There are two goals for treating AF: alleviation of symptoms and reducing the rate of stroke. At present, most patients are treated medically with either a rhythm- or rate-control strategy. The therapies below are often employed either in sequence or in conjunction with multiple approaches when initial therapies fail to correct the rhythm disorder.
- Rate control with drugs or AV node radiofrequency ablation
- Rhythm control with cardioversion, drugs or AF substrate ablation
- Prevention therapy for thromboembolism
- Anticoagulation therapy (drugs)
- Anti-platelet therapy (drugs)
- Left atrial appendage occlusion
The most frequently used rhythm control therapies include cardioversion, drugs or substrate ablation. Randomized trials such as AFFIRM and RACE have shown that the rhythm control approach is not consistently efficacious. With continuous monitoring, the rate of recurrent AF on optimized antiarrhythmic drug therapy has been shown to be approximately 90%.*
Non-pharmacologic options are also available, including the use of radiofrequency ablation to perform pulmonary vein isolation in an attempt to cure AF. These options also lack uniform success and, when successful, still require long-term anticoagulation in case the AF returns.
As embolization occurs with equal frequency in rhythm- or rate-control treatments, both approaches require long-term anticoagulation (except for patients deemed to be a low risk for embolic events).
Anticoagulation – no easy answers
Realities of Warfarin*
To prevent clot formation, many people with AF are placed on anticoagulation therapy. Currently, the standard is warfarin (Coumadin), which is utilized especially in patients who have increased risk factors. Warfarin was originally used as a poison and has many side effects, so it is often underutilized. Bleeding is the major adverse effect of warfarin. Other significant adverse reactions are chest pain, dizziness, rash, abdominal pain, joint and/or muscle pain and dyspnea to name only a few.
In patients who are taking warfarin, it is often difficult to maintain in therapeutic range due to its many food and drug interactions. It requires frequent blood draws to monitor its effectiveness. It is estimated that despite frequent monitoring and dose adjustment, patients’ test results are outside of the therapeutic range up to half of the time. The FDA Medication Guide lists over a hundred drugs and over 40 herbs that may interact with warfarin. Only about 50% of patients who are eligible for long-term warfarin are treated with it.
Other Medication options*
Other anticoagulants are under development and may prove to be a more effective treatment option. All have been non-inferior or better compared to warfarin in preventing stroke, but still demonstrate bleeding complications. All require long term compliance and there are currently no tests to assess effectiveness of anticoagulation. Due to shorter time ranges for effectiveness, missing one dose is potentially riskier than with warfarin.
Dabigatran: Twice daily, 2 doses (Increased bleeding events with higher dose)
Riviroxiban: Once daily
Apixaban: Twice daily
Considerations during anticoagulant therapy*
- Long-term compliance – regardless of the type of medication, taking medication daily is a life-long requirement. Depending on the type of medication, missing even one dose could increase the risk of stroke.
- Expense – newer anticoagulant medication is much more costly than traditional therapy.
- No antidote in emergencies – the effect of newer oral anticoagulants cannot be reversed in the case of bleeding emergencies.
- Renal function – newer anticoagulants can affect renal function.