EDC for atrial fibrillation clinical trials
AF trials split into two data problems: rare, adjudicated events in stroke prevention, and rhythm recordings in ablation and drug studies. Capture holds both with dated, audit-trailed records. Build free, no credit card.
- Stroke and bleeding events
- Recurrence and AF burden
- Anticoagulant dosing log
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Potential events awaiting packet
4
Dose-criteria checks done
212 / 218
Open bleeding queries
7
Visits with creatinine clearance
96%
2 awaiting records
What an AF trial needs from its EDC
- Event-driven endpoints: stroke and systemic embolism, major bleeding and clinically relevant non-major bleeding are rare, high-stakes events, usually reviewed by a clinical events committee against source documents.
- Bleeding scales named in the protocol: registered trials commonly use the ISTH definitions of major bleeding (a haemoglobin fall of at least 2 g/dL, transfusion of two or more units, a critical site, or fatal bleeding) and clinically relevant non-major bleeding. Use the exact version in your protocol.
- Rhythm endpoints for ablation and drug studies: recurrence is often any documented AF, flutter or tachycardia episode over 30 seconds after a blanking period (commonly three months in ablation protocols; confirm yours), plus AF burden from ambulatory or wearable monitoring.
- Dose rules that depend on lab values: anticoagulant dose often depends on age, weight and creatinine clearance, so the inputs must be on the form at each visit.
- Procedure safety: for ablation, tamponade, stroke, phrenic nerve injury, pulmonary vein stenosis and oesophageal injury are tracked separately from the efficacy endpoint.
Two kinds of AF trial
Stroke prevention and rhythm control need different forms
In a stroke-prevention study the headline outcome is a composite or a pair of events: stroke or systemic embolism for efficacy and major bleeding for safety. These events are rare, so trials are large and event-driven, and the data that matter are the event reports, not the routine visits. Capture can store a structured event form per suspected event (type, onset date, hospitalisation, imaging done, treatment, outcome) and the event dates and source documents that go to a clinical events committee. Capture does not provide an adjudication workflow: committee review runs in your own process, and the committee decision is entered back as a final classification with its date. Keep suspected and adjudicated classification as separate fields so both appear in the export. See adverse event reporting software for the safety structure and the SAE report form for serious events.
In ablation and rhythm-control studies the headline is time to first recurrence. Recording the recurrence is harder than it looks, because it depends on how rhythm was monitored: 12-lead ECGs at scheduled visits, patch or Holter recordings at fixed intervals, implanted monitors, or symptom-triggered recordings. Store each recording as a row with type, start and end dates, wear time and the result category entered by the reader. Do not collapse them into one yes or no: wear time is needed to judge whether a negative result is informative, and the blanking window requires the ablation date as an anchor. Capture does not read ECG files or connect to Holter or patch devices; recordings are summarised and entered by staff or loaded by your own process. See QTc calculator for the QTc fields that Capture can calculate during entry (Bazett and Fridericia).
Dose rules deserve their own edit checks. Capture can calculate Cockcroft-Gault creatinine clearance and eGFR (CKD-EPI 2021) from entered values and show them read-only during entry, so the dose-reduction criteria in the protocol (typically combinations of age, weight and renal function) can be checked at the form. A range or custom-value edit check can raise an automatic query when entered dose and calculated clearance do not match the rule you define. It is a data check, not dosing advice, and it does not replace the investigator. See also EDC for chronic kidney disease trials, since renal function limits many AF populations.
Risk scores and eligibility
Many AF protocols use the CHA2DS2-VASc score for eligibility and HAS-BLED for bleeding risk context. Capture has no built-in calculator for either, so record the component fields (age band, sex, heart failure, hypertension, diabetes, prior stroke, vascular disease) on the screening form and compute the score in the analysis, or enter the total with the source components beside it for review. See vital signs template and medical history template for building the components.
Monitoring type
MONTYPERecording start
MONSTDTCRecording end
MONENDTCWear time
WEARDAYCompare with minimum in protocol
AF, flutter or tachycardia over 30 seconds
AFRECDate of first episode
AFDTCOpens when episode is Yes
2026-04-09Which AF design are you running?
Common AF trial types and what to configure
| Design | Primary data | What to configure in Capture |
|---|---|---|
| Anticoagulant versus comparator | Stroke or systemic embolism, major bleeding, CRNM bleeding | Event forms with suspected and final classification; dosing log; renal inputs. If the comparator is a vitamin K antagonist, add a coagulation and INR log |
| Catheter ablation versus drug | Time to first recurrence after blanking; AF burden | Procedure form, monitoring rows with wear time, blanking date calculated from the ablation date |
| Rate or rhythm control strategy | Hospitalisation, quality of life, symptom burden | Visit forms plus EQ-5D layout; strategy-change log |
| Post-ablation antithrombotic strategy | Bleeding and thromboembolic events at 12 to 24 months | Long follow-up with event forms; monitoring rows |
| Device or digital detection | Detection rate, time to diagnosis | See EDC for medical device trials and wearable device studies |
Build the event and monitoring forms and test them with mock participants
Enter a suspected bleed, an ablation with a recurrence after blanking, and a dose-reduction case. Free sandbox, no credit card.
Follow-up and operations
Long follow-up, missed events and keeping the event list complete
Event-driven trials fail quietly when events are missed. Build prompts into every visit form that ask about hospitalisation, emergency visits, new neurological symptoms, bleeding and any change in antithrombotic therapy, and require an answer, not a blank. When an answer is Yes, skip logic opens the event form. Between visits, participants can answer a short check-in on their phone through a secure link with reminders, which helps catch events that never reach the site. A query is raised automatically if a visit date passes and the form is empty, and Capture lists open queries by site so monitors can chase them.
The anticoagulant dosing record is a repeating-row log: dose, start date, stop date, reason for any interruption (bleeding, procedure, other), because interruptions around ablation or surgery matter to the safety analysis. Treatment-emergent events should be tied to the dose in force on the event date, which is something the statistician can derive from the export. For monitoring, risk-based approaches reduce visits to sites that have clean data; see risk-based monitoring.
AF participants are often older with several medications. Concomitant therapy is part of the safety story (antiplatelets, NSAIDs, antiarrhythmics, drugs that interact with anticoagulants), so use concomitant medications as repeating rows. For heart failure overlap see EDC for heart failure trials, and for the broader cardiology picture EDC for cardiology trials. Data are hosted in the EU (Frankfurt) or the USA (N. Virginia), and the field-level audit trail records every change.
Before first participant
Atrial fibrillation study readiness checklist
Event definitions written
Stroke, systemic embolism and bleeding definitions copied from the protocol onto the event form help text.
Suspected and final classification
Separate fields for the site report and the committee decision, each dated.
Blanking window anchored
Ablation date captured; recurrence form shows the days since ablation.
Monitoring rows complete
Type, start, end, wear time and result for every recording.
Dose rule tested
A mock participant with borderline renal function checked against the edit check.
Interruption log
Anticoagulant interruptions with reasons and dates available in the export.
Does Capture run clinical event adjudication?
No adjudication workflow is claimed. Capture stores the site-reported event and the committee final classification with dates, and exports both. Packaging and review of source documents is done in your own process.
Can it read Holter or patch monitor files?
No device integration is claimed. Staff or your own data process enter the recording summary (type, dates, wear time, result), and the audit trail records each change.
Can Capture calculate creatinine clearance for dose rules?
Yes. Cockcroft-Gault creatinine clearance and eGFR (CKD-EPI 2021) are calculated during entry from the values entered, and edit checks you define can raise a query when dose and result disagree. The rule itself comes from your protocol.
Does it calculate CHA2DS2-VASc or HAS-BLED?
No. Record the components on the screening form and compute the score in analysis, or enter the total with the components beside it.
How are blanking windows handled?
Capture the ablation date and compute days since ablation during entry. The recurrence definition and window length come from your protocol and statistical plan.
Can I get SDTM datasets?
Yes. Capture exports CDISC SDTM as SAS XPT files with Define-XML, alongside CSV and Excel with an automatic data dictionary.
How much does it cost?
The sandbox is free with nearly every feature, no credit card. Plans and prices are on the pricing page.
Keep exploring
Related pages
EDC for cardiology trials
The cardiovascular overview.
EDC for heart failure trials
A common comorbidity.
EDC for hypertension trials
Blood pressure endpoints.
Coagulation and INR log
For vitamin K antagonist arms.
QTc calculator
Bazett and Fridericia.
Adverse event reporting software
Seriousness and sign-off.
Pricing
Free sandbox.
Start your AF study free
Free sandbox with nearly every feature. No credit card.