Mortality after catheter ablation of structural heart disease related ventricular tachycardia
Graphical abstract
Following VT ablation, 21% of patients underwent cardiac transplant and/or died during follow-up. A novel risk score (MORTALITIES-VA) was derived using univariate predictors of mortality. This score demonstrated good accuracy in predicting transplant and/or mortality during follow-up.
* Excluding ventricular tachycardia and ventricular fibrillation.
Abbreviations: ACEi, angiotensin converting enzyme inhibitor; ARB, angiotensin II receptor blocker; ARNI, angiotensin receptor neprilysin inhibitor; AUC, area under the curve; CV, cardiovascular; SHD, structural heart disease; VF, ventricular fibrillation; VT, ventricular tachycardia.
Introduction
Catheter ablation is efficacious in reducing the burden of ventricular tachycardia (VT) and implantable cardioverter defibrillator (ICD) therapies in patients with structural heart disease (SHD) and drug refractory VT [1]. Despite the overall efficacy of VT ablation in this setting, some patients may have progressive and advanced cardiomyopathies and/or significant comorbidities, which can impact long-term ablation outcomes [[2], [3], [4], [5], [6]].
Prior studies have described predictors of early- and medium-term mortality after VT ablation in populations undergoing ablation up until 2013 [[2], [3], [4], [5]], with reduced left ventricular ejection fraction (LVEF), underlying co-morbidities and increasing age commonly found to be associated with all-cause mortality [[2], [3], [4], [5]]. There is limited data available describing the specific causes of mortality after VT ablation and whether ventricular arrhythmia (VA) recurrence is commonly associated with, or indeed predictive of mortality after VT ablation, with only 2 prior studies from the same multi-centre registry, describing an association with VT recurrence and mortality both in the early- and medium-term after ablation [4,5].
We sought to further our understanding of why patients die after VT ablation, by systematically describing the cause and predictors of cardiac transplant and/or mortality in patients with SHD related VT, undergoing catheter ablation over a contemporary 10-year period at our tertiary referral hospital. Clinical, procedural and outcome data of those patients who underwent cardiac transplant and/or died during follow-up was compared to patients who remained alive, after final catheter ablation. We also propose a novel risk score for predicting transplant and/or mortality after VT ablation.
Section snippets
Methods
Between January 2011 and January 2020, consecutive patients with SHD undergoing catheter ablation for sustained monomorphic VT at a single tertiary centre, were included in this retrospective study. Patients who suffered from all-cause mortality during follow-up were identified using patient clinical records and the New South Wales registry of births, deaths, and marriages. When refractory VA was listed as the primary cause of death, this had to be proven through either ICD electrograms,
Results
Over a 10-year period, 175 consecutive patients with SHD underwent catheter ablation for sustained monomorphic VT. Overall median follow-up was 2.8 (IQR 1.9ā5.0) years. During this period, 37/175 (21%) patients underwent cardiac transplant (nĀ =Ā 5) and/or died (nĀ =Ā 32), with a median time to transplant and/or death of 7.9 (IQR 1.6ā27.1) months. Median follow-up in the patients that remained alive was 3.3 (IQR 2.4ā5.5) years.
Discussion
Our study describes the causes and predictors of cardiac transplant and/or all-cause mortality in patients undergoing catheter ablation for SHD related VT, in a single tertiary centre over a 10-year period. We compare the clinical, electrophysiologic and electroanatomic characteristics between the patients that underwent transplant and/or died and those that did not. We portray the following important findings:
- 1.
End-stage organ failure is the most common cause of cardiac transplant and/or
Limitations
This was an observational study, therefore the potential for selection bias is unavoidable. Given that cardiac transplant and all-cause mortality during medium-term follow-up after VT ablation is a relatively rare occurrence, our patient numbers were small, potentially under powering the significance of our statistical analysis. However, our numbers were comparable to the study by Santangeli et al. [6], in which the PAINESD score was derived. The single centre design of our study means that our
Conclusion
Cardiac transplant and/or mortality following catheter ablation of SHD related VT occurs in approximately 21% of patients during medium-term follow-up. The most common cause of transplant and/or death is end-stage organ failure, specifically cardiac failure. Independent predictors of transplant and/or all-cause mortality included chronic kidney disease, LVEFā¤35%, ageĀ ā„Ā 65Ā years, active malignancy, and failure of amiodarone to control VT before index ablation. VA recurrence was not an
Funding
This study was supported by the NSW early-mid Career Fellowship grant.
Declaration of Competing Interest
Dr. Saurabh Kumar is supported by the NSW early-mid Career Fellowship. Dr. Kumar has received research grants from Abbott Medical and Biotronik; he has received honoraria from Biosense Webster, Abbott Medical, Biotronik, and Sanofi Aventis. Mr. Timothy Campbell has received speakers' honoraria for Biosense Webster, Inc. in the last 12Ā months. Dr. Yasuhito Kotake is the recipient of Nihon Koden/Abbott arrhythmia Fellowship from the Japan Heart Rhythm Society. All other authors have reported no
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