Atrial Fibrillation

• Issues in Management of AF

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• Should We Maintain Sinus Rhythm?
• The AFFIRM trial
• The SAFE-T trial- amiodarone vs sotalol vs placebo

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• Anticoagulation in AF
  • Risk of Thromboembolism-CHADS2
  • "Moderate Risk" Patients
  • "High-Risk" Patients
  • Secondary Prevention
  • Target INR level for AF patients
  • Maintain INR in theurapeutic range

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• Clopidogrel
  • Anticoagulation slightly better than Clopidogrel with Aspirin
  • Clopidogrel with Asprin better than Aspirin alone for those not eligible for anticoagulation

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• Cardioversion
• Role of Transoesophageal Echo in Cardioversion

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• Use of ACE-inhibitors or ARBs
• ACE-inhibitors may reduce the risk of recurrent PAF in those with lone PAF

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• Non-Pharmacological Therapy
• Options

Thrombo-embolic risk in patients with atrial fibrillation but without high-risk features

The 2001 guidelines of the American Heart Association, American College of Cardiology, and European College of Cardiology lists three different schemes for assessing risk. There seems to be agreement that patients with no high-risk features and aged less than 65 years are at low-risk.

Low-risk patients on aspirin 300mg daily may have an event rate of less than 1% per year, and moderate-risk patients 2-3% per year.

One of these risk stratification schemes (which does not include echocardiographic findings) would classify as “moderate-risk” those with coronary disease or diabetes but without high-risk features. There is disagreement about whether well controlled hypertension should be regarded as a high-risk feature or intermediate-risk factor.

A large proportion of patients in the SPAF II trial had echocardiography and analysis of the data did suggest left atrial enlargement was an independent risk factor for increased risk of thromboembolism. An enlarged left atrium was defined as a high-risk feature in the AFFIRM trial.

Thromboembolic Risk in Chronic Atrial Fibrillation
High Risk	Moderate Risk	Low Risk
see SPAF III and AFFIRM trials' criteria	No high risk features	No high or moderate risk features and aged less than 65 years
	Those who would otherwise be at low risk but are aged more than 65 years
	Probably includes those without high risk features but with well controlled hypertension or with IHD or with diabetes

In cases of doubt, I would be influenced by the findings of echocardiography, in particular assessment of left atrial size (assessed in three dimensions), and assessment of left ventricular systolic or diastolic function.

Several transoesophageal echocardiographic findings have been associated with increased risk but it is uncommon for decisions in routine practise to be based on the findings of this examination.

Hitesh Patel, Cardiologist
26th May, 2004. Modified June, 2009.

Reference:
ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary. J Am Coll Cardiol 2001;38:1231–65).