Catheter Ablation of Haemodynamically Not-tolerated Electrical Storm in Structural Heart Disease

Catheter Ablation of Haemodynamically Not-tolerated Electrical Storm in Structural Heart Disease

This is a multi-center, parallel-group, randomized, open-label trial evaluating the clinical outcome and efficacy of emergency catheter ablation versus conventional stepped-care strategies in patients with haemodynamically not-tolerated ventricular tachycardia (VT).

The prognosis of haemodynamically not-tolerated VT in structural heart disease is very poor, with a high 30-day mortality rate >30%, resulting in extremely heavy medical burden. Current guidelines lack specific recommendations for managing this condition. The prevailing treatment strategy involves a sequential approach-beginning with anti-arrhythmic drugs, sedation, and anesthesia, followed by haemodynamic mechanical support devices. Catheter ablation is only used as the final rescue treatment. Typically, patients undergo repeated electrical cardioversion and receive multiple vasopressors and antiarrhythmic drugs, facing increased risks of complications from enhanced haemodynamic support. Studies have shown that these patients often eventually progress to irreversible pump failure, miss the window for effective catheter ablation, and ultimately die. Early cardioversion and maintenance of sinus rhythm, may significantly reduce mortality rates in patients with haemodynamically not-tolerated VT. Therefore, emergency catheter ablation is expected to reduce the mortality of haemodynamically not-tolerated ventricular tachycardia.

In this study, we aim to evaluate the effect of emergency catheter ablation in haemodynamically not-tolerated ventricular tachycardia. Current study will include 96 patients, and all patients will be randomized to either the emergency catheter ablation arm or stepped-care strategies arm in a 1:1 fashion. The follow-up duration is 1 year. The primary outcome is a composite outcome of VT recurrence, cardiovascular re-hospitalization, and all-cause mortality.

Inclusion Criteria:

1. Patients aged 18 to 80 years;
2. Having structural heart disease, including ischemic cardiomyopathy and nonischemic cardiomyopathy;
3. Haemodynamically not-tolerated, defined as persistent hypotension (systolic blood pressure <90 mmHg and mean arterial pressure 30 mmHg lower than baseline or <70 mmHg, with associated signs of end-organ hypoperfusion);
4. Electrical storm, defined as >3 VT episodes within 24 hours.

Exclusion Criteria:

1. Reversible causes of ventricular tachycardia or cardiomyopathy;
2. Ventricular thrombosis diagnosed by echocardiography and/or cardiac magnetic resonance;
3. Acute ST-segment-elevation myocardial infarction within 60 days;
4. Cardiac surgery within 60 days;
5. Unstable angina;
6. Pregnancy.