Predictor Of Ventricular Tachycardia Recurrence Research Articles

Acute post-procedural inducibility is a poor predictor of clinical outcomes in high-risk patients (PAINESD > 17) undergoing scar-related ventricular tachycardia ablation.

Ventricular tachycardia (VT) non-inducibility in response to programmed ventricular stimulation (PVS) is a widely used procedural endpoint for VT ablation despite inconclusive evidence with respect to clinical outcomes in high-risk patients. The aim is to determine the utility of acute post-ablation VT inducibility as a predictor of VT recurrence, mortality, or mortality equivalent in high-risk patients. We conducted a retrospective analysis of high-risk patients (defined as PAINESD > 17) who underwent scar-related VT ablation at our institution between July 2010 and July 2022. Patients' response to PVS (post-procedure) was categorized into three groups: Group A, no clinical VT or VT with cycle length > 240 ms inducible; Group B, only non-clinical VT with cycle length > 240 ms induced; and Group C, all other outcomes (including cases where no PVS was performed). The combined primary endpoint included death, durable left ventricular assist device placement, and cardiac transplant (Cox analysis). Ventricular tachycardia recurrence was considered a secondary endpoint (competing risk analysis). Of the 1677 VT ablation cases, 123 cases met the inclusion criteria for analysis. During a 19-month median follow-up time (interquartile range 4-43 months), 82 (66.7%) patients experienced the composite primary endpoint. There was no difference between Groups A and C with respect to the primary [hazard ratio (HR) = 1.21 (0.94-1.57), P = 0.145] or secondary [HR = 1.18 (0.91-1.54), P = 0.210] outcomes. These findings persisted after multivariate adjustments. The size of Group B (n = 13) did not permit meaningful statistical analysis. The results of post-ablation PVS do not significantly correlate with long-term outcomes in high-risk (PAINESD > 17) VT ablation patients.

Post-Ablation cardiac Magnetic resonance to assess Ventricular Tachycardia recurrence (PAM-VT study).

Conducting channels (CCs) detected by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related to ventricular tachycardia (VT). The aim of this work was to study the ability of post-ablation LGE-CMR to evaluate ablation lesions. This is a prospective study of consecutive patients referred for a scar-related VT ablation. LGE-CMR was performed 6-12 months prior to ablation and 3-6 months after ablation. Scar characteristics of pre- and post-ablation LGE-CMR were compared. During the study period (March 2019-April 2021), 61 consecutive patients underwent scar-related VT ablation after LGE-CMR. Overall, 12 patients were excluded (4 had poor-quality LGE-CMR, 2 died before post-ablation LGE-CMR, and 6 underwent post-ablation LGE-CMR 12 months after ablation). Finally, 49 patients (age: 65.5 ± 9.8 years, 97.9% male, left ventricular ejection fraction: 34.8 ± 10.4%, 87.7% ischaemic cardiomyopathy) were included. Post-ablation LGE-CMR showed a decrease in the number (3.34 ± 1.03 vs. 1.6 ± 0.2; P < 0.0001) and mass (8.45 ± 1.3 vs. 3.5 ± 0.6 g; P < 0.001) of CCs. Arrhythmogenic CCs disappeared in 74.4% of patients. Dark core was detected in 75.5% of patients, and its presence was not related to CC reduction (52.2 ± 7.4% vs. 40.8 ± 10.6%, P = 0.57). VT recurrence after one year follow-up was 16.3%. The presence of two or more channels in the post-ablation LGE-CMR was a predictor of VT recurrence (31.82% vs. 0%, P = 0.0038) with a sensibility of 100% and specificity of 61% (area under the curve 0.82). In the same line, a reduction of CCs < 55% had sensibility of 100% and specificity of 61% (area under the curve 0.83) to predict VT recurrence. Post-ablation LGE-CMR is feasible, and a reduction in the number of CCs is related with lower risk of VT recurrence. The dark core was not present in all patients. A decrease in VT substrate was also observed in patients without a dark core area in the post-ablation LGE-CMR.

Long-Term Outcomes after Catheter Ablation of Ventricular Tachycardia in Dilated vs. Ischemic Cardiomyopathy.

Ischemic (ICM) and dilated cardiomyopathy (DCM) represent the two main underlying heart diseases in patients referred for catheter ablation of ventricular tachycardia (VT). While VT ablation in ischemic cardiomyopathy is relatively well-studied, data in patients with DCM are still scarce. The study aimed to compare the acute and long-term outcomes in patients with ICM and DCM who underwent VT ablation at a high-volume center. Consecutive patients who underwent VT ablation from April 2018 to April 2021 were included retrospectively. Patients with ischemic cardiomyopathy were compared to those with dilated cardiomyopathy. The primary endpoint was rate of VT recurrences, the secondary endpoints included overall mortality, rehospitalization because of cardiac condition (VT, acute heart failure, acute myocardial infarction, heart transplantation or implantation of left ventricular assisting device), and major adverse cardiac events (MACE) at long-term follow-up. A total of 225 patients admitted for first VT ablation were included. A total of 156 patients (69%) revealed ICM and 69 (31%) DCM. After a mean follow-up of 22 months, the primary endpoint of VT recurrence occurred significantly more often in the patients with dilated cardiomyopathy (ICM n = 47; 37% vs. DCM n = 34; 64%; p = 0.001). In regard to the secondary endpoint of overall mortality, there was no difference between the two patient cohorts (DCM n = 9; 15% vs. ICM n = 22; 16%; p = 0.677); the patients with DCM showed significantly higher rehospitalization rates due to cardiac conditions (75% vs. 59%; p = 0.038) and more frequent MACE (68% vs. 52%; p= 0.036). In a Cox regression model, electrical storm at admission was shown to be a predictor for VT recurrence after successful catheter ablation (HR = 1.942: 95% CI 1.237–3.050; p = 0.004), while the ablation of every induced VT morphology during the procedure (HR = 0.522; 95% CI = 0.307–0.885; p = 0.016) contributed to a positive long-term outcome. DCM is associated with a higher risk of VT recurrence after catheter ablation compared to ICM. Furthermore, patients with DCM are more frequent re-hospitalized in the majority of cases due the VT recurrence. There is no difference in the long-term mortality between the two cohorts.

Predictors of long-term ventricular tachyarrhythmia recurrence after combined endo-epicardial ablation in patients with structural heart disease

Purpose. To identify predictors of ventricular tachycardia (VT) recurrence after endo-epicardial ablation in patients with structural heart disease.Methods. A prospective observational study included 39 patients with structural heart disease and indications for catheter ablation of ventricular tachyarrhythmia. Endo- and epicardial electroanatomical mapping of the ventricular myocardium and ablation of abnormal electrical activity areas were performed. Clinical, ECG characteristics, and voltage maps of bipolar potentials (limits of scar detection &lt;0.5 mV, normal activity &gt;1.5 mV) and unipolar signals (limits &lt;5.0 and &gt;9.0 mV, respectively) on endo- and epicardial surfaces were evaluated. Intraprocedurally, the procedure was considered effective when no VT was inducible; partially effective - when only clinical VT(s) was/were non-inducible. Scheduled patient visits or remote monitoring were performed at 6, 12 and 24 months, and then annually.Results. The mean age of the patients was 49.5±15.7 years (34 men and 5 women). VT recurrences at 6 months were more often detected in non-ischemic cardiomyopathy patients, in subjects with non-paroxysmal atrial fibrillation (42.9% vs. 7.4%), with a lower VT-QRS amplitude in lead III (0.6 [0.4;1.07] versus 1.28 [0.99; 1.53] mV), and when epicardial “scar” area prevailed over endocardial, P&lt;0.05 for all listed parameters. At 12-months, VT recurrence was more common in patients with partially effective ablation (33.3% vs. 5.0% in patients with effective ablation, P=0.02). The presence of electrical storm at the time of ablation was independently associated with recurrences (HR 4.32; 95% CI: 1.06-17.48; P=0.04).Conclusion. In a heterogeneous group of patients, clinical and electrophysiological factors associated with VT recurrence have been identified at various follow-up periods after endo-epicardial ablation. Electrical storm ablation is an independent predictor of VT recurrence in the long-term, up to 5 years of follow-up.

Factors predicting repeated ablation in ventricular tachycardia patients

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart Program Background Catheter ablation has emerged to be the principal treatment for recurrent ventricular tachycardia (VT). Previously, several predictors of VT recurrence have been described, such as LVESD, severe MR, incessant VT, ICD shocks and elevated LDH levels. However, factors predicting an additional ablation are unknown. Purpose We aimed to establish predictors of repeat ablation and compare to the predictors of ventricular arrhythmia recurrence during 1-year follow-up in structural heart disease. Methods Baseline medical history, laboratory results, imaging parameters, clinical properties of VTs, and procedural data were gathered in a structured database. Results Out of the 272 patients, 96 (35%) experienced recurrence and 36 (13%) had repeated procedures within 1 year. Independent predictors of recurrence were left ventricular end systolic diameter (HR = 1.516, p=0.015), severe mitral regurgitation (HR = 2.446, p = 0.002), incessant VT (HR = 1.64, p = 0.02), VT inducibility (HR = 3.71, p = 0.003), ICD shocks (HR = 1.95, p = 0.002) and elevated LDH levels (HR = 1.26, p = 0.003). Regarding redo ablation, elevated LDH level (HR = 1.64, p = 0.01), incessant VT (HR = 2.94, p &amp;lt; 0.001), ICD shocks (HR = 2.38, p = 0.02), only exit point ablation (HR = 2.14, p = 0.023) were independent predictors, while hypertension (HR = 0.32, p = 0.03), longer transmitral E-wave deceleration time (HR = 0.47, p = 0.04), substrate modification (HR = 0.47, p = 0.044) were protective. Conclusion Predictors of repeat ablation overlap only partially with those of VT recurrence. Predictors implying higher risk VT episodes predict both recurrence and repeat ablation while factors associated with more severe left ventricular systolic dysfunction predict recurrence but not a redo procedure.

Utility of Ischemia Testing Prior to Ablation for Sustained Monomorphic Ventricular Tachycardia.

The aim of this study was to determine the relationship between ischemia testing prior to ablation for sustained monomorphic ventricular tachycardia (VT) (SMVT) and post-ablation mortality and VT recurrence. As SMVT is generally caused by myocardial scar and not active ischemia, the utility of ischemia testing prior to SMVT ablation is unclear. Patients who underwent ablation for SMVT at 2 tertiary care centers between January 2016 and July 2018 were included in a retrospective study. A Kaplan–Meier survival analysis was performed, stratifying patients by pre-ablation ischemia testing for the endpoints of mortality and VT recurrence. A Cox multivariable regression analysis was performed to identify predictors of post-ablation VT recurrence. A total of 163 patients were included, with 46 (28%) patients undergoing ischemia testing prior to ablation. Only 5 of the 46 patients (11%) received revascularization pre-ablation. After a median follow-up period of 625 days (interquartile range, 292–982 days) following ablation, 97 of 163 patients (60%) had VT recurrence, and 32 patients (20%) had died. There was no difference in mortality or VT recurrence between patients who did or did not experience ischemia testing or revascularization. In the multivariable regression analysis, predictors of VT recurrence were the number of anti-arrhythmics failed, non-ischemic cardiomyopathy, sex, and cardiac magnetic resonance imaging pre-ablation. Neither ischemia testing nor revascularization was a significant predictor of VT recurrence in univariable or multivariable regression analysis. In conclusion, ischemia testing is frequently ordered prior to SMVT ablation but infrequently leads to revascularization and is not associated with post-ablation outcomes. The findings support adopting an individualized approach rather than performing routine ischemia testing.

Electrophysiological predictors of ventricular tachycardia recurrence in patients with structural heart disease after combined endo-epicardial substrate catheter ablation

Abstract Background Although there is a tremendous improvement in mapping and ablation techniques over the last decades, the recurrence rate of ventricular tachycardia (VT) in patients with structural heart diseases following endo-epicardial catheter ablation remains high. Purpose To determine predictors of VT recurrence in patients with structural heart disease after combined endo-epicardial radiofrequency (RF) VT ablation. Methods This prospective single-center study included 39 patients (34 men and 5 women, mean age 49.6±16.0 years), who underwent endo-epicardial mapping and ablation of the VT substrate. Etiology of structural heart diseases included: previous myocardial infarction (n=15); non-ischemic cardiomyopathy (n=24: 15 – arrhythmogenic right ventricular cardiomyopathy (ARVC), 6 – myocarditis, 3 – unspecified). First-line epicardial access was performed in 16 patients, as a second approach – in 23 subjects. We evaluated total ventricular myocardial areas, epi- and endocardial areas with bipolar low voltage (&amp;lt;1.5mV), scar area (bipolar &amp;lt;0.5mV), and unipolar low voltage (&amp;lt;5.0mV) and transient (&amp;lt;8.0mV) areas; areas of late potential registration were evaluated. Ratios of transient, low amplite and late-potential areas were calculated for endo- and epicardial surfaces, bipolar and unipolar maps. The following procedural electrophysiology characteristics were considered: inducibility of clinical VT, the number and morphology of induced VT, QRS width on sinus rhythm and VT, tachycardia cycle length, pseudo-delta wave extant and width, internal activation time, intrisicoud deflection time, and RS length. Clinical data such as echocardiography parameters, comorbidity and antiarrhythmic drug therapy were also taken into account. VT recurrences were documented using ICD/CRT-D interrogation, event ECG monitoring. Follow-up included mandatory visits at 6 and 12 months and unscheduled visits. Results Epicardial late potentials were registered in 69% of cases before ablation. Epicardial RF applications were delivered in 67% of patients; while only endocardial RF applications (including cases with intended epicardial substrate modification by endocardial ablation) were present in 28% cases. Non-inducibility of any VT plus abatement of local abnormal electrical activity was achieved in 32 (82%) of cases. The ratio epi/endo bipolar areas &amp;lt;0.5mV was much higher in patients with vs without VT recurrence at 6 months (4.3 (IQR: 2.5; 8.2) vs 0.75 (IQR:0.4; 1.6), P=0.001). A strong negative correlation was found between the induced VT cycle length and the ratio epi/endo bipolar areas &amp;lt;0.5mV: the shorter induced VT cycle length -the larger the area of the epicardial low voltage area (r=−0,52). Conclusion Regardless of epicardial substrate modification, patients with a larger epicardial low voltage area are more likely to have VT recurrence at 6 months after index ablation. A shorter induced VT cycle length is associated with a larger epicardial low-voltage area. Funding Acknowledgement Type of funding sources: None.

Ventricular tachycardia ablation in nonischemic cardiomyopathy

Abstract Introduction Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients. Methods Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression. Results In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34±12%, and mean age was 58±15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1–8), 41% (n=31) patients had VT recurrence and 28% died (n=19). Multivariate survival analysis identified LVEF (HR= 0.98; 95% CI 0.92–0.99, p=0.046) and VT storm at presentation (HR=2.38; 95% CI 1.04–5.46, p=0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5±6 days. The complication rate was 7% (n=5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P=0.046). Conclusion LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality. Funding Acknowledgement Type of funding sources: None.

Abstract 13646: Clinical Profile and Ablation Outcomes in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy and Biventricular Involvement

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disease which can involve both ventricles. This study aimed to elucidate the clinical profile and ablation efficacy in Chinese ARVC patients with biventricular (BiV) involvement. Methods and Results: Based on cardiovascular magnetic resonance findings, 255 ARVC patients were divided into two groups: the BiV involved group (n=137) and the isolated right ventricular (RV) involved group (n=118). Patients with BiV involvement were more likely to suffer from heart failure (28.5% vs. 8.5%; P &lt;0.001) and recurrent syncope (32.8% vs. 21.2%; P =0.038), and presented with lower heart transplantation-free survival and composed endpoint (death or heart transplantation)-free survival (all P &lt;0.05). Of the 255 subjects, 52 BiV involved patients and 77 isolated RV involved patients underwent catheter ablation for ventricular tachycardia (VT). After 5 years’ follow-up, the outcomes including VT recurrence and all-cause mortality in 2 groups showed no difference (all P &gt;0.05). The age, amount of induced VT during electrophysiology study and non-acute procedural success (partial success, defined as inducing the same VT with cycle length 30% longer after ablation; substrate modification only) were independent predictors of VT recurrence in BiV involved patients (all P &lt;0.05). Conclusion: BiV involvement in ARVC indicated worse symptoms and poor prognosis. Nonetheless, catheter ablation remained effective for VT control in this population. The younger age, more induced VTs and non-acute procedural success were associated with VT recurrence after ablation.

Catheter ablation for ventricular tachycardia in Chagas disease

Abstract Background Chagas disease (ChD) is a major cause of non-ischemic cardiomyopathy (NICM) in Latin America and is becoming more frequent in other parts of the world, especially due to immigration movements. Ventricular Tachycardia (VT) is more common in this type of NICM than others, and finding an effective treatment strategy still is a challenge. Catheter ablation is an option, but there is poor data regarding its efficacy and safety. Purpose Evaluate the outcomes after VT catheter ablation in ChD patients. Methods Data were collected by VT studies reports and patient record analysis, including comorbidities and clinical status at baseline and on follow-up. We analyzed all-cause mortality, one-year VT recurrence rate and procedure related major complications. Results Between January 2013 and December 2018, 157 catheter ablation procedures in 121 ChD patients were performed in our institution. The mean follow-up time was 22.6±22.1 (mean ± SD) months. Overall post procedure mortality was 33.1%, and mean survival time was 51.2 months (95% CI: 44.8–58. NYHA functional class (p=0.022), ejection fraction (p=0.020) and immediate ablation result (p 0.002) were predictors of all-cause mortality in the follow-up. Clinical VT inducibility after ablation was a predictor of VT recurrence at one year (p=0.04). An epicardial approach was performed in 125 (79%) procedures, and accidental right ventricle (RV) puncture occurred in 23 (18.4%), in which open-chest surgery for bleeding hemostasis was necessary in 4 procedures (3.2%). Conclusion Mortality and recurrence rates in ChD patients after VT ablation were high, and correlated with heart failure severity. Epicardial approach is often necessary in this subset of patients. There was a correlation between immediate ablation results and recurrence. Kaplan-Meier of cumulative survival Funding Acknowledgement Type of funding source: None

P980Evaluation of the outcomes of radiofrequency catheter ablation in patients with ischemic ventricular tachycardia

Abstract Background Ablation of ventricular tachycardia (VT) is an effective and safe treatment option in symptomatic patients under antiarrhythmic drugs or patients with frequent ICD therapies. Purpose We aimed to evaluate outcomes of VT catheter ablation in patients with ischemic VT. Methods All of the patients who underwent VT catheter ablation between June 2014 and November 2018 were included. Results 128 patients (120 male, 8 female) were included and mean age was 65 ± 10 years. Mean ejection fraction was 28.6 ± 8.2 %. Baseline characteristics were listed in Table-1. Mean follow-up was 22.3 ± 6.4 months. 52 (46.6 %) patients were admitted with electrical storm. Acute success rate was 96.6%. Complications including transient ischemic attack, deep venous thrombosis, pericardial effusion and inguinal hematoma were developed in 6 patients. Recurrence of VT was occured in 44 (34.4 %) patients and the presence of PCI history and admission with electrical storm were predictors of recurrence. All cause mortality was occured in 39 patients and predictors of all cause mortality was detected as follows; diabetes, NYHA stage &amp;gt;2, lower levels of EF and higher BNP levels. Cardiovascular mortality was developed in 28 patients and predictors were defined as, lower levels of EF, higher BNP levels and number of shock after index ablation. VT recurrence was not found to be related with both cardiovascular and all cause mortality. Conclusion VT ablation is a safe and effective option in patients with ischemic VT who are symptomatic despite optimal medical treatment. Admission with electrical storm and history of PCI were predictors of VT recurrence after ablation. Higher levels of BNP, lower EF values are related with both all cause and cardiovascular mortality. Table-1 Gender, male, (%) 120(93,8) Age(year) 65,5 ± 9,7 HT 93(72,7) DM 35(27,3) AF 41(32,0) NYHA class(pre-ablation) IIIIII IV 71(55,5)27(21,1)25(19,5) 5(3,9) Previous PCI 83(64,8) Previous Cardiac surgery CABG AVR MVR 72(56,3) 70(54,7 1(0,8) 4(3,1) LV EF (%)≤3031-40 ≥41 28,6 ± 8,290(70,3)28(21,9) 10(7,8) Electrical storm 52(40,6) LV EDD (mm) 63,8 ± 8,5 Baseline characteristics

129Magnetic resonance predictors of ventricular tachycardia recurrence after radiofrequency substrate ablation: septal and transmural channels

Abstract Ventricular tachycardia (VT) substrate-based ablation has become a gold standard in patients with structural heart disease. Success of VT ablation is related with mortality reduction. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is a powerful technique to assess substrate of VT. Myocardial fibrosis is electrically inert (Core) but it is surrounded by a ‘‘border-zone (BZ)’’ where normal cardiomyocytes intermingle with dense bundles of fibrosis. Slow impulse conduction in the BZ allows for the re-entry circuits leading to VT. Both the presence and extent of LGE have been associated with VT and SCD risk. LGE-CMR tissue characterization can be depicted as pixel signal intensity (PSI) maps and can guide VT ablation. The aim of this study was to analyze possible VT recurrence predictors in a long term follow-up of patients that underwent VT ablation (endo and/or epicardial) related with LGE-CMR PSI maps. We analyzed 234 consecutive patients (age: 63.2 ± 14 years, follow-up: 3.14 years ±1.8) undergoing VT ablation with scar-dechannelling technique at a single center from 2013 to 2018. 110 patients underwent a preprocedural LGE-CMR, and in 94 patients (85,5%) a CMR-aided ablation using the PSI maps was performed. All LGE-CMR images were semi-automatically processed using a dedicated software. PSI-based algorithm was applied to characterize the hyperenhanced area as core or BZ, using fixed threshold of the maximum intensity. A LV 3D shell was obtained and were imported into the navigation system. In the PSI maps, heterogenous tissue channels were defined as a continuous corridor of BZ surrounded by scar core or an anatomic barrier that connects 2 areas of healthy tissue. Results Overall recurrence of VT was 41.8 %. There was ICD shock reduction, from 43,6% to a 28,2% (ICD shocks before ablation 2,23 ± 7,32, after: 1,10 ± 2,92). Left ventricle mass predicted significantly VT recurrence (Mean 168,3 ± 53,3 vs 152,3 ± 46,4 g, HR 1,02 [1,01-1,02], p &amp;lt; 0.001). LGE distribuition was predictive of VT recurrence when a more than 40% of the interventricular septum was involved (62,5% vs 37,8%; HR 1,6 [1,01-1,02]; p = 0,044). No differences in recurrence were found among the patterns of LGE distribution (transmural/epicardial/subendocardial or peculiar segments localizations). The amount of BZ and the total amont of Core + BZ was related with VT recurrence (BZ 26,6 ± 13,9 vs 19,56 ± 9,69 g, HR 1,03 [1,01-1,06], p = 0,012; total Core + BZ 37,1 ± 18,2 vs 29,0 ± 16,3 g, HR 1,02 [1,00-1,04], p = 0,033). Finally VT recurrence was higher in patients with channels with transmural path (66,7% vs 31,4%, HR 3,25 [1,70-6,23], p &amp;lt; 0,001) or midmural channels (54,3% vs 27,6%, HR 2,49 [1,21–5,13], p = 0,013). CMR-aided scar dechanneling is a helpful and feasible technique which could identify patients with high risk of VT recurrence. High left ventricular mass, septal LGE distribution, transmural and midmural heterogeneous tissue channels were predictive factors of post ablation VT recurrence. Abstract Figure. VTchannel &amp; heterogeoneus tissue channel

P5699Endocardial vs. epicardial ventricular tachycardia ablation: a propensity score matched analysis

Abstract Introduction Direct comparisons of long-term clinical outcomes of endocardial vs. epicardial catheter ablation techniques for drug-resistant ventricular tachycardia (VT) have been scarcely reported. We aim to compare the long-term efficacy and safety of endocardial vs. epicardial catheter ablation (END-ABL and EPI-ABL, respectively) in a propensity score (PS) matched population. Methods Single-center observational registry including 215 consecutive patients who underwent END-ABL (181) or EPI-ABL (n=34) for drug-resistant VT between January 2007 and June 2018. Efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. A propensity score was used to match patients in a 1:1 fashion according to the following variables: VT storm at presentation, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) class III/IV at presentation, ischemic ethology, presence of implantable cardioverter-defibrillator (ICD), and previous endocardial catheter ablation. Independent predictors of VT recurrence were assessed by Cox regression. Results The PS yielded two groups of 31 patients each well matched for baseline characteristics (Table 1). Over a median follow-up of 2 years (IQR 1–3), 58% (n=18) ENDO-ABL patients had VT recurrence vs. 26% (n=8) in the EPI-ABL group (P=0.020). The yearly rates of VT recurrence were 28%/year for END-ABL vs. 11%/year for EPI-ABL (P=0.021). Multivariate survival analysis identified previous endocardial ablation (HR= 3.52; 95% CI 1.17–10.54, p=0.026) and VT storm at presentation (HR=3.57; 95% CI 1.50–8.50, p=0.004) as independent predictors of VT recurrence. EPI-ABL was independently associated with fewer VT recurrences (HR=0.28; 95 CI 0.12–0.69, p=0.005), but only in patients with a previous endocardial ablation (p for interaction = 0.004) – Figure A. No patients died at 30-days post-procedure. Hospital length of stay was similar between END-ABL and EPI-ABL (5 vs. 4 days respectively, p=0.139), as was the complication rate (6.5% vs. 12.9% respectively, p=0.390), although driven by different causes (Table 1). Conclusion VT storm at presentation and previous catheter ablation were independent predictors of VT recurrence. In patients with a previous failed endocardial catheter ablation, epicardial ablation seems to provide greater VT-free survival than repeat endocardial ablation. Both strategies seem equally safe.

Epicardial adipose tissue thickness as an independent predictor of ventricular tachycardia recurrence following ablation

Although several investigations have shown a relationship between increased epicardial adipose tissue (EAT) and atrial fibrillation (AF), the association between EAT and ventricular tachycardia (VT) has not been evaluated. We investigated the association between EAT and postablation VT recurrence. Sixty-one consecutive patients (mean age = 62.0 ± 13.9 years) undergoing VT ablation with preprocedural cardiovascular magnetic resonance imaging (CMR) were recruited. EAT thickness was measured using CMR in the right and left atrioventricular grooves (AVGs), right ventricular free wall, and anterior, inferior, and superior interventricular grooves. During a mean follow-up period of 392.9 ± 180.2 days, postablation VT recurrence occurred in 15 (24.6%) patients. EAT thickness was significantly higher in the VT recurrence group than in the nonrecurrent VT group at the right (18.7 ± 5.7 mm vs 14.1 ± 4.4 mm; P = .012) and left (13.3 ± 3.9 mm vs 10.4 ± 4.1 mm; P = .020) AVGs. The best cut-off points for predicting VT recurrence were calculated as 15.5 mm for the right AVG (area under receiver operating characteristic [ROC] curve = 0.74) and 11.5 mm for the left AVG (area under ROC curve = 0.72). Multivariate Cox regression analysis showed that preprocedural right AVG-EAT (hazard ratio: 1.2; 95% confidence interval: [1.06-1.39], P = .004) was the only independent predictor of VT recurrence after adjustment for covariates. Kaplan-Meier analysis showed a difference for postablation VT recurrence between the 2 groups, with right AVG-EAT thickness cut-off value of <15.5 mm vs ≥15.5 mm (log-rank, P = .003). We suggested a new possible imaging marker for risk stratification of postablation VT recurrence. A higher EAT may be associated with VT recurrence after catheter ablation of VTs.

Signal-Averaged Electrocardiography as a Noninvasive Tool for Evaluating the Outcomes After Radiofrequency Catheter Ablation of Ventricular Tachycardia in Patients With Ischemic Heart Disease: Reassessment of an Old Tool.

Inducibility of ventricular tachycardia (VT) has limited ability to predict recurrent VT after catheter ablation (CA). We sought to correlate the signal-averaged ECG (SAECG) with the endocardial scar characteristics in patients with ischemic VTs. We suggest that successful CA can result in normalization of the SAECG. Fifty patients (42 male; aged 67±10 years, ejection fraction 34±12%) with ischemic VTs were prospectively enrolled. SAECG was performed before and after CA. Patients with at least 2 abnormal criteria (filtered QRS ≥114 ms; root mean square 40 <20 μV, and low-amplitude potentials 40 >38 ms) were defined as having positive SAECG. There was a linear correlation between endocardial scar area (<1.5 mV) and filtered QRS (r=0.414; P=0.003). CA resulted in normalization of the SAECG in 6 patients. In patients with filtered QRS ≤120 ms, 13 (40.6%) patients had normal SAECG after CA compared with 7 (21.9%) before ablation (P=0.034). Patients with normal or normalized SAECG after CA had better VT-free survival compared with those whose SAECG remained abnormal. Abnormal SAECG after CA was a predictor for VT recurrence: hazard ratio=3.64; P=0.039 for the overall population, and hazard ratio=5.80; P=0.022 for patients having QRS ≤120 ms. There is a significant correlation between the surface SAECG and endocardial scar size in patients with ischemic VTs. A successful CA can result in normalization of SAECG that is associated with more favorable long-term outcomes. SAECG can be useful to assess the procedural success of VT ablation.

Safety, Long-Term Results, and Predictors of Recurrence After Complete Endocardial Ventricular Tachycardia Substrate Ablation in Patients With Previous Myocardial Infarction

Conduction channels and electrograms with isolated component/late potentials are sensitive markers of the substrate of post-myocardial infarction sustained monomorphic ventricular tachycardia (VT). Ablation of all conduction channels and isolated component/late potentials (complete endocardial VT substrate ablation [CEVTSA]) during sinus rhythm could simplify and facilitate the ablation procedure, mainly in patients without references for clinical VT substrate identification. The aim of this study was to assess the safety, efficacy, and predictors of VT recurrence after CEVTSA. Electroanatomic mapping and CEVTSA were performed in 59 post-myocardial infarction patients (mean age 67 ± 9 years, mean left ventricular ejection fraction 30 ± 11%), 24 of whom did not have clinical VT substrate references. The mean areas of scar (≤1.5 mV) and dense scar (≤0.5 mV) were 76 ± 42 and 34 ± 24 cm(2), respectively; isolated component/late potentials and conduction channels were identified and ablated in 97% and 83% of patients (mean ablation area 14 ± 10 cm(2)). No life-threatening complications occurred during the procedure. After 1 year and at the end of follow-up (mean 39 ± 21 months), 81% and 58% of patients were free of VT. No differences were observed between patients with and without specific clinical VT substrate identification. Univariate analysis identified the left ventricular ejection fraction, VT cycle length (VTCL), infarct location (inferior vs anterior), and dense scar area as predictors of VT recurrence, and Cox analysis identified VTCL (hazard ratio 0.42, p<0.001) and dense scar area (hazard ratio 2.65, p <0.0006) as independent predictors. No patients with dense scar area ≤25 cm(2) and VTCL >350 ms had recurrences. In conclusion, CEVTSA is safe and effective, even in patients without clinical VT substrate identification. Scar area and VTCL are valuable predictors of VT recurrence.