Risk of bleeding after dual antiplatelet therapy (DAPT) in patients treated with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)

Comprehensive ascertainment of bleeding in patients prescribed different combinations of dual antiplatelet therapy (DAPT) and triple therapy (TT, DAPT plus an anticoagulant) after coronary interventions in the UK: a population based cohort study (the ADAPTT study)

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN76607611

Enrollment

21961

Registered

2016-02-19

Start date

2016-04-01

Completion date

Unknown

Last updated

2023-07-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acute coronary syndrome Circulatory System

Interventions

The health technologies that will be assessed are: 1. DAPT: aspirin (75mg) and clopidogrel (75mg) (AC)

aspirin (75mg) and prasugrel (5mg or 10mg but not varying) (AP)

aspirin (75mg) and ticagrelor (90mg). The DAPT regimen is prescribed according to guidelines and does not vary. 2. Aspirin monotherapy: aspirin (75-300mg). All cardiology patients will be prescribed

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Patients will be included if they: 1. Are labelled as ‘acceptable’ for use in research by CPRD (a process that identifies and excludes patients with non-continuous follow up or patients with poor data recording that raises suspicion as to the validity of that patient’s record) 2. Are over 18 years of age 3. Have one year of medical history in CPRD before cohort entry (time of index procedure or event) 4. Have a record of aspirin monotherapy (Asp) or dual antiplatelet therapy (DAPT: aspirin and clopidogrel, AC; aspirin and prasugrel, AP; aspirin and ticagrelor, AT) in the year following the index procedure or event 5. No record of DAPT in the 3 month prior to the index procedure or event

Exclusion criteria

Exclusion criteria: Participants will excluded if they do not meet the above inclusion criteria

Design outcomes

Primary

Measure	Time frame
Bleeding event (classified as minor or major by WHO bleeding scale) These are all time to event outcomes, so duration of follow up will be time from index event (PCI, CABG or ACS event) to: date of first bleeding event (mortality, hospital admission for the secondary outcomes); 12 months after entry into the cohort (i.e. we will stop following people up if they had no event after 12 months); date of the end of period covered by the data extraction if this is less than 12 months after entry into the cohort; last date of continuous exposure to DAPT + 2 weeks to account for drug clearance (we will consider exposure to be continuous if < 2 weeks between repeat prescriptions); loss of follow up from CPRD. We will also identify all bleeding events during follow-up (12 months)	—

Measure

Time frame

Bleeding event (classified as minor or major by WHO bleeding scale) These are all time to event outcomes, so duration of follow up will be time from index event (PCI, CABG or ACS event) to: date of first bleeding event (mortality, hospital admission for the secondary outcomes); 12 months after entry into the cohort (i.e. we will stop following people up if they had no event after 12 months); date of the end of period covered by the data extraction if this is less than 12 months after entry into the cohort; last date of continuous exposure to DAPT + 2 weeks to account for drug clearance (we will consider exposure to be continuous if < 2 weeks between repeat prescriptions); loss of follow up from CPRD. We will also identify all bleeding events during follow-up (12 months)

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Secondary

Measure	Time frame
1. All-cause mortality 2. Cardiovascular mortality 3. Mortality from bleeding 4. Hospital admission These are all time to event outcomes, so duration of follow up will be time from index event (PCI, CABG or ACS event) to: date of first bleeding event (mortality, hospital admission for the secondary outcomes); 12 months after entry into the cohort (i.e. we will stop following people up if they had no event after 12 months); date of the end of period covered by the data extraction if this is less than 12 months after entry into the cohort; last date of continuous exposure to DAPT + 2 weeks to account for drug clearance (we will consider exposure to be continuous if < 2 weeks between repeat prescriptions); loss of follow up from CPRD.	—

Measure

Time frame

1. All-cause mortality 2. Cardiovascular mortality 3. Mortality from bleeding 4. Hospital admission These are all time to event outcomes, so duration of follow up will be time from index event (PCI, CABG or ACS event) to: date of first bleeding event (mortality, hospital admission for the secondary outcomes); 12 months after entry into the cohort (i.e. we will stop following people up if they had no event after 12 months); date of the end of period covered by the data extraction if this is less than 12 months after entry into the cohort; last date of continuous exposure to DAPT + 2 weeks to account for drug clearance (we will consider exposure to be continuous if < 2 weeks between repeat prescriptions); loss of follow up from CPRD.

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Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 11, 2026