Elimination of Local Abnormal Ventricular Activities: A New End Point for Substrate Modification in Patients With Scar-Related Ventricular Tachycardia Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial Treatment of ventricular tachycardia by transcatheter radiofrequency ablation in patients with ischemic heart disease. Catheter Ablation for the Treatment of Electrical Storm in Patients With Implantable Cardioverter-Defibrillators: Short- and Long-Term Outcomes in a Prospective Single-Center Study Incidence and predictors of major complications from contemporary catheter ablation to treat cardiac arrhythmias. Cost-effectiveness of catheter ablation in patients with ventricular tachycardia. Left Ventricular Remodeling and Ventricular Arrhythmias After Myocardial Infarction The 1+1 Trial: A Prospective Trial of a Dual- Versus a Single-Chamber Implantable Defibrillator in Patients With Slow Ventricular Tachycardias Factors influencing appropriate firing of the implanted defibrillator for ventricular tachycardia/fibrillation: findings from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II).
Background — Catheter ablation of ventricular tachycardia ( VT )  is effective and particularly useful in patients with frequent defibrillator interventions . Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT . Noninducibility is the most frequently used end point but is associated with significant limitations , so the optimal end point remains unclear . We hypothesized that elimination of local abnormal ventricular activities ( LAVAs ) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation . As an adjunct to this strategy , we used a new high-density mapping catheter and frequently used epicardial mapping . Methods and Results — Seventy patients ( age , 67±11 years ; 7 female ) with VT and structurally abnormal ventricle(s ) were prospect ively enrolled .  Conventional mapping was performed in sinus rhythm in all , and a high-density Pentaray mapping catheter was used in the endocardium ( n=35 ) and epicardially . LAVAs were recorded in 67 patients ( 95.7 % ; 95 % confidence interval , 89.2–98.9 ) . Catheter ablation was performed targeting LAVA with an irrigated-tip catheter placed endocardially via a transseptal or retro grade aortic approach or epicardially via the subxiphoid approach . LAVAs were successfully abolished or dissociated in 47 of 67 patients ( 70.1 % ; 95 % confidence interval , 58.7–80.1 ) . In multivariate analysis , LAVA elimination was independently associated with a reduction in recurrent VT or death ( hazard ratio , 0.49 ; 95 % confidence interval , 0.26–0.95 ; P=0.035 ) during long-term follow-up ( median , 22 months ) . Conclusions — LAVAs can be identified in most patients with scar-related VT . Elimination of LAVAs is feasible and safe and is associated with superior survival free from recurrent VT BACKGROUND In patients with ventricular tachycardia ( VT ) and a history of myocardial infa rct ion , intervention with an implantable cardioverter defibrillator ( ICD ) can prevent sudden cardiac death and thereby reduce total mortality . However , ICD shocks are painful and do not provide complete protection against sudden cardiac death . We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator . METHODS The Ventricular Tachycardia Ablation in Coronary Heart Disease ( VTACH ) study was a prospect i ve , open , r and omised controlled trial , undertaken in 16 centres in four European countries . Patients aged 18 - 80 years were eligible for enrolment if they had stable VT , previous myocardial infa rct ion , and reduced left-ventricular ejection fraction ( LVEF ; < or=50 % ) . 110 patients were r and omly allocated in a 1:1 ratio to receive catheter ablation and an ICD ( ablation group , n=54 ) or ICD alone ( control group , n=56 ) . R and omisation was done by computer-generated r and omly permuted blocks and stratified by centre and LVEF ( < or=30 % or > 30 % ) . Patients were followed up for at least 1 year . The primary endpoint was the time to first recurrence of VT or ventricular fibrillation ( VF ) . Analysis was by intention to treat ( ITT ) . This study is registered with Clinical Trials.gov , number NCT00919373 . FINDINGS 107 patients were included in the ITT population ( ablation group , n=52 ; control group , n=55 ) . Two patients ( one in each group ) withdrew consent immediately after r and omisation without any follow-up data and one patient ( ablation group ) was excluded because of a protocol violaton . Mean follow-up was 22.5 months ( SD 9.0 ) . Time to recurrence of VT or VF was longer in the ablation group ( median 18.6 months [ lower quartile 2.4 , upper quartile not determinable ] ) than in the control group ( 5.9 months [ IQR 0.8 - 26.7 ] ) . At 2 years , estimates for survival free from VT or VF were 47 % in the ablation group and 29 % in the control group ( hazard ratio 0.61 ; 95 % CI 0.37 - 0.99 ; p=0.045 ) . Complications related to the ablation procedure occurred in two patients ; no deaths occurred within 30 days after ablation . 15 device-related complications requiring surgical intervention occurred in 13 patients ( ablation group , four ; control group , nine ) . Nine patients died during the study ( ablation group , five ; control group , four ) . INTERPRETATION Prophylactic VT ablation before defibrillator implantation seemed to prolong time to recurrence of VT in patients with stable VT , previous myocardial infa rct ion , and reduced LVEF .  Prophylactic catheter ablation should therefore be considered before implantation of a cardioverter defibrillator in such patients . FUNDING St Jude Medical BACKGROUND Recurrent sustained ventricular tachycardia ( VT ) is not responsive to antiarrhythmic drugs in the majority of patients , who therefore need therapy with nonpharmacological methods . We evaluated prospect ively the feasibility , safety , and efficacy of transcatheter radiofrequency ( RF ) ablation of VT in 21 selected patients with ischemic heart disease and VT . METHODS AND RESULTS Twenty-one patients with ischemic heart disease and recurrent , drug-refractory VT documented by 12-lead ECG were selected who had sufficient hemodynamic tolerance of VT to undergo transcatheter mapping . Documented clinical VT was reproduced by programmed cardiac stimulation ( PCS ) , and the site of origin was localized by a combination of techniques , including pace mapping , activation-sequence mapping , recordings of middiastolic potentials , and application of re setting and entrainment principles . RF current at 55 V was applied ( 3.8 + /- 3.1 applications per patient ) for as long as 30 seconds at a time to target sites . Twenty-four distinct clinical VTs ( mean cycle length , 445 + /- 52 milliseconds ) were mapped and ablated in 21 patients . In 17 of 21 patients ( 81 % ) , the procedure was acutely successful , and the target clinical VT could no longer be induced by PCS after the procedure , whereas in 4 patients , clinical VT remained inducible . By contrast , VTs with shorter cycle length and different QRS morphology than the ablated VT could still be induced by PCS in 12 of 21 patients . One patient died in intractable congestive heart failure 10 days after the procedure , and the remaining 20 are alive at the end of the follow-up period . The majority of the patients continued to be treated with at least one additional mode of antiarrhythmic therapy ; 12 patients were still taking antiarrhythmic drugs , and 9 patients received an implantable cardioverter/defibrillator . During a mean follow-up period of 13.2 + /- 5.0 months , 9 of 20 patients ( 45 % ) had recurrent VT . In 4 patients , the recurrent VT was different than the previously ablated one . Clinical VT recurred in all 4 patients in whom RF ablation had been acutely unsuccessful . Four patients with recurrent VT underwent repeat RF ablation procedures that were acutely successful and had no further recurrence . CONCLUSION Transcatheter RF ablation is feasible but has only moderately high efficacy in a small , selected group of patients with ischemic heart disease and drug-refractory , highly frequent , hemodynamically tolerated , sustained VT . In the majority of the patients , this treatment technique is palliative rather than definitive , and many of the patients continue to require other methods of antiarrhythmic therapy Background — Electrical storm ( ES ) caused by recurrent episodes of ventricular tachycardia ( VT ) can cause sudden death in patients with implantable cardioverter-defibrillators and adversely affects prognosis in survivors . Catheter ablation has been proposed for treating ES , but its long-term effect in a large population has never been verified . Methods and Results — Ninety-five consecutive patients with coronary artery disease ( 72 patients ) , idiopathic dilated cardiomyopathy ( 10 patients ) , and arrhythmogenic right ventricular dysplasia/cardiomyopathy ( 13 patients ) undergoing catheter ablation for drug-refractory ES  were prospect ively evaluated . Short-term efficacy was defined by a complete protocol of programmed electric stimulation and by in-hospital outcome ; long-term analysis addressed ES recurrence , cardiac mortality , and VT recurrence . Pleomorphic/nontolerated VTs required electroanatomic and noncontact mapping in 48 and 22 patients , respectively , and percutaneous cardiopulmonary support in 10 patients . An epicardial approach was used in 10 patients . After 1 to 3 procedures , induction of any clinical VT(s ) by programmed electrical stimulation was prevented in 85 patients ( 89 % ) . ES was acutely suppressed in all patients ; a minimum period of 7 days with stable rhythm was required before hospital discharge . At a median follow-up of 22 months ( range , 1 to 43 months ) , 87 patients ( 92 % ) were free of ES and 63 patients ( 66 % ) were free of VT recurrence . Eight of 10 patients with persistent inducibility of clinical VT(s ) had ES recurrence ; 4 of them died suddenly despite appropriate implantable cardioverter-defibrillator intervention . All together , 11 of 95 patients ( 12 % ) died of cardiac-related reasons . In the group of patients presenting with all clinical VTs acutely abolished , no ES recurrence was documented , and cardiac mortality was significantly lower compared with the group of patients showing ≥1 clinical VT still inducible after catheter ablation . Conclusions — Advanced strategies of catheter ablation applied to a large population of patients are effective in the short-term treatment of ES . By preventing ES recurrence , catheter ablation may play a protective role over the long term and , together with long-term pharmacological therapy , may favorably affect cardiac mortality BACKGROUND Up date d underst and ing of the risks of catheter ablation is important because techniques have evolved for procedures treating non-life-threatening as well as potentially lethal arrhythmias . OBJECTIVE This prospect i ve study sought to assess the incidence and predictors of major complications from contemporary catheter ablation procedures at a high-volume center . METHODS Over a 2-year period , 1,676 consecutive ablation procedures  were prospect ively evaluated for major complications throughout 30 days postprocedure . Predictors of major complications were determined in a multivariate analysis adjusted for demographics , clinical variables , ablation type , and procedural factors . RESULTS Rates of major complications differed between procedure types , ranging from 0.8 % for supraventricular tachycardia , 3.4 % for idiopathic ventricular tachycardia ( VT ) , 5.2 % for atrial fibrillation ( AF ) , and 6.0 % for VT associated with structural heart disease ( SHD ) .  Ablation type ( ablation for AF [ odds ratio ( OR ) 5.53 , 95 % confidence interval ( CI ) 1.81 to 16.83 ] , for VT with SHD [ OR 8.61 , 95 % CI 2.37 to 31.31 ] , or for idiopathic VT [ OR 5.93 , 95 % CI 1.40 to 25.05 ] all referenced to supraventricular tachycardia ablation ) , and serum creatinine level > 1.5 mg/dl ( OR 2.48 , 95 % CI 1.07 to 5.76 ) were associated with increased adjusted risk of major complications , whereas age , gender , body mass index , international normalized ratio level , hypertension , coronary artery disease , diabetes , and prior cerebrovascular accident were not associated with increased risk . CONCLUSION In a large cohort of contemporary catheter ablation  , major complication rates ranged between 0.8 % and 6.0 % depending on the ablation procedure performed . Aside from ablation type , renal insufficiency was the only independent predictor of a major complication BACKGROUND This study evaluated the cost-effectiveness of catheter ablation therapy versus amiodarone for treating ventricular tachycardia ( VT ) in patients with structural heart disease . The analysis used a societal perspective for a hypothetical cohort of VT patients with implantable cardioverter-defibrillators , who were experiencing frequent shocks . METHODS AND RESULTS We calculated incremental cost-effectiveness of ablation relative to amiodarone over 5 years after treatment initiation . Event probabilities were from the Chilli r and omized clinical trial ( Chilli Cooled Ablation System , Cardiac Pathways Corporation , Sunnyvale , Calif ) , the literature , and a consensus panel . Costs were from 1998 national Medicare reimbursement schedules . Quality -of-life weights ( utilities ) were estimated using an established preference measurement technique . In a hypothetical cohort of 10 000 patients , 5-year costs were higher for patients undergoing ablation compared with amiodarone therapy ( $ 21 795 versus $ 19 075 ) . Ablation also produced a greater increase in quality of life ( 2.78 versus 2.65 quality -adjusted life-years [ QALYs ] ) . This yielded a cost-effectiveness ratio of $ 20 923 per QALY gained for ablation compared with amiodarone . Results were relatively insensitive to assumptions about ablation success and durability . In less severe patients with good ejection fractions who suffer their first VT episode , the incremental cost-effectiveness ratio was $ 6028 per QALY gained . These cost-effectiveness ratios are within the range generally thought to warrant technology adoption . CONCLUSIONS This study demonstrates that , from a societal perspective , catheter ablation appears to be a cost-effective alternative to amiodarone for treating VT patients Background —The relation between left ventricular ( LV ) remodeling and ventricular arrhythmias after myocardial infa rct ion is poorly documented . We investigated the relations between LV size , hypertrophy , and function and ventricular arrhythmias in 263 patients from the Survival and Ventricular Enlargement ( SAVE ) study , using quantitative 2D echocardiography and ambulatory ECG monitoring after myocardial infa rct ion . Methods and Results —Transthoracic 2D echocardiograms and arrhythmia monitoring were performed at baseline ( mean , 11 days ) and 1 and 2 years after infa rct ion . LV size , short-axis muscle ( mass ) area ( LVMA ) , and function were quantified from 2D echocardiograms . The prevalence of ventricular tachycardia ( VT ) and frequent ventricular ectopy ( premature ventricular contractions [ PVCs ] > 10/h ) was assessed from ambulatory ECG . VT and PVCs > 10/h occurred in 20 % and 29 % of patients at baseline , in 22 % and 35 % at 1 year and 23 % and 39 % at 2 years , respectively . VT and PVCs > 10/h at baseline and 1 and 2 years were significantly related to LV size , LVMA , and function . Furthermore , changes in LV size and function from baseline to 2 years predicted both VT and PVCs > 10/h . The study was underpowered to detect treatment effect of ACE inhibitors and & bgr;-adrenergic receptor blockers but did not alter the relations between ventricular arrhythmias , LV size , and function . Conclusions —Quantitative echocardiographic assessment of LV size , LVMA , and function and changes in these measurements over time predict ventricular arrhythmias after infa rct ion . Altered LV architecture and function during postinfa rct ion LV remodeling provide an important substrate for triggering high- grade ventricular arrhythmias Background —The tachycardia detection interval ( TDI ) in  implantable cardioverter/defibrillators ( ICDs ) is conventionally programmed according to the slowest documented ventricular tachycardia ( VT ) , with a safety margin of 30 to 60 ms . With this margin , VTs above the TDI may occur . However , longer TDIs are associated with an increased risk of inappropriate therapy . We hypothesized that patients with slow VTs ( < 200 bpm ) may benefit from a long TDI and a dual-chamber detection algorithm compared with a conventionally programmed single-chamber ICD . Methods and Results — Patients with VTs < 200 bpm were implanted with a dual-chamber ICD  that was r and omly programmed to a dual-chamber algorithm and a TDI of ≥469 ms or to a single-chamber algorithm with a TDI 30 to 60 ms above the slowest documented VT cycle length and the enhancement criteria of cycle length variation and acceleration . The primary combined end point was the number of all inappropriate therapies , VTs above the TDI , and VTs with significant therapy delay ( > 2 minutes ) . After 6 months , a crossover analysis was performed . Total follow-up was 1 year . One hundred two patients were included in the study . The programmed TDI was 500±36 ms during the dual-chamber phase and 424±63 ms during the single-chamber phase . For the primary end point ( inappropriate therapies , VTs above the TDI , or VTs with detection delay ) , a moderate superiority of the dual-chamber mode was found : Mann-Whitney estimator=0.6661 ; 95 % CI , 0.5565 to 0.7758 ; P=0.0040 . Conclusions —Dual-chamber detection with a longer TDI improves VT detection and does not increase the rate of inappropriate therapies despite a considerable increase in tachycardia burden OBJECTIVES The purpose of this study was to prospect ively examine the role of clinical , laboratory , echocardiographic , and electrophysiological variables as predictors of appropriate initial implantable cardioverter-defibrillator ( ICD ) therapy for ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) or death in the Multicenter Automatic Defibrillator Implantation Trial II ( MADIT-II ) population . BACKGROUND There is limited information regarding the determinants of appropriate ICD therapy in patients with reduced ventricular function after a myocardial infa rct ion . METHODS We used secondary analysis in one arm of a multicenter r and omized clinical trial in patients with a previous myocardial infa rct ion and reduced left ventricular function . RESULTS We analyzed baseline and follow-up data on 719 patients enrolled in the ICD arm of the MADIT-II study . Appropriate ICD therapy was observed in 169 subjects . Clinical , laboratory , echocardiographic , and electrophysiological variables , along with measures of clinical instability such as interim hospitalization for congestive heart failure ( IH-CHF ) and interim hospitalization for coronary events ( IH-CE ) , were examined with proportional hazards models and Kaplan-Meier time-to-event curves before and after first interim hospitalization . Interim hospitalization-CHF , IH-CE , no beta-blockers , digitalis use , blood urea nitrogen ( BUN ) > 25 , body mass index ( BMI ) > or = 30 kg/m2 , and New York Heart Association functional class > II were associated with increased risk for appropriate ICD therapy for VT , VF , or death . In a multivariate ( stepwise selection ) analysis , IH-CHF was associated with an increased risk for the end point of either VT or VF ( hazard ratio [ HR ] 2.52 , 95 % confidence interval [ CI ] 1.69 to 3.74 , p < 0.001 ) and for the combined end point of VT , VF , or death ( HR 2.97 , 95 % CI 2.15 to 4.09 , p < 0.001 ) . Interim hospitalization-CE was associated with an increased risk for VT , VF , or death ( HR 1.66 , 95 % CI 1.09 to 2.52 , p = 0.02 ) . CONCLUSIONS These results provide important mechanistic information , suggesting that worsening clinical condition and cardiac instability , as reflected by an IH-CHF or IH-CE , are subsequently associated with a significant increase in the risk for appropriate ICD therapy ( for VT/VF ) and death
Noninducibility of VT after VT ablation is associated with improved arrhythmia-free survival and all-cause mortality
BACKGROUND Although ventricular tachycardia ( VT ) ablation is a widely used therapy for patients with VT , the ideal end points for this procedure are not well defined .
We performed a meta- analysis of the published literature to assess the predictive value of noninducibility of postinfa rct ion VT for long-term outcomes after VT ablation .