CVD Part 2 Flashcards
What is afib?
Abnormal electrical conduction in the atria -> chaotic, uncoordinated contraction
What are the symptoms of afib (if not asymptomatic)? (4)
- Shortness of breath, fatigue
- Palpitations
- Chest discomfort
- Anxiety, sweating
What are two key clinical issues with afib?
- Significant ↑ risk of ischemic stroke (~5x)
- ANTICOAGULATION - ↑ Heart rate -> heart failure
- Need to control heart rate or rhythm
Manage stroke risk with? (2)
- Warfarin
- DOACs (dabigatran, rivaroxaban, apixaban, edoxaban)
Advanced age is a deterrent to anticoagulation, why? (3)
- Bleed risk
- Falls
- Drugs
- Medical conditions - Adherence, INR monitoring
- Cognitive impairment
- Limited mobility - Underestimation of benefit
What does the evidence for anticoagulation in older adults say?
Very good for stroke prevention
What to know about anticoagulation vs. ASA or ASA + Clopidogrel (2)
- ACTIVE-W Trial
- Aspirin + Clopidogrel vs Warfarin for stroke prevention in atrial fibrillation
- Trial terminated early due to superiority of warfarin (NNT = 47/1.3 years)
- NO difference in major bleeding rates between the two groups - ACTIVE-A Trial
- Aspirin vs aspirin plus clopidogrel in individuals unsuitable for warfarin
- Aspirin plus clopidogrel decreased the risk of stroke (NNT = 42/2.6 years)
- Also increased the risk of major bleeding (NNH = 42/2.6 years)
What are the advantages of DOACs? (4)
- > = Efficacy
- Less ICH
- No INR monitoring
- Fewer drug and food interactions
What are the disadvantages of DOACs? (6)
- Cost, EDS requirements?
- More GI bleeds
- Less long-term safety data
- Caution in renal impairment
- Contraindicated in severe renal impairment
- Not indicated with mechanical heart valves
Consider changing from warfarin to a DOAC when? (4)
- When starting on a medication with a significant DI with warfarin
- Practical considerations - can the pt get their blood work done as often as they need to?
- Basically all of the pros that we have talked about.
- Labile INRs - if you have someone with afib who has difficulty controlling INR, they should really be switched to a DOAC. Efficacy of warfarin drops dramatically below 2, and is doing basically nothing under 1.8 for stroke risk reduction. Bleed risk is big if above 3. So if consistently not within bounds then it’s a bitch to work with.
Warfarin is preferable when? (2)
- Severe renal dysfunction. Generally a CrCl <25, for sure CrCl <15 is when you would want to be on warfarin.
- Mechanical heart valves. DOACs not as effective in preventing strokes in these settings. Specifically, with a mechanical mitral heart valve, remember that’s when you need to target 2.5-3.5 INR and they need to be on aspirin.
Which DOAC to choose between dabigatran, rivaroxaban, edoxaban, and apixaban?
- Dabigatran – most GI upset, most highly renally eliminated
- Beer’s List drug if age > 75 - Rivaroxaban once daily dosing -> needs to be taken with food
- Beer’s List drug if age > 75 - Edoxaban once daily dosing
- Watch for drug interactions (↓ dose with strong P-GP inhibitors e.g. erythromycin, cyclosporine, dronaderone) - Apixaban best safety data (so far)
- Best choice when renal function is borderline
What are 4 considerations for anticoagulation in afib?
- Is there an indication for anticoagulation?
- Is there a high risk of bleeding or a contraindication to anticoagulation?
- Will the patient be able to adhere to therapy or monitoring requirements?
- Patient/family preferences?
According to the afib guidelines, what age patient is indicated for oral anticoagulation?
65+
HAS-BLED is a score to determine if there is a high risk of bleeding. What is it?
Hypertension
Abnormal renal or liver function
Stroke (caused by a bleed)
Bleeding
Labile INRs
Elderly (65+)
Drugs (ASA/NSAID) or alcohol (8+ drinks/week)
Caution if HAS-BLED score is >=_
3
When might we do anticoagulant + antiplatelet (3)
- Elective PCI without high risk features for thrombotic CV events
- ACS with PCI or elective PCI with high risk features for thrombotic CV events
- ACS without PCI
Will patients be able to adhere to the monitoring requirements of warfarin or DOACs? What to know?
- Warfarin:
- INR monitoring
- Ability to self-manage dosage adjustments? - DOACs:
- Consistent adherence is very important!
- Also need to check CBC, renal function ~q6months
What are factors to consider when deciding between rate vs. rhythm control? (3)
- Duration of afib
- Bothersome afib symptoms?
- Comorbid HF?
What is the main medication for rhythm control in afib?
Amiodarone
Likelihood of successful rhythm control _________ as afib duration increases
decreases
True or False? Regardless of rate or rhythm control, anticoagulation remains important
True