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

How much benefit do patients with previous thromboembolism and non-rheumatic atrial fibrillation get with anticoagulation with warfarin?

The European Atrial Fibrillation Trial randomised patients with recent transient ischaemic events or minor stoke were randomised to placebo, low dose aspirin or to oral anticoagulation therapy {target INR 2.5 to 4.0}. The qualifying thromboembolic event had to have occurred within three months of enrolment into the study. The mean age was just over 70 years, as in the SPAF III and AFFIRM trials.

The primary outcome events were death form vascular disease, non-fatal stroke (including intracranial haemorrhage), or systemic embolism. After an average follow-up of 2.3 years there was a 57 percent reduction in risk of outcome events. The annual event rate was reduced from 17 percent in the placebo group to 8 percent in the anticoagulant group. There was a non-significant reduction in the aspirin group compared with placebo {aspirin group event rate 15% per year}.

The risk of stroke alone was reduced from twelve percent to four percent per year by oral anticoagulant therapy.

Annual major bleeding rates in the anticoagulant group were 2.8 percent per year and similar to that noted in the SPAF III trial. The bleeding risk with low dose aspirin only was 0.9 percent per year, and 0.7 percent per year in the placebo group. The mean age of the participants was just over 71 years. This observation suggests that therapeutic anticoagulation in this age group increases risk of major bleeding by about two percent per year.

Of interest is the observation that in the anticoagulation group about half of recurrent events were minor strokes, whereas in the placebo group just over a third were minor strokes. In other words, not only were there fewer strokes in the group that was anticoagulated, but the strokes that occurred were more likely to be minor. At least one subsequent case-control study has also shown that the severity of stroke is less if patients have therapeutic anticoagulation vs sub-therapeutic anticoagulation.

Hitesh Patel, Cardiologist
8th September, 2004

References

• Secondary prevention in non-rheumatic atrial fibrillation after transient ischaemic attack or minor stroke. EAFT (European Atrial Fibrillation Trial) Study Group. Lancet 1993; 342(8882):1255-62
• Effect of Intensity of Oral Anticoagulation on Stroke Severity and Mortality in Atrial Fibrillation. N Engl J Med 2003;349:1019-26