DAPT Duration Curriculum Module: Teaching the Bleeding-Ischaemia Trade-Off

Module orientation

This module is delivered in the coronary strand of the programme to cardiology trainees preparing for exit examinations, interventional fellows, and consultants who run post-stent follow-up clinics. It is not a summary of what any single document says. The competence being built is different and harder: to defend a duration in front of a colleague, a haematologist and a surgeon, each of whom will push in a different direction. Participants who complete the module should be able to write an antithrombotic plan with a stated stop date and a stated reason, rather than a prescription that quietly persists for years.

Learning objectives

• Separate ischaemic from bleeding risk using structured instruments rather than impression.
• Attribute each major shortening or de-escalation strategy to the trial that supports it.
• Select a P2Y12 agent on the basis of presentation, age, comorbidity and interacting therapy.
• Construct a triple and dual antithrombotic plan for a stented patient with atrial fibrillation.
• Document a duration decision so that the next clinician inherits reasoning, not guesswork.

Block 1 — The clinic that frames the session

Three patients open the session, and the group is asked to prescribe before any evidence is discussed. A 44-year-old smoker with a single stent to the right coronary after inferior infarction. A 79-year-old woman with anaemia, chronic kidney disease and a long left anterior descending stent placed for stable angina. A 68-year-old man with atrial fibrillation, prior gastrointestinal haemorrhage and a bifurcation stent after non-ST-elevation infarction. The answers offered are almost always uniform — twelve months for everybody — and that uniformity is precisely the habit the module exists to dismantle.

The reasoning we install is sequential. Establish the indication for stenting, because chronic and acute presentations start from different defaults. Establish thrombotic risk from anatomy and comorbidity. Establish bleeding risk formally. Only then choose a duration, and record the date on which the second agent stops. Follow-up material for the counselling conversation is drawn from our post-stent counselling course text.

Block 2 — Scoring both risks explicitly

Trainees consistently score ischaemic risk well and bleeding risk badly, so the module weights the second more heavily. Anatomical and clinical features raising thrombotic risk include left main or proximal left anterior descending intervention, true bifurcation stenting with two stents, total stent length beyond about 60 mm, multivessel stenting in a single sitting, treated chronic total occlusion, diabetes on insulin, chronic kidney disease, prior infarction and any previous stent thrombosis.

Bleeding risk is assessed with a named instrument. PRECISE-DAPT is the scoring system most examiners expect at the point of discharge, the Academic Research Consortium high bleeding risk criteria define the population studied in abbreviated-therapy trials, and HAS-BLED remains familiar to physicians managing anticoagulation. Whichever is used, events should subsequently be described using BARC definitions so that a nuisance bruise is not confused with a transfusion-requiring haemorrhage. The point drilled hardest is that a patient can occupy both high-risk categories simultaneously, and that the correct response is a shorter, more potent-sparing regimen rather than paralysis.

Block 3 — The monotherapy evidence

This block is taught as attribution practice: every strategy must be tied to the study that generated it.

The directional summary we ask candidates to reproduce is that shortening dual therapy and continuing a single potent agent reduces bleeding without a demonstrable excess of ischaemic events in appropriately selected patients, while extension beyond a year benefits a narrower group defined by prior infarction, complex anatomy and diffuse disease. Candidates rehearsing trial attribution across the wider syllabus use the cardiology board sprint course text.

Block 4 — Default durations and when to leave them

Defaults are taught as starting positions to be argued away from. After intervention for chronic coronary syndrome with a contemporary drug-eluting platform, six months of dual therapy is the customary anchor, shortened to one to three months where bleeding risk is high and anatomy is simple. After an acute coronary syndrome, twelve months is the anchor, shortened in the same way when bleeding risk dominates, and extended when ischaemic features cluster. Current guidance favours individualisation over a fixed calendar for every patient, and the module frames every deviation as a documented trade-off rather than as a preference.

Agent selection follows presentation. Clopidogrel suits chronic coronary syndrome, older patients, higher bleeding risk and those requiring concomitant anticoagulation. Ticagrelor suits acute presentations and higher thrombotic risk in patients who tolerate its dosing frequency and dyspnoea. Prasugrel is appropriate after intervention for acute syndromes in patients without prior stroke or transient ischaemic attack and with acceptable bleeding risk, with dose reduction in the elderly and low-weight. De-escalation from a potent agent to clopidogrel after the early high-risk weeks is an accepted strategy, guided where available by platelet function or genotype testing. The stent-related background is developed in the advanced PCI techniques course text.

Block 5 — The anticoagulated patient

The atrial fibrillation case is the one participants most often get wrong, so it receives a dedicated block. The evidence base — WOEST, PIONEER AF-PCI, RE-DUAL PCI and AUGUSTUS — points consistently in one direction: minimise the duration of triple antithrombotic therapy, drop aspirin early, prefer a direct oral anticoagulant over a vitamin K antagonist where there is no mechanical valve or significant mitral stenosis, and continue an oral anticoagulant with clopidogrel as dual antithrombotic therapy for the remainder of the first year. In practice, triple therapy is often confined to the peri-procedural period and the first week, extended only when thrombotic risk is exceptional.

Two practical additions are taught alongside. Proton pump inhibition should be prescribed for anyone with gastrointestinal risk factors receiving combination therapy. And after twelve months, most patients continue on the anticoagulant alone, a step frequently forgotten because nobody owns the decision. Antithrombotic planning in complex comorbidity is expanded in the heart failure, rhythm and risk factor collection.

Block 6 — Writing the plan

The module closes with a writing exercise, because a duration decision that lives only in the operator’s head is not a plan. Each participant produces a discharge paragraph naming the agents, the intended stop date for the second agent, the reason for departing from the default, the bleeding score used, and the clinician responsible for review. Papers are exchanged and critiqued. The commonest deficiency is an unstated stop date, which is exactly how patients arrive in clinic four years later on unchanged therapy.

Self-check

• Which trial supports dropping aspirin and continuing ticagrelor after high-risk intervention? TWILIGHT.
• Which trial specifically enrolled patients meeting high bleeding risk criteria? MASTER DAPT.
• A stented patient with atrial fibrillation and prior gastrointestinal bleeding. Regimen at day ten? Direct oral anticoagulant plus clopidogrel, aspirin already stopped, with gastric protection.
• Name a scoring instrument for bleeding risk at discharge. PRECISE-DAPT, with the Academic Research Consortium criteria defining the high bleeding risk phenotype.
• Prasugrel in a 78-year-old with prior transient ischaemic attack? No — prior cerebrovascular events contraindicate it and age warrants a different agent.

How this module is taught in the course

Delivery is a two-hour interactive clinic. The three opening cases are revisited at the end, and participants are asked to explain what changed in their prescribing and why. A trial attribution quiz runs at the midpoint, and the writing exercise is submitted for faculty comment. Written support comes from the acute coronary syndromes course text and the interventional and acute care book collection; those preparing for written papers add the stem set in the cardiology MCQ course question bank. A continuous prose treatment of the same evidence is available as the reference article on DAPT duration after PCI.

Module FAQ

Does the module give a single recommended duration?

Deliberately not. It gives anchors and the arguments for moving away from them, because a fixed answer would be wrong for a large minority of patients.

How much trial detail must be memorised?

Names, populations and directions of effect. Precise event rates are not required and are frequently misremembered; examiners reward correct attribution far more often than recalled percentages.

Is platelet function testing taught as routine?

No. It is presented as a selective tool for de-escalation decisions and for patients with recurrent events on treatment, not as a universal step.

Who should take this module before the interventional strand?

Anyone running a post-stent clinic, including general physicians and pharmacists attached to cardiology services, since most duration errors are made after discharge rather than in the laboratory.

Reviewed by Dr A M Thirugnanam, MD, MSICP, FSCAI, Ph.D., Senior Interventional Cardiologist — who runs the discharge-planning exercise in this module using anonymised prescriptions from his own follow-up clinic.