving in both payer and hospital perspectives. The investment required to fund RM (a fee for service in the payer perspective, and staffing costs for hospitals), was more than offset by the lower rate of hospitalizations for CV-related disease. RM adoption generated savings of -€4,771 and -€6,752 per patient in 2 years, in the payer and hospital perspective, respectively.

Conclusion

RM of patients carrying CIED improves short-term (2-years) morbidity and mortality risks, compared to SM and reduces direct management costs for both hospitals and healthcare services.

Appropriate Use Criteria of Left Atrial Appendage Closure Devices: Latest Evidences

Atrial fibrillation is the most common arrythmia and it is linked to an increased risk of stroke. Even if anticoagulation therapy reduces the rate of stroke the benefits of this therapy have to been balanced with the increased risk of hemorrhagic event. Left atrial appendage closure is a valid alternative to long term anticoagulation in patients with atrial fibrillation and high hemorrhagic risk. Actually new devices with different features have been tested and introduced progressively in the clinical practice. Improvements preprocedural imaging evaluation and the learning curve of the operators led to percutaneous left atrial appendage closure a safe and effective procedure. A good knowledge of different devices and the technique of implant is necessary for optimization percutaneous left atrial appendage closure and the reduction of complications during the acute phase and follow up.

Emergency Management of Electrical Storm: A Practical Overview

Electrical storm is a medical emergency characterized by ventricular arrythmia recurrence that can lead to hemodynamic instability. The incidence of this clinical condition is rising, mainly in implantable cardioverter defibrillator patients, and its prognosis is often poor. Early acknowledgment, management and treatment have a key role in reducing mortality in the acute phase and improving the quality of life of these patients. In an emergency setting, several measures can be employed. Anti-arrhythmic drugs, based on the underlying disease, are often the first step to control the arrhythmic burden; besides that, new therapeutic strategies have been developed with high efficacy, such as deep sedation, early catheter ablation, neuraxial modulation and mechanical hemodynamic support. The aim of this review is to provide practical indications for the management of electrical storm in acute settings.

Left atrial function after standalone totally thoracoscopic left atrial appendage exclusion in atrial fibrillation patients with absolute contraindication to oral anticoagulation therapy

Background

Left atrial appendage (LAA) is a common source of thrombi in patients with atrial fibrillation (AF). The effect on left atrial (LA) function of the Totally Thoracoscopic (TT)-LAA exclusion with epicardial clip is currently unknown. This study aims at evaluating the effect of TT-LAA exclusion on LA function.

Methods

Standalone TT-LAA exclusion with the clip device was performed in 26 patients with AF and contraindication to oral anticoagulation (OAC). A 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound were performed preoperatively. Clip positioning and LAA exclusion were guided and confirmed by intraoperative trans-esophageal echo. To evaluate LA function, standard transthoracic echocardiography and 2D strain of LA were performed before surgery, at discharge and at 3-month follow-up.

Results

The mean CHA2DS2-VASc and HASBLED scores were 4.6 and 2.4 respectively. There were no major complications during the procedure. At median follow-up of 10.3 months, 1 (3.8%) non-cardiovascular death, 1 (3.8%) stroke and 4 (15.4%) cardiovascular hospitalizations occurred. At 2D strain of LA, the reservoir function decreased significantly at discharge, compared to baseline and recovered at 3-months follow-up. Furthermore, NT-proBNP increased significantly after the procedure with a return to baseline after 3 months. Changes in E/A were persistent at 3 months.

Conclusion

Our data in a small cohort suggest that TT-LAA exclusion with epicardial clip can be a safe procedure with regards to the atrial function. The LAA amputation impairs the reservoir LA function on the short term, that recovers over time.

Programming Optimization in Implantable Cardiac Monitors to Reduce False-Positive Arrhythmia Alerts: A Call for Research

No studies have investigated whether optimizing implantable cardiac monitors (ICM) programming can reduce false-positive (FP) alerts. We identified patients implanted with an ICM (BIOMONITOR III) who had more than 10 FP alerts in a 1-month retrospective period. Uniform adjustments of settings were performed based on the mechanism of FP triggers and assessed at 1 month. Eight patients (mean age 57.5 ± 23.2 years; 37% female) were enrolled. In 4 patients, FPs were caused by undersensing of low-amplitude premature ventricular contractions (PVCs). No further false bradycardia was observed with a more aggressive decay of the dynamic sensing threshold. Furthermore, false atrial fibrillation (AF) alerts decreased in 2 of 3 patients. Two patients had undersensing of R waves after high-amplitude PVCs; false bradycardia episodes disappeared or were significantly reduced by limiting the initial value of the sensing threshold. Finally, the presence of atrial ectopic activity or irregular sinus rhythm generated false alerts of AF in 2 patients that were reduced by increasing the R-R variability limit and the confirmation time. In conclusion, adjustments to nominal settings can reduce the number of FP episodes in ICM patients. More research is needed to provide practical recommendations and assess the value of extended ICM programmability.

Left atrial function after standalone totally thoracoscopic left atrial appendage exclusion in af patients with absolute contraindication to oral anticoagulation therapy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left atrial appendage (LAA) is the source of more than 90% of thrombi in patients with atrial fibrillation (AF).  The Totally Thoracoscopic (TT) LAA exclusion with epicardial clip has become a safe and effective procedure, but the effect on left atrial (LA) function remains unknown.

Purpose

The aim of this study was to assess the effect of TT LAA exclusion on LA function.

Methods

20 patients (15 males) with non-valvular AF and contraindication to oral anticoagulation therapy (OAT) or antiplatelet therapy underwent standalone TT LAA exclusion with the Atriclip Pro II device. All patients were screened preoperatively with 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound. Intraoperative Atriclip Pro II positioning and LAA exclusion were guided and confirmed by trans-esophageal echo. To objectify LA function, transthoracic echocardiography with 2D Speckle tracking was performed before surgery, at discharge and at 3-month follow-up. All patients were not on anticoagulation nor antiplatelet therapy at the time of surgery, at discharge and at control visit.

Results

Baseline characteristics are reported in Table I. There were no major complications during the procedures. One non cardiovascular death, one minor stroke and 4 hospitalizations occur at 1-year follow up. The reservoir LA function considering the strain measurements dramatically decreased few days after the procedure and it recovered at 3-month follow-up compared to baseline, even though the LA volume is augmented (Table II). Furthermore, NT pro-BNP increased and ventricular strain decreased significantly after the procedure recovering over time.

Conclusion

TT LAA exclusion with Atriclip Pro II device is a safe and effective procedure in preventing AF related stroke in patients with contraindication to OAT. Our findings suggest that the LAA epicardial clip impairs immediately the reservoir LA function that recovers over time. Abstract Table I  Abstract Table II

Determinants of severe bradycardia in adolescents hospitalized for anorexia nervosa

BACKGROUND

Severe bradycardia is an indication supporting hospitalization in adolescents with eating disorders. Some adolescents with anorexia nervosa (AN) and significant weight loss present with a normal pulse rate at admission, whereas others have severe bradycardia, suggesting that total weight loss is not the most important determinant of bradycardia. The aims of this study were to define the prevalence of severe bradycardia as the cause for hospital admission in adolescents with AN, to evaluate correlations between known determinants of severe bradycardia and pulse rate at admission, and to evaluate the average time required to recover from severe bradycardia after re-feeding.

METHODS

Ninety-nine hospitalized patients with AN were enrolled. Weight loss history, anthropometric, laboratory, and electrocardiogram data were collected at admission to and at discharge from hospital. Multivariate analysis was performed to detect the most important determinants of severe bradycardia.

RESULTS

Forty-eight percent of the AN patient admissions were due to severe bradycardia (AN-B+ group). Patients in this group had a higher maximum lifetime weight (P = 0.0045), greater premorbid weight loss (P = 0.0011), and more rapid weight loss (P = 0.0001). Multivariate analysis showed that recent weight loss is an independent predictor of bradycardia at hospital admission (R² : 0.35, P = 0.0001). Severe bradycardia normalized after minimal weight gain of 0.25 ± 0.18 kg/day for 3-10 days.

CONCLUSIONS

This study confirms that recent weight loss is probably the most important determinant of severe bradycardia in adolescents with AN.

Implantable cardioverter-defibrillators in elderly patients: outcome and predictors of mortality

PURPOSE

The implantable cardioverter-defibrillator (ICD) is the therapy of choice for the prevention of sudden cardiac death. The number of elderly patients receiving ICDs is increasing. This study aimed to assess the outcome of patients according to their age at the time of implantation, and to identify variables potentially associated with patient survival.

METHODS

Between June 2009 and December 2019, we retrospectively enrolled all consecutive patients in whom ICD implantation had been performed for primary or secondary prevention at our center.

RESULTS

During the study period, 670 patients underwent ICD implantation. We stratified the population into four age-classes: Class 1 (23%) (pts aged less than 60 years), Class 2 (28%) (pts aged between 60 and 70 years), Class 3 (39%) (pts aged between 70 and 80 years) and Class 4 (9%) (pts aged 80 years or older). Over a median follow-up of 42 months, the rate of deaths in Class 4 was higher than in Classes 1 and 2 (log-rank test, P < 0.01), but was comparable to that in Class 3 (P = 0.407). With increasing age, we observed more complications at the time of implantation and during follow-up. On multivariate analysis, higher NYHA class, creatinine level and CHA₂DS₂-VASc score were identified as independent predictors of death, while age was not associated with worse prognosis. Higher body mass index, higher NYHA class and CHA₂DS₂-VASc score were also confirmed as independent predictors of hospitalizations or death due to any cause.

CONCLUSION

This study showed good survival in ICD patients in all age-groups, including those aged ≥80 years. The CHA₂DS₂-VASc score seems to be a stronger predictor of death than age.

COVID-19 pandemic and elderly: is the curtain dropped for urgent pacemaker implantations?

BACKGROUND

Permanent cardiac pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmia. During the COVID-19 outbreak, it has been reported a decrease in the incidence of acute coronary syndrome, but few data are available about pacemaker implantation rates. This study aimed to analyze patients referred to our center with permanent cardiac pacing indication during the COVID-19 outbreak.

METHODS

We compared the number, the characteristics and the outcomes of patients who underwent urgent pacemaker implantation between March and April 2019 (Group I) with those performed in the corresponding 2020 period (Group II).

RESULTS

A total of 27 patients (Group I) were implanted in March-April 2019 and 34 patients (Group II) in the corresponding 2020 period. In both groups, about half of the patients received a dual-chamber pacemaker. No significant differences in baseline patients' characteristics were observed. The most frequent indication was advanced atrio-ventricular block with a prevalence of 78% and 62% in Group I and II, respectively. The rate of procedural complications, the in-hospital and 1-month mortality were also similar between the two groups.

CONCLUSIONS

In our regional referral center, we observed a routine activity in terms of urgent pacemaker implantations for the treatment of symptomatic bradyarrhythmia during the COVID-19 outbreak.

COVID-19 pandemic and elderly: is the curtain dropped for urgent pacemaker implantations?

BACKGROUND

Permanent cardiac pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmia. During the COVID-19 outbreak, it has been reported a decrease in the incidence of acute coronary syndrome, but few data are available about pacemaker implantation rates. This study aimed to analyse patients referred to our centre with permanent cardiac pacing indication during the COVID-19 outbreak.

METHODS

We compared the number, the characteristics and the outcomes of patients who underwent urgent pacemaker implantation between March and April 2019 (Group I) with those performed in the corresponding 2020 period (Group II).

RESULTS

A total of 27 patients (Group I) were implanted in March-April 2019 and 34 patients (Group II) in the corresponding 2020 period. In both groups, about half of the patients received a dual-chamber pacemaker. No significant differences in baseline patients' characteristics were observed. The most frequent indication was advanced atrio-ventricular block with a prevalence of 78% and 62% in Group I and II, respectively. The rate of procedural complications, the in-hospital and 1-month mortality were also similar between the two groups.

CONCLUSIONS

In our regional referral center, we observed a routine activity in terms of urgent pacemaker implantations for the treatment of symptomatic bradyarrhythmia during the COVID-19 outbreak.

Is the systematic use of mapping systems during His Bundle catheter ablation cost-effective? A single-center experience

AIM

Three-dimensional (3D) nonfluoroscopic mapping systems (NMSs) are generally used during the catheter ablation (CA) of complex arrhythmias. We evaluated the efficacy, safety, and economic advantages of using NMSs during His-Bundle CA (HB-CA).

METHODS

A total of 124 consecutive patients underwent HB-CA between 2012 and 2019 in our EP Laboratory. We compared two groups: 63 patients who underwent HB-CA with fluoroscopy alone from 2012 to 2015 (Group I) and 61 patients who underwent HB-CA with the aid of NMSs from 2016 to 2019 (Group II). Two cost-effectiveness analyses were carried out: the alpha value (AV) (ie, a monetary reference value of the units of exposure avoided, expressed as $/man Sievert) and the value of a statistical life (VSL) (ie, the amount of money that a community would be willing to pay to reduce the risk of a person's death owing to exposure to radiation, it is not the cost value of a person's life). The cost reduction estimated by means of both these methods was compared with the real additional cost of using NMSs.

RESULTS

The use of NMS resulted in reduced fluoroscopy time in Group II {median 1.35 min} in comparison with Group I {median 4.8 min (P < .05)}. The effective dose reduction (ΔE) was 1.16 milli-Sievert.

CONCLUSION

The use of NMS significantly reduces fluoroscopy time. However, the actual reduction is modest and in our EP Laboratory this reduction is not cost-effective. Indeed, when the ΔE is referred to country and agency tables for absolute values of AV or VLS, it is not economically advantageous in almost all cases.

Epicardial left ventricular lead implantation in cardiac resynchronization therapy patients via a video-assisted thoracoscopic technique: Long-term outcome

BACKGROUND

Epicardial placement of the left ventricular (LV) lead via a video-assisted thoracoscopic (VAT) approach is an alternative to the standard transvenous technique.

HYPOTHESIS

Long-term safety and efficacy of VAT and transvenous LV lead implantation are comparable. To test it, we reviewed our experience and we compared the outcomes of patients who underwent implantation with the two techniques.

METHODS

The VAT procedure is performed under general anesthesia, with oro-tracheal intubation and right-sided ventilation, and requires two 5 mm and one 15 mm thoracoscopic ports. After pericardiotomy at the spot of the epicardial target area, pacing measurements are taken and a spiral screw electrode is anchored at the final pacing site. The electrode is then tunneled to the pectoral pocket and connected to the device.

RESULTS

105 patients were referred to our center for epicardial LV lead implantation. After pre-operative assessment, 5 patients were excluded because of concomitant conditions precluding surgery. The remaining 100 underwent the procedure. LV lead implantation was successful in all patients (median pacing threshold 0.8 ± 0.5 V, no phrenic nerve stimulation) and cardiac resynchronization therapy was established in all but one patient. The median procedure time was 75 min. During a median follow-up of 24 months, there were no differences in terms of death, cardiovascular hospitalizations or device-related complications vs the group of 100 patients who had undergone transvenous implantation. Patients of both groups displayed similar improvements in terms of ventricular reverse remodeling and functional status.

CONCLUSIONS

Our VAT approach proved safe and effective, and is a viable alternative in the case of failed transvenous LV implantation.

An Economic Analysis of the Systematic Use of Mapping Systems during Catheter Ablation Procedures: Single Center Experience

INTRODUCTION

In this study we estimated the cost-effectiveness of adopting 3D Nonfluoroscopic Mapping Systems (NMSs) for catheter ablation (CA).

METHODS

This study includes patients who underwent supraventricular tachycardia (SVT) CA and atrial fibrillation (AF) CA from 2007 to 2016. A comparison was conducted between a reference year (2007) and the respective years for the two types of procedure in which the maximum optimization of patients' exposure using NMSs was obtained. We compared the data of all SVT CA performed solely using fluoroscopy in 2007 (Group I) and all SVT CA procedures performed using fluoroscopy together with an NMS in 2011 (Group II). There was also an important comparison made between AF CA procedures performed in 2007 (Group III) and AF CA in 2012 (Group IV), where patients' treatment in both years included the use of an NMS but where the software and hardware versions of the NMS were different. Two cost-effectiveness analyses were carried out. The first method was based on the alpha value (AV): the AV is a monetary reference value of avoided unit of exposure and is expressed as $/mansievert. The second one was based on the value of a statistical life (VSL): the VSL does not represent the cost value of a person's life, but the amount that a community would be willing to pay to reduce the risk of a person's death. The costs estimated from these two methods were compared to the real additional cost of using an NMS during that type of procedure in our EP Lab.

RESULTS

The use of NMS reduced the effective dose of about 2.3 mSv for SVT and 23.8 mSv for AF CA procedures. The use of NMS, applying directly AV or VSL values, was not cost-effective for SVT CA for the most countries, whereas the use of an NMS during an AF CA seemed to be cost-effective for most of them.

CONCLUSIONS

In our analysis the cost-effectiveness of the systematic use of NMSs strongly depended on the AV and VSL values considered. Nonetheless, the approach seemed to be cost-effective only during AF CA procedures.

A late presentation of congenital cardiac anomaly: Accessory chordae from the left atrium causing severe mitral regurgitation

Mitral regurgitation secondary to accessory mitral valve (MV) chordae of the left atrium is an extremely rare congenital disease. A 85-year-old female (NYHA I-II) was hospitalized for investigations. An echocardiogram showed calcification of the MV with mild stenosis and moderate regurgitation. Transesophageal three-dimensional echocardiogram revealed a band-like structure extending from the distal third of the anterior wall of the left atrium to the MV. This accessory chordae determined severe systolic regurgitation and mild mitral stenosis. The patient was referred for consideration of cardiac surgery but was refused for comorbidities and anatomy. Usually aberrant chordae determinant valvulopathies are detected and treated at a much younger age. The delay of the symptoms could be explained in our case with the progressive growth and dilatation of the left atrium causing traction of the aberrant chord resulting in an increase in the leaflet prolapse and regurgitation.

Atrial fibrillation and NPPA gene p.S64R mutation: are cardiologists helpless spectators of healthy mutation carriers?

AIMS

Heterozygous p.(Ser64Arg) mutation in the natriuretic peptide precursor A gene has been associated with atrial fibrillation in the presence of common single nucleotide polymorphisms (rs10033464 and rs2200733; 4q25) that would act as modifiers.

METHODS

We screened natriuretic peptide precursor A gene in 583 individuals and identified three unrelated carriers of the p.(Ser64Arg) mutation (0.5%).

RESULTS

Only one of the three mutation carriers had episodes of atrial fibrillation. Cascade screening of the three families identified seven additional mutation carriers, none showing atrial fibrillation. The patients with atrial fibrillation also carried the rs2200733, which was however found in four additional nonatrial fibrillation family members and carriers of the p.(Ser64Arg). The prevalence of atrial fibrillation in p.(Ser64Arg) carriers was 10% and in those combining the mutation with the risk single nucleotide polymorphisms was 20%. In the unique mutated patient with atrial fibrillation, the arrhythmias was refractory to both pharmacological and ablation treatment, during 16 years of follow-up; his electrophysiological phenotype was characterized by short atrial cycle lengths with a median value of 131 ms that suggests shortening of atrial action potential.

CONCLUSION

The prevalence of p.(Ser64Arg) mutation is low in the general population as is the prevalence of atrial fibrillation in mutation carriers (1/10). Atrial fibrillation in the affected mutated patient was lone at onset and progressively evolved with peculiar electrophysiological patterns.

The need to modify patient selection to improve the benefits of implantable cardioverter-defibrillator for primary prevention of sudden death in non-ischaemic dilated cardiomyopathy

Left ventricular ejection fraction (LVEF) ≤35% is a major determinant for implantable cardioverter-defibrillator (ICD) therapy for primary prevention of sudden death (SD) in patients with non-ischaemic dilated cardiomyopathy (DCM). However, as a risk marker for SD, low LVEF has limited sensibility and specificity. Selecting patients according to the current guidelines shows that most DCM patients do not actually benefit from ICD implantation and may suffer collateral effects and that many patients who are at risk of SD are not identified because a large proportion of SD patients exhibit only mildly depressed LVEF. Identifying patients who are at risk of SD on the sole basis of LVEF appears to be an over-simplification which does not maximize the benefit of ICD therapy. Owing to the complexity of the substrates underlying SD, multiple risk factors used in combination could probably predict the risk of SD better than any individual risk marker. Among non-invasive tests, microvolt T-wave alternans and cardiac magnetic resonance with late gadolinium enhancement may contribute to a better SD risk stratification by their high negative predictive value. Genetics may further contribute because approximately one-third of DCM patients have evidence of familial disease, and mutations in some known disease genes, including LMNA, have been associated with a high risk of SD. In this review, we critically analyse the current indications for ICD implantation and we explore existing knowledge about potentially predicting markers for selecting DCM patients who are at high and low risk of SD.

Thromboembolic event rate in paroxysmal and persistent atrial fibrillation: data from the GISSI-AF trial

BACKGROUND

Few data on the thromboembolic (TE) risk of paroxysmal and persistent atrial fibrillation (AF) are available. This study aimed to assess the incidence of TE events in paroxysmal and persistent AF.

METHODS

We performed a subset post hoc analysis of 771 patients with paroxysmal and 463 with persistent AF enrolled in the multicenter, prospective, randomized, double-blind, placebo-controlled GISSI-AF trial - comparing the efficacy of valsartan versus placebo in preventing AF recurrences - where the choice of antithrombotic treatment was left to the judgment of the referring physician. TE and major outcome events were centrally validated. AF recurrences were detected by frequent clinic visits and a transtelephonic monitoring device with weekly and symptomatic transmissions.

RESULTS

Eighty-five percent of patients had a history of hypertension, and the 7.7% had heart failure, left ventricular dysfunction, or both. The mean CHADS2 score was 1.41±0.84. TE and major bleeding events were observed at a low incidence among the overall population at 1-year follow-up (0.97% and 0.81%, respectively). The univariate and multivariable analyses revealed no statistically significant differences in the incidence of TE, major bleeding events or mortality in paroxysmal and persistent AF patients. TE events were more common among women than men (p=0.02). The follow-up examination showed under- or overtreatment with warfarin in many patients, according to guideline suggestions. Warfarin was more frequently prescribed to patients with persistent AF (p<0.0001) and patients with AF recurrences (p<0.0001). AF recurrences were noninvasively detected in 632 (51.2%) patients. In patients without AF recurrences, the TE event rate was 0.5% versus 1.74%, 1.28%, and 1.18% for those with only symptomatic, only asymptomatic or both symptomatic and asymptomatic AF recurrences, respectively, but the difference was not statistically significant, even after adjusting for warfarin treatment and the CHADS2 score (HR 2.93; CI 95%; 0.8-10.9; p=0.11).

CONCLUSIONS

TE and major bleeding events showed a very low incidence in the GISSI-AF trial population, despite under- or overtreatment with warfarin in many patients. TE events had a similar rate in paroxysmal and persistent AF.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

NCT00376272.

[New frontiers for an ancient disease: genetics of atrial fibrillation]

Atrial fibrillation (AF) is the commonest sustained arrhythmia in clinical practice, but its treatment is still a challenge for modern cardiology. During the last decade new insights regarding AF genetic background have been achieved. Familial aggregation suggesting a potential heritability was well known in the pre-molecular era. Now, research on the molecular basis of the disease is providing evidence that familial AF is mostly autosomal, both dominant and recessive, and genetically heterogeneous. Mutations in several disease genes with different functional effects may be associated with AF. Early results encourage family studies and monitoring. In addition, genome-wide association studies have recently identified common polymorphisms associated with an increased risk of AF in different large populations. These studies are contributing to provide early answers, but also raise new questions. In this review we analyze existing knowledge on genetics of AF and related potential clinical impact.

Autosomal recessive atrial dilated cardiomyopathy with standstill evolution associated with mutation of Natriuretic Peptide Precursor A

BACKGROUND

Atrial dilatation and atrial standstill are etiologically heterogeneous phenotypes with poorly defined nosology. In 1983, we described 8-years follow-up of atrial dilatation with standstill evolution in 8 patients from 3 families. We later identified 5 additional patients with identical phenotypes: 1 member of the largest original family and 4 unrelated to the 3 original families. All families are from the same geographic area in Northeast Italy.

METHODS AND RESULTS

We followed up the 13 patients for up to 37 years, extended the clinical investigation and monitoring to living relatives, and investigated the genetic basis of the disease. The disease was characterized by: (1) clinical onset in adulthood; (2) biatrial dilatation up to giant size; (3) early supraventricular arrhythmias with progressive loss of atrial electric activity to atrial standstill; (4) thromboembolic complications; and (5) stable, normal left ventricular function and New York Heart Association functional class during the long-term course of the disease. By linkage analysis, we mapped a locus at 1p36.22 containing the Natriuretic Peptide Precursor A gene. By sequencing Natriuretic Peptide Precursor A, we identified a homozygous missense mutation (p.Arg150Gln) in all living affected individuals of the 6 families. All patients showed low serum levels of atrial natriuretic peptide. Heterozygous mutation carriers were healthy and demonstrated normal levels of atrial natriuretic peptide.

CONCLUSIONS

Autosomal recessive atrial dilated cardiomyopathy is a rare disease associated with homozygous mutation of the Natriuretic Peptide Precursor A gene and characterized by extreme atrial dilatation with standstill evolution, thromboembolic risk, preserved left ventricular function, and severely decreased levels of atrial natriuretic peptide.

Renin-Angiotensin System and AtrialFibrillation:Understanding the Connection

Atrial fibrillation (AF) arises as a result of a complex interaction of triggers, perpetuators and the substrate. The recurrence of AF may be partially related to a biologic phenomenon known as remodeling, in which the electrical, mechanical, and structural properties of the atrial tissue and cardiac cells are progressively altered,creating a more favorable substrate. Atrial remodeling is in part a consequence of arrhythmia itself. Therefore,to prevent and to treat AF, much attention has been directed to upstream therapies to alter the arrhythmia substrate and to reduce atrial remodeling. The renin-angiotensin-aldosterone system (RAAS) plays a keyrole in these strategies. In this review we analyze the experimental and clinical evidence regarding the efficacy of RAAS inhibitors in AF treatment. In the primary prevention of AF, meta-analyses have shown that risk of new-onset AF in patients with congestive heart failure and left ventricular dysfunction is reduced by RAAS inhibitors, whereas in hypertensive and post-myocardial infarction patients, the results are less evident. In the secondary prevention of AF, some large, prospective, randomized, placebo-controlled studieswith angiotensin II-receptor blockers returned negative results. Unfortunately, the approach of using RAASinhibitors as antiarrhythmic drugs to prevent both new-onset and recurrent AF is in decline because negativetrial results are accumulating, with the exception of the results in patients with congestive heart failure.

Clinical characteristics of patients with asymptomatic recurrences of atrial fibrillation in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Atrial Fibrillation (GISSI-AF) trial

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia that frequently recurs after restoration of sinus rhythm. In a consistent percentage of cases, AF recurrences are asymptomatic, thus making its clinical management difficult in relation to both therapeutic efficacy and thromboembolic risk.

METHODS

The GISSI-AF trial enrolled 1,442 patients in sinus rhythm with previous AF episodes. Patients were randomized to valsartan or placebo and followed for 12 months. To improve the likelihood of detecting arrhythmic recurrences, arrhythmic follow-up was based on both programmed or symptom-related control visits and transtelephonic electrocardiographic transmissions. The present post hoc analysis was performed on 1,638 arrhythmic episodes that occurred in 623 patients.

RESULTS

Asymptomatic AF recurrences were present in 49.5% of patients. In multivariable analysis, asymptomatic AF recurrences were significantly associated with a longer duration of qualifying arrhythmias (odds ratio [95% CI] 1.57 (1.26-1.97), P < .0001). A lower ventricular response (P < .001) and a longer duration of the arrhythmic recurrence (P < .001) characterized asymptomatic episodes. Patients with asymptomatic events were more likely to be in AF at the time of electrocardiographic control at the end of the 12-month follow-up (adjusted odds ratio [95% CI] 4.9 (2.8-8.4), P < .001). Moreover, a higher CHADS(2) (Congestive heart failure, history of Hypertension, Age≥75 years, Diabetes mellitus, and past history of Stroke or TIA doubled) score and a more frequent use of amiodarone, calcium-channel blockers, and digitalis characterized patients with asymptomatic, whereas 1C drugs were more often used in subjects with symptomatic recurrences.

CONCLUSION

Asymptomatic AF recurrences were frequent in the GISSI-AF study population in patients who were more likely to develop persistent-permanent AF and were characterized by an increased thromboembolic risk.

[Unsatisfactory results of upstream therapy with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers for the prevention of recurrent atrial fibrillation]

Atrial fibrillation (AF) is a very common arrhythmia. Currently available tools to control arrhythmic recurrences (antiarrhythmic agents, catheter ablation) are not entirely satisfactory. Recently attention has been directed to upstream therapy, in order to alter the arrhythmia substrate; the most promising drugs seem to be those targeting the renin-angiotensin-aldsterone system. Several post-hoc analyses from large trials, in different clinical situations, confirmed the efficacy of angiotensin-converting enzyme-inhibitors and angiotensin II receptor blockers in primary prevention of AF. On the contrary prospective randomized, placebo-controlled, and double-blind studies showed negative results as for secondary prevention of AF. The GISSI-AF trial, the largest study (1442 patients) dealing with the use of angiotensin II receptor blockers in prevention of AF recurrences, has not demonstrated any difference between patients treated with valsartan (51.4% AF recurrences in a 12-month follow-up) vs. the placebo group (52.1%, p = NS). Therefore, available data do not support the use of these drugs in secondary prevention of AF.

Ischemia induced by transesophageal atrial pacing stress echocardiography predicts long-term mortality

OBJECTIVES

It was the aim of this study to investigate the long-term value of transesophageal atrial pacing in predicting death in patients with known or suspected coronary artery disease.

BACKGROUND

Exercise, dobutamine and dipyridamole stress echocardiography are all effective in predicting cardiac death. Transesophageal atrial pacing stress echocardiography (TAPSE) is a safe alternative to pharmacologic tests, but no information is available on prognosis with TAPSE.

METHODS

One thousand and ten TAPSE were performed in 975 consecutive patients. TAPSE was feasible in 970 tests (96%); after exclusion of the 35 patients with more than 1 TAPSE and those 42 lost at follow-up (mean 4.5 +/- 3.7 years, median 6 years), the final population consisted of 857 patients (675 males, 58 +/- 9 years old). The Cox model was used to analyze the association of clinical, resting and TAPSE variables with cardiac death.

RESULTS

TAPSE was abnormal in 281 (32%) patients. There were 46 cardiac-related deaths (5%), 25 among the 281 patients with an abnormal test (8.9%) and 21 among the 576 patients with a normal test (3.6%). The predictors of cardiac death were age, previous revascularization, resting wall motion score index and its variation during TAPSE. Abnormal TAPSE significantly increases the value of models predicting cardiac death. Moreover, cardiac mortality increased progressively with the extent of the induced ischemia.

CONCLUSIONS

TAPSE is a useful tool in predicting death in patients with known or suspected coronary artery disease and might be considered an alternative to pharmacologic stressors.

Safety of percutaneous left heart catheterization directly performed by cardiology fellows: a cohort analysis

BACKGROUND

No previous study has analyzed the possible responsibility of fellows-in-training in terms of the risk of complications during cardiac catheterization. Thus, we sought to identify possible risk factors for access site complications following cardiac catheterization procedures, with particular attention to the role of cardiology fellows.

METHODS

A total of 1,288 left heart catheterization procedures (both diagnostic and interventional), performed over a 1-year period at a university hospital, were retrospectively evaluated to determine the incidence of local complications (pseudoaneurysm, arterio-venous fistula, major hematoma or bleeding, vascular dissection). Several clinical (age, gender, previous coronary artery bypass surgery, indication to the exam) and procedural (procedure performed by the fellow, access site, type of procedure, urgent setting, use of glycoprotein IIb/IIIa inhibitors, simultaneous right heart catheterization, use of closure devices) covariables were considered. Major adverse cardiovascular and cerebrovascular events (MACCE: death, myocardial infarction, cerebrovascular event) were also assessed.

RESULTS

The overall access site complication rate was 2.6%. On multivariate regression analysis, the only two predictors of local complications were female gender (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.6-6.5) and femoral approach (OR 3.9, 95% CI 1.2-12.1). The rate of MACCE was 1.2%, mainly after percutaneous coronary interventions, with only 1 death overall (0.07%). Procedures performed by cardiology fellows were not associated with an increased incidence of either complication.

CONCLUSIONS

Cardiology fellows can safely perform cardiac catheterization procedures without an increase in the rate of local and major cardiovascular complications. Of course, the presence and watchful supervision of an attending physician is still essential to ensure both patient safety and optimal training.