In a patient with stable angina and left atrial enlargement who is in normal sinus rhythm on electrocardiogram, should anticoagulation be initiated?

No, Do Not Initiate Anticoagulation for Stable Angina with Left Atrial Enlargement in Normal Sinus Rhythm

Anticoagulation is not indicated in patients with stable angina and left atrial enlargement who remain in normal sinus rhythm without documented atrial fibrillation or flutter. 1, 2

Core Principle: Anticoagulation Requires Documented Arrhythmia

• The decision to anticoagulate is based exclusively on documented atrial fibrillation or flutter, not on anatomic findings like left atrial enlargement alone. 1
• All major guidelines require either documented AF/flutter or a CHA₂DS₂-VASc score calculation (which itself presumes AF exists) before initiating anticoagulation for stroke prevention. 3, 1
• Left atrial enlargement is a risk factor for developing AF, but it does not independently warrant anticoagulation in the absence of documented arrhythmia. 3

When NSR on ECG Means No Anticoagulation

• A single ECG showing normal sinus rhythm does not exclude paroxysmal AF, but anticoagulation should not be started based on suspicion alone. 1
• If there is clinical concern for paroxysmal AF (palpitations, unexplained stroke, heart failure), extended cardiac monitoring (24-48 hour Holter or event monitor) should be performed to document arrhythmia before starting anticoagulation. 3
• The ESC guidelines recommend yearly ambulatory ECG monitoring in high-risk populations (such as cardiac amyloidosis), but this is for detection purposes, not empiric treatment. 3

Special Exception: Cardiac Amyloidosis

• The only clinical scenario where anticoagulation may be considered in NSR with left atrial enlargement is cardiac amyloidosis, where guidelines suggest considering anticoagulation in selected cases due to high thrombosis risk even without AF. 3
• However, your patient has stable angina, not cardiac amyloidosis, so this exception does not apply. 3
• Even in cardiac amyloidosis, the ESC statement only recommends "considering" anticoagulation in NSR with specific echocardiographic findings (decreased A-wave amplitude, low left atrial appendage velocities), not routine use. 3

Risk Stratification Requires Documented AF First

• The CHA₂DS₂-VASc scoring system is only applicable to patients with documented atrial fibrillation; it should not be calculated or used to guide anticoagulation decisions in patients with NSR. 1, 2
• Males with CHA₂DS₂-VASc ≥2 or females with ≥3 require anticoagulation, but this recommendation explicitly applies only to AF patients. 1

Common Pitfall to Avoid

• Do not confuse "risk factors for AF" (such as left atrial enlargement, hypertension, heart failure) with indications for anticoagulation. 1
• Aspirin is not an acceptable alternative for stroke prevention and should not be used as a compromise in this situation. 2
• The presence of stable angina (coronary artery disease) does not independently warrant anticoagulation in NSR; it only modifies antiarrhythmic drug selection if AF were present. 3

What You Should Do Instead

• Optimize medical management of stable angina with beta-blockers, antiplatelet therapy (aspirin or P2Y12 inhibitor), and statins. 3
• If there is any clinical suspicion for paroxysmal AF (symptoms of palpitations, unexplained dyspnea, prior stroke/TIA), order extended cardiac monitoring (minimum 24-48 hours, ideally 7-30 days) to document arrhythmia. 3
• If AF is subsequently documented on monitoring, then initiate anticoagulation based on CHA₂DS₂-VASc score at that time. 1, 2
• Reassess periodically, as left atrial enlargement increases the future risk of developing AF, but do not anticoagulate preemptively. 3