Early ventricular tachycardia (VT) catheter ablation is not associated with lower all-cause or cardiovascular (CV) mortality in patients with an implantable cardioverter-defibrillator (ICD), although it is correlated with a lower risk of VT recurrences, ICD shocks, and ICD therapies. These findings were published in Heart Rhythm.
Researchers conducted a meta-analysis to assess the efficacy for multiple outcomes following early VT catheter ablation in patients with an ICD. They conducted a systematic search of studies from PubMed, EMBASE, and Cochrane databases from inception to April 2022.
Eligible studies were randomized controlled trials that included adults aged older than 18 years with an ICD and history of VT and/or ICD therapies and trials that had an early VT ablation strategy; a control group; and the outcomes of all-cause mortality, VT recurrence, CV hospitalization, heart failure (HF) hospitalization, 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 were in the control group. Participants’ mean age ranged from 54 to 71 years, 81% to 95.8% were men, and about 92.1% of the sample had ischemic cardiomyopathy.
All studies included data on all-cause mortality and appropriate ICD shocks, 7 included information on CV mortality and VT recurrences, and 6 studies included data on appropriate ICD therapies.
Early VT catheter ablation was not associated with decreased all-cause mortality (pooled odds ratio [OR], 0.91; 95% CI, 0.63-1.31; I2=0%; P =.6) and CV mortality (pooled OR, 0.82; 95% CI, 0.51-1.32; I2=0%; P =.41). Early VT catheter ablation was associated with a decrease in VT recurrences (pooled OR, 0.64; 95% CI, 0.46-0.87; I2=19.6%; P =.007), ICD shocks (pooled OR, 0.53; 95% CI, 0.35-0.79; I2= 45.5%; P =.002), and ICD therapies (pooled OR, 0.54; 95% CI, 0.36-0.80; I2=44.5%; P =.002).
A total of 7 studies included data on CV hospitalization, 6 had data on VT storm and HF hospitalization, and 4 studies included information on slow VT rates.
Early VT catheter ablation was not associated with a reduced rate of HF hospitalization (pooled OR, 1.02; 95% CI, 0.44-2.37; I2=17.5%; P =.96) and slow VT rates (pooled OR, 0.48; 95% CI, 0.14-1.69; I2=64.5%; P =.25). Early VT catheter ablation was associated with a reduced CV hospitalization incidence (pooled OR, 0.67; 95% CI, 0.51-0.88; I2=0.8%; P =.004) and VT storm (pooled OR, 0.59; 95% CI, 0.40-0.87; I2=0%; P <.001).
In 7 studies that reported information on non-CV mortality outcomes, no significant differences were found between early VT ablation and control individuals. In 5 studies that reported on physical and mental quality of life, no significant differences were found between the 2 groups.
Among several limitations, the included studies have different demographic data, sex, methodologies, ICD programming, and ablation protocols, which may results in residual and unmeasurable biases. Also, the meta-analysis might be underpowered, particularly regarding hard endpoints that do not significantly differ. Furthermore, not all details on procedural characteristics are available, and diversities in control groups and other alternative strategies could lead to biases in the findings.
“This study emphasized the benefits of VT CA [catheter ablation] primarily in reducing VT recurrences, appropriate ICD shock, ICD therapies, and CV hospitalization,” the study authors noted. “…future studies should be conducted to confirm whether early VT CA can have similar benefits in patients with NICM [nonischemic cardiomyopathy] who were referred for VT ablation.”
Prasitlumkum N, Navaravong L, Desai A, et al. Impact of early ventricular tachycardia ablation in patients with an implantable cardioverter defibrillator: an updated systematic review and meta-analysis of randomized control trials. Heart Rhythm. Published online July 9, 2022. doi: 10.1016/j.hrthm.2022.07.005