Comparision of PVC Ablation Techniques (PVC)

Several reports have shown the utility of PVC ablation with cryo catheters. The aim of this study is to compare the outcomes and safety of Cryo vs. RF for PVCs.

Background: Radiofrequency (RF) catheter ablation (CA) is an effective therapeutic strategy in eliminating refractory idiopathic ventricular outflow tract (OT) ventricular arrhythmias (VA). However, early and late recurrences occur commonly. RFCA has also been reported to be associated with collateral damage and pain. The use of Cryo ablation as a safer alternative energy source been previously described. In several reports Cryo was reported to successfully treat VA originating from the OT in the absence of ablation related pain and collateral damage to adjacent structures such as the coronaries. When comparing outcomes and complications of catheter ablation of VA from the papillary muscles of the left ventricle with either Cryo or RF, Cryo was found to be associated with significantly higher success rates and lower recurrence rates than RFCA. Aim: To compare the outcomes and safety of Cryo vs. RF for PVCs. Methods: Patients with PVC VA will be randomized in a 1:1 fashion to RFCA or Cryo ablation. All procedures will be done using a 3-dimensional mapping system (EnSite™ NavX™ system, St. Jude Medical). Ablation will be performed at sites with earliest activation or at least pacemap exhibiting QRS morphology match of >11/12. Endpoint of procedure will be elimination and non inducibility of the clinical VA. All patients will undergo continuous monitoring for at least 12 hours post procedure and 12 lead Holter and exercise testing 1 month post procedure. Successful ablation will be defined as absence of clinical VA or > 50% reduction in arrhythmia burden on Holter in the absence of anti-arrhythmic medications.

Group sample sizes of 44 in Group 1 and 44 in Group 2 achieve 80% power to detect a difference between the group proportions of -0.2000. The proportion in Group 1 (the treatment group) is assumed to be 0.2500 under the null hypothesis and 0.0500 under the alternative hypothesis. The proportion in Group 2 (the control group) is 0.2500. The test statistic used is the two-sided Z test with pooled variance. The significance level of the test was targeted at 0.0500. The significance level actually achieved by this design is 0.0531.

Successful ablation will be defined as absence of clinical VA or > 50% reduction in arrhythmia burden on Holter in the absence of anti-arrhythmic medication.

Comparison of complications such as pericardial effusion/ tamponade, coronary artery damage and post procedure pericardial pain requiring medical management.

Inclusion criteria: Patients referred for PVC ablation. Age ≥ 18 years on a date of consent. Exclusion criteria: Contraindications for ablation Serious known concomitant disease with a life expectancy of < 1 year Elderly patients >80 years of age Pregnancy or nursing Unwilling or unable to give informed consent

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