Heart transplantation as a rescue strategy for patients with refractory electrical storm

Catheter ablation vs advanced therapy for patients with severe heart failure and ventricular electrical storm

BACKGROUND

Current data on outcomes of an initial strategy of catheter ablation vs advanced therapy in patients with severe heart failure (HF) and electric storm (ES) are limited.

OBJECTIVE

The purpose of this study was to evaluate the outcomes of ventricular tachycardia (VT) ablation vs left ventricular assist device (LVAD) or heart transplantation (HT) in patients with severe HF and ventricular ES.

METHODS

Patients with severe HF and ES who underwent VT ablation, LVAD, or HT between 2012 and 2022 at our medical center were reviewed. Severe HF was defined as ejection fraction ≤ 35% or presence of severe restrictive, valvular, or genetic cardiomyopathy. We assessed in-hospital adverse events and 1-year outcomes between the 2 groups.

RESULTS

Of the 73 patients, 43 (58.9%) underwent VT ablation and 30 (41.1%) received advanced therapy (21 HT (70%) and 9 LVAD (30%)). One-year survival was similar (76.7% vs 86.7%; log-rank, P = .308). However, 10 patients (23.3%) in the ablation group underwent HT during follow-up. After multivariable analysis, United Network for Organ Sharing status 1 or 2 according to VT criteria (hazard ratio 5.52; 95% confidence interval 1.27-24.12; P = .023) and early VT recurrence (hazard ratio 5.67; 95% confidence interval 1.68-19.09; P = .005) were associated with HT or mortality in patients who underwent VT ablation.

CONCLUSION

Patients with severe HF and ES who underwent VT ablation had similar overall survival to patients who directly proceeded with advanced therapy, although rates of HT were high during follow-up. Predictors of HT or mortality after catheter ablation include United Network for Organ Sharing status 1 or 2 according to VT criteria and early VT recurrence.

Extracorporeal Membrane Oxygenation for Patients With Electrical Storm or Refractory Ventricular Arrhythmias: Management and Outcomes

Patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) are at high risk for ventricular arrhythmias due to derangements in myocardial perfusion, hemodynamics, and heightened catecholamine states. Existing data on the management and outcomes of patients with electrical storm or refractory ventricular tachycardia/fibrillation (VT/VF) treated with VA-ECMO are primarily derived from retrospective observational studies. Typical survival rates are in the range of 40%-50%, with 15%-20% of patients undergoing VT ablation and 30%-40% of patients requiring advanced heart failure therapies (cardiac transplant or durable left ventricular assist device). Similarly, there is a paucity of published data on VT/VF management for patients while on VA-ECMO, as these data are largely extrapolated from patients with electrical storm. Although many of the treatment principles (identifying reversible causes, antiarrhythmic drugs, VT ablation, and reduction of adrenergic tone) are translatable, several aspects require special consideration when managing VT/VF in the VA-ECMO patient population. Among carefully selected patients on VA-ECMO who underwent VT ablation, reported recurrence rates were ∼ 30% and a sizeable proportion of them (30%-40%) required advanced heart failure therapy as an exit strategy. In addition, there are specific issues that require consideration for patients on VA-ECMO who undergo VT ablation, such as vascular access, ECMO access site complications, and bleeding due to systemic anticoagulation. Optimal management of VT/VF in this patient population requires ongoing reassessment and dialogue among electrophysiology, heart failure, and critical care specialists. Additional research is needed to better inform the care of this very high-risk patient population.

Impact of Catheter Ablation of Electrical Storm on Survival: A Propensity Score-Matched Analysis

BACKGROUND

Electrical storm (ES) is a life-threatening condition, associated with substantial early and subacute mortality. Catheter ablation (CA) is a well-established therapy for ES. However, data regarding the impact of CA on the short-term and midterm survival of patients admitted for ES remain unclear.

OBJECTIVES

This multicenter study aimed to investigate the impact of CA of ES on survival outcomes, while accounting for key patient characteristics associated with treatment selection.

METHODS

A propensity score-matching (PSM) analysis was performed on 780 consecutive patients admitted for ES in 4 tertiary centers. PSM (1:1) based on the main characteristics associated with the use of CA or medical therapy alone was performed, resulting in 2 groups of 288 patients.

RESULTS

After PSM, patients who underwent CA (n = 288) and those treated with medical therapy alone (n = 288) did not present any significant differences in the main demographic characteristics, ES presentation, and management. Compared with medical therapy alone, CA was associated with a significantly lower rate of ES recurrence at 1 year (5% vs 26%; P < 0.001). Similarly, CA was associated with a higher 1-year (91% vs 81%; P < 0.001) and 3-year (78% vs 71%; P = 0.017) survival after discharge. In subgroup analyses, effect of ablation therapy remained consistent in patients older than 70 years of age (HR: 0.39; 95% CI: 0.24-0.66), with substantial efficacy in patients with a LVEF <35% (HR: 0.39; 95% CI: 0.27-0.59).

CONCLUSIONS

In propensity-matched analyses, this large study shows that CA-based management of patients admitted for ES is associated with a reduction in mortality compared with medical treatment, particularly in patients with a low ejection fraction.

Hypertrophic obstructive cardiomyopathy with recurrent ventricular tachycardias: from catheter ablation and stereotactic radiotherapy to heart transplant-a case report

Background

Management of hypertrophic obstructive cardiomyopathy (HOCM) is often challenging, depending on clinical manifestation. This case report illustrates the complex treatment of HOCM with associated recurrent ventricular arrhythmias.

Case summary

A 54-year-old female with HOCM diagnosed in 2012 underwent a failed attempt for alcohol septal ablation, implantation of an implantable cardioverter-defibrillator, and repeated radiofrequency ablations (including ablation of the septal bulge to reduce LV obstruction). For ventricular tachycardia (VT) recurrences, she had stereotactic arrhythmia radioablation with subsequent epicardial cryoablation from mini-thoracotomy, and endocardial ablation with pulsed field energy. The situation was finally solved by mechanical support and heart transplantation.

Discussion

A few important lessons can be learned from the case. First, radiofrequency ablation was used successfully to decrease left outflow tract obstruction. Second, stereotactic radiotherapy has been used after four previous endo/epicardial catheter ablations to decrease the recurrences of VT. Third, mini-thoracotomy was used after previous epicardial ablation with subsequent adhesions to modify the epicardial substrate with cryoenergy. Fourth, pulsed field ablation of atrial fibrillation resulted in an excellent therapeutic effect. Fifth, pulsed field ablation was also used to modify the substrate for VT, and was complicated by transient AV block with haemodynamic deterioration requiring mechanical support. Finally, a heart transplant was the ultimate solution in the management of recurrent VT.

ECMO for drug-refractory electrical storm without a reversible trigger: a retrospective multicentric observational study

AIMS

Drug-refractory electrical storm (ES) is a life-threatening medical emergency. We describe the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in drug-refractory ES without a reversible trigger, for which specific guideline recommendations are still lacking.

METHODS AND RESULTS

Retrospective observational study in four Iberian centres on the indications, treatment, complications, and outcome of drug-refractory ES not associated with acute coronary syndromes, decompensated heart failure, drug toxicity, electrolyte disturbances, endocrine emergencies, concomitant acute illness with fever, or poor compliance with anti-arrhythmic drugs, requiring VA-ECMO for circulatory support. Thirty-four (6%) out of 552 patients with VA-ECMO for cardiogenic shock were included [71% men; 57 (44-62) years], 65% underwent cardiopulmonary resuscitation before VA-ECMO implantation, and 26% during cannulation. Left ventricular unloading during VA-ECMO was used in 8 (24%) patients: 3 (9%) with intraaortic balloon pump, 3 (9%) with LV vent, and 2 (6%) with Impella. Thirty (88%) had structural heart disease and 8 (24%) had an implantable cardioverter-defibrillator. The drug-refractory ES was mostly due to monomorphic ventricular tachycardia (VT) and ventricular fibrillation (VF) (59%), isolated monomorphic VT (26%), polymorphic VT (9%), or VF (6%). Thirty-one (91%) required deep sedation, 44% overdrive pacing, 36% catheter ablation, and 26% acute autonomic modulation. The main complications were nosocomial infection (47%), bleeding (24%), and limb ischaemia (21%). Eighteen (53%) were weaned from VA-ECMO, and 29% had heart transplantation. Twenty-seven (79%) survived to hospital discharge (48 (33-82) days). Non-survivors were older [62 (58-67) vs. 54 (43-58); P < 0.01] and had a higher first rhythm disorder-to-ECMO interval [0 (0-2) vs. 2 (1-11) days; P = 0.02]. Seven (20%) had rehospitalization during follow-up [29 (12-48) months], with ES recurrence in 6%.

CONCLUSIONS

VA-ECMO bridged drug-refractory ES without a reversible trigger with a high success rate. This required prolonged hospital stays and coordination between the ECMO centre, the electrophysiology laboratory, and the heart transplant programme.

Enhancing Heart Transplantation: Utilizing Gas-Loaded Nanocarriers to Mitigate Cold/Hypoxia Stress

Gas-loaded nanocarriers (G-LN) show promise in improving heart transplantation (HTx) outcomes. Given their success in reducing cell death during normothermic hypoxia/reoxygenation (H/R) in vitro, we tested their integration into cardioplegic solutions and static cold storage (SCS) during simulated HTx. Wistar rat hearts underwent four hours of SCS with four G-LN variants: O2- or N2-cyclic-nigerosyl-nigerose-nanomonomers (CNN), and O2- or N2-cyclic-nigerosyl-nigerose-nanosponges (CNN-NS). We monitored physiological-hemodynamic parameters and molecular markers during reperfusion to assess cell damage/protection. Hearts treated with nanomonomers (N2-CNN or O2-CNN) showed improvements in left ventricular developed pressure (LVDP) and a trend towards faster recovery of the rate pressure product (RPP) compared to controls. However, nanosponges (N2-CNN-NS or O2-CNN-NS) did not show similar improvements. None of the groups exhibited an increase in diastolic left ventricular pressure (contracture index) during reperfusion. Redox markers and apoptosis/autophagy pathways indicated an increase in Beclin 1 for O2-CNN and in p22phox for N2-CNN, suggesting alterations in autophagy and the redox environment during late reperfusion, which might explain the gradual decline in heart performance. The study highlights the potential of nanomonomers to improve early cardiac performance and mitigate cold/H/R-induced stunning in HTx. These early improvements suggest a promising avenue for increasing HTx success. Nevertheless, further research and optimization are needed before clinical application.

Management of cardiogenic shock: a narrative review

Cardiogenic shock (CS) is characterized by low cardiac output and sustained tissue hypoperfusion that may result in end-organ dysfunction and death. CS is associated with high short-term mortality, and its management remains challenging despite recent advances in therapeutic options. Timely diagnosis and multidisciplinary team-based management have demonstrated favourable effects on outcomes. We aimed to review evidence-based practices for managing patients with ischemic and non-ischemic CS, detailing the multi-organ supports needed in this critically ill patient population.