Usefulness of a limited linear ablation of post-myocardial infarction ventricular tachycardia using a standardized approach based on sinus rhythm mapping

Comparison of Complications of Catheter Ablation for Ventricular Arrhythmias in Adults With Versus Without Structural Heart Disease

Catheter ablation (CA) is an effective treatment for ventricular arrhythmias (VA), with a potential for complications. The presence of structural heart disease (SHD) is associated with a higher complication rate although there is no data comparing CA of VA between patients with SHD and those without. We aimed to compare trends, morbidity, and mortality associated with real world practice of CA for VA (ventricular tachycardia and premature ventricular contraction) based on the presence of SHD. Using weighted sampling in the National Inpatient Sample database, we collected and compared characteristics and outcomes of patients with or without SHD that underwent CA of VA. Among 34,907 patients that underwent CA for VA (1999-2013), 18,014 (51.6%) had SHD. Major and all complications occurred among 1,135/18,014 (6.3%) and 2139/18,014 (11.9%) patients with SHD respectively compared with 355/16,893 (2.1%) and 739/16,893 (4.4%) for patients without SHD, p < 0.001 for both comparisons. Furthermore, 452/18,014 (2.51%) with SHD died versus 20/16,893 (0.12%) without SHD, p < 0.001. Heart failure was associated with an odds ratio (OR) of 3.09 for major complications (95%CI: 1.53-6.27, p = 0.002) for patients with SHD while coronary artery disease OR for major complications was 2.47 (95%CI: 1.44-4.23, p = 0.001) for patients without SHD. There was a significant increase in major complications over the 15-year study period in patients with SHD, p < 0.001. In conclusion, the presence of SHD during CA for VA increased the complication rate of major and any complications by approximately threefold for both and the hospital mortality by >20-fold compared with patients without SHD.

Impact of New Technologies and Approaches for Post-Myocardial Infarction Ventricular Tachycardia Ablation During Long-Term Follow-Up

BACKGROUND

During the past years, many innovations have been introduced to facilitate catheter ablation of post-myocardial infarction ventricular tachycardia. However, the predictors of outcome after ablation were not thoroughly studied.

METHODS AND RESULTS

From 2009 to 2013, consecutive patients referred for post-myocardial infarction ventricular tachycardia ablation were included. The end point of the procedure was complete elimination of local abnormal ventricular activities (LAVA) and ventricular tachycardia (VT) noninducibility. The predictors of outcome with primary end point of VT recurrence were assessed. A total of 125 patients were included (age: 64±11 years; 7 women) for 142 procedures. The left ventricle was accessed via transseptal, retrograde aortic, and epicardial approaches in 87%, 33%, and 37% of patients, respectively. Three-dimensional electroanatomical mapping system was used in 70%, multipolar catheter in 51%, and real-time image integration in 38% (from magnetic resonance imaging in 39% and multidetector computed tomography in 93%) of patients. Before ablation, VT was inducible in 75%, and endocardial/epicardial LAVA were present in 88%/75%. After ablation, complete LAVA elimination was achieved in 60%, and VT noninducibility in 83%. During a median follow-up of 850 days (interquartile range, 439-1707), VT recurrence was observed in 36%. Multivariable analysis identified 3 independent outcome predictors: the ability to achieve complete LAVA elimination (R(2)=0.29; P<0.0001; risk ratio=0.52 [0.38-0.70]), the use of real-time image integration (R(2)=0.21; P=0.0006; risk ratio=0.49 [0.33-0.74]), and the use of multipolar catheters (R(2)=0.08; P=0.05; risk ratio=0.75 [0.56-1.00]).

CONCLUSIONS

Achievement of complete LAVA elimination and use of scar integration from imaging and multipolar catheters to focus high-density mapping are independent predictors of VT-free survival after catheter ablation for post-myocardial infarction ventricular tachycardia.

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

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 (1950–2013), EMBASE (1988–2013), the Cochrane Controlled Trials Register (Fourth Quarter, 2012), and reports presented at scientific meetings (1994–2013). 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).

Conclusions—

Noninducibility of VT after VT ablation is associated with improved arrhythmia-free survival and all-cause mortality.

Catheter ablation of electrical storm in a collaborative hospital network

An electrical storm (ES) is defined as multiple ventricular arrhythmia episodes leading to implantable cardioverter defibrillator interventions. Although conventional rhythm stabilization might be of help acutely, ES involves high mortality and morbidity. We evaluated the effect of catheter ablation strategies in the setting of an interhospital collaborative network on the recurrence of ventricular arrhythmia episodes and mortality in patients with ES. Consecutive patients presenting for invasive treatment of ES from December 2007 to December 2009 were included. All patients underwent catheter ablation of ventricular arrhythmia. The strategies were adapted to the individual cardiac pathologic features. The follow-up examination constituted periodic implantable cardioverter defibrillator interrogation. A total of 32 patients were included. Of the 32 patients, 29 (91%) had monomorphic ventricular tachycardia and 3 ventricular fibrillation. The mean number of implantable cardioverter defibrillator-treated episodes within 7 days before ablation was 16 ± 11. Of the 32 patients, 27 underwent ablation within 24 hours after admission, and 5 underwent acute ablation within 8 hours. In 3 patients, epicardial ablation was performed. In all but 2 patients (6%), the clinical arrhythmia was successfully ablated. During a median follow-up of 15 months, 10 patients (31%) had recurrences of sustained ventricular arrhythmia, including 2 patients (6%) with recurrent ES. Three patients (9%) died during the follow-up period. In conclusion, catheter ablation effectively suppressed ventricular arrhythmia midterm recurrences in patients presenting with ES. Catheter ablation is complex in these severely sick patients. The recurrence rate of ventricular arrhythmia appears to be 31% and the mortality rate to be 9%. Collaborative hospital networks to increase the prompt availability of ES ablation might help to optimize the ES outcome.