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.

Epicardial mapping as first intention approach for structural ventricular tachycardia ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

In several structural arrhythmogenic diseases that comprise intricate endocardial, intramural and epicardial substrates, endocardial ablation of ventricular tachycardia (VT) is not sufficient and epicardial ablation has lately become a complementary and necessary tool.

Purpose

To evaluate the clinical characteristics of patients (pts) most suitable for first intention epicardial VT ablation.

Methods

Single-center prospective study of consecutive pts with structural heart disease undergoing first intention epicardial VT mapping between August 2015 and June 2021. Decision for epicardial approach was based on the etiology, VT electrocardiogram (ECG) and cardiac magnetic resonance (CMR) results. Under general anesthesia, subxiphoid access using a Tuhoy needle was done using fluoroscopic guidance and with high-density epicardial mapping was performed. Epicardial ablation was performed if relevant arrhythmogenic findings were locally confirmed.

Results

First intention epicardial VT ablation was attempted in 18 pts (mean age 59.8±12 years,94% male) of whom 16 had non-ischemic dilated cardiomyopathy (NICM,idiopathic:11; post-myocardis:4; hereditary:1) and 2 had right ventricular arrhythmogenic cardiomyopathy. Mean LVEF was 33% and 79% had a previous ICD (53% in primary prevenon). 69% were referred for ablation due to arrhythmic storm (1pt in cardiogenic shock). Epicardial access was achieved in 17 pts (94%), without acute complications. In 35% pts with NICM the decision for epicardial approach was based on the detection of subepicardial CMR delayed-hyperenhancement and relevant epicardial arrhythmic substrate was confirmed by mapping in all cases. In 3 pts radiofrequency (RF) applicaons were not performed at epicardium, as no abnormal electrograms were locally detected, and an addional endocardial approach was prosecuted. The mean overall procedure and fluoroscopic time were 123 and 28min, respectively, with a mean RF application me of 51min. After the procedure 1pt required pericardial drainage due to inflammatory pericardial effusion. No other acute complications occurred. During a mean follow-up of 2.8±1.8 years, only 3pts (17%) had VT recurrence; 5pts (28%) died due to end-stage heart failure and 2pts (11%) underwent heart transplantation.

Conclusion

In NICM a first intention epicardial VT ablation performed by experienced operators/centers is efficient, particularly if guided by CMR findings,and presents a safety profile.

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.

Upgrade pacemaker to CRT: predictors and the importance of LVEF

Funding Acknowledgements

Type of funding sources: None.

Introduction

Nowadays 10-15% of CRT implantaon is upgrading from paents (pts) with pacemaker (PMK) who develop reduced LVEF and worsening symptoms from HF. There are few retrospecve studies showing some predictors of pts with single or dual chamber PMK that may need upgrade to CRT, but it is not completely established which pts may benefit the most.

Purpose

To identify predictors at follow-up of upgrading pacemaker to CRT in a population with pacemaker implantation.

Methods

Single center case-control study of pts that performed upgrading to CRT-pacemaker (CRT-P) in our hospital. We excluded pts that performed upgrade to CRT-D. We compare to a PMK populaon matched to age at implantaon and cause of PMK implantaon. Demographic, clinic and electrocardiographic (ECG) data were considered at baseline. Echocardiographic evaluation was performed before pacemaker/CRT upgrading implantaon and at follow-up. Predictors of upgrading were evaluated by the Cox regression. Prognosc impact of LVEF was evaluated as upgrading to CRT-P by Kaplan-Meier curves.

Results

We included 71 pts that performed CRT-P upgrade (mean age 77±10; 49,6% male, mean LVEF before PMK 54.9±9.2%) and 71 pts with pacemaker implantaon (mean age 78 ± 11; 50,4% male; mean LVEF 60.9±7.2%). The clinical characteriscs, ECG and echocardiographic were similar between pacemaker and CRT-P-upgrade, except atrial fibrillaon being more prevalent in PMK group (57.5% vs 42.5% p=0.039). Mortality was not different duringfollow-up between the two groups. In univariate analysis, QRS duraon (PMK: 115ms vs upgrade CRT-P: 132 ms, p=0.038), LVEF (PMK: 60.9% vs upgrade CRT-P: 54.9%, p=0.002) and LV end-diastolic diameter (LVEDD) (PMK: 48.9.4 ± 6.6mm vs upgrade CRT-P: 56.4 ± 6.6mm, p=0.001), LV end-sistolic diameter (LVESD) (PMK: 29.5 ± 6.5mm vs upgrade CRT-P: 37.9 ± 9 mm, p=0.006) were associate to upgrading to CRT. In our population, the unique independent predictor was lower LVEF(Long Rank 6.108, p=0.013) – Figure 1. The best LVEF cut- off to predict upgradingto CRT was 55% (AUC 0.954, sensitivity 64%, specificity 84%) – Figure 2.

Conclusion

In our populaon of CRT upgrading pts, a broad QRS duraon, lower LVEF and a higher LVEDD and LVESD were associated to upgrade to CTR-P. We try to establish a new value for LVEF that could lead to upgradingto CRT-P, and maybe the classical cut-off of 50% should be reviewed.

P1457Does high density mapping increase the efficacy of ischemic ventricular tachycardia ablation?

Introduction

 The treatment of ventricular tachycardia (VT) in patients (pts) with ischemic heart disease (IHD) represents a challenge because of its high morbidity and mortality rates and low long-term success rates. In the VANISH clinical trial, 51% of pts undergoing the conventional ablation technique developed within 2 years the combined outcome of mortality or electrical storm (ES) or appropriate CDI shock. The use of high-density substrate maps can lead to greater precision in substrate evaluation and ideally to improved ablation success.

Objectives

 To assess the efficacy of substrate-guided ischemic VT ablation using high-density mapping.

Methods

 Single-center prospective study of consecutive IHD pts submitted to endocardial ablation of substrate-guided VT using multipolar catheters (PentaRayTM or HDGridTM) and three-dimensional mapping systems with automatic annotation software. The maps were evaluated in order to identify the intra-cicatricial channels (areas of bipolar voltage <1.5mV) in which sequential propagation of local abnormal ventricular activities (LAVAs) were observed, during or after QRS. The ablation strategy aimed at the abolition of all intra-cicatricial LAVAs, directing the radiofrequency applications primarily to the entrances of the channels. The success of ablation was assessed by the primary outcome (death by any cause or ES or appropriate CDI shock) at 2 years and compared to the population of the VANISH study undergoing conventional ablation, using Cox regression and Kaplan- Meier survival analysis.

Results

 We included 40 patients, 95% males, 70 ± 8 years, mean ejection fraction 34 ± 10%. 82% on previous amiodarone therapy and 72% were ICD carriers. 32% underwent ablation during hospitalization for ES and 20% had previously undergone VT ablation. The median duration of substrate mapping was 74 minutes, with a mean of 2290 collected points. Major complications were seen in 1 patient (aortic dissection). During a mean follow-up time of 17.3 ± 12.9 months, the long-term success rate of VT ablation was 75%. Additionally, there was a reduction in the proportion of patients receiving amiodarone before vs after ablation (82% vs. 45% respectively). The rate of events observed during follow-up was lower than expected, namely by comparison with the population of the VANISH study undergoing conventional ablation (25% vs 51% at 24 months, HR 0.42 CI 95% 0.2-0.88, p = 0.022), reflecting a relative risk reduction of 58%.

Conclusions

 High density mapping allows a detailed characterization of the dysrhythmic substrate in patients with VT in an IHD context. Our results suggest that these technological innovations may be improving the clinical success of VT ablation.

Abstract Figure.

864A modified snare technique improves left ventricular lead implant success and response rate to cardiac resynchronization therapy

Introduction

Left ventricular (LV) lead placement is often the most challenging aspect of cardiac resynchronization therapy (CRT) device implantation, with a failure rate up to 10% due to complex coronary anatomies.

Purpose

To evaluate the efficacy of a modified snare technique in the LV lead implantation in cases of standard technique failure and to evaluate its impact in the response rate to CRT.

Methods

A prospective study was conducted of patients indicated for a CRT implant. When LV lead delivery to the target vessel failed using standard techniques, a modified snare technique was implemented, using a secondary coronary sinus delivery sheath introduced through the same venous puncture.  Patients were evaluated every 6 months. Efficacy was quantified by long-term surgical intervention rates. Patients were evaluated with transthoracic echocardiography before CRT implant and between 6-12 months post-implant. Patients with ejection fraction (EF) elevation ≥ 10% or LV end-systolic volume (ESV) reduction ≥ 15% were classified as responders. Patients with EF elevation ≥ 20% or LV ESV reduction ≥ 30% were classified as super-responders. Time to surgical revision and mortality were evaluated by the Cox regression and Kaplan-Meier methods.

Results

From 2015-2019, 566 CRTs were implanted (26.1% female, 72 ± 10.2 years old, follow-up duration 18.9 ± 15.8 months). The standard LV implant technique failed in 94 cases (16.6%), of which the modified snare technique was successful in 92 (97.9%) with LV lead implant in a lateral vein in 94.7% of cases. Baseline clinical characteristics were similar between patients who implanted LV lead with snare vs standard technique (p = NS). The 4-year surgical intervention rate was lower with the modified snare implant technique than with the standard technique (3.2% vs. 10.2%, HR 0.26, 95% CI 0.08-0.84, p < 0.05), with a relative risk reduction of 74% and a number needed to treat to prevent one surgical intervention of 14. The intervention rate was also lower regarding LV lead implant failure or dislodgement rates (0% vs. 5.3%, p < 0.05). Major complications were similar between groups.

In addition, the response rate to CRT was higher in the modified snare technique than in the standard approach (71.1% vs 55.0%, p < 0.05). In patients who implanted the LV lead with the snare technique, EF increased from 28.1 ± 8.2% to 36.1 ± 11.1% (p < 0.05) and LV ESV decreased from 127.8 ± 64.0mL to 99.8 ± 61.1mL (p = 0.01).

The super-response rate was similar between groups (33.3% vs 27.8%, p = NS).

Conclusion

For challenging coronary sinus anatomies that preclude LV lead placement by standard methods, this modified snare alternative was effective, with significantly lower surgical intervention rates and a higher response rate to resynchronization therapy. This higher than expected response rate with the snare technique, evaluated by remodeling criteria, may be explained by the implant of LV lead in the desired target lateral vein.

Abstract Figure.

P578Multipoint pacing in cardiac resynchronization therapy - how to improve remodeling criteria and its impact in quality of life

Background

Despite the reduction in mortality and hospitalization rates, resynchronization therapy still has 30-40% of non-responders. Several studies are ongoing to evaluate if novel programming techniques such as multipoint pacing (MPP) increase the conversion rate of non-responder to responder to CRT. However, there is still lack of information about conversion to super-responders and the impact in quality of life of MPP.

Purpose

To evaluate the impact of MPP in conversion to super-responders and its impact in the quality of life of patients.

Methods

Randomized clinical trial of non-AF patients with indication for CRT and who implanted the Quartet™ quadripolar left ventricle (LV) lead. After implant, CRTs were programmed on biventricular pacing according to the latest activated area for 6 months. After a 6-month follow-up, patients were randomized in a 1:1 fashion to MPP ON or MPP OFF. MPP was programmed with the two widest spaced LV electrodes and with a LV1-LV2 to LV2-RV delay of 5ms. Patients were followed-up for 12 months with a 6-month evaluation of NTproBNP, echocardiographic remodeling criteria (LV end systolic volume (ESV) and LV ejection fraction), and quality of life (QoL) evaluated by EQ-5D, Minnesota Living with Heart Failure (MLWHF) questionnaire and 6-minute walk test (6MWT).

Results

 76 patients were included in this trial, 62 with a completed 12-month follow-up (average age 67.2 ± 10.2 years old, 32.3% female gender, dilated cardiomyopathy in 77.4%). Among these patients, 24 were randomized to MPP ON, 28 to MPP OFF. Six patients died and 4 were lost to follow-up. Baseline clinical and echocardiographic characteristics were similar between groups (p = NS).

At 6 months, the overall response rate (reduction in ESV≥15%) was 75%. At twelve months, patients randomized to MPP ON had a super-response rate (reduction in ESV≥30%) higher than patients with MPP OFF (75% vs 39.3%, p = 0.01).

Between 6-12 months, patients assigned to MPP ON had a higher reduction in ESV (93.4 ± 52.3mL to 82.1 ± 40.5mL, p = 0.04) and an improvement in LVEF (38.3 ± 9.8% to 45.1 ± 11.1%, p < 0.01) compared to patients with MPP OFF (92.2 ± 47.3mL to 95.4 ± 47.5mL, p = NS; 37.1 ± 12.0% to 40.2 ± 9.2%, p = NS). Additionally, QoL of patients with MPP ON improved during follow up (EQ-5D 78.3% to 86.3%, p < 0.01; MLWHF 12.1 to 6.6, p = 0.03, 6MWT 316m to 239m, p = NS; NTproBNP 1608 ± 2450pg/mL to 775 ± 914pg/mL, p = NS) and was unchanged in MPP OFF patients (76.6% to 74.2%; MLWHF 12.7 to 12.7; 6MWT 338m to 299m, NTproBNP 1112 ± 1442pg/mL to 1383 ± 2118pg/mL, for all p = NS).

Conclusion

In our population, patients with CRT programmed with MPP ON, when compared to MPP OFF, had an improvement in the super-response rate and in quality of life. These results may be consequence from a more favorable reverse remodeling due to MPP, with a higher reduction in the LV end systolic volume.

Abstract Figure.

P1402Isolation of pulmonary veins with duty-cycled circular multi-polar catheter: randomized controlled clinical trial

Introduction

Pulmonary vein isolation (PVI) is the central element in the ablation of atrial fibrillation (AF), and can be obtained with different ablation modalities. The duty-cycled circular multi-pole catheter PVAC® (Medtronic) allows linear application of radiofrequency energy, with the production of circumferential lesions. Conceptually, it can make ablation simpler and faster in patients with favorable anatomy.

Objectives

To evaluate the safety and efficacy of ablation with a PVAC® catheter and to compare it with the conventional technique point-by-point (PbP) with irrigated catheter.

Methods

Clinical trial with single-blinded patients with AF refractory to antiarrhythmic therapy, randomized (1: 1) for ablation with PVAC® or PbP. The ablation strategy consisted of PVI, complemented with ablation of the cavo-tricuspid isthmus in patients with history of concomitant flutter. 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 AF-free survival or any maintained supraventricular tachycardia (duration > 30seconds).

Results

354 patients (67.5% males, 58 ± 12 years, PbP: 175, PVAC: 179) were included, of which 59.1% had paroxysmal, 26.2% short-standing persistent and 14.7% had long-standing persistent AF. Baseline characteristics were similar between groups. Among patients treated with PVAC, 93.1% of the pulmonary veins were isolated (620/666), similar to the 98.3% immediate success of the PbP group (697/709). Although the complication rate was similar in both groups (PVAC: 4.9% vs. PbP: 7.8%; P = NS), the risk of hemopericardium was lower with PVAC (0% vs. 4.6%; P = 0.013). Two patients treated with PVAC developed stroke (1.13% vs. 0%; P = NS). The duration of the procedure was lower among the patients treated with PVAC [136 (100-180) vs. 230 (188-270) min; P <0.001], with no difference in fluoroscopy time [24.4 (14.5-36.8) vs. 27.1 (17.0-45.0) min]. The success rate after 1st ablation at 36 months was 68%, with no differences between groups. The success rate after multiple ablations increased to 85.8%, with no differences between groups.

Conclusion

The multipolar PVAC catheter can represent an added value in AF ablation, making the procedure simpler and faster, ensuring similar efficacy to the conventional technique and with a lower risk of cardiac tamponade. The present trial suggests the need for clinically manifested stroke risk surveillance, which may be increased with this technique.

Abstract Figure.

P983Long-standing persistent atrial fibrillation: what can we achieve with ablation?

Introduction

Atrial fibrillation (AF) ablation presents suboptimal results in patients (pts) with persistent long-lasting forms (LSPAF, AF ≥12 months). Recently, the STAR AF-II trial has shown that in these pts complex additional strategies do not improve success compared to only performing pulmonary vein isolation (PVI).

Objectives

To evaluate the success of AF ablation, particularly in long-standing persistent AF

Methods

Single-center prospective study of pts with AF submitted to ablation. 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 ablation 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 in our population and with pts included in STAR-II AF trial.

Results

620 patients were submitted to AF ablation, 67% male, 58±12 years, including 78 pts (13%) with LSPAF - pts with paroxysmal and persistent short duration AF represented 61% and 26% of the population. In LSPAF, VPI was performed with irrigated catheter (N=33), PVAC (N=44) or nMARQ (N=1), complemented by CTI ablation in 15, linear left atrial lesions in 3, ablation of areas of low voltage in 3 and elimination of fractionated electrograms in 1 patient.

With a median follow-up of 426 days (94–989), the 3-year success rate after a single procedure was 53% in LSPAF, lower than that observed in patients with paroxysmal AF (69%) or short-duration persistent AF (61%) - LogRank P=0.002. The risk of arrhythmias was double in LSPAF vs paroxysmal AF (HR: 2.0; P=0.001). However, after an average of 1.2 procedures/patient, the success rate in LSPAF was 80% at 3 years, comparable to that observed for other types of AF (Log Rank 2.5, p=0.29). Effectively, the long-term success rate of our LSPAF pts treated with PVI and very selective additional strategies was higher than that observed in the STAR-II AF pts treated with PVI and indiscriminate complex ablations (80% vs. 69%, t-test p<0.001, with similar mean follow-up).

Conclusions

AF ablation is more effective if it is performed earlier in the natural history of the disease. However, even in LSPAF, high success rates are achieved through PVI-based ablation strategies, although more procedures are required.