Clinical trial NCT05866731: The Heart Rhythm Twins Study
Official title: The Heart Rhythm Twins Study -- A Pilot Study in Identical and Fraternal Twins
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Premature Atrial Complex
Premature Ventricular Contraction
Keywords: twin
Lead sponsor: University of California, San Francisco
Sponsor class: OTHER
First posted: 2023-05-19
Enrollment: 120
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Same-sex sets of twins from anywhere in the world can enroll, as all study procedures can be done remotely. Both twins must enroll to participate.

Brief summary: Premature atrial contractions (PACs) and premature ventricular contractions (PVCs) are observed in the majority of individuals monitored for more than a few hours. Although the clinical course of PACs and PVCs is usually benign, it has been described that high PAC or PVC frequency causes various comorbidities and worsens outcomes in different patient groups. For example, PACs can initiate episodes of atrial fibrillation, and PAC count is highly specific in predicting diagnosis of incident atrial fibrillation. Increasing PVC frequencies are an important predictor of incident heart failure.

While conventional wisdom dictates that common environmental exposures determine PAC and PVC frequencies, this has not born out in rigorous studies. Whether PAC and PVC frequencies may have genetic underpinnings remains unknown.

Comparisons between identical twins and fraternal twins can provide estimates of heritability. Fraternal twins are an ideal control because, like identical twins, they share a womb, have the same birthday, and their environment while growing up are as similar as between identical twins. However, while identical twins share approximately 100% of the same inherited DNA, fraternal twins share, on average, about 50%. By monitoring identical and fraternal twins with portable electrocardiograms (ECGs), we will be able to count the PACs and PVCs over a consecutive timespan to describe the familial aggregation of these complexes. This, to our knowledge, would be the first study to compare PAC and PVC frequencies in identical and same-sex fraternal twins, providing the first assessment of how genetical inheritance may influence cardiac ectopy burdens.


Eligibility criteria: Inclusion Criteria:

* Identical or same-sex fraternal sets of twins
* English-speaking

Exclusion Criteria:

* Pregnancy
* Current anti-arrhythmic medication use (including beta blockers)
* Diagnosis of congenital heart disease
* Diagnosis of persistent or permanent atrial fibrillation
* Prior cardiac ablation

Primary outcomes:
measure: Frequency of premature atrial contractions (PACs)
timeFrame: Maximum of 2 weeks
measure: Frequency of premature ventricular contractions (PVCs)
timeFrame: Maximum of 2 weeks
Secondary outcomes:
Other outcomes:
Locations:
city: San Francisco
country: United States
facility: University of California, San Francisco
state: California
Study officials:
affiliation: University of California, San Francisco
name: Greg Marcus, MD, MAS
role: PRINCIPAL_INVESTIGATOR
References: