Comparing morning versus bedtime aspirin for cardiovascular health

Randomized Comparison of Morning Versus Bedtime Administration of Aspirin: A Cardiovascular Circadian Chronotherapy (C3) Trial

Phase 4 Interventional Herlev and Gentofte Hospital · NCT05932472

This study is testing if taking aspirin at bedtime works better than taking it in the morning for people who are already using aspirin to protect their heart health.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment32706 (estimated)
Ages18 Years and up
SexAll
SponsorHerlev and Gentofte Hospital Academic / other
Locations1 site (Hellerup)
Trial IDNCT05932472 on ClinicalTrials.gov

What this trial studies

This trial investigates whether taking aspirin at bedtime is more effective than taking it in the morning for reducing major adverse cardiovascular events in patients already on aspirin therapy. It utilizes a pragmatic, registry-based, open-label, randomized controlled design, leveraging Denmark's nationwide health registries for participant identification and data collection. Participants will provide electronic informed consent and will be randomized to either morning or bedtime aspirin administration without the need for in-person visits.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older who are currently on chronic aspirin treatment.

Not a fit: Patients who are not currently taking aspirin or those under 18 years old may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved cardiovascular outcomes for patients through optimized aspirin administration timing.

How similar studies have performed: Previous pilot studies have suggested potential benefits of bedtime aspirin administration, indicating a promising avenue for further investigation.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age \>=18 years
* Current chronic treatment with aspirin (as recorded in the Danish National Prescription Registry and confirmed by the participant via questionnaire)
* Signed informed consent

Exclusion Criteria:

* There are no exclusion criteria for this trial

Where this trial is running

Hellerup

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions AtherosclerosisCardiovascular DiseasesDrug EffectAspirinCardiovascular DiseasePreventionCircadian RhythmRandomized Controlled Trial
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.