Early Ventricular Tachycardia Research Articles

Emergent Ablation for VentricularTachycardia: Predictors of Prolonged Hospitalization and Mortality.

Patients with ventricular tachycardia (VT) frequently present in unstable VT and are subject to urgent/high-risk ablation procedures. Clinical predictors of prolonged hospitalization and mortality are needed for optimal management of these patients. This study seeks to identify factors associated with prolonged hospitalization and mortality in emergent unplanned VT ablation procedures. Fifty consecutive patients hospitalized emergently for VT with structural heart disease who underwent catheter ablation were prospectively followed up for outcomes and complications. Of the 50 patients (mean ± SD age 67.6 ± 12.8 years), 86.0% were male, 62.0% had ischemic cardiomyopathy, and their median left ventricular ejection fraction was 28.5%. Hospital stay<7days (median 3days) occurred in 28 (56.0%) patients (Group 1) and >7days (median 10days) or death<7days occurred in 22 (44.0%) patients (Group 2). PAINESD score and left ventricular ejection fraction were similar between the groups. Compared with Group 1, Group 2 had significantly worse NYHA functional class III or higher (25.0% vs 63.6%; P=0.006), electrical storm (46.4% vs 77.3%; P=0.027), and prior failed VT ablation (35.7% vs 68.2%; P=0.023). Multivariable analysis showed that NYHA functional class III or higher and prior failed VT ablation were predictive of prolonged hospital stay. After ablation, compared with Group 1, Group 2 had worse heart failure (10.7% vs 54.5%; P=0.001), VT recurrences (3.6% vs 68.2%; P< 0.001), and 7 deaths within 30days. Patients undergoing emergent VT ablation are at high risk for prolonged hospital stay, which is predicted by NYHA functional class III or higher and a prior failed ablation. Early VT recurrences and worsening heart failure contribute to prolonged hospitalization and a high 30-day mortality.

Catheter ablation vs advanced therapy for patients with severe heart failure and ventricular electrical storm

BackgroundCurrent data on outcomes of an initial strategy of catheter ablation vs advanced therapy in patients with severe heart failure (HF) and electric storm (ES) are limited. ObjectiveThe purpose of this study was to evaluate the outcomes of ventricular tachycardia (VT) ablation vs left ventricular assist device (LVAD) or heart transplantation (HT) in patients with severe HF and ventricular ES. MethodsPatients with severe HF and ES who underwent VT ablation, LVAD, or HT between 2012 and 2022 at our medical center were reviewed. Severe HF was defined as ejection fraction ≤ 35% or presence of severe restrictive, valvular, or genetic cardiomyopathy. We assessed in-hospital adverse events and 1-year outcomes between the 2 groups. ResultsOf the 73 patients, 43 (58.9%) underwent VT ablation and 30 (41.1%) received advanced therapy (21 HT (70%) and 9 LVAD (30%)). One-year survival was similar (76.7% vs 86.7%; log-rank, P = .308). However, 10 patients (23.3%) in the ablation group underwent HT during follow-up. After multivariable analysis, United Network for Organ Sharing status 1 or 2 according to VT criteria (hazard ratio 5.52; 95% confidence interval 1.27–24.12; P = .023) and early VT recurrence (hazard ratio 5.67; 95% confidence interval 1.68–19.09; P = .005) were associated with HT or mortality in patients who underwent VT ablation. ConclusionPatients with severe HF and ES who underwent VT ablation had similar overall survival to patients who directly proceeded with advanced therapy, although rates of HT were high during follow-up. Predictors of HT or mortality after catheter ablation include United Network for Organ Sharing status 1 or 2 according to VT criteria and early VT recurrence.

Ventricular Tachycardia and Hospital Readmission in Patients Discharged From the Hospital After an Acute Myocardial Infarction

BackgroundAlthough ventricular tachycardia (VT) occurring during hospitalization for an acute myocardial infarction (AMI) increases mortality risk, its relationship with 30-day postdischarge rehospitalization has not been examined. MethodsUsing data from the Worcester Heart Attack Study, we examined the association between early (during the first 48 hours of admission) and late (after 48 hours from admission) VT with 30-day postdischarge all-cause and cardiovascular disease (CVD)-related rehospitalization while analytically controlling for several demographic and clinical factors. ResultsThe study population consisted of 3534 patients who were hospitalized with an AMI between 2005 and 2015 (average age, 67.2 years; 40.7% women); VT occurred in 452 patients (13.7%), with the majority of instances (81.2%) occurring within 48 hours of admission. The 30-day all-cause rehospitalization rate was 17.3%, with 70.9% of the hospitalizations related to CVD. The odds of rehospitalization were 1.63 times (95% confidence interval [CI] = 0.99-2.69) and 1.12 times (95% CI = 0.83-1.51) higher for patients with AMI who developed late VT and early VT, respectively, compared to patients who did not develop VT. The risk of rehospitalization among patients with late VT was higher (odds ratio = 2.22 (95% CI = 0.79-6.26) in those with ST-segment-elevation AMI, compared to those with non-ST-segment-elevation AMI (odds ratio = 1.45 (95% CI = 0.81-2.57); early VT was not associated with rehospitalization in patients with either AMI subtype. No significant association was present between the occurrence of VT and CVD-related rehospitalization. ConclusionsPatients who develop late VT may experience a higher risk of 30-day rehospitalization following hospital discharge for AMI, especially among those with ST-segment-elevation AMI. Larger studies are needed to confirm our findings.

The significance of early-onset malignant arrhythmias in ST-elevation myocardial infarction patients treated with primary percutaneous coronary intervention and their relationship with biomarkers

Background/Aim. Patients who were treated with primary percutaneous coronary intervention (pPCI) and survived ventricular tachycardia (VT) and ventricular fibrillation (VF) in the first 48 hrs after ST-elevation myocardial infarction (STEMI) had, in most investigations, a similar long-term prognosis of the outcome, compared to those patients who did not have VT and VF during the first 48 hrs after STEMI. The aim of the study was to determine the association of myocardial infarction markers: creatine kinase-MB fraction (CK-MB), heart failure marker ? B-type natriuretic peptide (BNP), and systemic inflammation factor ? C-reactive protein (CRP) with early VT and VF onset, in relation to patient mortality during the first six months after STEMI. Methods. The retrospective study included 971 patients with STEMI treated with pPCI for ten years. VF and sustained VT (sVT) were detected outside of the hospital and during the first 48 hrs of hospitalization. Results. During the first 4 8 hrs from admission, 1 08 ( 11.1%) patients had life-threatening arrhythmias, of which 75 (69.4%) had VF, and 33 (30.6%) had sVT and were treated with direct current ? DC shock and intravenous amiodarone. Intrahospital mortality was significantly higher in patients with VF/sVT in the first 48 hrs compared to patients without VF/sVT (14.8% vs. 5.7%, p = 0.001). BNP level had higher accuracy in the prediction of six-month death than the maximum blood level of CRP in patients without VF/sVT after 48 hrs. However, in patients with early-onset malignant arrhythmias, BNP showed a lower level of accuracy in predicting the six-month mortality, a s did the CRP values, which had almost the same level of accuracy. Admission glycemia had a much lower predictive value in both groups of patients compared to BNP and C RP [ 0.705 ( 0.628? 0.781), p &lt; 0.001 and 0.662 (0.521?0.803), p = 0.046, respectively]. In either of the groups, maximum CK-MB levels were not significant in predicting the six-month all-cause mortality. Conclusion. Our study indicates that STEMI patients with early onset of VF and sVT, treated with pPCI, with a high BNP level, have a statistically significantly higher mortality rate compared to patients with a lower BNP level.

Abstract 18987: A 10-Year Contemporary Analysis of Outcomes of Patients With Amyloidosis and VT Underdoing Ventricular Tachycardia (VT) Ablation

Introduction: Cardiac amyloidosis (CA) can lead to heart failure and arrhythmias as a result of electromechanical cardiac remodeling. CA is most associated with atrial fibrillation, however, small studies have shown that the highest risk population is those with ventricular tachycardia (VT). There are limited studies on the clinical implications of patients with cardiac amyloidosis and VT undergoing VT ablation (VTA) versus medical therapy. This study’s aim is to assess mortality and outcomes in patients with CA undergoing VTA vs medical therapy. Hypothesis: We anticipate CA patients undergoing VTA will have better outcomes than their medically managed counterparts. Methods: The US National Inpatient Sample (NIS) was searched for patients with CA with and without VTA as a secondary diagnosis using ICD-9/10 codes from 2010 to 2020. Primary outcomes were inpatient mortality, hospital length of stay (LOS), and total hospital charges (TOTHC). Data analysis utilized propensity matching via the Kernel Method. Results: his study included 357,350 patients with CA, of which 92,750 underwent VT ablation (Group A), which was compared with CA patients receiving medical therapy (Group B). Group A had decreased mortality (5.27% vs 11.33%, p&lt;0.0001), but increased LOS (+6.81 days, p&lt;0.0001, CI: 6.15-7.47), and TOTHC ($240,459.80, p&lt;0.0001, CI: 105,536.40-375,383.30). Secondary analysis is described in Table 1. Conclusions: Although LOS and TOTHC were increased in patients with CA with VTA, overall mortality was decreased compared to those with CA managed medically. Numerous risk factors were identified that worsen hospital outcomes in this population. Our study demonstrates that early referral to EP and early VT ablation could be the best management strategy for patients with CA and VT as they had significantly reduced mortality compared to the group which only had medical management.

A method to identify which patients will have VT substrate ablation targets prior to ablation procedure

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Dr Nanthakumar is a recipient of the Mid-career Investigator Award from the Heart &amp; Stroke Foundation of Ontario Background Recent trials in ventricular tachycardia (VT) ablation suggest that early ablation could reduce VT burden. A method to predict which patients will have substrate ablation targets based on non-invasive testing prior to the procedure does not exist and could be of value in selecting ideal patients for early VT substrate ablation. Decrement-evoked potential (DeEP) mapping is used to identify VT substrate ablation targets.1 A method for predicting which patients would have DeEP targets on a pre-ablation 12-lead ECG has not yet been developed. Objective To develop a metric to predict the presence of physiological substrate VT ablation targets from the 12-lead ECG. Method 22 electrophysiology (EP) lab VT cases that had undergone DeEP mapping were extracted from the CARTO® 3 system and were analysed retrospectively. For each case, DeEP was calculated by subtracting last component of the nearfield evoked response in the pacing train (S1) from the latest component of the nearfield evoked decremented response of the extra stimulus (S2). By inference, 12-lead ECG prediction was calculated by subtracting the width of the 12-lead surface ECG envelope of S1 from the width of the 12-lead ECG envelope of S2. Cases were divided into three categories: - Cases displaying intracardiac DeEP between 0-10ms – no ablation targets - Cases displaying intracardiac DeEP between 10-50ms – DeEP positive - Cases displaying intracardiac DeEP &amp;gt;50ms – prominent DeEP present Results Out of the 22 cases, 8 were characterised as no ablation targets, 12 as DeEP positive, and 2 as prominent DeEP present. The 12-lead surface ECG measurement means were 3.5±4.6ms for the no ablation target group, 23.2±9.1ms for positive DeEP group, and 80.9±8.1ms for prominent DeEP group. The surface ECG decrement was significantly different P&amp;lt;0.0001 between the three groups. Consequently, we propose that ECG QRS widening of envelope width of 20ms or more may indicate the presence of DeEP targets during invasive mapping. Conclusion It may be possible to detect which patients will have substrate ablation targets based on 12-lead ECG, prior to the VT ablation procedure. Additionally, this prediction rule, based on its association with arrhythmogenic potentials, may be able to predict which ambulatory patients who have not had manifest VT, may be prone to develop VT thus help identify early VT ablation candidates. This concept should be validated in larger data sets and is ideal for training and testing using surface ECG envelopes with artificial intelligence algorithms.

Determining physiological VT ablation targets in the era of early VT ablation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Professor Nanthakumar is a recipient of the Mid-career Investigator Award from the Heart &amp; Stroke Foundation of Ontario. Background Ablation targets in the era of early ventricular tachycardia (VT) ablation will likely be driven by substrate-based physiological target approaches rather than activation mapping. Decrement evoked potentials (DeEP) have been co-localized to the diastolic VT circuit and are used as a method to perform VT ablation when VT cannot or should not be induced.1 Traditionally these potentials are evoked by a single extrastimulus. The incremental utility of a second extrastimulus in detecting these potentials has not been evaluated. Purpose We studied the utility of the second extra stimulus (S3) in detecting substrate ablation over the first extra stimulus (S2) following a drivetrain (S1) of 8 beats at 600ms. Methods DeEP was measured as the time difference between the pacing stimulus and the nearfield local activation delay on the bipolar electrogram during the S1 drivetrain and after the S2 or S3 respectively. Decrement of ≥10ms was considered a positive DeEP site. A total of 157 sites from 6 patients with VT were analysed. The incremental value of S3-induced DeEP was compared to the S2-induced DeEP. Results The mean decrement was significantly greater on the S3 compared to the S2 (41.8±35.6ms for S3 vs 25.8±20.4ms for S2, P &amp;lt;0.0001). The mean incremental value of the S3 was 15.9ms (95% CI, 11.5-20.3ms). From the 157 intracardiac electrograms studied, 79.1% had a positive DeEP with S2 alone. At the same electrode locations, an additional S3 evoked DeEP in 82.2% of sites. Conclusion When physiological substrate is present on the first extra stimulus, the second extra stimulus magnifies the identification of the target. However, we found in our study that the second extrastimulus uncovered a hidden arrhythmogenic substrate in only 3.1% additional mapped sites. Consequently, the utility of the second extrastimulus in identification of hidden substrate needs to be balanced with the risk of induction of potentially unstable rhythms.

EN-452414-1 IMPACT OF MULTI-DIRECTIONAL PACING ON LATE SIGNAL ACTIVATION, ACTIVATION SLOWING AND REPOLARIZATION GRADIENTS TO LOCALIZE RE-ENTRANT VENTRICULAR TACHYCARDIA CIRCUITS IN A PORCINE INFARCT MODEL.

Optimal signal parameters and substrate mapping strategies for identifying key arrhythmogenic sites in ventricular tachycardia (VT) ablation are not established. To evaluate multi-directional pacing on the distribution of late signal activation, activation slowing and repolarization gradients in relation to critical sites of re-entrant VT, in a porcine infarct model. Electrophysiology studies were performed 4 weeks post-infarction in 13 pigs using the EnSite Precision system (Abbott, IL, USA), and the Advisor HD Grid (Abbott) multi-electrode catheter. Substrate maps were created during right ventricular (RV), left ventricular (LV), and biventricular pacing (BIV), and sinus rhythm (SR). Sites of early, mid-, and late-diastolic signals of induced VT’s were delineated. Off-line analysis compared these critical VT sites to algorithmically identified 20 most vulnerable sites of latest activation timing within and post-QRS, and the largest activation (GradAT) and activation recovery interval gradients (GradARI). 34 VTs were mapped with at least one diastolic recorded component, with a mean tachycardia cycle length of 236.5 ± 32.4 ms. 48 sinus rhythm and pacing maps were obtained, 10 using BIV pacing (mean points 375 ± 263), 13 using LV pacing (mean points 610 ± 334), 13 from RV pacing (mean points 603 ± 263) and 12 in sinus rhythm (mean points 1078 ± 654). Late potential (LP) mapping in sinus rhythm was taken as the established clinical standard for statistical comparison with all other protocols, displayed in Figure 1. GradARI using RV pacing provided the closest localization for VT exit and entrance, with a median distance of 10.6mm (IQR 5.0mm, p <0.05) and median 9.4mm (IQR 8.0mm, p <0.05) compared to LP in sinus rhythm, respectively. LAT with BIV pacing provided closest VT isthmus localization for VT isthmus, with a median of 5.5mm (IQR 7.15mm, p <0.05) compared to LP in sinus rhythm (Figure 1). A global sensitivity and specificity analysis was performed on all points. GradARI mapping in SR reported the highest AUC (area – under curve) for early diastolic VT signals (AUC 0.96, sensitivity 93%, specificity 91%), mid-diastolic signals (AUC 0.92, sensitivity 84%, specificity 88%) and late diastolic signals (AUC 0.92, sensitivity 88%, specificity 84%). Sites with the largest ARI gradients in sinus rhythm best predict critical sites of VT in this model, with the most effective protocol being RV pacing examining ARI gradients.

Frequency of Ventricular Tachycardia in First 48 Hours of ST-Elevation Myocardial Infarction

ST-elevation myocardial infarction (STEMI) has a poor long-term prognosis associated with early ventricular tachycardia (VT). Objective: To find out the frequency of ventricular tachycardia in the first 48 hours of ST-elevation myocardial infarction. Methods: After approval from the Hospital ethical committee, the study was conducted in the department of cardiology Hayatabad medical complex Peshawar from 1st October 2020 to 31st March 2021. All the patients having new onset ST-elevation Myocardial infarction as per Operational definition, both genders, aged between 40 and 75 years and who have given consent were included in the study. Non-probability consecutive sampling technique is being used for the sampling. Results: Standard deviation was ±1.357 years, while the average age was 51.56. Gender-wise distribution among patients male was 89(53.6%) and female was 77(46.4%). Distribution of duration of disease among patients 12-24 hours 80(48.2%) and more than 24 hours 86(51.8%) was 100(52.4%). Family History of coronary artery disease (CAD) 84(50.6%), diabetes mellitus 93(56.0%), hypertension 110(66.3%) and smoking status was 118(71.1%). Distribution of ventricular tachycardia was present among 103(62.0%) patients and was absent in 63(38.0%) patients. Conclusions: Ventricular tachycardia is the most common tachycardia occurring in patients in the first 48 hours who sustained myocardial infarction. It was shown that bradyarrhythmia was more common in patients with inferior wall myocardial infarction while ventricular tachycardia was found to be more in patients with anterior wall myocardial infarction.

Electrical Storm in the ICU – When all Options Run Out

The management of patients with ischaemic cardiomyopathy presenting with refractory ventricular arrhythmias may be challenging and is associated with high morbidity and mortality. The authors present the case of a 72-year-old male patient with a known history of severe ischemic cardiomyopathy and impaired left ventricular function (LVEF 29%) with a previous episode of incessant ventricular tachycardia (VT), previously submitted to VT catheter ablation and implantable cardioverter-defibrillator (ICD) implantation in secondary prevention. Due to hyperthyroidism with amiodarone, he was under dofetilide therapy. In this case report, we detail the step-by-step approach undertaken in the management of a complex case of refractory electrical storm. The therapeutic approach included the use of several anti-arrhythmic drugs (amiodarone, lidocaine and esmolol), manual ICD anti-tachycardia pacing and cardioversion, sedation and mechanical ventilation, extracorporeal life support with VA-ECMO and VT catheter ablation under VA-ECMO support. Unfortunately, despite every measure undertaken, the patient developed incessant VT culminating in haemodynamic collapse and death. The role of mechanical circulatory support in haemodynamically unstable patients with refractory ventricular arrhythmias and undergoing VT catheter ablation is also explored, as well as other treatment options that may be considered in the management of electrical storm, such as early coronary angiography, autonomic modulation, and surgical VT ablation with electroanatomical mapping.

Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia

BackgroundRecurrent ventricular tachycardia (VT) due to dilated cardiomyopathy (DCM) is difficult to treat, and long-term outcome data are limited. ObjectivesThe aim of this study was to identify predictors of mortality or heart transplantation (HTx) and VT recurrence. MethodsConsecutive patients with DCM accepted for radiofrequency catheter ablation (RFCA) of VT at 9 centers were prospectively enrolled and followed. ResultsOf 281 consecutive patients (mean age 60 ± 13 years, 85% men, mean left ventricular ejection fraction [LVEF] 36% ± 12%), 35% had VT storm, 20% had incessant VT, and amiodarone was unsuccessful in 68%. During follow-up of 21 months (IQR: 6-30 months), 67 patients (24%) died or underwent HTx, and 138 (49%) had VT recurrence (45 within 30 days, defined as early); the 4-year rate of VT recurrence or mortality or HTx was 70%. Independent predictors of mortality or HTx were early VT recurrence (HR: 2.92; 95% CI: 1.37-6.21; P < 0.01), amiodarone at discharge (HR: 3.23; 95% CI: 1.43-7.33; P < 0.01), renal dysfunction (HR: 1.92; 95% CI: 1.01-3.64; P = 0.046), and LVEF (HR: 1.36; 95% CI: 1.0-1.84; P = 0.052). LVEF ≤32% identified patients at risk for mortality or HTx (area under the curve: 0.75). Mortality or HTx per 100 person-years was 40.4 events after early, compared with 14.2 events after later VT recurrence and 8.5 events with no VT recurrence after RFCA (P < 0.01 for both). Patients with early recurrence and LVEFs ≤32% had a 1-year rate of mortality or HTx of 55%. VT recurrence was predicted by prior implantable cardioverter-defibrillator shocks, basal anteroseptal VT origin, and procedural failure but not LVEF. ConclusionsPatients with DCM needing RFCA for VT are a high-risk group. Following RFCA, approximately one-half remain free of VT recurrence. Early VT recurrence with LVEF ≤32% identifies those at very high risk for mortality or HTx, and screening for mechanical support or HTx should be considered. Late VT recurrence after RFCA does not predict worse outcome.

Correlation of exit sites of inducible ventricular tachycardia post-ST elevation myocardial infarction on electrophysiology study, with region of infarct.

Ventricular arrhythmia (VA) is the most common cause of sudden cardiac death post-ST elevation myocardial infarction (STEMI). Ventricular tachycardia (VT) may be inducible in electrophysiology studies (EPS) early (<40 days) post-STEMI. Whether it originates from the infarct site remains unknown. We examined the correlation between inducible VT and infarct location post-STEMI. To investigate the correlation between inducible VT and infarct location post-STEMI. We retrospectively analysed 46 patients from 2005 to 2017 with STEMI who underwent early programmed ventricular stimulation through EPS (>48 h post-STEMI and <40 days from admission). Gated heart pool scans were used to visualise infarct scar regions, and VT exit sites were derived from induction 12-lead electrocardiography. Patients were followed up for primary outcomes of recurrent VA and all-cause mortality. Forty-six patients were included for analysis, with 50 uniquely induced VT exit sites. Mean left ventricular ejection fraction was 30 ± 8.7% and 22% had impaired right ventricular ejection fraction. Mean time from presentation to EPS was 16 ± 31.3 days. Of the induced VT, 44 (88%) were from within scar and scar-border regions, whereas 6 (12%) of the induced VT were found to be remote to imaging-derived scar. Over a median follow-up period of 75 months, 6 (13%) patients died, and 7 (15%) patients had recurrent VA. No deaths occurred in patients with remote VT. The majority of early inducible post-infarct VT arises from acute myocardial scar; however, a small portion arises from sites remote from scars with a possible focal aetiology.

Impact of early ventricular tachycardia ablation in patients with an implantable cardioverter-defibrillator: An updated systematic review and meta-analysis of randomized controlled trials

There is limited information on whether early catheter ablation (CA) for ventricular tachycardia (VT) is associated with better outcomes compared with alternative strategies in patients with implantable cardioverter-defibrillator (ICD). The purpose of this article was to assess the efficacy of early VT CA in patients with ICD. EMBASE, PubMed, and Cochrane were searched from inception to April 2022. Randomized controlled trials comparing the efficacy of early VT CA with control groups, both in patients with ICD, were included in the analysis. Data on effect estimates in individual studies were extracted and combined via random effects meta-analysis using the DerSimonian and Laird method, a generic inverse variance strategy. Nine randomized controlled trials with 1106 patients (n = 1018, 92.1% with ischemic cardiomyopathy and n = 88, 7.9% with nonischemic cardiomyopathy) were evaluated. VT CA was associated with reduced VT recurrences (odds ratio [OR] 0.64; P = .007), appropriate ICD shocks (OR 0.53; P = .002), ICD therapies (OR 0.54; P=.002), and cardiovascular hospitalization (OR 0.67; P=.004). However, no significant differences were observed in terms of mortality rate, heart failure hospitalization, and quality of life between the early VT CA and control groups. Early CA was beneficial in reducing VT burden and ICD therapies. However, it did not affect mortality rate and quality of life. Since most patients in the included studies presented with ischemic cardiomyopathy, further studies on nonischemic cardiomyopathy should be conducted to validate if early CA has similar outcomes.

The outcome spectrum for Dilated Cardiomyopathy and Ventricular Tachycardia: results from the prospective, multicenter, DCM-VT ablation study

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The study was partially supported by an investigator initiated grant from Biosense Webster (a Johnson &amp; Johnson company) Background Recurrent sustained ventricular tachycardia (VT) due to nonischemic dilated cardiomyopathy (DCM) is difficult to treat and long-term outcome data are limited. Objective We aimed to identify predictors for mortality or heart transplantation (MHT) and VT recurrence. Methods Consecutive DCM patients accepted for VT catheter ablation (RFCA) in 9 centers were prospectively enrolled and followed. Results Of 281 consecutive patients (age 60±13yrs, 85% men, LVEF 36±12%) 35% had VT storm, 20% incessant VT, and 68% failed amiodarone. During a median follow-up of 21 (IQR 6-30) months after RFCA (epicardial in 58%, no RFCA due to inaccessible target in 6.4%), 67(24%) patients died/underwent HT and 138(49%) had VT recurrence (45 within 30 days defined as early); the cumulative 4-year rate of VT or MHT was 70% and of MHT 38%. In multivariable analysis predictors of MHT were early VT recurrence (HR 2.92 (CI1.37-6.21), p&amp;lt;0.01), amiodarone at discharge (HR 3.23 (CI1.43-7.33, p&amp;lt;0.01), renal dysfunction (HR 1.92 (CI1.01-3.64), p=0.046), and LVEF (HR 1.36 (CI 1.0-1.84), p=0.052). A LVEF ≤32% was the optimal threshold to identify patients at risk for MHT (AUC 0.75). MHT per 100 person-years was 40.4 after early VT recurrence and significantly higher, compared to 14.2 after later VT recurrence and to 8.5 after RFCA with no VT recurrence (both p&amp;lt;0.01). Mortality rates for patients with VT recurrence after 30 days were not significantly higher than for patients with no VT recurrences Patients with early recurrence and LVEF≤32% had a 1-year MHT rate of 55% (figure). VT recurrence was predicted by prior ICD shocks, basal antero-septal VT origin, and procedural failure but not LVEF. Conclusion DCM patients needing RFCA for VT are a high-risk group. Following RFCA half remain free of VT recurrences. Early VT recurrence with LVEF&amp;lt;0.32 identifies those with a very high risk and screening for mechanical support/ HT should be considered. Late VT recurrence after RFCA does not predict worse outcome.

CA-533-02 STANDARD CARDIAC RADIOABLATION DOSE (25 GRAY) DOES NOT CAUSE MYOCYTE INJURY OR NEW FIBROSIS

Noninvasive cardiac radioablation (CRA) is an emerging therapy for refractory ventricular tachycardia (VT). Focused radiation to the heart is expected to cause local myocardial destruction with replacement fibrosis (ablation effect). The extent this effect in humans is unknown. To measure the CRA ablation effect with serial serum biomarkers and late gadolinium enhanced cardiac MRI (LGE-CMR). Single-center, IRB-approved case series of patients with refractory VT (ENCORE-VT NCT02919618). Patients without contraindication underwent LGE-CMR and blood draws at three timepoints: before treatment, 3 days, and 3 months after treatment. Left ventricle (LV) scar burden was assessed using semi-automatic contouring (Medis, Netherlands), blinded to location of radioablation. Global and segmental scar burden (%) was compared across timepoints. Segments targeted for radioablation (25 Gray) were compared to surrounding and off-target segments. Blood samples were analyzed for high-sensitivity troponin-I (Tn-I, marker of myocyte injury) and galectin-3 (Gal3, marker of fibroblast activation and fibrosis). 7 patients were included for analysis: mean age 64 years, 14% female, 57% nonischemic cardiomyopathy, 86% with history of VT storm, mean LVEF 32% (range 19-58%). Mean number of cardiac segments targeted for radioablation was 4 (range 3-8), resulting in mean cardiac treatment volume (CTV) 29 cm3 and planning treatment volume (PTV) 114 cm3. Mean scar burden at baseline was 49% (range 29-68%). Changes in scar burden at 3 days and 3 months were -0.4% (IQR = 5.5%) and 3.3% (IQR = 3%). Segment-by-segment analysis (Figure 1) showed no significant scar progression in segments targeted for radioablation (mean 68% to 68% to 71%), segments surrounding the target (43% to 44% to 47%), or off-target segments (44% to 42% to 46%). Serum Tn-I and Gal3 were not significantly changed (Figure 2). Compared to VT burden before treatment, all 7 patients had substantial reduction 6 months after treatment (4 had > 95% burden reduction, 1 had resolution of incessant slow VT). Despite improvement in VT burden, there was no appreciable cardiac injury or replacement fibrosis after CRA with 25 Gray. The mechanism of early VT control with cardiac radioablation is not myocyte injury or fibrosis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Relation of Early Monomorphic Ventricular Tachycardia to Long-Term Mortality in ST-Elevation Myocardial Infarction

Early ventricular tachycardia (VT) and ventricular fibrillation (VF) are associated with increased in-hospital mortality but do not influence the long-term prognosis in ST-elevation myocardial infarction (STEMI). Recent data advocate a differential approach to the type of arrhythmia and indicate long-term mortality hazard associated with monomorphic VT. We aimed to evaluate the prognostic value of early monomorphic VT compared to nonmonomorphic VT/VF in a nonselected cohort of STEMI patients. Consecutive STEMI patients admitted for primary percutaneous coronary intervention from 2007 to 2010 were included. Clinical characteristics were obtained from the Swedish national SWEDEHEART registry. The occurrence and type of early VT/VF were verified in medical records. All-cause mortality 8 years after STEMI was assessed using the Swedish Cause of Death Register. A total of 2,277 STEMI patients were included (age 66 ± 12 years, 70% male), among them 35 (1.5%) with early monomorphic VT and 115 (5.1%) with nonmonomorphic VT/VF. Patients with monomorphic VT had similar clinical characteristics compared to those with nonmonomorphic VT/VF. In total, 22 patients (63%) with monomorphic VT and 43 (37%) with nonmonomorphic VT/VF died by 8 years of follow-up (p=0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF in univariate analysis (HR 2.03, 95% CI 1.21 to 3.39, p=0.007) and after adjustment for age and history of myocardial infarction (MI) (HR 1.74, 95% CI 1.02 to 2.97, p=0.041). Early monomorphic VT in STEMI is associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF and deserves further studies to refine risk stratification strategies.

The incidence, time distribution and prognostic value of monomorphic ventricular tachycardia in ST-elevation myocardial infarction: the prespecified analysis of VALIDATE SWEADHEART trial

Abstract Background The assessment of prognostic impact of ventricular arrhythmias in ST-elevation myocardial infarction (STEMI) is currently based mainly on their timing with regard to the symptom onset and does not distinguish between monomorphic ventricular tachycardia (VT) and polymorphic VT/ventricular fibrillation (VF). However, recent data indicate long-term hazard of monomorphic VT occurring early in the course of STEMI. Purpose To evaluate the incidence, time distribution and prognostic value of early monomorphic VT compared to polymorphic VT/VF in STEMI patients treated by primary percutaneous coronary interventions (PCI). Methods A prespecified analysis of the multicentre prospective registry-based randomised VALIDATE-SWEDEHEART trial included STEMI patients enrolled at 16 sites in Sweden between June 2014 and September 2016. Source data verification regarding the type and timing of arrhythmia from all patients with VT/VF during STEMI was performed. Survival status was obtained from the Swedish national population registry. Endpoint was total mortality at 180 days. Results In total, 2886 patients were identified. Among them, 97 (3.4%) had VF or polymorphic VT, 16 (0.5%) monomorphic VT, 6 (0.2%) had other undefined shockable rhythm. Total mortality (10.9% vs 2.8%, p≤0.001) was higher among patients with VT/VF. VT/VF was associated with total mortality (HR 3.18 95% CI 1.74–5.8; p≤0.001) after adjustment on age, gender and myocardial infarction localisation. In patients discharged from hospital, VT/VF did not influence the long-term prognosis. Patients with monomorphic VT had similar clinical characteristics as compared to those with polymorphic VT/VF. The time distribution of VT/VF differed with regard to the type of arrhythmia: 63% of monomorphic VT/VF episodes occurred after PCI (n=10) compared to 24% (n=23) of all documented polymorphic VT/VF, p=0.003. Total mortality (12.5% vs 10.3%, p=0.678) did not differ between patients with monomorphic VT and polymorphic VT/VF. In Cox model, total mortality was not associated with the type of arrhythmia (Figure). Conclusion Early VT/VF is a marker of poor short-term outcome in patients with STEMI, which does not affect long-term prognosis in those who are successfully resuscitated and discharged from hospital. The incidence of monomorphic VT in STEMI treated by primary PCI is low, and it occurs mainly after PCI. Though no significant difference in mortality was found between patients with monomorphic VT and polymorphic VT/VF, the observed low incidence hampers drawing conclusions with regard to the prognostic hazard impact of monomorphic VT. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Swedish Heart Lung Foundation

Long-Term Outcomes of Bilateral Cardiac Sympathetic Denervation for Refractory Ventricular Tachycardia.

This study sought to explore the long-term arrhythmic outcomes of bilateral cardiac sympathetic denervation (BCSD). BCSD has been associated with improved arrhythmic outcomes in patients with refractory ventricular arrhythmias. However, whether BCSD antiarrhythmic effects are sustained long after the procedure is still uncertain. We included consecutive patients who underwent BCSD because of refractory ventricular tachycardia (VT) and had at least 18months of follow-up. VT recurrence after BCSD was evaluated to assess arrhythmic outcomes. The occurrence of VT episodes within the first 12weeks after the procedure was assessed to explore the impact of early VT recurrence on late arrhythmia-free survival. Twenty patients (42 ± 16 years; 55% male) were included in the analysis. Nineteen (95%) patients had structural heart disease (left ventricular ejection fraction: 0.46 ± 0.14). Class I or class III drugs failed for all patients, and the mean number of VT ablation procedures was 2.5 ± 1.6. Over a mean follow-up of 1,300 ± 321days (median: 1,276 days [Interquartile range (IQR): 1,181 to 1,480 days), 11 (55%) patients remained VT free after sympathectomy. Freedom from sustained VT or implantable cardioverter-defibrillator shock was 60% (95% confidence interval: 0.35 to 0.77) and 54.5% (95% confidence interval: 0.31 to 0.73) after BCSD at 1 and 4 years. Early VT recurrence was not associated with worse late arrhythmia-free survival rates. BCSD was associated with longstanding antiarrhythmic effects in patients with refractory ventricular arrhythmias. The occurrence of VT episodes early after the procedure was not associated with worse late arrhythmic outcomes.

Early monomorphic ventricular tachycardia is associated with increased long-term mortality in STEMI

Abstract Background Malignant ventricular arrhythmias occurring early during ST-elevation myocardial infarction (STEMI) are known to markedly contribute to increased in-hospital mortality, but not to influence the long-term prognosis. However recent data advocate differential approach to the type of arrhythmia and indicate long-term hazard of monomorphic ventricular tachycardia (VT). Purpose We aimed to evaluate the prognostic value of monomorphic VT compared to non-monomorphic VT or ventricular fibrillation (VF) during the first 48 hours of STEMI in non-selected cohort of STEMI patients admitted for primary PCI. Methods Consecutive STEMI patients admitted to a tertiary care hospital for primary PCI during 2007–2010 were included. The Swedish national SWEDEHEART registry was used for assessment of clinical characteristics and the presence of VT/VF during index admission. The occurrence and type of VT/VF during the first 48 hours from symptom onset were verified in medical records. Information on all-cause mortality endpoint 8 years after STEMI was obtained from the Swedish Cause of Death Register. Results In total, 2277 patients were included (age 66±12 years, 70% male). Early monomorphic VT during index STEMI was documented in 35 (1.5%) and non-monomorphic VT or VF – in 115 (5.1%) patients. Patients with monomorphic VT had similar clinical characteristics compared to those with non-monomorphic VT/VF with a trend of higher prevalence of history of myocardial infarction by index admission among those with monomorphic VT (31% vs 21%, p=0.256). In total, 22 (63%) patients with monomorphic VT and 43 (37%) with non-monomorphic VT/VF died by 8 years of follow up (p=0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF in a univariate analysis (HR 2.03, 95% CI 1.21–3.39, p=0.007) and after adjustment for age and history of myocardial infarction (HR 1.74, 95% CI 1.02–2.97, p=0.041) (Figure). Conclusion Monomorphic VT during the first 48 hours of STEMI is associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF and deserves further studies in order to refine risk stratification strategies. Survival after STEMI by VT/VF &amp;lt;48 hours Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): The Swedish Heart-Lung Foundation

Abstract 16742: Early Recurrence of Ventricular Tachycardia is Associated With Greater One-Year Mortality Among Patients With Severe Heart Failure

Background: Ventricular tachycardia (VT) is common in patients with severe heart failure (HF). Objective: We sought to determine whether early recurrence of VT is associated with worse survival. Methods: We performed retrospective analysis of patients presenting to a tertiary referral hospital between 2006-2017 with VT and severe HF (defined as New York Heart Association functional Class IV or any Interagency Registry for Mechanically Assisted Circulatory Support score) for whom electrophysiology consultation was requested. A comparison was made in baseline characteristics and outcomes between those with early VT recurrence (within 30 days of initial consult) and those without early VT recurrence. Results: Of 129 patients, 47% underwent ablation while 53% were managed medically. Mean age was 60±12 years, 84% were males, ischemic cardiomyopathy was present in 55%, mean LVEF was 24±12%, and 77% had a preexisting ICD. Early recurrence of VT was observed in 25 patients (19%). Those with early recurrence had lower mean LVEF (20±7% vs 25±12%, p =0.032), were less likely to have an ICD prior to presentation (56% vs 82%, p =0.015), were more likely to have been treated with only medications (80% vs 20%, p =0.003), had greater in-hospital mortality (28% vs 5%, p =0.002) and experienced a longer hospitalization (23±19 vs 17±16 days), compared to those without early recurrence. There was no significant difference in other baseline characteristics between groups. Patients with early recurrence had significantly worse 1-year survival 56% vs 82% (Figure), with OR 3.5, 95% CI [1.3,8.9]. Conclusion: Early VT recurrence among patients with severe heart failure is associated with increased mortality within the year following presentation. VT ablation should be considered to help mitigate risk of early recurrence and associated morbidity in such patients.