Efficacy and Safety of memanTine in the Treatment Of Frequently symPtomatic Atrial Premature Beats (STOP-AP)

Efficacy and Safety of memanTine in the Treatment Of Frequently symPtomatic Atrial Premature Beats: a Multicenter Randomized Double-blind Placebo-controlled Study

A multicenter, randomized, double-blind, placebo-controlled study to expIore the efficacy and safety of Memantine hydrochIoride tabIets to treat patients with frequent PACs.

Study Overview

• Status: Completed
• Conditions: Atrial Premature Beats, Contractions, or Systoles
• Intervention / Treatment: Drug: Memantine Hydrochloride 10 MG; Drug: Placebo

Detailed Description

After preliminary screening, the target patients will undergo continuous 3-day (72-hour) monitoring with a wearable holter patch(as baseline data) to assess the number of baseline atrial premature beats. Based on the monitored data, it will be determined whether the subjects meet the inclusion criteria. Eligible participants will be randomly assigned in a 1:1 ratio (on Day 0) to either the experimental group (administered with hydrochloride memantine tablets) or the control group (placebo). A total of 256 subjects will be enrolled, with 128 subjects in each group, stratified by age (age ≥ 65 years vs. age < 65 years) and the number of atrial premature beats (≥ 5000 beats/24h vs. < 5000 beats/24h).

The subjects in the experimental group will take hydrochloride memantine tablets according to the following regimen:Week 1: Half tablet per dose (5mg/dose), twice daily, taken orally at the same time in the morning and evening (with a recommended dosing interval of 12 hours ± 2 hours).Week 2 to Week 6: One tablet per dose (10mg/dose), twice daily, taken orally at the same time in the morning and evening (with a recommended dosing interval of 12 hours ± 2 hours).

Control group (placebo): The subjects in the control group will take placebo according to the following regimen:Week 1: Half tablet per dose, twice daily, taken orally at the same time in the morning and evening (with a recommended dosing interval of 12 hours ± 2 hours).Week 2 to Week 6: One tablet per dose, twice daily, taken orally at the same time in the morning and evening (with a recommended dosing interval of 12 hours ± 2 hours).

The study consists of a screening period (D0-D7 days), a treatment period (D8-D42 days), and a follow-up period (D43-D56 days).The start dates for the 3-day ambulatory holter patch are as follows: D25-D28, D39-D42, and D53-D56.

• Study Type: Interventional
• Enrollment (Actual): 256
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200120
      • Shanghai East Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age between 18 and 80 (inclusive).
2. Presence of symptoms related to premature atrial contractions (PACs) during screening, with PACs occurring ≥1000 times/24 hours.
3. Understanding and willingness to comply with the study procedures and methods, voluntary participation in the study, and signing an informed consent form.

Exclusion Criteria:

1. Atrial fibrillation, atrial flutter, or persistent atrial tachycardia (confirmed by electrocardiogram within the past 6 months or detected by continuous 3-day (72h) monitoring with a wearable Holter monitor at baseline); or ventricular tachycardia (excluding occasional short episodes of ventricular tachycardia during sleep) or ventricular fibrillation.
2. Occurrence of a stroke event, including hemorrhagic/ischemic stroke and transient ischemic attack (TIA), within the past 6 months prior to screening; history of cardiac surgery, myocardial infarction (MI), percutaneous coronary intervention (PCI), or atrial arrhythmia radiofrequency ablation within the past 3 months prior to screening.
3. Left ventricular ejection fraction (LVEF) ≤40%; or New York Heart Association (NYHA) functional class III or IV.
4. Sick sinus syndrome, second-degree type II or higher atrioventricular block, or bifascicular block without permanent pacemaker implantation.
5. Ongoing use of amiodarone within the past 4 weeks prior to screening, or ongoing use of antiarrhythmic drugs other than amiodarone, as well as Chinese herbal medicine with antiarrhythmic effects within the past 1 weeks prior to screening.
6. Presence of unstable angina, severe congenital heart disease (excluding patent foramen ovale), post-artificial heart valve replacement, acute myocarditis, acute endocarditis, rheumatic heart valve disease,Hypertrophic obstructive cardiomyopathy.
7. Coexistence of other diseases with an expected survival period of less than 1 year.
8. Active hepatitis or significant liver dysfunction (ALT or AST >3 times the upper limit of normal [ULN], TBIL >3 ULN).
9. Severe renal insufficiency (calculated estimated glomerular filtration rate [eGFR] <40 ml/min/1.73m² using the CKD-EPI equation).
10. Received investigational drugs or medical device treatments in other clinical trials within 1 month prior to screening or within 5 half-lives (whichever is longer).
11. Pregnancy, lactating women, or positive pregnancy test result before randomization.
12. Hyperthyroidism that has not been properly treated and thyroid function has not returned to normal, the perioperative period of cardiothoracic surgery (one week before surgery to two weeks after surgery), uncorrected electrolyte disturbances (serum K+ > 5.5 mmol/L or < 3.5 mmol/L, serum magnesium < 1.5 mmol/L, etc.); chronic obstructive pulmonary disease (COPD) combined with respiratory failure or infection that has not been corrected, etc.
13. History of epilepsy, seizures, or mental illness.
14. Known allergy to memantine hydrochloride tablets or their excipients.
15. Patients currently receiving memantine treatment for moderate or severe Alzheimer's disease.
16. Other circumstances where the investigator deems the subject unsuitable for inclusion in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Memantine; Take Memantine Hydrochloride for intervention	Drug: Memantine Hydrochloride 10 MG; Take Memantine Hydrochloride for intervention First week, 5mg(half the tablet), p.o.，bid. Second to Sixth week, 10mg(one tablet), p.o., bid
Placebo Comparator: Placebo; Take placebo for intervention	Drug: Placebo; Take placebo for intervention First week, half the tablet, p.o., bid. Second to Sixth week, one tablet, p.o., bid

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
percentage reduction of 24-hour premature atrial beats count	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour premature atrial beats count was then calculated. percentage reduction of 24-hour premature atrial beats count = (24-hour premature atrial beats count(baseline)-24-hour premature atrial beats count (sixth week) ) /24-hour premature atrial beats count(baseline)	The sixth week after intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SF-36 score change	Participants accepted the Mos 36-item Short Form Health Survey evaluation at baseline and sixth after intervention. SF-36 score change= SF-36 score (baseline)-SF-36 score (sixth week)	The sixth week after intervention
change of 24-hour premature atrial beats count	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour premature atrial beats count was then calculated. change of 24-hour premature atrial beats count =24-hour premature atrial beats count(baseline)-24-hour premature atrial beats count (observation time)	The fourth, sixth and eighth week after intervention
change of 24-hour premature atrial beats burden	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour premature atrial beats burden was then calculated. change of 24-hour premature atrial beats burden =24-hour premature atrial beats burden(baseline)-24-hour premature atrial beats burden (observation time)	The fourth, sixth and eighth week after intervention
change of 24-hour non-sustained atrial tachycardia episodes	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour premature atrial beats episodes was then calculated. change of 24-hour non-sustained atrial tachycardia episodes=24-hour non-sustained atrial tachycardia episodes (baseline)- 24-hour non-sustained atrial tachycardia episodes (observation time)	The fourth, sixth and eighth week after intervention
change of 24-hour non-sustained atrial tachycardia burden	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour non-sustained atrial tachycardia burden was then calculated. change of 24-hour non-sustained atrial tachycardia burden =24-hour non-sustained atrial tachycardia burden(baseline)- 24-hour non-sustained atrial tachycardia burden (observation time)	The fourth, sixth and eighth week after intervention
change of 24-hour sustained atrial tachycardia, atrial flutter and atrial fibrillation episodes	Participants accepted 3-day holter patch monitor at baseline, fourth, sixth and eighth week after intervention. Average 24-hour sustained atrial tachycardia, atrial flutter and atrial fibrillation episodes was then calculated. change of 24-hour non-sustained atrial tachycardia episodes=newly discovered 24-hour non-sustained atrial tachycardia episodes (observation time)	The fourth, sixth and eighth week after intervention
The proportion of new-onset persistent atrial tachycardia, atrial fibrillation (AF), and atrial flutter during continuous 72-hour monitoring at weeks 4, 6, and 8	The proportion of subjects with persistent atrial tachycardia, AF, and atrial flutter ≥ 30 seconds first recorded during the planned continuous 72-hour electrocardiographic monitoring at weeks 4, 6, and 8.This endpoint will be calculated based on the first occurrence of SAT, AF, or AFL during the respective 72-hour monitoring windows;	The fourth, sixth and eighth week after intervention
Cumulative incidence of new-onset AF from week 0 to week 8:	the proportion of subjects with AF ≥ 30 seconds first recorded at any follow-up window at weeks 4, 6, and 8 from randomization to the end of week 8. If the same subject has AF at weeks 4, 6, the first occurrence of AF is counted as one case, with a maximum of one count per subject	The eighth week after intervention
Efficacy analysis of atrial premature beats or non-sustained atrial tachycardia	Efficacy Criteria for Atrial Premature Beats Treatment: A reduction of ≥50% in the average number of atrial premature beats over 24 hours compared to baseline after taking the study drug (Memantine Hydrochloride Tablets or placebo). Efficacy Criteria for Non-sustained Atrial Tachycardia Treatment: A reduction of ≥50% in the average burden of non-sustained atrial tachycardia over 24 hours compared to baseline after taking the study drug (Memantine Hydrochloride Tablets or placebo).	The fourth, sixth and eighth week after intervention
Safety profile of memantine in patients with frequent symptomatic PACs	The incidence of adverse events (including psychiatric symptoms, seizures, bradycardia, new-onset heart failure, etc.), serious adverse events, laboratory test abnormalities, and abnormal electrocardiogram findings.	The eighth week after intervention

Collaborators and Investigators

• Sponsor: Shanghai East Hospital
• Investigators: Principal Investigator: Yihan Chen, Doctor, Shanghai East Hospital

Study record dates

Study Major Dates

• Study Start (Actual): August 29, 2024
• Primary Completion (Actual): March 21, 2025
• Study Completion (Actual): May 16, 2025

Study Registration Dates

• First Submitted: July 9, 2024
• First Submitted That Met QC Criteria: July 9, 2024
• First Posted (Actual): July 15, 2024

Study Record Updates

• Last Update Posted (Actual): November 25, 2025
• Last Update Submitted That Met QC Criteria: November 19, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: randomized; memantine; double-blinded; placebo control; Atrial Premature Beats
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Cardiac Complexes, Premature; Pathological Conditions, Signs and Symptoms; Atrial Premature Complexes; Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Adamantane; Bridged-Ring Compounds; Amantadine; Memantine
• Other Study ID Numbers: 2024YS-146

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No