Catheter ablation of early ventricular tachycardia (VT) is not associated with reduced all-cause or cardiovascular (CV) mortality in patients with an ICD, although it is associated with a reduced risk of recurrence of ventricular tachycardia, ICD shock, cardioverter-defibrillator and implantable cardioverter-defibrillator therapies. These results have been published in Heartbeat.
The authors conducted a meta-analysis to evaluate the efficacy of multiple outcomes after early ventricular catheter ablation in patients with an ICD. They performed a systematic search of studies from the PubMed, EMBASE and Cochrane databases from inception to April 2022.
Eligible studies were randomized controlled trials that included adults over 18 years of age with an ICD and a history of VT and/or ICD treatments and trials with an early VT ablation strategy. Control group and outcome of all-cause mortality, VT recurrence, CV hospitalization, hospitalization for heart failure (HF), VT storm, CV mortality, non-CV mortality, and quality of life.
The analysis included 9 randomized controlled trials with 1106 patients, of whom 545 were in the catheter ablation group and 471 in the control group. The mean age of participants ranged from 54 to 71 years, 81% to 95.8% were men, and approximately 92.1% of the sample had ischemic cardiomyopathy.
All studies included data on all-cause mortality and appropriate ICD trauma, 7 included information on CV mortality and VT recurrence, and 6 studies included data on appropriate ICD therapies.
Early ablation with a VT catheter was not associated with lower all-cause mortality (pooled odds ratio [OR], 0.91; 95% CI, 0.63-1.31; And the2= 0%; s = .6) CV mortality (pooled OR, 0.82; 95% CI, 0.51–1.32; I2= 0%; s = .41). Early VT catheter ablation was associated with lower VT recurrence (pole OR, 0.64; 95% CI, 0.46–0.87; I2= 19.6%; s = .007), ICD shocks (pooled OR, 0.53; 95% CI, 0.35-0.79; I2= 45.5%; s = .002), and ICD treatments (pooled OR, 0.54; 95% CI, 0.36–0.80; I2= 44.5%; s = .002).
A total of 7 studies included data on CV hospitalization, 6 had data on storm VT and HF hospitalization, and 4 studies included information on slow VT rates.
Early VT catheter ablation was not associated with lower HF hospitalization (pooled OR, 1.02; 95% CI, 0.44–2.37; I2= 17.5%; s = .96) and slow VT rates (pooled OR, 0.48; 95% CI, 0.14-1.69; I2= 64.5%; s = .25). Early VT catheter ablation was associated with a lower rate of hospitalization (pooled odds ratio, 0.67; 95% confidence interval, 0.51–0.88; I2= 0.8%; s = .004) and Storm VT (pooled OR, 0.59; 95% CI, 0.40–0.87; I2= 0%; s <.001).
In 7 studies reporting information on non-CV-related mortality outcomes, no significant differences were found between early VT resection and control individuals. In 5 studies dealing with physical and mental quality of life, no significant differences were found between the two groups.
Among many limitations, the included studies have different demographic data, gender, methodologies, International Classification of Diseases programming, and ablation protocols, which may lead to residual and unmeasurable biases. Also, the meta-analysis may be weak, particularly with regard to challenging endpoints that do not differ significantly. Furthermore, not all details regarding procedural characteristics are available, and diversity in control groups and other alternative strategies can bias the results.
This study confirmed the benefits of VT CA [catheter ablation] Primarily in reducing VT recurrence, appropriate ICD trauma, ICD treatments, and CV hospitalization,” the study authors note. “…Prospective studies should be conducted to confirm whether VT CA can have similar benefits in patients with NICM [nonischemic cardiomyopathy] who were referred for a VT resection. “
Prasitlumkum N, Navaravong L, Desai A, et al. Effect of ablation of early ventricular tachycardia in patients with an implantable defibrillator: an updated systematic review and meta-analysis of randomized control trials.. Heartbeat. Published online July 9, 2022. doi: 10.1016/j.hrthm.2022.07.005