A multicentre randomised study on percutaneous stellate ganglion block as first line treatment in patients with electrical storm: the STAR 2 study

The primary objective of this study is to evaluate whether percutaneous stellate ganglion block (PSGB) demonstrates superior efficacy compared to amiodarone in achieving complete suppression of treated ventricular arrhythmias (VA) during the first three hours following treatment initiation in patients experiencing electrical storm. Efficacy is measured by the number of patients who achieve complete suppression of VA requiring intervention with antitachycardia pacing (ATP), internal defibrillation, or external defibrillation. This objective addresses a critical clinical need in managing electrical storm, a life-threatening condition characterized by recurrent ventricular arrhythmias, by comparing an interventional approach to the current standard pharmacological therapy.

The sponsor has not provided information regarding the total number of participants enrolled in this clinical trial. The study population includes **adult participants** aged 18 years and older of **both genders**. Participants present with **electrical storm**, characterized by more than three episodes of **fast ventricular tachycardia** or **ventricular fibrillation** treated by internal or external defibrillator within 12 hours before randomization, with at least one episode occurring within three hours prior to enrollment. The trial population consists of individuals with any **structural heart disease**, including those with **acute or chronic coronary disease** and **catecholaminergic polymorphic ventricular tachycardia**. All participants require defibrillator intervention, either internal or external, for the treatment of fast ventricular tachycardia or ventricular fibrillation. The sponsor has not provided specific information regarding lifestyle considerations such as diet, physical activity, or habits for this study population.

This clinical trial is a multicentre randomised study evaluating percutaneous stellate ganglion block as first-line treatment in patients experiencing electrical storm. The trial is designed as a randomised controlled study comparing the efficacy of percutaneous stellate ganglion block against amiodarone hydrochloride, which is considered the standard of care. The study is classified as a Phase IV trial. The investigational intervention involves the administration of bupivacaine hydrochloride solution for injection at a maximum daily dose of 150 mg and lidocaine hydrochloride monohydrate solution for injection at a maximum daily dose of 600 mg, both administered via paravertebral use. The comparator arm receives amiodarone hydrochloride solution for injection at a maximum daily dose of 1200 mg administered via intravenous injection. The maximum treatment period for all medicinal products is one day.

The primary objective is to assess whether the efficacy of percutaneous stellate ganglion block, expressed as the proportion of patients with complete suppression of treated ventricular arrhythmias during the first three hours after treatment, is superior to amiodarone. Treated ventricular arrhythmias include those managed with antitachycardia pacing, internal direct current shock, or external direct current shock. The primary endpoint is defined as the proportion of patients achieving complete suppression of treated ventricular arrhythmias during the first three hours following treatment administration.

Eligible participants must meet the following principal inclusion criteria: age 18 years or older; more than three episodes of fast ventricular tachycardia or ventricular fibrillation treated by internal or external defibrillator within 12 hours before randomisation, with at least one episode occurring within three hours before randomisation; fast ventricular tachycardia or ventricular fibrillation requiring internal or external treatment; presence of any structural heart disease; acute or chronic coronary disease; or catecholaminergic polymorphic ventricular tachycardia.

The estimated recruitment start date is October 15, 2025, with an estimated study completion date of October 15, 2027. The expected duration of individual participant involvement is limited to the acute treatment phase and the initial three-hour observation period following intervention, with a maximum treatment duration of one day. Early termination from the study may occur under conditions specified in the protocol, though specific termination criteria are not detailed in the available documentation.

The study utilizes two experimental treatment modalities and one comparator treatment. The experimental treatments consist of bupivacaine hydrochloride and lidocaine hydrochloride monohydrate administered via percutaneous stellate ganglion block, while the comparator treatment is amiodarone hydrochloride administered intravenously.

BUPISEN 5 mg/ml solution for injection contains bupivacaine hydrochloride as the active substance. This medicinal product is supplied as a solution for injection and is administered via paravertebral use. The maximum daily dose is 150 mg, with a maximum total dose of 150 mg. The maximum treatment period is 1 day. This product serves as an experimental treatment in the trial.

Lidocaina Kabi 20 mg/ml solution for injection contains lidocaine hydrochloride monohydrate as the active substance. This medicinal product is supplied as a solution for injection and is administered via paravertebral use. The maximum daily dose is 600 mg, with a maximum total dose of 600 mg. The maximum treatment period is 1 day. This product serves as an experimental treatment in the trial.

Amiodarone Hikma 50 mg/ml solution for injection contains amiodarone hydrochloride as the active substance. This medicinal product is supplied as a solution for injection and is administered via intravenous injection. The maximum daily dose is 1200 mg, with a maximum total dose of 1200 mg. The maximum treatment period is 1 day. This product serves as the comparator treatment and represents the standard of care for the condition under investigation.

The primary efficacy endpoint will be assessed by evaluating the proportion of patients with complete suppression of treated ventricular arrhythmias during the first three hours after treatment. Treated ventricular arrhythmias include those managed with antitachycardia pacing, internal direct current shock, or external direct current shock. The study aims to determine whether percutaneous stellate ganglion block demonstrates superior efficacy compared to amiodarone in achieving complete suppression of these arrhythmic episodes within the specified three-hour timeframe following intervention.