Anticoagulation in Atrial Fibrillation: A UK Primary-Care Guide (NICE NG196)

Stroke prevention in atrial fibrillation is one of the highest-value decisions made in general practice, and NICE NG196 settled most of the arguments. Direct-acting oral anticoagulants are first-line. Aspirin has no role. Bleeding risk is assessed with ORBIT, and a high score is a prompt to optimise, not to withhold. The detection, risk scoring, initiation, and monitoring all sit largely in primary care.

This is the practical picture in 2026: who to anticoagulate, what to start, how to think about bleeding risk, and the patients on your register who are on the wrong thing. It is written for UK GPs, GP registrars, GP pharmacists, advanced clinical practitioners, and trainees. NICE NG196 and the BNF remain the authoritative references; this post summarises and links, it does not substitute for clinical judgement.

Who to anticoagulate

NICE uses CHA2DS2-VASc to estimate stroke risk. A score of 2 or more is high risk, and anticoagulation should be offered unless there is a genuine contraindication. For men with a score of 1, anticoagulation should be considered. A score of 0 in men — or 1 in a woman where the only point comes from sex — does not warrant anticoagulation.

The decision is shared, and it is not withheld because someone looks like they might bleed. Bleeding risk is managed separately, not used as a veto.

DOACs first-line, and aspirin out

NICE recommends a DOAC in preference to a vitamin K antagonist such as warfarin, and goes further: people established on warfarin should be invited to discuss switching. Apixaban, dabigatran, edoxaban, and rivaroxaban are all options, and the choice is individualised.

Two groups on the register deserve a deliberate look. The first is anyone still taking aspirin for AF stroke prevention — aspirin monotherapy is not recommended, and these patients carry bleeding risk without the protection an anticoagulant would give. The second is well-controlled warfarin patients who have never been offered the switch conversation. Neither needs a new appointment to identify; both need one to resolve.

Bleeding risk: ORBIT, not a veto

NICE NG196 uses the ORBIT score for bleeding risk, having moved on from HAS-BLED because ORBIT was better at identifying those genuinely at low risk.

The framing matters more than the score. A high bleeding-risk result is a list of things to fix — uncontrolled blood pressure, alcohol excess, concurrent NSAIDs or antiplatelets, a fall risk worth addressing — not a reason to leave a high-stroke-risk patient unprotected. Modify what is modifiable, then reassess and, in most cases, anticoagulate.

Choosing a DOAC — and the edoxaban shift

For most patients, DOAC choice is settled by local formulary, renal function, and interactions rather than by a head-to-head clinical edge. Many integrated care boards now prefer edoxaban first-line on cost grounds, following NHS England procurement recommendations, while reserving the alternatives for patients in whom edoxaban is unsuitable.

Renal function is the variable to watch. It determines both choice and dose, should be checked before starting, and rechecked periodically — more often as eGFR falls, and especially during intercurrent illness. Dabigatran is the most renally cleared of the four. The BNF holds the renal thresholds and dose adjustments for each agent, and they are not interchangeable.

A note on rate and rhythm

Anticoagulation is independent of how the rhythm itself is managed. For symptom control, NICE recommends rate control first-line for most people with AF — a standard beta-blocker (not sotalol) or a rate-limiting calcium-channel blocker such as diltiazem or verapamil — with rhythm control reserved for specific situations. The key point for stroke prevention is that restoring sinus rhythm does not remove the need to anticoagulate a patient whose CHA2DS2-VASc score warrants it.

A note on what this post is — and is not

This is a guideline summary for awareness. It is not a substitute for NICE NG196, the BNF, or local prescribing policy. Risk scores, DOAC choice, and renal dosing should be confirmed against the source before prescribing. Clinical decisions remain the responsibility of the prescribing clinician.

The Monday Clinical Brief publishes weekly summaries of the most important new papers and guideline updates across 31 UK medical specialties — including prescribing decisions like this one. We surface them, summarise them, and link to them, so practice-changing material does not get missed in a busy clinical week.

Related reading

• Statins and CVD prevention in UK primary care 2026 (NICE NG238) — the other major cardiovascular-risk decision made routinely in general practice.
• SGLT2 inhibitors for CKD in UK primary care 2026 (TA1075) — renal function drives DOAC choice, and these patients often overlap.
• NICE NG28 February 2026: SGLT2 inhibitors first-line for type 2 diabetes — diabetes is part of the CHA2DS2-VASc score and a common comorbidity in AF.

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