Effects of Carvedilol on Suppressing the Premature Ventricular Complex/Ventricular Tachycardia From Outflow Tract (FOREVER)

Keimyung University

Status and phase: Unknown; Phase 4

Conditions: Carvedilol; Ventricular Premature Complexes; Outflow Tract

Treatments: Drug: Flecainide; Drug: Carvedilol

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT03587558

2017-07-022

Details and patient eligibility

About

Carvedilol is known to be effective in reducing ventricular arrhythmias and mortality in patients with heart failure. It is suggested that one of the mechanisms is its ability to block store overload-induced Calcium release which activates spontaneous calcium release by Ryanodine receptors. Ventricular outflow tract tachyarrhythmia is known to be associated with calcium overload due to activation of Ryanodine receptors. The aim of this study is to evaluate the efficacy of Carvedilol on premature ventricular complex(PVC)/ventricular tachycardia(VT) originating from outflow tract.

Full description

Carvedilol is one of the third-generation beta-blockers effective in reducing ventricular arrhythmias and mortality in patients with heart failure. Antioxidative and alpha - blocking effects, along with nonselective beta - blockade, have been described as a mechanism of effect in various diseases.

The antiarrhythmic effect of carvedilol inhibiting atrial fibrillation or ventricular arrhythmia has been reported, but its mechanism is not yet clear. Among them, inhibition of store overload-induced Ca2+ release (SOICR) is suggested as an antiarrhythmic mechanism of carvedilol.

Stimulation of the beta receptor leads to the entry of calcium into the sarcoplasmic reticulum (SR) by opening the L-type calcium channel. The influx of calcium through the L-type calcium channel also increases the calcium release through the Ryanodine receptor (RyR) in the sarcoplasmic reticulum. This is called Ca-induced Ca release and is known as a normal physiological response. However, when calcium overload in the myofibrillar body occurs, spontaneous calcium release, known as SOICR, can occur through RyR, which can make triggered activity by inducing Na+/Ca2+ exchanger present in myocardium, leading to severe arrhythmia. Among several beta-blockers, only carvedilol has been known as a drug that can directly inhibit SOICR in combination with beta-blockade effect.

Ventricular tachyarrhythmia originating from the ventricular outflow tract is an arrhythmia occurring in a patient with normal cardiac function. The mechanism of the arrhythmia is known to be triggered activity which is caused by activation of RyR due to increased cyclic adenosine monophasphate, resulting in calcium overload, eventually causing activation of Na+/Ca2+ exchanger. The aim of this study is to evaluate the efficacy of Carvedilol on PVC/VT originating from outflow tract.

Enrollment: 104 estimated patients

Sex: All

Ages: 19 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients with ventricular premature complexes/ventricular tachycardias originating from ventricular outflow tract confirmed on the 12-lead surface ECG

• Patients with PVC burden of 5% or more in 24-hour Holter monitoring

• Patients with normal left ventricular function

  • left ventricular ejection fraction ≥50%

• Patients without structural heart disease

Exclusion criteria

• Pregnant, trying to become pregnant or breast feeding
• History of bronchial asthma
• History of coronary arterial disease

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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104 participants in 2 patient groups

Carvedilol group

Experimental group

Description:

Patients in this group are taking carvedilol to inhibit outflow tract PVC/VT. Dilatrend® sustained release form of Chong Kun Dang Pharmaceutical will be used (initial dose: 8 mg sustained release form). Outpatient follow-up will be performed every 2 weeks and the dose is increased from the initial dose to a maximal tolerable dose, at the discretion of the investigator.

Treatment:

Drug: Carvedilol

Flecainide group

Active Comparator group

Description:

Patients in this group are taking flecainide to inhibit outflow tract PVC/VT. Tambocor® of JW Pharmaceutical will be used. Outpatient follow-up will be performed every 2 weeks and the dose is increased from the initial dose to a maximal tolerable dose, at the discretion of the investigator.

Treatment:

Drug: Flecainide