Prospective Observational Cohort Study of Fetal Atrial Flutter & Supraventricular Tachycardia

NCT ID: NCT03376438

Last Updated: 2025-05-31

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 330 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2017-06-08
• Study Completion Date: 2025-03-31

Brief Summary

The FAST Trial Registry is a prospective observational cohort study of fetuses with a new diagnosis of atrial flutter (AF) or supraventricular tachycardia (SVT) that is severe enough to consider prenatal treatment (see eligibility criteria below). Aims of the Registry include to establish a large clinical database to determine and compare the efficacy and safety of different prenatal treatment strategies including observation without immediate treatment, transplacental antiarrhythmic fetal treatment and direct fetal treatment from the time of tachycardia diagnosis to death, neonatal hospital discharge or to a maximum of 30 days after birth.

Detailed Description

Few studies are specifically designed to address health concerns relevant during pregnancy. The consequence is a lack of evidence on best clinical practice. This includes mothers and their babies when pregnancy is complicated by an abnormally fast heart rate up to 300 beats per minute due to supraventricular tachyarrhythmia (SVA) in the unborn baby (fetus). Although fetal SVA, including AF and other forms of SVT, is the most common cause of intended in-utero fetal therapy, our knowledge of drug effects on the baby and the co-treated mother is still limited. The Fetal Atrial Flutter and Supraventricular Tachycardia (FAST) Therapy Trial is a prospective multi-center trial to address this knowledge gap in order to guide future patient management to the best of care.

FAST Trial components include:

1. A prospective Registry (FAST Registry; see this document) as well as

2. Three prospective Randomized Clinical Trials (FAST RCTs; see ClinicalTrials.gov #NCT02624765).

The FAST Registry is a prospective observational cohort study to determine the impact of different prenatal treatment strategies on patients diagnosed with fetal AF without hydrops, AF with hydrops, SVT without hydrops, and SVT with hydrops. All management decisions including the choice of antiarrhythmic medication or the decision to observe without treatment are at the discretion of the treating physician. The primary outcome measure will be the proportion of term deliveries of live-born children with a normal cardiac rhythm. Secondary outcome measures include the efficacy of 1st line, 2nd line, 3rd line, and maintenance drug therapy in controlling the different arrhythmias prior to birth and patient safety.

Participation of a site in the FAST Registry requires experience with the perinatal management of fetal AF and SVT, local REB/IRB approval and an executed legal contract with the Hospital for Sick Children, Toronto.

Participation of a patient in the FAST Registry requires that all inclusion and none of the exclusion criteria are fulfilled (see below). Enrollment is possible within 2 days of the arrhythmia diagnosis and the initial management decision.

Conditions

Atrial Flutter; Tachycardia, Supraventricular; Tachycardia, Atrial Ectopic; Tachycardia, Reciprocating; Tachycardia Atrial; Tachycardia, Atrioventricular Nodal Reentry; Tachycardia, Paroxysmal; Fetal Hydrops

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Prospective observational cohorts

1\) Atrial flutter without fetal hydrops; 2) Atrial flutter with fetal hydrops; 3) Supraventricular tachycardia without fetal hydrops; and 4) Supraventricular tachycardia with fetal hydrops

Prospective observational cohorts

Intervention Type: OTHER

Patients with AF or SVT that is significant enough to consider prenatal treatment are eligible for enrollment. Management decisions are made at each patient encounter by the primary physician based on clinical findings and may include: 1) no antiarrhythmic treatment; 2) transplacental antiarrhythmic treatment; 3) direct fetal antiarrhythmic treatment; 4) delivery. Patients enrolled in the FAST Registry will be followed from the time of enrollment until the baby is discharged after birth.

Interventions

Prospective observational cohorts

Patients with AF or SVT that is significant enough to consider prenatal treatment are eligible for enrollment. Management decisions are made at each patient encounter by the primary physician based on clinical findings and may include: 1) no antiarrhythmic treatment; 2) transplacental antiarrhythmic treatment; 3) direct fetal antiarrhythmic treatment; 4) delivery. Patients enrolled in the FAST Registry will be followed from the time of enrollment until the baby is discharged after birth.

Intervention Type: OTHER

Other Intervention Names

Non-randomized antiarrhythmic fetal drug therapy

Eligibility Criteria

Inclusion Criteria

1. Mother has provided written informed consent to participate

2. Fetal AF or SVT with or without hydrops

3. Tachyarrhythmia that is significant enough to justify immediate transplacental pharmacological treatment:

• Tachycardia ≥ 180 bpm during at least 10% of observation time of 30 minutes or longer
• Tachycardia ≥ 170 bpm during +100% of time (≤ 30 0/7 weeks of gestation)
• Tachycardia ≥ 280 bpm (irrespective of SVA duration)
• SVT with fetal hydrops (irrespective of duration)

4. Gestational age <36 0/7 weeks at time of enrollment

5. Singleton Pregnancy

6. Healthy mother with ± normal pre-treatment cardiovascular findings:

• ECG within normal range (sinus rhythm; QTc ≤ 0.47; PR ≤ 0.2 sec; QRS: ≤ 0.12 sec; insignificant anomalies; isolated premature beats; isolated complete right bundle
• Maternal resting heart rate ≥ 50 bpm
• Maternal systolic BP ≥ 85 mmHg

Exclusion Criteria

1. Primary delivery for postnatal cardioversion

2. Antiarrhythmic fetal treatment for more than 2 days at time of enrollment

3. Any maternal-fetal conditions associated with high odds of premature delivery and/or death

4. History of significant maternal heart condition (open heart surgery; sick sinus syndrome; long QT, Brugada syndrome; ventricular tachycardia; WPW syndrome; high-degree heart block; cardiomyopathy)

• Minimum Eligible Age: 16 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

Edgar Jaeggi

OTHER

Sponsor Role: lead

Responsible Party

Edgar Jaeggi

Senior Associate Scientist Emeritus Edgar Jaeggi, MD FRCPC

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Edgar Jaeggi, MD, FRCPC

Role: PRINCIPAL_INVESTIGATOR

The Hospital for Sick Children, Toronto, ON, Canada

Locations

Phoenix Children's Hospital

Phoenix, Arizona, United States

University of California, San Francisco

San Francisco, California, United States

Children's Hospital Colorado

Denver, Colorado, United States

Children's National Medical Center

Washington D.C., District of Columbia, United States

Johns Hopkins All Children's Hospital

Saint Petersberg, Florida, United States

John Ochsner Heart & Vascular Institute

New Orleans, Louisiana, United States

Boston Children's Hospital

Boston, Massachusetts, United States

Children's Health Care

Minneota, Minnesota, United States

Children's Mercy Kansas City

Kansas City, Missouri, United States

Cohen Children's Medical Centre/Northwell Health - Lake Success

Lake Success, New York, United States

Columbia University

New York, New York, United States

Cincinnati Children's Hospital Medical Centre

Cincinnati, Ohio, United States

Vanderbilt University Medical Center

Nashville, Tennessee, United States

Inc Pediatric Cardiology of Austin Practice

Austin, Texas, United States

Texas Children's Hospital

Houston, Texas, United States

University of Utah

Salt Lake City, Utah, United States

West Virginia University Research Corporation

Morgantown, West Virginia, United States

Children's Hospital of Wisconsin

Milwaukee, Wisconsin, United States

The Royal Women's Hospital

Melbourne, , Australia

Associação Beneficente Síria - Hospital do Coração

São Paulo, , Brazil

University of Alberta

Edmonton, Alberta, Canada

The U of British Columbia

Vancouver, British Columbia, Canada

Alberta Children's Hospital

Calgary, Ontario, Canada

London Health Sciences Centre

London, Ontario, Canada

The Hospital for Sick Children

Toronto, Ontario, Canada

Mount Sinai Hospital

Toronto, Ontario, Canada

CHU Saine-Justine

Montreal, Quebec, Canada

University Hospital Brno

Brno, , Czechia

Pediatric Research Center

Helsinki, , Finland

Centre Hospitalier Universitaire

Grenoble, Alpes, France

Queen Mary Hospital

Hong Kong, Hong Kong, Hong Kong

Leiden University Medical Centre

Leiden, , Netherlands

National Medical Research Center for Obstetrics, Gynecology and Perinatology

Moscow, , Russia

BCNatal - Hospital Sant Joan de Deu

Barcelona, , Spain

Hospital Virgen de las Nieves

Granada, , Spain

Queen Silvia Children's Hospital

Göteborg, Skåne County, Sweden

Lund University

Lund, , Sweden

Karolinska University Hospital, Astrid Lindgen Childrens Hospital

Solna, , Sweden

Inselspital Universitatsspital Bern

Bern, , Switzerland

Birmingham Women's and Children's NHS Foundation Trust

Birmingham, , United Kingdom

St George's University Hospital Foundation Trust

London, , United Kingdom

Countries

United States; Australia; Brazil; Canada; Czechia; Finland; France; Hong Kong; Netherlands; Russia; Spain; Sweden; Switzerland; United Kingdom

Other Identifiers

1000048953

Identifier Type: -

Identifier Source: org_study_id