What is the treatment for a 75-year-old patient with atrial fibrillation (AF) and tachycardia?

Treatment for 75-Year-Old with Atrial Fibrillation and Heart Rate 101

For a 75-year-old patient with atrial fibrillation and a heart rate of 101 bpm, initiate oral anticoagulation with a direct oral anticoagulant (DOAC) and implement rate control with a beta-blocker or non-dihydropyridine calcium channel blocker, targeting a resting heart rate <100 bpm. 1, 2, 3

Anticoagulation: The Critical Priority

Oral anticoagulation is mandatory at age 75, regardless of other risk factors. 1, 3

• At 75 years, the patient automatically receives 2 points on the CHA₂DS₂-VASc score, placing them at high risk for stroke (>4% annually without anticoagulation). 1, 3
• The stroke risk without anticoagulation (2-5% annually) substantially exceeds bleeding risk with treatment. 3
• Age alone is never a contraindication to anticoagulation in high-risk patients. 1, 3

DOAC Selection and Dosing

Direct oral anticoagulants are preferred over warfarin due to lower intracranial hemorrhage risk and elimination of INR monitoring. 2, 3

• Apixaban 5 mg twice daily is the standard dose. 2
• Reduce to apixaban 2.5 mg twice daily only if ≥2 of the following: age ≥80 years, weight ≤60 kg, or creatinine ≥1.5 mg/dL. 2
• Alternative DOACs include rivaroxaban 20 mg daily (15 mg if CrCl 30-50 mL/min) or dabigatran. 3, 4

If warfarin is used instead, some experts recommend a target INR of 1.6-2.5 for patients ≥75 years to minimize bleeding risk, though others maintain the standard 2.0-3.0 range. 1, 3

Rate Control Strategy

Rate control with chronic anticoagulation is the recommended initial strategy for most patients with atrial fibrillation, as demonstrated by AFFIRM, RACE, PIAF, and STAF trials showing non-inferiority to rhythm control for mortality and morbidity. 1, 2, 3, 5

Target Heart Rate

• Goal resting heart rate: <100 bpm 2, 3
• The current heart rate of 101 bpm is minimally elevated and may not require aggressive intervention, but optimization is warranted. 2

First-Line Rate Control Agents

Beta-blockers are first-line for rate control in patients without structural heart disease or heart failure. 2, 3

• Metoprolol is specifically recommended and should be titrated to achieve target heart rate at rest and during exercise. 2
• Alternative agents include diltiazem or verapamil (non-dihydropyridine calcium channel blockers). 3
• Avoid digoxin as sole agent in active patients, as it fails to control heart rate during exercise. 1, 2

When to Consider Rhythm Control

Rhythm control should only be pursued if symptoms persist despite adequate rate control, not as first-line therapy. 2

Essential Baseline Evaluation

Before initiating treatment, obtain:

• 12-lead ECG to confirm atrial fibrillation. 2
• Renal function (creatinine/eGFR) before starting DOACs. 2, 3
• Thyroid function, electrolytes, complete blood count, and hepatic function to identify reversible causes. 2
• Transthoracic echocardiogram to assess for structural heart disease. 2
• Blood pressure measurement - hypertension control is critical to reduce both ischemic stroke and intracerebral hemorrhage risk with anticoagulation. 3

Critical Monitoring Requirements

• Renal function monitoring at least annually when using DOACs, more frequently if clinically indicated. 2, 3
• Never discontinue anticoagulation after cardioversion or if sinus rhythm is restored - stroke risk persists based on underlying risk factors (age 75), not current rhythm. 2, 3, 5
• In RACE trial, 21 of 35 thromboembolic complications occurred under rhythm control, predominantly with inadequate anticoagulation. 5

Common Pitfalls to Avoid

• Do not use aspirin alone or aspirin plus clopidogrel as primary stroke prevention in this patient - it is inadequate for AF patients eligible for anticoagulation. 2
• Do not pursue rhythm control with antiarrhythmic drugs as first-line without attempting rate control with safer agents first. 2
• Do not withhold anticoagulation due to fall risk or age concerns - the stroke prevention benefit outweighs bleeding risk even in elderly patients. 1, 3, 6
• Avoid intravenous digoxin, diltiazem, or verapamil if heart failure with reduced ejection fraction is present, as these may worsen hemodynamics. 1