Prophylactic mechanical circulatory support for protected ventricular tachycardia ablation: A meta-analysis of the literature

[Role of ventricular tachycardia ablation in patients with systolic heart failure]

Patients with systolic heart failure (HF) and structural heart disease often suffer from ventricular tachycardias (VTs), which lead to increased morbidity and mortality. Despite advancements in pharmacological therapy and the use of implantable cardioverter-defibrillators, treatment options are limited due to side effects and decreased effectiveness. Catheter ablation (CA) has emerged as a promising therapy for drug-refractory VTs, especially in patients with structural heart disease. This article reviews current knowledge on the indications, efficacy, and long-term prognosis of CA in patients with HF. Additionally, it discusses the importance of preprocedural planning, risk stratification, and emerging therapeutic strategies such as mechanical circulatory support and stereotactic arrhythmia radioablation. The complex relationship between VT and HF, as well as potential risks like acute hemodynamic decompensation, are also addressed.

Impact of mechanical circulatory support on in-hospital outcomes among patients with ventricular tachycardia requiring ablation

BACKGROUND

Ventricular tachycardia (VT) ablation is a high-risk procedure, particularly due to the potential for hemodynamic instability. Mechanical circulatory support (MCS) is increasingly utilized to manage these risks. This study investigated the in-hospital outcomes of VT ablation with MCS use, emphasizing its impact on mortality and procedural complications.

METHODS

We retrospectively analyzed patients undergoing VT ablation from 2019 to 2020, using the National Inpatient Sample data. Patients aged 18 years and over were included. MCS includes a percutaneous left ventricular assist device (pLVAD), extracorporeal membrane oxygenation (ECMO), and intraaortic balloon pump (IABP). We also conducted a subgroup analysis for patients experiencing cardiogenic shock (CS). The primary outcome was in-hospital mortality; secondary outcomes included acute kidney injury (AKI), AKI-requiring dialysis, any bleeding events, gastrointestinal bleeding, ischemic stroke, heart transplant, and durable LVAD (dLVAD) utilization.

RESULTS

We included 14 450 patients, of whom 6.5% utilized MCS. The MCS group showed a higher in-hospital mortality rate than the non-MCS group (24% vs. 2%, p < 0.01). Secondary outcomes showed statistically higher rates in the MCS group compared to the non-MCS groups. Stratification by MCS modality did not affect outcomes except that pLVAD was associated with lower rates of AKI. In the CS subgroup, the MCS group exhibited significantly higher mortality compared to the non-MCS group (32% vs. 8.4%, p < 0.01).

CONCLUSIONS

The use of MCS during VT ablation is associated with increased in-hospital mortality, underscoring the severity of cases requiring such support. These findings show the need for careful assessment and optimal usage of MCS to enhance patient outcomes.

Percutaneous mechanical support in catheter ablation of ventricular arrhythmias: hype or hope?

Catheter ablation (CA) has become an established treatment strategy for managing recurrent ventricular tachycardias (VTs) in patients with structural heart disease. In recent years, percutaneous mechanical circulatory support (PMCS) devices have been increasingly used intra-operatively to improve the ablation outcome. One indication would be rescue therapy for patients who develop haemodynamic deterioration during the ablation. However, more efforts are focused on identifying subjects who are at high risk of such deterioration and could benefit from the pre-emptive use of the PMCS. The third reason to use PMCS could be the inability to identify diffuse substrate, especially in non-ischaemic cardiomyopathy. This paper reviews available experiences using various types of PMCS in different clinical scenarios. Although PMCS allows mapping during VT, it does not significantly influence acute outcomes and not convincingly long-term outcomes. On the contrary, the complication rate appears to be higher in PMCS cohorts. Our data suggest that even in patients with severe left ventricular dysfunction, the substrate modification can be performed without the need for general anaesthesia and risk of haemodynamic decompensation. In end-stage heart failure associated with the electrical storm, implantation of a left ventricular assist device (or PMCS with a transition to the left ventricular assist device) might be the preferred strategy before CA. In high-risk patients who are not potential candidates for these treatment options, radiotherapy could be considered as a bail-out treatment of recurrent VTs. These approaches should be studied in prospective trials.

Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory: A State-of-the-Art Review

Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.

Procedural Adaptations to Avoid Haemodynamic Instability During Catheter Ablation of Scar-related Ventricular Tachycardia

Classically, catheter ablation for scar-related ventricular tachycardia (VT) relied upon activation and entrainment mapping of induced VT. Advances in post-MI therapies have led to VTs that are faster and haemodynamically less stable, because of more heterogeneous myocardial fibrosis patterns. The PAINESD score is one means of identifying patients at highest risk for haemodynamic decompensation during attempted VT induction, who may, therefore, benefit from alternative ablation strategies. One strategy is to use temporary mechanical circulatory support, although this warrants formal assessment of cost-effectiveness. A second strategy is to minimise or avoid VT induction altogether by employing a family of 'substrate'-based approaches aimed at identifying VT isthmuses during sinus or paced rhythm. Substrate mapping techniques are diverse, and focus on the timing, morphology and amplitude of local ventricular electrograms - sometimes aided by advanced non-invasive cardiac imaging modalities. In this review, the evolution of VT ablation over time is discussed, with an emphasis on procedural adaptations to the challenge of haemodynamic instability.

The Use of Cardioprotective Devices and Strategies in Patients Undergoing Percutaneous Procedures and Cardiac Surgery

In the United States, about one million people are seen to visit the operating theater for cardiac surgery annually. However, nearly half of these visits result in complications such as renal, neurological, and cardiac injury of varying degrees. Historically, many mechanisms and approaches have been explored in attempts to reduce injuries associated with cardiac surgery and percutaneous procedures. Devices such as cardioplegia, mechanical circulatory support, and other methods have shown promising results in managing and preventing life-threatening cardiac-surgery-related outcomes such as heart failure and cardiogenic shock. Comparably, cardioprotective devices such as TandemHeart, Impella family devices, and venoarterial extracorporeal membrane oxygenation (VA-ECMO) have also been proven to show significant cardioprotection through mechanical support. However, their use as interventional agents in the prevention of hemodynamic changes due to cardiac surgery or percutaneous interventions has been correlated with adverse effects. This can lead to a rebound increased risk of mortality in high-risk patients who undergo cardiac surgery. Further research is necessary to delineate and stratify patients into appropriate cardioprotective device groups. Furthermore, the use of one device over another in terms of efficacy remains controversial and further research is necessary to assess device potential in different settings. Clinical research is also needed regarding novel strategies and targets, such as transcutaneous vagus stimulation and supersaturated oxygen therapy, aimed at reducing mortality among high-risk cardiac surgery patients. This review explores the recent advances regarding the use of cardioprotective devices in patients undergoing percutaneous procedures and cardiac surgery.