An observational study in Premature Ventricular Beats, Premature Ventricular Complexes and Premature Ventricular Contraction (PVC), sponsored by University of Athens. Recruiting at 6 sites in Greece. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-07-02.
Sponsored by University of Athens · Observational
The UNIFLECA study is a prospective, single-arm, observational cohort evaluating the efficacy, safety, and tolerability of flecainide (in the form of Sanocard) in adults with frequent idiopathic premature ventricular contractions (PVCs) and suspected PVC-induced cardiomyopathy (PVCi-CMP). Frequent PVCs-defined as a burden >5% on two separate 24-hour Holter recordings-are increasingly recognized as a cause of reversible systolic dysfunction in patients without structural heart disease.
Participants undergo a comprehensive baseline evaluation including echocardiography, occasionally cardiac MRI, and coronary angiography or equivalent testing to confirm the absence of structural abnormalities. Patients are enrolled only if they are ineligible or unwilling to undergo catheter ablation, and have no contraindications to flecainide.
Flecainide therapy is initiated at a starting dose of 100 mg/day and titrated up to 200 mg/day, guided by ECG findings, symptom response, and QRS duration. Regular follow-up occurs at three-month intervals over three years, with periodic 24-hour Holter monitoring and assessment of symptoms, LVEF, and adverse events.
The primary outcome is the reduction in PVC burden. Secondary outcomes include improvement in LVEF, symptom relief (measured by structured questionnaires), adverse effects, and long-term treatment adherence. The study aims to generate real-world data on the non-invasive management of PVCs with flecainide and explore its role as an alternative to ablation in carefully selected patients.
The UNIFLECA study is a prospective, single-arm, non-randomized observational cohort designed to evaluate the long-term efficacy and safety of flecainide (in the form of Sanocard) in adult patients with frequent idiopathic premature ventricular contractions (PVCs) and suspected PVC-induced cardiomyopathy (PVCi-CMP). Despite being considered benign in structurally normal hearts, a persistently high PVC burden-particularly above 10%-is increasingly recognized as a cause of reversible left ventricular dysfunction and a potential trigger for cardiomyopathy. This condition is frequently underdiagnosed and may lead to unnecessary treatments or delayed intervention.
The study targets a unique population: symptomatic patients with idiopathic PVCs who have structurally normal hearts and have either declined catheter ablation or are ineligible for invasive procedures. Each patient undergoes comprehensive baseline cardiac evaluation, including transthoracic echocardiography, cardiac magnetic resonance imaging (CMR) to exclude late gadolinium enhancement or myocardial scar, and coronary angiography or non-invasive equivalent to rule out ischemic heart disease. Two 24-hour Holter ECG recordings, taken at least 30 days apart, are used to confirm persistent high PVC burden (>5%).
Flecainide, a Class IC antiarrhythmic agent with sodium channel-blocking properties, is administered as monotherapy. The initial dose is 100 mg/day and may be titrated up to 200 mg/day based on clinical response, patient tolerability, and QRS interval monitoring. Beta-blockers are discontinued unless used for unrelated comorbidities such as hypertension. Patients are monitored with serial 12-lead ECGs, Holter recordings, and echocardiograms at baseline and every three months over a total follow-up period of three years.
The primary endpoint is the percentage reduction in PVC burden as measured by 24-hour Holter ECG. Secondary endpoints include (1) improvement in left ventricular ejection fraction (LVEF), (2) symptom relief as assessed by structured patient questionnaires focusing on palpitations, bradysphygmia, fatigue, dizziness, and exercise intolerance, (3) incidence of adverse events including proarrhythmia, conduction disturbances, and neurological side effects, and (4) adherence to long-term flecainide therapy, including need for dose modifications or drug discontinuation.
This investigator-initiated study is being conducted across tertiary arrhythmia centers in Greece. It aims to fill a significant evidence gap in the long-term pharmacologic management of idiopathic PVCs and PVCi-CMP. Preliminary results indicate significant PVC burden reduction and symptomatic improvement, supporting the potential utility of flecainide as an effective non-invasive therapeutic option in appropriately selected patients. Data from this study will contribute to optimizing treatment strategies for idiopathic ventricular arrhythmias in the absence of structural heart disease, supporting the use of personalized medicine and risk stratification.
102 studies on the registry are indexed under Ventricular Premature Complexes; 32 are open to participants now.
This study's planned enrollment of 300 is above the median of 125 across 39 observational studies indexed under Ventricular Premature Complexes.
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The study population in the UNIFLECA trial consisted of adult patients with frequent idiopathic premature ventricular contractions (PVCs), defined by a PVC burden greater than 5% on multiple 24-hour Holter monitoring. All participants had structurally normal hearts, confirmed by comprehensive imaging including echocardiography, cardiac MRI if necessary, and coronary angiography to exclude cardiomyopathy or ischemic heart disease.
Eligible individuals were required to have no contraindications to flecainide therapy and no history of sustained ventricular arrhythmias, significant conduction abnormalities, or inherited channelopathies. Patients were selected based on the presence of symptoms such as palpitations or fatigue and a clinical suspicion of PVC-induced cardiomyopathy, without the use of other antiarrhythmic drugs.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Persistent, high PVC Burden (\>5%) in 24h Holter Monitoring
Drug: Flecainide (monotherapy)
• Medication: Flecainide acetate, administered orally. * Initial Dosing and Titration: * Patients were started on an appropriate dose based on body weight and renal function. * The typical starting dose was 100-150 mg per day, split into two doses. * Dosing was titrated as needed, depending on patient response and tolerability, under close ECG and clinical monitoring. * Monitoring Protocol: * Continuous ECG monitoring during drug initiation (especially in-hospital or via Holter). * Regular outpatient follow-up visits, including: * 12-lead ECGs * Holter monitoring * Echocardiography (to monitor LVEF and assess for reverse remodeling) * ECG parameters (QRS width, QTc interval) were closely monitored for proarrhythmic changes.
PVC Burden Reduction
Change in 24-hour Holter-measured PVC burden from baseline to 3 years. Unit of Measure: Percent (%)
Time frame: 3 years
Change in Left Ventricular Ejection Fraction (LVEF)
* Measured by echocardiography. * Unit: Percent (%)
Time frame: 3 years
Safety and tolerability of flecainide
* Incidence of adverse effects (e.g., proarrhythmia, dizziness). * Unit: Number of participants with event
Time frame: 3 years
Symptom improvement (Questionnaire Score)
• Structured patient-reported symptom score (palpitations, fatigue, etc.). • Unit: Score on scale (e.g., 0-10)
Time frame: 3 years
Treatment Adherence and Dose Adjustments
* Rate of dose changes or discontinuation due to side effects. * Unit: Number of participants
Time frame: 3 years
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