SAECG - advances in Brugada stratification

Funding Acknowledgements

Type of funding sources: None.

Introduction

Brugada syndrome (BrS) is a relevant cause of sudden cardiac death (SCD) in young adults. Several risk factors have been identified, but clinical decision making remains extremely challenging, particularly in asymptomatic patients.

Purpose

To explore the usefulness of the non-invasive assessment of late potentials (LPs) based signal-averaged ECG (SAECG) for risk stratification in BrS.

Methods

Prospective single-center study of patients with BrS included from 2003 to 2021. LPs were evaluated by SA-ECG with determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40ms terminal portion of the QRS (RMS40) and duration of the low amplitude electric potential component of the terminal portion of the QRS (LAS40) in conventional and modified right precordial leads.

The primary endpoint was the occurrence of malignant arrhythmic events (MAEs), defined as a composite of SCD or appropriate shocks. Uni- and multivariate Cox regression survival analyses were used to identify significant prognostic predictors considering the clinical, genetic, and electrocardiographic characteristics as well as the tercile distribution of the SAECG parameters. A risk score was computed incorporating the significant LPs variables and its usefulness for prognostic stratification was explored using Kaplan Meier survival analysis.

Results

Our cohort consisted of 117 patients (mean age: 47±13 years, 33% male), including 75 (65%) with type 1 spontaneous pattern and 92 (79%) asymptomatic individuals. Symptoms at presentation included syncope in 16 pts (14%) and polymorphic VT/cardiac arrest in 4 (3.4%).

During a median follow-up of 4.1±0.3 years, 8 pts (6.8%) suffered MAEs: 3 (2.6%) with SCD and 5 (4.3%) with appropriate shocks.

The risk of events differed in relation to the several SAECG parameters (Table 1), increasing linearly with the fQRS duration determined either in the conventional (HR 1.03, 95% CI 1.01-1.06, p=0.008) or modified leads (HR: 1.03, 95% CI 1.01- 1.05, p=0.003). The SAECG score incorporated as risk markers a fQRS ≥113ms and a RMS40 <13 μV. Patients with both risk markers presented a 7-fold increased risk (HR 7.17, 95% CI 1.29-40, p = 0.025), independently of the baseline symptomatic status and ECG pattern.

Conclusion

This study shows that the non-invasive assessment of LPs based on SAECG is useful for prognostic stratification of BrS. It was possible to identify a subset of patients presenting a high risk of events who may deserve individualized preventive strategies.

Non-ischemic cardiomyopathy: what predicts survival and ICD shocks after ventricular tachycardia ablation?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Patients (pts) with non-ischemic cardiomyopathy (NICM) present an increased morbidity and mortality from sustained monomorphic ventricular tachycardia (VT). Implantable cardiac defibrillators effectively terminate VT, but ablation is usually required to prevent recurrences and appropriate shocks. Although several risk factors have been pointed out, clear prognostic predictors need to be established and addressed.

Purpose

To evaluate risk factors associated with all-cause mortality and ICD shocks in NICM pts submitted to VT ablation.

Methods

Prospective, observational, single-centre study of pts with NICM submitted to VT ablation using high density mapping tools.The primary outcome was all-cause death or VT recurrence terminated with appropriate ICD shock during long-term follow up. Kaplan-Meier analysis was used to estimate the long-term event-free survival. Uni and multivariate Cox regression analyses were used to determine relevant prognostic predictors.

Results

A total of 27 consecutive pts with NICM were referred for a first-ever VT ablation procedure between June 2015 and June 2021 (males: 93%; mean age: 61±12 years). The mean left ventricular ejection fraction (LVEF) was 35±12% and 70% of pts had NYHA class I or II.

During a mean follow-up of 29 ± 19 months, VT recurrences requiring ICD shocks occurred in 25.9% of pts. VT ablation success and the risk of ICD shocks were not associated with any of the clinical characteristics. Long-term all-cause mortality was 37%. In univariate analysis, LVEF <30%, NT-proBNP, NYHA classification III-IV, chronic kidney disease (CKD), ICD for secondary prevention and prior VT ablation (p=0.08) were associated with reduced survival. On multivariate analysis, CKD was identified as the strongest independent survival predictor (HR 6.9; CI95%: 1.5-23-2, p=0.010)

Conclusions

In pts with NIDM, VT ablation may be successful even in pts with advanced heart disease. However, long-term survival will depend mostly on the stage of disease progression and is strongly associated with the clinical markers of end-stage heart failure. Therefore, a timely referral is crucial to derive the best clinical benefit from VT ablation in this population.

Additional features in Brugada Syndrome stratification: frequent PVC and QRS duration

Funding Acknowledgements

Type of funding sources: None.

Introduction

Brugada syndrome (BrS) is a channelopathy with high prevalence of malignant arrhythmic events. The risk stratification in patients (pts) with Brugada electrocardiographic (ECG) pattern is of major importance, to prevent sudden cardiac death (SCD). A higher risk is evidenced in spontaneous type 1 pattern when compared with induced type-1 pattern, as so other electrocardiographic features have been explored aiming to detect additional prognostic factors.

Purpose

To evaluate the association of QRS duration and frequent premature ventricular contractions (PVC) with malignant arrhythmic events.

Methods

Prospective single-center study of consecutive pts with BrS, with spontaneous or induced type 1 pattern included from 2003 to 2021. All pts were enrolled in a protocol including annual non-invasive assessment with ECG and 24-hours Holter monitoring. Primary endpoints were defined as SCD or appropriate shocks in the context of ventricular tachycardia or fibrillation (VT/FV) during follow-up. Cox regression and Kaplan-Meier survival analyses were used to determine the association between the baseline ECG and Holter characteristics and the long-term risk of arrhythmic events.

Results

A total of 117 pts was included, 75 (65%) with a spontaneous type 1 pattern and 44 (33%) with an induced type 1 pattern. The mean age was 47±13years and 38 (32.5%) were male.

During a median follow-up of 4.1±0.3 years, the primary endpoint occurred in 8 (6.8%) pts, with sudden cardiac death in 3 (2.6%) and appropriate shocks due to VT/FV in 5 (4.3%). Pts who suffered arrhythmic events had presented at the study inclusion higher QRS duration (124±18 vs. 108±16ms, p= 0.014) and more frequent PVCs on 24-hour Holter (169±297 vs. 29±198; p = 0.001) - Figure 1. Indeed, the presence of QRS ≥119ms was associated with a 7-fold higher risk (HR: 7.250, 95% CI 1.619-32.461, p = 0.010) and the presence of more than 6 PVC on 24-hour Holter was also associated with a 5-fold higher risk of malignant arrhythmic events (HR 5.376, 95% 1.186-24.260, p = 0.029).

Conclusion

QRS duration and frequent PVC may established themselves as additional risk factors. In our cohort, they were both predictors of arrhythmic events during follow-up and thus can further complement BrS risk stratification.

Apical versus septal pacing - can we chose the localization of ventricular lead in order to prevent upgrade to cardiac resynchronization therapy?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Right ventricular apical pacing (RVAp) may be deleterious to ventricular function and hemodynamics due to pacing induced dyssynchrony. In the last decades, some studies showed that RVAp has been associated with heart failure, deterioration of left ventricular function and high mortality. Some patients (pts) may need, during the follow up (FUP), an upgrade to cardiac resynchronizaon therapy (CRT). New techniques have emerged such as RV lead implantation in the high septum or outflow RV tract (RVOT) and, more recently, His bundle/LB pacing.

Purpose

To compare the need for upgrade to CRT in patients with RVAp versus septal/RVOT pacing.

Methods

Retrospective single-center study of consecutive pts that implanted pacemakers in a tertiary center between January 1995 and December 2020. We collected data regarding pacing indication, RV pacing site (apex versus septum/RVOT) and need for an upgrade to CRT during follow up (FUP).

Our primary endpoint was upgrade to CRT during the FU period. In the model, the impact of localization of the implanted lead on the survival free from upgrade was estimated assuming a neutral effect on mortality. Statistical analysis was performed using T-student test and logistic regression.

Results

We included 8761 pts, 60.2% (n=5275) were male, with a mean age of 76.5±10.7 years. The main indications for pacemaker implantation were (1) complete atrioventricular (AV) block (2239, 25.6%), (2) sick sinus syndrome (2211, 25.2%), (3) atrial fibrillation with AV block or bradycardia with significant pauses (17.4%) and (4) Mobitz II 2nd degree AV block (1467, 16.7%).

RVAp was performed in 1746 (20%) patients and RVOT/septal pacing in 6933 patients (80%; RVOT in 657 (9,5%)). During FUP, 26 (1,5%) RVAp pts and 52 (0,8%) RVOT/septal pacing pts underwent upgrade to CRT, in a total of 78 pts (CRT-P in 54 patients and CRT-D in 24 patients).

We observed that patients with RVAp had twice the risk of CRT upgrade during FUP (OR: 2,0 (IC 95% 1,25-3,21), p=0,004) when compared to patients with RVOT/septal pacing.

Conclusions

Patients with RVAp presented a 2-fold higher risk for upgrade to CRT when compared to patients with RVOT/septal pacing in our center. This retrospective analysis shows that lead implantation in the septum/RVOT should be preferred instead of the apex to reduce pacing induced dyssynchrony and need for CRT upgrade.

Is it possible to predict mortality and recurrence of VT afterablation? PAINESD risk score applicability vs new predictors

Funding Acknowledgements

Type of funding sources: None.

Introduction

Catheter ablation (CA) prevents ventricular tachycardia (VT) recurrences in patients (pts) with structural heart disease (SHD), and might have a favorable outcome, but is associated with severe short-term complications. Identification of pts at high risk of periprocedural acute haemodynamic decompensation has important implications at procedural planning.

The PAINESD risk score is a promising tool to predict VT ablation procedure-related mortality.

Aim

To evaluate the accuracy of the PAINESD risk score to predict short-term mortality after structural VT ablation and to compare it with other conventional clinical predictors.

Methods

Prospective, observational, single-centre study of consecutive pts with SHD (ischemic or nonischemic), referred for VT-CA. High-density substrate maps were collected, through endocardial, epicardial or combined endo-epicardial approaches according to clinical data and operator preference. The primary endpoint was 30-day mortality or hemodynamic decompensation. Univariate Cox regression analysis was used to identify relevant clinical predictors and to compare them with the PAINESD risk score. Multivariable Cox proportional hazards regression models were used to estimate predictors of 30-day mortality.

Results

A total of 102 pts with SHD referred for VT ablation were evaluated(mean age: 67±11 years, 94% male, 78.4% in NYHA class I-II; mean LVEF was 34±11%). The baseline PAINESD risk score was 12.39±5.8, 19.6% at low risk, 36.3% at intermediate risk and 27.5% at high risk of adverse events. Overall 30-day mortality was 4.9%. The PAINESD did not predict 30-days mortality or hemodynamic decompensation (p= 0.93). Indeed, a non- significant trend to higher short and long-term mortality was noticed in high-risk score pts – Figure 1. On univariate analysis age>65 years (p=0.019), LVEF <35% (p=0.049), body mass index<28kg/m2 (p=0.019), CKD (p=0.001) and previous VT ablation (p=0.022) were prognostic predictors. On multivariate analysis, only LVEF<35% (HR2.225; CI95% 1.004-4-774,p=0.038) and CKD (HR 3.35; CI95%: 1.31-8.51, p=0.011) were independent predictors of short-term prognosis.

Conclusions

In our population, LVEF<35% and CKD were the strongest predictors of short-term mortality. PAINESD risk score was not accurate in predicting adverse events. New score systems must be derived for prognostic stratification in this population, incorporating the reduction on the actual short-term event rates after VT ablation.

Predictors of survival in patients submitted to typical atrial flutter ablation

Introduction

Cavo-tricuspid isthmus ablation (CTA) is the first line procedure in patients with typical atrial flutter (AFL) for adequate rhythm and symptoms control with low complication rates and excellent results. Given its apparent simplicity, rarely do we take clinical factors in account before referral.

Aim

To identify predictors of survival after typical AFL ablation.

Methods

Single-center retrospective study of pts with typical AFL submitted to ablation between 2015 and 2019. Pts clinical characteristics were collected. Statistical analysis was performed using Cox regression (for multivariate analysis), Chi-square and Mann-Whitney (for univariate analysis) to identify predictors of survival.

Results

A total of 476 pts (66±12 years, 80% males) underwent CTA. Regarding global clinical characteristics, median body mass index (BMI) 27.3 (IQ 24.5–30.4), median CHA2DS2-VASc score 2 (IQ 1–3), 27.3% with diabetes, 53.9% with dyslipidemia, 69.5% with hypertension, 12% with current tobacco abuse, thyroid disfunction in 10.9%, ischaemic cardiomyopathy in 13.7%, heart failure in 27.8% (3.6% of pts with reduced ejection fraction), chronic kidney disease (CKD) stage 3 or more in 17.7%, obstructive sleep apnea (OSA) in 11.9% and chronic obstructive pulmonary disease (COPD) in 9.5% of pts. Before CTA ablation, 444 pts were under anticoagulation, which was stopped in 293 pts after the procedure. The follow up period was 2.8 years.

In this population, COPD (p=0.005), CKD (p<0.001), heart failure (p=0.0027) and BMI less than 25 (p=0.02) were associated with reduced survival on univariate analysis; patients with BMI between 25 and 30 had better prognosis. On multivariate analysis, CKD was the only independent predictor of reduced survival (HR 0.366; CI95%: 0.132–0.737, p=0.005). There was no difference between genders (p=NS).

A CHA2DS2-VASc score of ≥4 predicted higher mortality (HR: 3.0) in all three groups, although the anti-coagulation suspension had no impact on survival (p=NS).

Conclusion

In this subset of patients, the presence of COPD, heart failure, BMI less than 25 and CHA2DS2-VASc score ≥4 predicted reduced survival, being CKD stage 3 or more an independent predictor. The suspension of anti-coagulation didn't impact on survival. These results can help us to better select pts to the procedure and decide on whether to stop anti-coagulation, although larger studies are still needed.

Funding Acknowledgement

Type of funding sources: None. BMI impact on survivalCKD impact on survival

Cryoablation: safety of same day discharge

Introduction

Discharge after overnight hospital stay is standard procedure in patients submitted to elective atrial fibrillation (AF) ablation. Taking into consideration the low rate of cryoablation procedure complications could the same day discharge be an option?

Purpose

To assess the safety of same day discharge of patients submitted to AF cryoablation.

Methods

Single-center retrospective study of consecutive patients admitted to elective AF cryoablation in a tertiary center between February 2017 and November 2020. Patients were divided into two groups: same day discharge and next day discharge. Only patients submitted to ablation until 4 p.m. were included. Complication rates were obtained up to six months after the procedure. Complications were defined as death, pericardial tamponade, hematoma requiring evaluation and/or intervention, major bleeding requiring transfusion, hospital admission related to the procedure.

Results

One hundred fifty-four patients were included, with a mean age of 61±10.9 years, 66.2% were males, 18.2% with diabetes, 65.6% with dyslipidemia, 77.9% with hypertension, 10.4% with chronic kidney disease KDIGO stage 3 or more. Median follow-up of 436 [178 – 729] days. Most of the patients had paroxysmal (73.4%) and persistent short duration AF (23.4%). Sixty-two patients (40.3%) were early discharged and there were no differences between the two groups regarding epidemiological and clinical characteristics (p=NS).

A very low rate of complications in both groups was observed, occurring in 6.5% of patients with early discharge and in 8.7% of patients in overnight stay, without statistical significance between the two groups (p=0.61). The most frequent complications were local hematoma (5 patients, 2 in early discharged group), pericardial effusion (3 patients, all in overnight stay), femoral pseudo-aneurism (2 patients, 1 in each group) and arteriovenous fistula (1 patient in overnight stay group). The type of complications did not differ between the two groups (p=0.51). Two patients died during follow up, and this was unrelated to the procedure. In addition, no difference in success rate and arrhythmic recurrence was observed between the two groups (p=NS).

Conclusion

Our study suggests that it is safe to early discharge patients submitted to AF ablation, reducing the hospital stay length in selected patients. Larger studies are needed to confirm this data before routine implementation of this strategy.

Funding Acknowledgement

Type of funding sources: None.

It is possible to predict mortality after ICD implantation?

Introduction

Implantable Cardioverter Defibrillators (ICD) therapy is not recommended in patients who do not have a reasonable expectation of survival for at least 1 year, although specific recommendations regarding clinical or functional status evaluation are lacking.

Purpose

To identify predictors of all-cause mortality in patients who implanted an ICD.

Methods

Prospective single-center study of patients who implanted ICD between 2015 and 2019. Clinical characteristics were evaluated at baseline and mortality was assessed using the national registry of citizens. We performed uni and multivariate analysis to compare clinical characteristics of patients who died and who survived using Cox regression and Kaplan-Meier methods. For the predictor creatinine, we assessed the discrimination power and the best cut-off using the area under the ROC curve (AUC) method.

Results

From 2015–2019, 414 ICDs were implanted (81% male, 62±12 years-old), and 50 (13%) of the patients died after a median follow-up of 23 [11–41] months. Patients who died during the follow-up were older (67±9 vs 61±12, p=0.002), had more diabetes (48% vs 33%, p=0.033) and a higher creatinine (1.23 [0.84–1.86] vs 1.00 [0.84–1.22], p<0.001). The remaining comorbidities were similar between groups (Fig. 1). Patients who died had more frequently an ICD implanted after complication associated with a previous device or as a pacemaker upgrade (6% vs 2%, p=0.030). They also had a higher frequency of ischaemic cardiomyopathy (i-CMP) (82% vs 56%, p=0.002) and of ejection fraction (EF) ≤50% (96% vs 82%, p=0.040). The best cut-off value of creatinine to predict mortality with a sensitivity of 65% and a specificity of 72% was 1.2mg/dl (AUC 0.650; CI95% 0.53–0.77). After adjusting for diabetes, i-CMP, EF ≤50% and upgrade/re-implantation after complication, we found that age (HR 1.033; 95% CI 1.00–1.06, p=0.041) and creatinine ≥1.2mg/dl (HR 2.134; 95% CI 1.09–4.19, p=0.028) were independent predictors of all-cause mortality.

Conclusion

In our cohort of patients who underwent ICD implantation for primary or secondary sudden cardiac death prevention, the all-cause mortality over a median follow-up period of 23 [11–41] months was 13%. We found that in addition to age, a baseline creatinine level ≥1.2mg/dl increases by 2-fold mortality in patients who undergo ICD implantation. Decisions regarding ICD candidacy should not be based on age alone but should also consider creatinine that predisposes to mortality despite ICD implantation.

Funding Acknowledgement

Type of funding sources: None. All cause mortality

Risk stratification in patients with Brugada syndrome: the role of the late potentials evaluated by signal-averaged ECG

Introduction

Brugada syndrome (BS) is a relevant cause of sudden death in individuals without structural heart disease. The accuracy of the available methods for risk stratification is very limited and the investigation of new methodologies to improve the identification of patients at risk is under intensive investigation. Recently the pathophysiological relevance of anomalous, fragmented and prolonged electrograms on the epicardial surface of the right ventricular outflow tract (RVOT) has been described. Therefore, the study of signal-averaged ECG (SA-ECG) has become attractive since it may allow the non-invasive evaluation of these electrical anomalies. In order to maximize the detection capacity and to focus the evaluation in the RVOT, we developed an alternative methodology of electrode positioning directed to this area of interest.

Purpose

To characterize the study of late potentials (LP) by SA-ECG in patients with SB and to evaluate its association with the occurrence of arrhythmia events.

Methods

Prospective single centre study of patients (pts) with BS. LP were evaluated by SA-ECG with determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40) and duration of the low amplitude electric potential component (40 microV) of the terminal portion of the QRS (LAS40) in conventional and modified leads (addressed to RVOT). The association of LP with the risk of definite malignant dysrhythmias due to sudden death, ventricular fibrillation, ventricular tachycardia or appropriate shock of the implantable cardioverter defibrillator (ICD) was evaluated and the acuity of the prognostic stratification was determined by the area under the receiver operator characteristic curve (ROC).

Results

A total of 76 pts (69.7% men, age 48±12 years) were studied, of which 33 had a spontaneous type 1 pattern and 43 had a type 1 pattern induced by flecainide. During a median follow-up of 1.6 years, 13 pts (17.1%) had symptoms potentially related to BS and 6 (10.5%) had malignant arrhythmias [including two pts who suffered sudden death (2.6%).

The pts who had malignant dysrhythmias presented higher values of fQRS (125±23 vs. 108±18, p=0.046) and LAS40 (54±13 vs. 40±11, p=0.014), and lower values of RMS40 only in the modified leads (11±5 vs. 22±19, p=0.041). The parameters of the SA-ECG were significant prognostic predictors.

The acuity of each of the parameteres alone was moderate and the parameters that were identified as more powerful predictors of risk were those derived from the modified leads (Figure).

Conclusion

The LP evaluated by SA-ECG may be relevant in the prognostic stratification of patients with BS, since it seems to be associated with the risk of malignant ventricular arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

Is balloon cryoablation effective in common pulmonary trunk?

Introduction

Common pulmonary trunk (CPT) accounts for the most frequent pulmonary vein anatomical variation. The most frequent technique used for pulmonary vein isolation (PVI) is point-by-point radiofrequency, using cryoablation (CB) is still debatable. Some few studies have shown the feasibility and safety of CB in CPT atrial fibrillation (AF) patients (pts), most of them performed angio-CT prior to ablation.

Purpose

To analyzed AF pts with and without CPT submitted to CB in regarding of success rate and safety.

Methods

Single-center retrospective study of consecutive AF pts refractory to antiarrhythmics submitted to CB between 2017 and 2020. Before the procedure auriculography was performed in all pts to verify variations in pulmonary veins, however the procedure was not modify regarding the presence of CPT. Clinical records were analyzed to determine baseline characteristics, success rate and complications. Monitoring was performed with a 7-day event loop recorder at 3, 6 and 12 months and annually from the 2nd year. Success was defined by recurrence of AF (duration >30 seconds). Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using Chi-square and Mann-Whitney analysis.

Results

A total of 232 pts (60±12 years, 68% males) underwent CB. 29 pts had CPT (28 – common left pulmonary trunk and 2 – common right pulmonary trunk). Baseline characteristics were similar between groups, except for CHA2DS2VASc score and prior cerebrovascular disease history which were higher in CPT pts (3±2 vs 2±2, p=0.001; 24.1% vs 6.8%, p=0.007, respectively). The mean baseline CHA2DS2VASc was 2±2 and the median post-CB follow-up was 135 (IQ 32–249) days.

Both the 1 and 3 year arrhythmic recurrence after AF ablation was not significantly different when comparing CPT and non CPT group with a 3 year success rate of 95.8% in pts with CPV against 86.5% in pts without CPT (p=0.299).

There was no difference between groups (p=0.296; p=0,164, respectively) regarding the time of the procedure, radiation dose and rate of complications.

Conclusions

In our experience, balloon cryoablation for PVI is a safe and successful procedure in patients with CPT anatomical variation.

Funding Acknowledgement

Type of funding sources: None.

Long-Term outcome of ventricular tachycardia catheter ablation in ischemic heart disease patients using a high-density mapping substrate-based approach: a prospective cohort study

Funding Acknowledgements

Type of funding sources: None.

Introduction and objective

Radiofrequency catheter ablation (RCA) for ventricular tachycardia (VT) in patients with ischemic heart disease (IHD) is associated with a reduced risk of VT storm and implantable cardioverter defibrillator (ICD) shocks. We aim to report the long-term outcome after a single RCA procedure for VT in patients with IHD using a high-density substrate-based approach.

Methods

We conducted a prospective, observational, single-centre and single-arm study involving patients with IHD, referred for RCA procedure for VT using high-density mapping catheters. Substrate mapping was performed in all patients. Procedural endpoints were VT noninducibility and local abnormal ventricular activities (LAVAs) elimination. The primary end point was survival free from appropriate ICD shocks and secondary end points included VT storm and all-cause mortality.

Results

Sixty-four consecutive patients were included (68 ± 9 years, 95% male, mean ejection fraction 33 ± 11% , 39% VT storms, and 69% appropriate ICD shocks). LAVAs were identified in all patients and VT inducibility was found in 83%. LAVAs elimination and noninducibility were achieved in 93.8% and 60%, respectively. After a mean follow-up of 25 ± 18 months, 90% and 85% of patients are free from appropriate ICD shocks at 1 and 2 years, respectively. The proportion of patients experiencing VT storm decreased from 39% to 1.6%. Overall survival was 89% and 84% at 1 and 2 years, respectively.

Conclusions

RCA of VT in IHD using a high-density mapping substrate-based approach resulted in a long-term steady freedom of ICD shocks and VT storm. Abstract Figure. Appropriate shock & all cause mortality

Catheter ablation of long-standing persistent atrial fibrillation: the ugly type of AF?

Funding Acknowledgements

Type of funding sources: None.

Introduction

In atrial fibrillation (AF) patients (pts), catheter ablation (CA) by isolating pulmonary veins (PVI) is the most effective therapeutic option in order to maintain sinus rhythm. The success rate of CA relies on type and duration of AF, being more successful in pts with paroxysmal AF and presenting suboptimal success in pts with long-standing persistent AF (LSPAF, >12 months).

Purpose

To evaluate the success of AF ablation, particularly in LSPAF.

Methods

Single-center prospective study of pts submitted to CA between 2004 and 2020. The strategy, regardless of the type of AF, was based on PVI, complemented by cavo-tricuspid isthmus line (CTI) in pts with history of flutter. Additional CA strategies were selectively considered in pts with stable atypical flutter conversion, persistent triggers or no electrograms in the VPs. Pts were monitored with Holter/7-day event loop recorder (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (> 30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation as a function of the clinical type of AF.

Results

862 pts were submitted to AF ablation (67.3% male, mean age of 58 ± 0.41 years), including 130 pts (15.1%) with LSPAF, 63.3% with paroxysmal AF and 21.6% with short-duration persistent AF (SDPAF). In LSPAF, PVI was performed with irrigated catheter in 26.4%, PVAC in 39.5% and cryoablation in 34.1%. With a mean follow up period of 838 (IQ 159-1469) days, the 3-year success rate after a single procedure was 54.1% in LSPAF, compared to 72.4% in paroxysmal AF and 61.6% in SDPAF (LogRank - p < 0.0001 - figure 1). The risk of arrhythmic recurrence was 37% higher in patients with LSPAF comparing with other groups (HR 0.63 CI 95% 0.43-0.92, p 0.016).

However after a mean of 1.17 procedures/patients, the success difference between groups was not detect (LogRank – p = 0.112 – figure 2). With additional ablation procedures (REDO), the success rate at 3 years was 82.9% LSPAF pts, compared 88.2% in paroxysmal AF pts and 83.6% in SDPAF pts.

In LSPAF pts, different ablation techniques did not predict arrhythmic recurrence. Regarding comorbidities, higher prevalence of peripheral arterial disease (PAD, p = 0.005) a higher NT-proBNP (p = 0.006) and left auricular volume (p = 0.045) were associated with arrhythmic relapse.

Conclusions

AF ablation is more effective when performed earlier in the natural history of the disease. However, even in LSPAF pts, with additional procedures an acceptable rate of success can be achieve, independently from the ablation techniques. Abstract Figures 1 and 2: Success of AF ablation

Can we use the CHA2DS2VASc score in Atrial Flutter?

Funding Acknowledgements

Type of funding sources: None.

Introduction

CHA2DS2VASc score is a well stablished prognostic score in atrial fibrillation population. However, considering patients with isolated atrial flutter no prognostic score are defined, regarding the embolic risk of this population.

Purpose

To evaluate the capacity of CHA2DS2VASc score to predict cardiovascular death and major adverse cardiovascular events (MACE) in flutter patients (pts).

Methods

Single-center retrospective study of pts submitted to CTA between 2015 and 2019, comprising two groups: I – pts with lone AFL; II – patients with AFL and prior AF. Clinical records were analyzed to determine the occurrence of MACE during the long-term follow up, defined as death (of cardiovascular or unknown cause), stroke, clinically relevant bleed or hospitalization due to heart failure or arrhythmic events. CHA2DS2VASc score was categorized into 3 groups: 0-1; 2-3; >4. Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using uni- and multivariate Cox regression analyses.

Results

A total of 476 pts (66 ± 12 years, 80% males) underwent CTA: group I – 284 pts (60%), II – 192 pts (40%). Baseline characteristics were similar between groups, except for age with group I pts being older (68 ± 12, 64 ± 11, p < 0.01). The mean baseline CHA2DS2VASc was 2.3 ± 1.5 and the median post-CTA follow-up was 2.8 year. Considering global population, CHA2DS2VASc score was an independent predictor of cardiovascular death (OR: 1.49 95%CI 1.09-1.79, p = 0.08) and was a predictor of MACE even after adjustment for the diagnose of prior AF (OR 1.88, 95% IC 1.094-3.249, p = 0.022). Considering only the pts in group I CHA2DS2VASc score was a predictor of MACE (OR 3.03, 95% CI 1.112-8.278, p = 0.03) after adjustment for sex and age. Regarding the different MACE components, the score was a predictor of stroke (OR 4.45, IC 1.66-13.39, p = 0.04). In flutter pts CHA2DS2VASc score did not predict cardiovascular death.

Conclusions

 In our population CHA2DS2VASc score was able to predict MACE events and stroke in patients with isolated atrial flutter. This suggests that in the future CHA2DS2VASc score could be applied to establish embolic risk in atrial flutter. Abstract Figure.

The pacemaker ventricular lead position and outcomes in patients upgrading to crt

Funding Acknowledgements

Type of funding sources: None.

Introduction

 

Adverse hemodynamic effects of right ventricular pacing are known, and the optimal right ventricular lead position is still being a matter of debate. According to the guidelines, upgrade to cardiac resynchronization therapy (CRT) is recommended in patients with indication for pacemaker and left ventricular ejection fraction less than 50% or who need more than 40% of ventricular pacing.

Purpose

 

To compare clinical outcomes and ejection fraction in patients with previous pacemaker (apical versus septal right ventricular pacing) who are upgrated to CRT. 

Methods

 

Single-center retrospective study of 94 consecutive patients who had previous pacemaker and upgraded to CRT over a 4-year period. Of these patients, 64 had previous apical lead pacemaker and 30 had previous septal lead pacemaker. Data on comorbidities, New York Heart Association (NYHA), left ventricular ejection fraction and hospitalizations due to heart failure were collected.

The results were obtained using Chi-square, Mann-Whitney and t-test.

Results

Patients with septal pacemaker had significantly more diabetes (p = 0.04) and chronic obstructive pulmonary disease (p = 0.01), tended to be more symptomatic (p = 0.198) and had more days of hospitalization before and after pacemaker implantation (12 ± 3 versus 7 ± 2 days and 8 ± 4 versus 3 ± 1 days, respectively), mostly due heart failure decompensation. 

Although there were no significant differences in the initial ejection fraction in patients with apical or septal pacemaker implantation (31.2 ± 1.2% and 29.1 ± 1.5%, respectively, p = 0.323), the time to upgrade to CRT was significantly shorter in patients with septal pacemaker implantation (1999 ± 227 days versus 3005 ± 279 days, p = 0.005). 

After upgrading to CRT, patients with apical lead had a significant increase in ejection fraction (8.2%, p = 0.011), while patients with septal lead had a non-significant improvement of ejection fraction (4.5%, p = 0.448). In both, apical and septal lead patients, there was a significant improvement in NYHA class after upgrade to CRT (p = 0.03 and p = 0.02, respectively).

Conclusion

 

Although patients with septal lead had more comorbidities and hospitalizations due to heart failure, they do not benefit from the upgrade to CRT, unlike what happens in patients with apical lead. These findings can be explained by the fact that the septal lead minimizes ventricular desynchrony induced by right ventricular pacing.

Long-term risk of major cardiovascular events after cavotricuspid isthmus ablation: when and in whom to discontinue oral anticoagulation?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cavotricuspid isthmus ablation (CTA) is the 1st line therapy to accomplish rhythm control in typical atrial flutter (AFL). Several studies have shown that AFL is frequently associated with AF, which may be silent, posing the patient at risk of systemic embolism. Nowadays, there are no formal recommendations for OAC after CTA in patients with isolated AFL.

Aim

To determine the risk of MACE after CTA and compare: 1) the presence of concomitant AF, 2) concomitantly performing PVI and 3) persistence on OAC.

Methods

Single-center retrospective study of  pts submitted to CTA between 2015 and 2019, comprising 3 groups: I – pts with lone AFL; II – patients with AFL and prior AF submitted to CTA only; and III – patients with AFL and prior AF submitted to PVI and CTA. Clinical records were analyzed to determine the occurrence of MACE - death (of CV or unknown cause), stroke, clinically relevant bleed or hospitalization due to HF or arrhythmic events. Long-term OAC was defined as its persistence over 18 months after CTA. Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using uni- and multivariate Cox regression analyses.

Results

A total of 476 pts (66 ± 12 years, 80% males) underwent CTA: group I – 284 pts (60%), II – 109 pts (23%) and III – 83 pts (17%). Baseline characteristics were similar between groups, except for age with group I pts being older (68 ± 12, 67 ± 11, 61 ± 11, p < 0.03). The mean baseline CHA2DS2VASc was 2.3 ± 1.5 and the median post-CTA follow-up was 2.8 year. The 1-, 3- and 5-years MACE risk was 7%, 21% and 32%, respectively and did not differ significantly between groups. OAC was suspended on the long-term in 105 pts (23%), at a mean of 241 days post-CTA. Suspension of OAC was significantly associated with lower MACE risk (HR: 0.26, 95%CI 0.12-0.56, p = 0.001). This effect was independent of the age and CHA2DS2VASc. The prognostic benefit of OAC suspension was driven by the group I and was not verified in patients with concomitant AF. In group I, withdraw of OAC (56 pts - 27%) was associated with a 70% relative risk reduction in the 5-year MACE risk (16% vs 43%, HR: 0.30, 95%CI 0.13-0.69, p = 0.005). In group I, OAC was suspended in patient who were younger (65 ± 11 vs. 69 ± 12, p = 0.002), had lower CHA2DS2VASc (1.9 ± 1.6 vs. 2.7 ± 1.4, p < 0.001) and less often had cerebral vascular disease (1% vs. 8%, p = 0.036), HF (14% vs. 38%, p = 0.001), ischemic cardiomyopathy (9% vs. 19%, p = 0.04) and HTN(61% vs. 75%, p = 0.019).

Conclusions

In pts with AFL submitted to CTA, the long-term risk of MACE is frighteningly high, even in the ones without prior documentation of concomitant AF. Pts with prior AF presenting at the electrophysiological procedure in typical AFL and submitted just to CTA were not significantly harmed, from a prognostic perspective. In pts with lone AFL submitted to successful CTA, it may be reasonable to suspend OAC within 18 months provided that the concomitant AF is carefully excluded. Abstract Figure.

Early discharge after cryoablation procedure: is it safe?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Discharge after overnight hospital stay is standard procedure in patients submitted to elective atrial fibrillation (AF) ablation. Taking into consideration the low rate of cryoablation procedure complications could the same day discharge be an option?

Purpose

To access the safety of same day discharge of patients submitted to AF cryoablation.

Methods

Single-center retrospective study of consecutive pts admitted to elective AF cryoablation in a tertiary center between February 2017 and November 2020. Patients were divided into two groups: same day discharge and next day discharge. Only patients submitted to ablation until 4 p.m. were included. Complication rates were obtained up to six months after the procedure. Complications were defined as death, pericardial tamponade, hematoma requiring evaluation and/or intervention, major bleeding requiring transfusion, hospital admission related to the procedure.

Results

One hundred fifty-four pts were included, with a mean age of 61 ± 10.9 years, 66.2% were males, 18.2% with diabetes, 65.6% with dyslipidemia, 77.9% with hypertension, 10.4% with chronic kidney disease KDIGO stage 3 or more. Median follow-up of 436 (IQ 178 – 729) days. Most of the pts had paroxysmal (73.4%) and persistent short duration AF (23.4%). Sixty-two pts (40.3%) were early discharged and there were no differences between the two groups regarding epidemiological and clinical characteristics (p = NS).

A very low rate of complications in both groups was observed, occurring in 6.5% of pts with early discharge and in 8.7% of pts in overnight stay, without statistical significance between the two groups (p = 0.61). The most frequent complications were local hematoma (5 pts, 2 in early discharged group), pericardial effusion (3 pts, all in overnight stay), femoral pseudo-aneurism (2 pts, 1 in each group) and arteriovenous fistula (1 pt in overnight stay group). The type of complications did not differ between the two groups (p = 0.51). Two pts died during the follow up, unrelated with the procedure.

In addition, no difference in success rate and arrhythmic recurrence was observed between the two groups. (p = NS)

Conclusion

Our study suggests that is safe to early discharge pts submitted to AF ablation, reducing the hospital stay length in selected pts. Larger studies are needed to confirm this data before routine implementation of this strategy.

Withdrawal of anti-arrhythmic therapy after cavo-tricuspid isthmus ablation of typical atrial flutter

Funding Acknowledgements

Type of funding sources: None.

Introduction

Medical management of typical atrial flutter (AFL) is sometimes unsuccessful and may have adverse effects. Symptom control using radiofrequency cavo-tricuspid isthmus ablation (CTA) is a feasible alternative, given the fact that it is a simple procedure with a low rate of complications. However, in some patients (pts), new atrial arrhythmias may develop and the decision of anti-arrhythmic therapy (AAT) withdrawal is usually patient-based.

Purpose

To predict the recurrence of atrial arrhythmias (AR) after CTI ablation between pts that suspended AAT and those that maintained AAT.

Methods

Single-center retrospective study of pts with typical AFL submitted to ablation between 2015 and 2019. Pts clinical characteristics, current and follow up therapy were collected. Holter and/or 7-day event loop recorder were performed during the follow up to identify AR. For statistical analysis, we applied Chi-square, Mann-Whitney and Cox regression to identify predictors of AR.

Results

CTA ablation was performed in 476 pts (mean age: 66.3 ± 11.7 years, 79.8% males). At time of ablation most pts were in EHRA II class (70.8%) and 44.6% of pts had at least mild left atrial dilatation on transthoracic echocardiography. The mean follow up time was 2.8 years.

Two-hundred sixty-nine pts (57,6%) were under anti-arrhythmic therapy (AAT) before the ablation. After the procedure, 58 pts withdrawn AAT before AR and 8 pts after AR. During the follow-up period, we observed AR of typical AFL in 17 pts (3.6%), atypical AFL in 35 pts (7.4%) and AF in 118 pts (24.8%).

There were no statistically significant differences regarding AR between pts that maintained and suspended AAT (p = NS). Concerning the pts that suspended AAT, thyroid disfunction (p = 0.012), higher CHADs-VASc score (p = 0.033), ischemic cardiomyopathy (p = 0.001) and tobacco abuse (p = 0.005) were predictors of AR, being the last two also independent predictors (HR 0.243; 95%CI 0.76-0.778, p = 0.017; HR 4.449; 95%CI 1.128-17.553, p = 0.033, respectively). 

Conclusion

After CTA ablation, AF is the most frequent recurrent arrhythmia. Interestingly, the withdrawn of AAT didn’t seem to predict the recurrence of arrhythmic events. The decision of stopping AAT must be individualized regarding patients’ clinical characteristics. Abstract Figure 1: AAT withdrawal and AR

P3808iBox-CRT: Better response, less complicated, equally fast

Introduction

The optimization of the left ventricle (LV) pacing site guided by the electrical delay increases CRT response rate (RR), however it's necessary to develop technology that allows its universal use.

Purpose

The aim is automatically, and operator-independent, access the conduction delay between the right ventricular (RV) stimulus and the LV available veins in order to select the LV pacing site. It is further intended to compare the total procedure and radiation times in relation to an historical control group.

Methods

Prospective, single-center study that included patients undergoing CRT implant according to the current ESC Guidelines. All patients were submitted to a clinical, electrocardiographic and echocardiographic basal evaluation prior to CRT implantation and at 6 months of follow-up.

To evaluate conduction delays between the RV lead and the LV available veins (RV-LV delay), an external interface - intelligent Box for CRT (iBox-CRT) was used. Four measurements in at least two different tributary veins were made. The implant of all the LV leads was guided by the longest measured delay.

A positive response to CRT was defined as an improvement of >10% in left ventricle ejection fraction (LVEF) or a reduction of end-systolic volume (ESV)>15%. The results were compared to a control group (CG) of pts submitted to CRT implantation in the conventional way.

Results

60 patients were included (68.3% males, 38% ischemic, mean age 67.4±10.2 years) and submitted to CRT implant (37 CRT-P; 23 CRT-D). At basal evaluation, LVEF was 28±7%, end-diastolic volume (EDV) was 200±73ml and ESV 145±64ml. CG (n=51) had similar characteristics.

The RR was 85.7%, significantly higher compared to the CG (55.9%, p=0.003). The ESV reduced 38.2±3% in responders vs 5.7±2% in non-responders (NR) (p=0,005), EDV reduced 33.3±16% in responders vs 13.6±10% in NR (p=0.002), the mean LVEF improved 11% in responders vs −1% in NR (p=0.02).

At follow-up, the mean ESV in the study group (SG) was 89±44 ml vs 132±75ml in the CG (p=0.002) and the EDV 136±51 vs 190±78 (p=0.007).

In addition to a much better response rate, the responders in the study group had significantly higher mean LVEF at follow-up (39±11% vs 37±7%, p=0.032).

The mean intra-procedure RV-LV delay was 187±34mseg. In the responder group the baseline delay was usually higher (190±35 msec) vs NR group RV-LV delay (165±23 msec; p=NS).

Compared with CG, the automatic assessment of RV-LV delay with iBox-CRT did not increase fluoroscopy time (15±16min vs 18±16; p=NS) and shortened procedure time (65±34 vs 108±83min, p<0.005).

Conclusions

The iBox-CRT use enabled an automatic and operator independent RV-LV delays measurement, in order to implant the LV lead at the most delayed site. This technique translated into a major increase in CTR response rate, not compromising the procedure duration nor increasing the radiation exposure.