Noninducibility in Postinfarction Ventricular Tachycardia as an End Point for Ventricular Tachycardia Ablation and Its Effects on Outcomes

Abstract

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 postinfarction VT for long-term outcomes after VT ablation. Methods and Results-We performed a systematic review of MEDLINE (1950MEDLINE ( -2013, EMBASE (1988EMBASE ( -2013, the Cochrane Controlled Trials Register (Fourth Quarter, 2012), and reports presented at scientific meetings (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013). Randomized controlled trials, case-control, and cohort studies of VT ablation were included. Outcomes reported in eligible studies were freedom from VT/ventricular fibrillation and all-cause mortality. Of the 3895 studies evaluated, we identified 8 cohort studies enrolling 928 patients for the meta-analysis. Noninducibility after VT ablation was associated with a significant increase in arrhythmia-free survival compared with partial success (odds ratio, 0.49; 95% confidence interval, 0.29-0.84; P=0.009) or failed ablation procedure (odds ratio, 0.10; 95% confidence interval, 0.06-0.18; P<0.001). There was also a significant reduction in all-cause mortality if patients were noninducible after VT ablation compared with patients with partial success (odds ratio, 0.59; 95% confidence interval, 0.36-0.98; P=0.04) or failed ablation (odds ratio, 0.32; 95% confidence interval, 0.10-0.99; P=0.049). Web-based search engine OVID with explode option for each subject term and the option AND for combining keywords. The MEDLINE was searched from January 1950 to May 2013. The MeSH terms included VT and ablation. We also used a previously developed MEDLINE search strategy to retrieve the strongest scientific studies of treatment by conducting a sensitive search. 11 The EMBASE database was searched from January 1988 to 2013 with keywords including VT and catheter ablation. The Cochrane Controlled Trials Register was searched with a similar approach. All searches were performed in May 2013. We conducted additional searches using 11 author names frequently cited in narrative reviews of VT ablation, as well as modified versions of the Cochrane Optimal Search Strategy. 12 The bibliographies of 10 most recent narrative review articles were also hand-searched. To reduce bias, we restricted our searches to articles reported in English language. 13 Because the meta-analysis was an analysis of prior published studies, an institutional review board approval is not applicable. Conclusions-Noninducibility Study SelectionRandomized controlled trials, case-control, or cohort studies evaluating ablation for treatment of VT were eligible. Case-control and cohort studies were defined according to the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) statement. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses...

Reassessing Noninducibility as Ablation Endpoint of Post-Infarction Ventricular Tachycardia

“…6 However, the predictive value of noninducibility for VT recurrence is limited because ≤30% of patients who are rendered noninducible experience VT recurrences and more than half of the patients who remain inducible for nonclinical VTs do not present recurrence on short-term follow-up. 5 In line with prior recommendations, the majority of patients included in former studies of post-MI VT ablation had an advanced disease with poor left ventricular function, presenting with multiple VT episodes refractory to antiarrhythmic drugs (AAD), including amiodarone. [1][2][3][4][5]7 More recently, ablation early in the course of the arrhythmic disease has been recommended based on 2 randomized trials.…”

“…5 In line with prior recommendations, the majority of patients included in former studies of post-MI VT ablation had an advanced disease with poor left ventricular function, presenting with multiple VT episodes refractory to antiarrhythmic drugs (AAD), including amiodarone. [1][2][3][4][5]7 More recently, ablation early in the course of the arrhythmic disease has been recommended based on 2 randomized trials. 8,9 Because of the reported high recurrence rates, despite noninducibility, new ablation end points like elimination of late or abnormal potentials have been suggested for all patients with scar-related VT, irrespective of baseline patient characteristics and clinical presentation.…”

“…[1][2][3][4][5] Noninducibility is therefore currently used as procedural end point in many electrophysiology laboratories and the only endorsed by the current expert consensus. 6 However, the predictive value of noninducibility for VT recurrence is limited because ≤30% of patients who are rendered noninducible experience VT recurrences and more than half of the patients who remain inducible for nonclinical VTs do not present recurrence on short-term follow-up.…”

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

“…Ablation techniques aiming at the elimination of the endocardial LPs and scar homogenization have been proven effective in treating VT. [3][4][5][6] Although the VT noninducibility after catheter ablation (CA) is commonly used as a procedural end point, some important limitations question the role of programmed ventricular stimulation (PVS) as a proof of long-term success after ablation. [7][8][9] We suggested that the LPs in SAECG correlate with the endocardial scar area and LPs in electro-anatomic maps of patients with ischemic cardiomyopathy. Further, we hypothesized that substrate-guided ablation and abolition of the endocardial LPs can result in normalization of the SAECG.…”

Ventricular Tachycardia Ablation – The Right Approach for the Right Patient

“…[9][10][11] Patients who have VT rendered non-inducible by an ablation procedure have a lower VT recurrence rate and mortality compared with those who still have inducible arrhythmias after the ablation. 12 Catheter ablation has also been shown to be effective in the treatment of VT storm in patients with SHD receiving chronic AAD therapy. 13 In the setting of non-ischaemic SHD, catheter ablation outcome varies according to the nature of the underlying heart disease, with a greater need for epicardial mapping and ablation, higher recurrence rate and more AAD use in long-term follow-up.…”