Therapeutic inertia in rhythm control strategies in hospitalized patients with fibrillation: Insights from Hellenic Cardiorenal Morbidity Snapshot (HECMOS) study

BACKGROUND

Current guidelines recommend a rhythm control strategy in patients with symptomatic atrial fibrillation (AF) while catheter ablation has been shown to be a safer and more efficacious approach than antiarrhythmic medications.

METHODS

HECMOS was a nationwide snapshot survey of cardiorenal morbidity in hospitalized cardiology patients. In this sub-study, we included 276 cases who had a history of AF, particularly on the rhythm strategy, and catheter ablation procedures had been performed before the index admission.

RESULTS

Among 276 AF patients (mean age: 76.4 ± 11.5 years, 58 % male), 60.9 % (N = 168) had persistent AF and 39.1 % (N = 108) had paroxysmal AF. Heart failure was the main cause of admission in 54.3 % (N = 145) of the patients, while 14.1 % (N = 39) were admitted due to paroxysmal AF, 7.3 % (N = 20) due to bradyarrhythmic reasons, and 6.5 % (N = 18) suffered from acute coronary syndrome. Most importantly, heart failure with reduced ejection fraction was present in 76 (27 %) patients. Only 10 patients out of the total (3 %, mean age 59.7 years) had undergone AF ablation while electrical cardioversion had been attempted in 37 (13.4 %) patients. Interestingly, in this AF population with heart failure, 3.6 % (N = 10) had a defibrillator implanted (4 single-chamber), and only 1.5 % (N = 4) had a cardiac resynchronization therapy defibrillator (CRT-D).

CONCLUSION

High prevalence of persistent AF was detected in hospitalized patients, with heart failure being the leading cause of admission and main co-morbidity. Rhythm control strategies are notably underused, along with CRT-D implantation in patients with AF and heart failure.

Interventional management of mitral regurgitation and sleep disordered breathing: "Catching two birds with one stone"

Sleep disordered breathing (SDB), mostly constituting of obstructive and central sleep apnea (OSA and CSA, respectively), is highly prevalent in the general population, and even more among patients with cardiovascular disease, heart failure (HF) and valvular heart disease, such as mitral regurgitation (MR). The coexistence of HF, MR and SDB is associated with worse cardiovascular outcomes and increased morbidity and mortality. Pulmonary congestion, as a result of MR, can exaggerate and worsen the clinical status and symptoms of SDB, while OSA and CSA, through various mechanisms that impair left ventricular dynamics, can promote left ventricular remodelling, mitral annulus dilatation and consequently MR. Regarding treatment, positive airway pressure devices used to ameliorate symptoms in SDB also seem to result in a reduction of MR severity, MR jet fraction and an improvement of left ventricular ejection fraction. However, surgical and transcatheter interventions for MR, and especially transcatheter edge to edge mitral valve repair (TEER), seem to also have a positive effect on SDB, by reducing OSA and CSA-related severity indexes and improving symptom control. The purpose of this review is to provide a comprehensive analysis of the common pathophysiology between SDB and MR, as well as to discuss the available evidence regarding the effect of SDB treatment on MR and the effect of mitral valve surgery or transcatheter repair on both OSA and CSA.

Management of Patients With Unexplained Syncope: Derivation and Validation of a Simplified 2-Step Diagnostic Approach

BACKGROUND

The aim of this study was to develop a structured 2-step approach, based on noninvasive diagnostic criteria, that led to an electrophysiology study in patients with unexplained syncope.

METHODS AND RESULTS

Two independent cohorts were used: the derivation cohort with 665 patients based on electronic health record data to develop our 2-step diagnostic approach, and the validation cohort based on 160 prospectively screened patients, presenting with unexplained syncope episodes. Noninvasive electrocardiographic and imaging markers and an electrophysiology study-based invasive assessment were combined. A positive diagnostic approach according to our study's prespecified criteria resulted in a decision to proceed with a permanent pacemaker/implantable cardioverter-defibrillator. The primary end point was the time until the event of recurrent syncope (syncope-free survival). Number needed to treat was calculated for patients with a positive diagnostic approach. The number of patients with unexplained syncope and borderline sinus bradycardia needed to treat was 5, and the number of patients with unexplained syncope and bundle branch block needed to treat was 3 over a mean follow-up of ≈4 years. After the structured 2-step approach, the primary outcome occurred in 14 of 82 (17.1%) with a pacemaker/implantable cardioverter-defibrillator and 19 of 57 (33%) with a negative approach, with a mean follow-up of ≈2.5 years (29.29±12.58 months, P=0.03).

CONCLUSIONS

The low number needed to treat in the derivation cohort and the low percentage of syncope recurrence in the validation cohort supports the proposed 2-step electrophysiology-inclusive algorithm as a potentially low-cost, 1-day, structured tool for these patients.

Anticoagulation Status and Left Atrial Appendage Occlusion Indications in Hospitalized Cardiology Patients with Atrial Fibrillation: A Hellenic Cardiorenal Morbidity Snapshot (HECMOS) Sub-Study

Background and Objectives: The proper use of oral anticoagulants is crucial in the management of non-valvular atrial fibrillation (AF) patients. Left atrial appendage closure (LAAC) may be considered for stroke prevention in patients with AF and contraindications for long-term anticoagulant treatment. We aimed to assess anticoagulation status and LAAC indications in patients with AF from the HECMOS (Hellenic Cardiorenal Morbidity Snapshot) survey. Materials and Methods: The HECMOS was a nationwide snapshot survey of cardiorenal morbidity in hospitalized cardiology patients. HECMOS used an electronic platform to collect demographic and clinically relevant information from all patients hospitalized on 3 March 2022 in 55 different cardiology departments. In this substudy, we included patients with known AF without mechanical prosthetic valves or moderate-to-severe mitral valve stenosis. Patients with prior stroke, previous major bleeding, poor adherence to anticoagulants, and end-stage renal disease were considered candidates for LAAC. Results: Two hundred fifty-six patients (mean age 76.6 ± 11.7, 148 males) were included in our analysis. Most of them (n = 159; 62%) suffered from persistent AF. The mean CHA2DS2-VASc score was 4.28 ± 1.7, while the mean HAS-BLED score was 1.47 ± 0.9. Three out of three patients with a a CHA2DS2-VASc score of 0 or 1 (female) were inappropriately anticoagulated. Sixteen out of eighteen patients with a CHA2DS2-VASc score 1 or 2 (if female) received anticoagulants. Thirty-one out of two hundred thirty-five patients with a CHA2DS2-VASc score > 1 or 2 (if female) were inappropriately not anticoagulated. Relative indications for LAAC were present in 68 patients with NVAF (63 had only one risk factor and 5 had two concurrent risk factors). In detail, 36 had a prior stroke, 17 patients had a history of major bleeding, 15 patients reported poor or no adherence to the anticoagulant therapy and 5 had an eGFR value < 15 mL/min/1.73 m2 for a total of 73 risk factors. Moreover, 33 had a HAS-BLED score ≥ 3. No LAAC treatment was recorded. Conclusions: Anticoagulation status was nearly optimal in a high-thromboembolic-risk population of cardiology patients who were mainly treated using NOACs. One out of four AF patients should be screened for LAAC.

Electrocardiographic Characteristics, Identification, and Management of Frequent Premature Ventricular Contractions

Premature ventricular complexes (PVCs) are frequently encountered in clinical practice. The association of PVCs with adverse cardiovascular outcomes is well established in the context of structural heart disease, yet not so much in the absence of structural heart disease. However, cardiac magnetic resonance (CMR) seems to contribute prognostically in the latter subgroup. PVC-induced myocardial dysfunction refers to the impairment of ventricular function due to PVCs and is mostly associated with a PVC burden > 10%. Surface 12-lead ECG has long been used to localize the anatomic site of origin and multiple algorithms have been developed to differentiate between right ventricular and left ventricular outflow tract (RVOT and LVOT, respectively) origin. Novel algorithms include alternative ECG lead configurations and, lately, sophisticated artificial intelligence methods have been utilized to determine the origins of outflow tract arrhythmias. The decision to therapeutically address PVCs should be made upon the presence of symptoms or the development of PVC-induced myocardial dysfunction. Therapeutic modalities include pharmacological therapy (I-C antiarrhythmic drugs and beta blockers), as well as catheter ablation, which has demonstrated superior efficacy and safety.

Effects of dietary interventions on cardiovascular outcomes: a network meta-analysis

CONTEXT

Next to a large body of epidemiological observational studies showing that the Mediterranean diet (MD) is an important lifestyle determinant of cardiovascular risk, there is less relevant evidence from well-conducted randomized controlled trials (RCTs) with hard cardiovascular outcomes.

OBJECTIVE

The objective of the study was to identify the most effective dietary intervention for reducing cardiovascular morbidity and mortality.

DATA SOURCES

A systematic approach following PRISMA network meta-analyses reporting guidelines was applied to a search of electronic databases (MEDLINE, Cochrane Central Register of Controlled Trials, and Embase) without language restrictions, supplemented by scanning through bibliographies of studies and meetings' abstract material. Inclusion criteria were RCTs conducted in an adult population, investigating the effects of different type of diets or dietary patterns on all-cause mortality and cardiovascular outcomes of interest.

DATA EXTRACTION

Data extraction for each study was conducted by 2 independent reviewers.

DATA ANALYSIS

A frequentist network meta-analysis using a random-effects model was conducted. Death from any cardiovascular cause was defined as the primary outcome. A total of 17 trials incorporating 83 280 participants were included in the systematic review. Twelve articles (n = 80 550 participants) contributed to the network meta-analysis for the primary outcome. When compared with the control diet, only the MD showed a reduction in cardiovascular deaths (risk ratio = 0.59; 95% confidence interval, 0.42-0.82). Additionally, MD was the sole dietary strategy that decreased the risk of major cardiovascular events, myocardial infarction, angina, and all-cause mortality.

CONCLUSIONS

MD may play a protective role against cardiovascular disease and death for primary and also secondary prevention.

SYSTEMATIC REVIEW REGISTRATION

Center for Open Science, https://doi.org/10.17605/OSF.IO/5KX83.

Rationale and Design of a Randomized Controlled Clinical Trial on the Safety and Efficacy of Flecainide versus Amiodarone in the Cardioversion of Atrial Fibrillation at the Emergency Department in Patients with Coronary Artery Disease (FLECA-ED)

Pharmacologic cardioversion is a well-established alternative to electric cardioversion for hemodynamically stable patients, as it skips the risks associated with anesthesia. A recent network meta-analysis identifies the most effective antiarrhythmics for pharmacologic cardioversion with flecainide exhibiting a more efficacious and safer profile towards faster cardioversion. Moreover, the meta-analysis of class Ic antiarrhythmics revealed an absence of adverse events when used for pharmacologic cardioversion of AF in the ED, including patients with structural heart disease. The primary goals of this clinical trial are to prove the superiority of flecainide over amiodarone in the successful cardioversion of paroxysmal atrial fibrillation in the Emergency Department and to prove that the safety of flecainide is non-inferior to amiodarone in patients with coronary artery disease without residual ischemia, and an ejection fraction over 35%. The secondary goals of this study are to prove the superiority of flecainide over amiodarone in the reduction in hospitalizations from the Emergency Department due to atrial fibrillation in the time taken to achieve cardioversion, and in the reduction in the need to conduct electrical cardioversion.

Management of Patients With Unexplained Syncope and Bundle Branch Block: Predictive Factors of Recurrent Syncope

Syncope in patients with bundle branch block (BBB) is often due to advanced atrioventricular (AV) block. The objective of the present "real-world" study was to evaluate the optimal management in patients with unexplained syncope and BBB and to identify factors that predict the recurrence of syncope. This is a single-center observational prospective registry of 131 consecutive patients undergoing invasive electrophysiology study (EPS) for recurrent unexplained presyncope or syncope attacks and BBB. When the EPS-derived diagnosis was reached, a decision to proceed with a permanent pacemaker was offered to the patient. An implantable loop recorder was inserted in the rest of the population. A total of 131 consecutive patients with unexplained syncope and BBB (67.2% male; age 63.7 ± 16.5 years) underwent EPS during the study period. The distribution of conduction disturbance patterns was as follows: isolated left bundle branch block (LBBB): 23.7%; LBBB with first AV block: 8.4%; isolated right bundle branch block (RBBB): 10.7%; RBBB with first AV block: 8.4%; isolated left anterior/posterior fascicular block: 13%; left anterior/posterior fascicular block with first AV block: 5.3%; isolated bifascicular block: 16.8%; and bifascicular block with first AV block: 13.7%. In the multivariate analysis, the only predictors of recurrent syncope were bifascicular block (hazard ratio (HR): 4.16, 95% confidence interval (CI): 1.29, 13.41, P: 0.017) and HV interval ≥ 60 msec (HR: 3.58, 95% CI: 1.12, 11.46, P: 0.032). An EPS-based strategy identifies a subset of patients who will benefit from permanent pacing. HV interval ≥ 60 msec and the presence of a bifascicular block were strongly related to syncope recurrence.

Effectiveness and safety of a time to isolation strategy of cryoballoon ablation of atrial fibrillation: A systematic review and meta-analysis

AIM

We conducted a systematic review and meta-analysis of randomized and observational studies with a control group to evaluate the effectiveness and safety of a time to isolation (TTI)-based strategy of cryoballoon ablation (CBA) in the treatment of atrial fibrillation (AF).

METHODS

Three electronic databases (MEDLINE, Cochrane Central Register of Controlled Trials, and Embase) without language restrictions were searched. The intervention assessed was a TTI-based strategy of CBA in the treatment of AF. TTI was defined as the time from the start of freezing to the last recorded pulmonary veins' potential. The comparison of interest was intended conventional protocol of CBA. The primary endpoint was freedom from atrial arrhythmia.

RESULTS

Nine studies were deemed eligible (N = 2289 patients). Eight studies reported freedom from atrial arrhythmia and pooled results showed a marginally similar success rate between the two protocols (odds ratio [OR]: 1.24; 95% confidence interval [CI]: 0.98-1.56). A prespecified subgroup analysis verified that a high dose TTI strategy (with >120 s duration of cryotherapy post-TTI) compared to the conventional protocol could significantly increase the patients without atrial arrhythmia during follow-up (OR: 1.39; 95% CI: 1.05-1.83). TTI strategy could also significantly decrease total procedure time (SMD: -26.24 min; 95% CI: -36.90 to -15.57) and phrenic nerve palsy incidence (OR: 0.49; 95% CI: 0.29-0.84).

CONCLUSION

Moderate confidence evidence suggests that an individualized CBA dosing strategy based on TTI and extended (>2 min post-TTI) duration of CBA is accompanied by fewer recurrences post-AF ablation.

Prevention of radial artery spasm during coronary angiography with transdermal glyceryl trinitrate patches: the NURSE-TTS trial

Background/Introduction

One of the most common complications encountered during transradial procedures is radial artery (RA) spasm, whereas its management remains a challenge.

Purpose

We hypothesized that in patients undergoing cardiac catheterization via the RA, the use of transdermal nitroglycerin (NTG) patches applied to skin over the RA puncture site may prevent the occurrence of radial artery spasm.

Methods

NURSE-TTS (Nitrate Use to Obtain Radial Spasm Embarrassment) is a parallel-group, randomized, double-blind, placebo-controlled trial evaluating the impact of transdermal NTG application to RA spasm prevention. 146 patients were consecutively enrolled from February 2021 to December 2021 from an experienced center in Greece and underwent diagnostic coronary angiography. The primary endpoint was the exerting force of the RA measured by the dynamometer in Newton.

Results

The primary endpoint of the dynamometer measurements was found to be significantly different between the two groups. The treatment group's mean force was 5.95±2.60 and 7.21±2.82 for the placebo group respectively (p=0.007). The multivariate analysis confirmed that NTG patches affected radial spasm (treatment group p=0,010, 95% CI: −2,038, −0,282; age p=0,010, 95% CI: −0,099, −0,014; male gender p=0,011, 95% CI: −2,612, −0,349; CKD p=0,044, 95% CI: 0,064,0,951).

Conclusions

This is the first prospective randomized study demonstrating that the application of transdermal NTG 10mg on skin for 30 minutes before coronary angiography resulted in lower exerting force of the cannulated radial artery thus lower arterial spasm.

Funding Acknowledgement

Type of funding sources: None.

Atrial high-rate episodes in patients with devices without a history of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial high-rate episodes (AHREs) recorded with cardiac implantable electronic devices (CIEDs) have been associated with the development of clinical atrial fibrillation (AF) and increase in stroke, and death risk.

Purpose

We sought to perform a systematic review with a meta-analysis to evaluate the prevalence of AHREs detected by CIEDs, their association with stroke risk, development of clinical AF, and mortality among patients without a documented history of AF.

Methods

We searched several databases, ClinicalTrials.gov, references of reviews, and meeting abstract books without any language restrictions up to 9 September 2020. We studied patients with CIEDs in whom AHREs were detected. Exclusion criteria were an AF history. Our primary outcome was the risk of ischemic stroke in patients with AHREs.

Results

We deemed eligible eight studies for the meta-analysis enrolling a total of 4322 patients with CIED and without a documented AF history. Evidence of moderate certainty suggests that patients with documented AHREs were 4.45 times (95% CI 2.87–6.91) more likely to develop clinical AF. Evidence of low confidence suggests that AHREs were associated with a 1.90-fold increased stroke risk (95% CI 1.19–3.05).

Conclusion

The present systematic review and meta-analysis demonstrated that among patients without a documented history of AF, the detection of AHREs by CIEDs was associated with significant increased risk of clinical AF and stroke.

Reappraising the role of class Ic antiarrhythmics in atrial fibrillation

PURPOSE

The objective of the present systematic review was to compare the effectiveness and safety of class Ic agents for cardioversion of paroxysmal atrial fibrillation (AF), in patients with and without structural heart disease (SHD).

METHODS

We focused on RCTs enrolling at least 50 adult patients with electrocardiogram-documented paroxysmal AF that compared either two pharmacological class Ic cardioversion agents (flecainide, propafenone), regardless of study design (parallel or crossover). We searched MEDLINE and the Cochrane Central Register of Controlled Trials. Initial search was performed from inception to 15 July 2021 with no language restrictions.

RESULTS

Intravenous flecainide is the most effective option for pharmacologic cardioversion of AF since only 2 patients need to be treated in order to cardiovert one more within 4 h. Most importantly, class Ic agents appear to be safe in the context of pharmacologic cardioversion of AF irrespective of the presence of SHD, pointing towards a possible reappraisal of the role in this setting.

CONCLUSION

We suggest that class Ic agents (with flecainide appearing to be more effective) should be used for pharmacologic cardioversion in stable AF patients presenting in emergency department with unknown medical history, after excluding severe cardiac disease through a bedside examination.

REGISTRATION NUMBER (DOI)

Available in https://osf.io/apwt7/ , https://doi.org/10.17605/OSF.IO/APWT7.

Autonomic Neuromodulation for Atrial Fibrillation Following Cardiac Surgery: JACC Review Topic of the Week

Autonomic neuromodulation therapies (ANMTs) (ie, ganglionated plexus ablation, epicardial injections for temporary neurotoxicity, low-level vagus nerve stimulation [LL-VNS], stellate ganglion block, baroreceptor stimulation, spinal cord stimulation, and renal nerve denervation) constitute an emerging therapeutic approach for arrhythmias. Very little is known about ANMTs' preventive potential for postoperative atrial fibrillation (POAF) after cardiac surgery. The purpose of this review is to summarize and critically appraise the currently available evidence. Herein, the authors conducted a systematic review of 922 articles that yielded 7 randomized controlled trials. In the meta-analysis, ANMTs reduced POAF incidence (OR: 0.37; 95% CI: 0.25 to 0.55) and burden (mean difference [MD]: -3.51 hours; 95% CI: -6.64 to -0.38 hours), length of stay (MD: -0.82 days; 95% CI: -1.59 to -0.04 days), and interleukin-6 (MD: -79.92 pg/mL; 95% CI: -151.12 to -8.33 pg/mL), mainly attributed to LL-VNS and epicardial injections. Moving forward, these findings establish a base for future larger and comparative trials with ANMTs, to optimize and expand their use.

Permanent pacemaker implantation in unexplained syncope patients with electrophysiology study-proven atrioventricular node disease

BACKGROUND

Syncope, whose cause is unknown after an initial assessment, has an uncertain prognosis. It is critical to identify patients at highest risk who may require a pacemaker and to identify the cause of recurrent syncope to prescribe proper therapy. Aim of this study was to evaluate the effect of permanent pacing on the incidence of syncope in patients with unexplained syncope and electrophysiology study-proven atrioventricular node disease.

MATERIAL AND METHODS

This was an observational study based on a prospective registry of 236 consecutive patients (60.20 ± 18.66 years, 63.1% male, 60.04 ± 9.50 bpm) presenting with recurrent unexplained syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). The decision to implant a permanent pacemaker was made in all cases by the attending physicians according to the results of the EPS. 135 patients received the antibradycardia pacemaker (ABP), while 101 declined.

RESULTS

The mean of reported syncope episodes was 1.97 ± 1.10 (or presyncope 2.17 ± 1.50) before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (49.19 ± 29.58 months), the primary outcome event (syncope) occurred in 31 of 236 patients (13.1%), 6 of 135 (4.4%) in the ABP group as compared to 25 of 101 (24.8%) in the no pacemaker group (p < 0.001).

CONCLUSION

Among patients with a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined atrioventricular node disease, identifies a subset of patients who will benefit from permanent pacing.

Stereotactic Arrhythmia Radioablation as a Novel Treatment Approach for Cardiac Arrhythmias: Facts and Limitations

Stereotactic ablative radiotherapy (SABR) is highly focused radiation therapy that targets well-demarcated, limited-volume malignant or benign tumors with high accuracy and precision using image guidance. Stereotactic arrhythmia radioablation (STAR) applies SABR to treat cardiac arrhythmias, including ventricular tachycardia (VT) and atrial fibrillation (AF), and has recently been a focus in research. Clinical studies have demonstrated electrophysiologic conduction blockade and histologic fibrosis after STAR, which provides a proof of principle for its potential for treating arrhythmias. This review will present the basic STAR principles, available clinical study outcomes, and how the technique has evolved since the first pre-clinical study. In addition to the clinical workflow, focus will be given on the process for stereotactic radiotherapy Quality Assurance (QA) tests, as well as the need for establishing a standardized QA protocol. Future implications and potential courses of research will also be discussed.

Atrial High-Rate Episodes in Patients with Devices Without a History of Atrial Fibrillation: a Systematic Review and Meta-analysis

PURPOSE

Atrial high-rate episodes (AHREs) recorded with cardiac implantable electronic devices (CIEDs) have been associated with the development of clinical atrial fibrillation (AF) and increase in stroke and death risk. We sought to perform a systematic review with a meta-analysis to evaluate the prevalence of AHREs detected by CIEDs, their association with stroke risk, development of clinical AF, and mortality among patients without a documented history of AF.

METHODS

We searched several databases, ClinicalTrials.gov, references of reviews, and meeting abstract books without any language restrictions up to 9 September 2020. We studied patients with CIEDs in whom AHREs were detected. Exclusion criterion was AF history. Our primary outcome was the risk of ischemic stroke in patients with AHREs.

RESULTS

We deemed eligible eight studies for the meta-analysis enrolling a total of 4322 patients with CIED and without a documented AF history. The overall AHRE incidence ratio was estimated to be 17.56 (95% CI, 8.61 to 35.79) cases per 100 person-years. Evidence of moderate certainty suggests that patients with documented AHREs were 4.45 times (95% CI 2.87-6.91) more likely to develop clinical AF. Evidence of low confidence suggests that AHREs were associated with a 1.90-fold increased stroke risk (95% CI 1.19-3.05). AHREs were not associated with a statistically significant increased mortality risk.

CONCLUSION

The present systematic review and meta-analysis demonstrated that among patients without a documented history of AF, the detection of AHREs by CIEDs was associated with significant increased risk of clinical AF and stroke.

REGISTRATION NUMBER (DOI)

Available in https://doi.org/10.17605/OSF.IO/ZRF6M .

Permanent pacemaker implantation in unexplained syncope patients with electrophysiology study-proven atrioventricular node disease

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Syncope, whose cause is unknown after an initial assessment, has an uncertain prognosis. It is critical to identify patients at highest risk who may require a pacemaker and to identify the cause of recurrent syncope to prescribe proper therapy

Purpose

Aim of this study was to evaluate the effect of permanent pacing on the incidence of syncope in patients with unexplained syncope and electrophysiology study-proven atrioventricular node disease.

Methods

This was an observational study based on a prospective registry of 236 consecutive patients (60.20 ± 18.66 years, 63.1% male, 60.04 ± 9.50 bpm) presenting with recurrent unexplained syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. 135 patients received the ABP, while 101 denied.

Results

The mean of reported syncope episodes was 1.97 ± 1.10 (or presyncope 2.17 ± 1.50) before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (49.19 ±  29.58 months), the primary outcome event (syncope) occurred in 31 of 236 patients (13.1%), 6 of 135 (4.4%) in the ABP group as compared to 25 of 101 (24.8%) in the no pacemaker group (p &lt; 0.001).

Conclusion

Among patients with a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined atrioventricular node disease, identifies a subset of patients who will benefit from permanent pacing.

Noninvasive risk factors for the prediction of inducibility on programmed ventricular stimulation in post-MI patients with ejection fraction over 40% at SCD risk, insights from the PRESERVE EF study

Funding Acknowledgements

Type of funding sources: None.

Background

Sudden cardiac arrest (SCA) in post myocardial infarction (post-MI) patients with a relatively preserved left ventricular systolic function (LVEF≥40%) has an annual incidence of 1%, in the absence of adequate risk stratification methods and guideline recommendations for primary prevention. In the PRESERVE-EF study we used a two-step SCA risk stratification approach to detect patients at risk for major arrhythmic events. Seven noninvasive risk factors (NIRFs) were extracted from ambulatory electrocardiography (AECG). Patients with at least one NIRF present were referred for invasive programmed ventricular stimulation (PVS). Inducible patients received an ICD.

Purpose

To assess the performance of NIRFs extracted from 24hr AECG, based on the PRESERVE EF criteria, in predicting inducibility.

Methods

The PRESERVE EF study enrolled 575 patients. Two hundred and four of them had at least one NIRF and an indication for PVS, but 52 of them declined. Finally, 41 out of 152 patients who underwent PVS were inducible. For the present analysis data from these 152 patients (mean age 60 ± 10years, LVEF 49 ± 6%, 89% males) were analyzed. Chi-square test, univariate logistic regression and areas under ROC curves were calculated for the PVS inducibility endpoint.

Results

Age, male gender and LVEF for the PVS inducible patients group (n = 41) and the noninducible patients group (n = 111) were, respectively: 61 ± 9years vs 59 ± 10years (p = 0.310), 98% vs 86% (p = 0.048), 45 ± 4% vs 51 ± 7% (p &lt; 0.001). Among NIRFs examined, LVEF ≤ 50%, nsVT≥1/24hour and presence of LPs on SAECG presented high and significant Odds Ratios (ORs) for a positive PVS study end point. A simple risk score based on cutoff points of LVEF ≤ 50%, NSVTepisode≥1/24hour and presence of LPs missed only 1 out of the 41 inducible patients and yielded: OR 14.146 (p = 0.01) with a high sensitivity 98% but low specificity 26% for a positive PVS (AUC = 0.65).

Conclusion

Cut off points of LVEF ≤ 50%, nsVTepisode≥1/24hour and presence of LPs were important predictors of inducibility. A simple risk score based on these predictors achieves high sensitivity but low specificity.  The final decision for an ICD implantation should be based on a positive PVS, which is irreplaceable in risk stratification.

Pharmacologic Cardioversion in Patients with Paroxysmal Atrial Fibrillation: A Network Meta-Analysis

PURPOSE

We sought to indirectly compare and rank antiarrhythmic agents focusing exclusively on adults with paroxysmal atrial fibrillation in order to identify the most effective for pharmacologic cardioversion over different time settings (4 h as primary, and 12, 24 h as secondary outcomes).

METHODS

We searched several databases from inception to March 2020 without language restrictions, ClinicalTrials.gov, references of reviews, and meeting abstract material. We included randomized controlled trials of patients with AF lasting ≤7 days comparing either two or more intravenous (i.v.) or oral (p.o.) pharmacologic cardioversion agents or an agent against placebo. For each outcome, we performed network meta-analysis based on the frequentist approach.

RESULTS

Forty-one trials (6013 patients) were included in our systematic review. Moderate confidence evidence suggests that i.v. vernakalant and flecainide have the highest conversion rate within 4 h, possibly allowing discharge from the emergency department and reducing hospital admissions. Intravenous and p.o. formulations of class IC antiarrhythmics (flecainide more so than propafenone) are superior regarding conversion rates within 12 h, while amiodarone efficacy is exhibited in a delayed fashion (within 24 h), especially if ranolazine is added.

CONCLUSION

Our network meta-analysis identified with sufficient power and consistency the most effective antiarrhythmics for pharmacologic cardioversion over different time settings, with vernakalant and flecainide exhibiting a safer and more efficacious profile toward faster cardioversion.

P1682Triglycerides are related to left ventricular mass in hypertensive patients, independently of other cardiometabolic risk factors: The effect of gender

Introduction

LDL cholesterol (LDL-C) is a strong cardiovascular risk factor and the main goal of treatment for both primary and secondary prevention. However, triglycerides (TGs) also convey a significant prognostic role. Left ventricular hypertrophy (LVH) increases cardiovascular risk in hypertensive patients. The purpose of the present study was to investigate the association of left ventricular mass (LVM) with TGs in never treated hypertensive patients.

Methods

We studied 760 never treated, non diabetic, hypertensive patients. Participants were subjected to transthoracic echocardiography and LVM was calculated according to the Devereux formula, indexed to body surface area (LVMI). Lipid variables including LDL-C, TGs, HDL-C, apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) were measured in all patients.

Results

In multivariate regression analysis, LVMI was independently associated with TGs after adjustment for age, gender, smoking, SBP, glucose, LDL-C and ApoB/ApoA1 ratio (b=0.07, p=0.04). Gender-stratified analysis indicated that TGs were related to LVMI in men (b=0.15, p=0.001) but not in women (p=NS). In addition, TGs were associated with LVH in men increasing the odds by 7% to present LVMI over 115 g/m2 after controlling for age, smoking, SBP and glucose (OR: 1.07 per 10 mg/dl increase in TGs, 95% CI: 1.02–1.14, p=0.01).

Conclusion

TGs are strong determinants of LVMI in hypertensive patients, independently of other cardiometabolic risk factors, including LDL-C. The gender discrepancy may suggest a gender-specific effect of TGs on LV structure. Future studies need to clarify whether lowering TGs may induce regression of LVH, thus improving cardiovascular risk in hypertensive patients.

P5432Invasive assessment by atrial volume-pressure loops of the acute changes in left atrial function induced by pulmonary vein antral isolation

Background

Atrial volume-pressure loops are considered the best method to assess left atrium (LA) function. Changes in atrial function induced by pulmonary vein (PV) antral isolation of atrial fibrillation (AF) have not been documented thus far using this approach.

Purpose

We aimed to evaluate changes in LA function in patients with paroxysmal atrial fibrillation (PAF) undergoing catheter ablation by atrial volume-pressure loops.

Methods

Patients undergoing for the first time catheter ablation of PAF by PV antral isolation and PV-LA junction ablation, as clinically indicated, were enrolled from 2 centers. Each center enrolled consecutive patients undergoing PV antral isolation using the same method i.e. radiofrequency or cryoballoon ablation. Patients with severe mitral stenosis or regurgitation, any prosthetic valve, left atrial thrombus or severe systolic or diastolic dysfunction of the left ventricle were excluded. Before and after the procedure, all patients underwent real-time three-dimensional transthoracic echocardiogram to evaluate volume changes of the LA during an entire cardiac cycle, while simultaneously recording LA pressure by a 6F angiographic catheter following transseptal puncture. After the procedure, LA volume and pressure recordings were gated offline by ECG, and were used to plot the LA pressure as a function of LA volume, thus creating a volume-pressure loop. The A loop area is a measure of the booster pump function of the LA. The V loop area expresses the reservoir function of the LA. Pressure and volume data at the clockwise ascending limb of the volume-pressure loop were fitted to the exponential function P = bxea·V, where P = instantaneous LA pressure; V = LA volume; a is the passive elastic chamber stiffness constant (cm–3) that determines the slope of the exponential curve, and b is the elastic constant (mm Hg).

Results

34 patients with PAF were analysed, 12 treated with radiofrequency ablation and 22 with cryoablation. The procedure was uneventful in all cases. Mean LA pressure, A-wave amplitude, and V-wave amplitude were all significantly increased post-procedurally (p<0.001 for all). The area of the A-loop decreased (Post: 40.69 ml·mm Hg [IQR 13.7–71.3] vs. Pre: 64.2 ml·mm Hg [IQR 30.9–86.9]; p=0.001), whereas the area of the V-loop increased (Post: 96.5 ml·mm Hg [IQR 45.1–230.5] vs. Pre: 79.2 ml·mm Hg [IQR 46.9–149.7]; p=0.016). Although the elastic constant increased (p<0.001), there was no significant difference in the passive chamber elastic constant (p=0.30).

Conclusion

Volume-pressure loops can assess procedural changes in LA function. Catheter ablation of AF is associated with a decrease the LA booster pump function of the LA, and in increase in the left atrial reservoir function. Moreover, there is an increase in LA pressures that is observed in the absence of change in LA stiffness.

P1910Impact of pulmonary vein antral isolation by radiofrequency catheter or cryoballoon on left atrial function assessed by volume-pressure loops

Background

Atrial volume-pressure loops are used to assess left atrium (LA) function. Catheter ablation of paroxysmal atrial fibrillation (PAF) by pulmonary vein (PV) antral isolation can be performed either with radiofrequency (RF) catheter or with cryoballoon and might affect LA function.

Purpose

We explored a potential difference in changes in LA function by volume-pressure loops between patients with PAF undergoing either RF catheter or cryoballoon ablation.

Methods

Patients undergoing for the first time catheter ablation of PAF by PV antral isolation and PV-LA junction ablation, as clinically indicated, were enrolled from 2 centers. Each center enrolled consecutive patients undergoing PV antral isolation using the same method ie RF or cryoballoon ablation. Patients with severe mitral stenosis or regurgitation, any prosthetic valve, left atrial thrombus or severe systolic or diastolic dysfunction of the left ventricle were excluded. Pre and post procedure, all patients underwent real-time 3D transthoracic echocardiogram to evaluate volume changes of the LA during an entire cardiac cycle, while recording LA pressure by a 6F angiographic catheter following transseptal puncture. After the procedure, LA volume and pressure recordings were gated offline by ECG, and were used to plot the LA pressure as a function of LA volume, thus creating a volume-pressure loop. The A loop area is a measure of the LA booster pump function. The V loop area expresses the LA reservoir function. Pressure and volume data at the clockwise ascending limb of the volume-pressure loop were fitted to the exponential function P = bxea·V, where P = instantaneous LA pressure; V = LA volume; a is the passive elastic chamber stiffness constant (cm–3) that determines the slope of the exponential curve, and b is the elastic constant (mm Hg).

Results

34 patients with PAF were analysed, 12 treated with RF ablation and 22 with cryoablation. The procedure was uneventful in all cases. In the overall cohort, mean LA pressure, A-wave and V-wave amplitude were all increased post-procedurally (p<0.001); A-loop area decreased (p=0.001), whereas V-loop area increased (p=0.016). Although the elastic constant increased (p<0.001), there was no significant difference in the passive chamber elastic constant (p=0.30).

Changes in both A-loop and V-loop areas were similar between RF and cryoablation (p=0.18 and p=0.36, respectively). However, compared to cryoablation, RF ablation had a lower increase in the elastic constant (b=-2.24; 95% CI: −10.56 to −1.78), and a higher increase in the passive elastic chamber stiffness constant (b=0.078; 95% CI: 0.016 to 0.140).

Conclusion

Both in RF- and cryo-ablation and in a similar extent, the LA booster pump function is decreased, and LA reservoir function is increased. LA pressure is increased in RF ablation mainly due to an acute increase in LA stiffness, whereas in cryoablation this increase is observed in the absence of change in LA stiffness.

6082A prospective, multicenter, nationwide, observational study of flecainide controlled release on the quality of life of patients with atrial fibrillation in Greece, the REFLEC-CR study

Background/Introduction

Atrial fibrillation (AF) is the most common cardiac arrhythmia with a considerable impact on patients' quality of life (QoL). Flecainide acetate, is a class Ic antiarrhythmic agent, recommended as first line treatment in AF patients without underlying structural heart disease.

Purpose

This prospective, multicenter, nationwide, observational study aimed to evaluate the effect of oral treatment with controlled-release (CR) flecainide administered once daily on AF patients' QoL and treatment compliance during a 12-week period.

Methods

A total of 70 cardiologists participated in the study enrolling consecutive adult patients with paroxysmal or persistent AF, treated with flecainide CR in the context of a rhythm control strategy. The effect on QoL was assessed by the Canadian Cardiovascular Society Severity of Atrial Fibrillation scale (CCS-SAF) measured at baseline and at 12 weeks of treatment.

Results

In total, 679 patients (53.2% females, mean age 65.9±11.7 years, 86.9% paroxysmal AF) were included in the analysis. At least one prior antiarrhythmic treatment was documented in 43.8% of patients. The initial daily dose of flecainide CR was 100mg in 71.7% of the patients, with a titration to 200mg by the end of study achieved in 67%. In 93.6% of patients an excellent compliance score (100%) to treatment was recorded at the end of the study period. Treatment with flecainide CR resulted in a significant improvement in QoL as presented in the table.

Table 1 CCS-SAF score Baseline (Week 0) End of study visit (Week 12) N=679 N=634 Class 1 (minimal effect on QoL) 343 (50.5) 464 (73.2) Class 2 (minor effect on QoL) 253 (37.2) 140 (22.1) Class 3 (moderate effect on QoL) 73 (10.8) 28 (4.4) Class 4 (severely impairs QoL) 10 (1.5) 2 (0.3) CCS-SAF continuous score   Mean ± SD 1.64±0.73 1.32±0.57 Change from baseline‡   Mean (95% CI) −0.325 (−0.379, −0.271)   p-value <0.0001 ‡Paired t-test is used.

Conclusions

This prospective, multicenter, observational study demonstrated that treatment of AF patients with flecainide CR, was associated with a significant improvement of QoL and excellent compliance to treatment.

Acknowledgement/Funding

Sponsored by WinMedica S.A.

P1674High intensity interval exercise program in heart failure patients seems to benefit cardiac power along with aorto-ventricular mechanical pump capacity and cardiorespiratory indices

Background

Cardiac power has been suggested as the most power predictor of mortality in heart failure (HF) patients. In those patients aorta elastic properties and compensation is lost, systolic (and pulse) pressure are therefore reduced and associated with a decrease in ejection duration and pump efficiency. Cardiac rehabilitation programs have showed enhancement in cardiac performance and quality of life in HF patients.

Aim

Aim of this work was to evaluate the effect of high-intensity interval exercise (i.e., 30 sec at 100% of max workload, followed by 30 sec at rest, on a day-by-day 30 minutes working-out schedule for 12 weeks), on cardiac power, diastolic function indices, right ventricle performance and cardiorespiratory parameters among chronic HF patients.

Methods

72 consecutive HF patients (NYHA class II-IV, ejection fraction <50%) who completed the study (exercise training group, n=33, 63±9 years, 88% men, and control group, n=39, 56±11 years, 82% men), underwent cardiopulmonary stress test, non-invasive high-fidelity tonometry of the radial artery, pulse wave velocity measurement using a SphygmoCor device, and echocardiography before and after completion of the training program. Cardiac power output (CPO) (W) was calculated as mean arterial pressure × CO/451, where mean arterial pressure = [(systolic blood pressure − diastolic blood pressure)/3] + diastolic blood pressure.

Results

Both groups reported similar medical characteristics and physical activity status. General mixed effects models revealed that the intervention group increased 6MWT (by 13%, p<0.05); increased cycle ergometry WRpeak (by 25%, p<0.01), showed higher O2max by 31% (p<0.001) and lower VE/VCO2 (p=0.05), whereas patients in the control group showed nosignificant changes in the aforementioned indices. Also, in the intervention group Emv/Vp was decreased by 14% (p=0.06); E to A ratio by 24% (p=0.004) and E to Emv ratio by 8% (p=0.05); while Stv increased by 25% (p=0.01). Most importantly, the intervention group reduced pulse wave velocity by 9% (p=0.05) and increased augmentation index by 26%; and VTI by 4% (p=0.05); Those parameters were not significantly changed on control group (all p>0.05).

Conclusion

Hight intensity exercise rehabilitation program revealed beneficial effect on left ventricular diastolic indices and right ventricle performance. As, in those patients compensation of the aorta is also lost and the LV cannot generate the extra force necessary to completely overcome the late systolic augmented pressure, the increase in the augmented pressure (AIa) observed in the intervention group reflects the benefit in aorto-ventricular coupling and cardiac power that boosts systolic pressure and restores a positive influence in pressure, like in early stages of HF.

Acknowledgement/Funding

None

Signal-averaged electrocardiography: Past, present, and future

Signal-averaged electrocardiography records delayed depolarization of myocardial areas with slow conduction that can form the substrate for monomorphic ventricular tachycardia. This technique has been examined mostly in patients with coronary artery disease, but its use has been declined over the years. However, several lines of evidence, derived from hitherto clinical data in patients with healed myocardial infarction, indicate that signal-averaged electrocardiography remains a valuable tool in risk stratification, especially when incorporated into algorithms encompassing invasive and noninvasive indices. Such an approach can aid the more precise identification of candidates for device therapy, in the context of primary prevention of sudden cardiac death. This article reappraises the value of signal-averaged electrocardiography as a predictor of arrhythmic outcome in patients with ischemic heart disease and discusses potential future indications.

Electrophysiology Catheter-Facilitated coronary sinus cannulation and implantation of cardiac resynchronization therapy systems

BACKGROUND

Cardiac resynchronization therapy (CRT) device implantation is hampered by difficult placement of the left ventricular (LV) lead. We have routinely used a steerable electrophysiology catheter to guide coronary sinus (CS) cannulation and facilitate LV lead positioning. The aim of this prospective study is to present our results with this approach in 138 consecutive patients receiving a CRT device over 10 years.

METHODS

The study included 120 men and 18 women, aged 64.8±11.4 years, with coronary disease (n=63), cardiomyopathy (n=72), or other disease (n=3), and mean ejection fraction of 24.5±4.5%. Devices were implanted for refractory heart failure and dyssynchrony, all but 2 in the presence of left bundle branch block. Implanted devices included biventricular pacemakers (CRT-P) (n=33) and cardioverter defibrillators (CRT-D) (n=105).

RESULTS

Using the electrophysiology catheter, the CS could be engaged in 134 (97.1%) patients. In 4 patients failing CS cannulation, a dual-chamber device was implanted in 2, and bifocal right ventricular pacing was effected in 2. Bifocal (n=2) or conventional (n=1) systems were implanted in another 3 patients, in whom the LV lead got dislodged (n=2) or removed because of local dissection (n=1). Thus, finally, a CRT system was successfully established in 131 (94.9%) patients. There were 3 patients with CS dissection, of whom 1 was complicated by cardiac tamponade managed with pericardiocentesis. There were no perioperative deaths. During follow-up (31.0±21.2 months), clinical improvement was reported by 108 (82.4%) patients.

CONCLUSION

Routine use of an electrophysiology catheter greatly facilitated CS cannulation and successful LV lead placement in ∼95% of patients undergoing CRT system implantation.

Cryoballoon ablation of atrial fibrillation: a practical and effective approach

Medical management of atrial fibrillation (AF), the most common arrhythmia in the general population, has had modest efficacy in controlling symptoms and restoring and maintaining sinus rhythm. Since the seminal observation in 1998 that pulmonary veins host the triggers of AF in the majority of cases, electrical isolation of all pulmonary veins constitutes the cornerstone of ablation in patients with symptomatic AF. However, due to the elaborate and tedious technique of the conventional point-by-point method with radiofrequency ablation guided by electroanatomical mapping, newer, more versatile single-shot techniques, such as cryoballoon ablation, have been sought and developed over recent years and are progressively prevailing. Cryoballoon ablation appears to be the most promising practical and effective approach, and we review it here by presenting all available relevant data from the literature as well as from our own experience in an attempt to apprise colleagues of the significant progress made over the last several years in this important field of electrophysiology.

Prevalence of late potentials on signal-averaged ECG in patients with psychiatric disorders

BACKGROUND

Sudden cardiac death (SCD) occurs three times more often in psychiatric patients than in the general population. QRS fragmentation (QRSfr) and signal-averaged electrocardiography (SAECG) are simple, inexpensive, readily available tools for detecting the presence of abnormal depolarization and late potentials (LPs) in these patients, a result of either the underlying disease or treatment.

METHODS

Frequency of LP detection by SAECG and QRSfr was studied in 52 psychiatric patients and compared with 30 healthy (without known structural heart disease or occurrence of ventricular arrhythmia) controls. Patients were then prospectively followed up and incidence of SCD was recorded.

RESULTS

LP prevalence was significantly higher in patients than in controls (16/52-31% vs 2/30-7%, p=0.012), while QRSfr was similar between these two groups (p=0.09). Of the LP presence criteria, the root mean square value at terminal 40msec of the QRS (RMS40) was significantly lower in patients (32μV, SD=19μV, vs 46μV, SD=32μV, p=0.015). Among patients, no differences were noted between the LP positive and negative groups regarding age, sex, number of medications, class of antipsychotics and defined daily doses. Mean follow-up was 46months (SD=11) and during it 3 patients suffered SCD. Although 2 SCD victims had both LPs and QRSfr concurrently present, neither of them, nor their simultaneous presence could definitely account for the events.

CONCLUSIONS

LP prevalence in psychiatric patients was significantly higher than in controls. SAECG performance was feasible in all cases and constitutes a readily available tool for assessing myocardial electrophysiological alterations in this patient group.