Afib therapeutics Flashcards
Define acute Afib (2)
- AF of <48h
- Paroxysmal AF (occurring in critical care or causing the acute illness, i.e severe)
OR
First symptomatic persistent Afib
Once patient is diagnosed with acute afib,
What do you do if hemodynamically stable (2)
Rate control:
- Beta blocker
- Diltiazem/verapamil
- Digoxin
Consider anticoagulant
Once patient is diagnosed with acute afib,
and hemodynamically stable, what do you if patient remains in afib for:
<48 hours?
48+ hours ?
<48 hours?
- anti-arrhythmics +/- cardioversion
48+ hours
- TEE-guided cardioversion (look inside to make sure there is not clot first)
- 3 weeks anticoagulation then cardioversion
What defines hemodynamic instability (any of 5)
- Ventricular rates > 150 bpm
- Ongoing chest pain
- Systolic <90 mmHg
- Heart failure
- Reduced consciousness
Once patient is diagnosed with acute afib,
and hemodynamically UNstable,
What do you if it is life-threatening?
Emergency electrical cardioversion
Once patient is diagnosed with acute afib,
and hemodynamically UNstable,
What do you if it is not life-threatening?
Check if they have Permanent Afib
Once patient is diagnosed with acute afib,
and hemodynamically UNstable, not life-threatening,
Patient has permanent Afib?
Rate control
- beta blocker
- NDHPs
Once patient is diagnosed with acute afib,
and hemodynamically UNstable, not life-threatening,
Patient does NOT have/unknown permanent Afib?
- TEE-guided cardioversion (look inside to make sure there is not clot first)
- 3 weeks anticoagulation then cardioversion
What is considered high risk where you need to have at least 3 weeks of OAC before cardioversion
or could perform a TEE to exclude left atrial thrombus? (4)
- Valvular Afib
- NVAF duration <12 AND recent stroke/TIA
- NVAF duration 12-48 AND chads 2+
- NVAF duration over 48h+
All high risk
When would you go directly to cardioversion and initiate OAC if possible before? (low risk) (3)
- Hemodynamically unstable acute Afib
- NVAF <12 AND NO recent stroke
- NVAF 12-48 hours AND chads 0-1
What do you initiate after cardioversion for everyone?
4 weeks anticoagulation
Pharmacologic cardioversion
Which class drugs are used for RHYTHM control?
Rate control?
Rhythm control
- class I (Na blockers)
- class III (K+ blockers)
Rate control
- Class II (BB)
- Class IV (NDHPs)
Which class of drugs share rate-controlling properties?
Class III
Which drugs specifically have demonstrated efficacy for cardioversion (rhythm control) (5)
Which are more efficacious?
Class 1c
- flecainide
- propafenone
Class 3
- ibutilide
- amiodarone
- dronedarone
Class 1c are better than class 3 for CARDIOVERSION
In stable patients, with no evidence of HF,
what drugs do we use?
Beta-blockers
NDHPs
When do we use both BB and NDHP for rate control?
What to monitor
If no evidence of rate control
Monitor for AV nodal blockade
In stable patients, with evidence of HF (acute),
what drugs do we use?
Digoxin
Amiodarone
(recall: do not use BB in acute HF)
What drugs can we use for wolff-parkinson-white syndrome patients (preexcitation) (2)
What is CI? why?
Contraindicated
- BB, CCB, Digoxin
- block AV conduction but NOT slow conduction through accessory pathway (can lead to ventricular fibrillation)
Use:
Procainamide (Class 1a)
OR
Ibutilide (Class 3)
What does CHADS2 score estimate?
What does it stand for
Annual risk of stroke in AFIB patients
C HF
H HTN
A Age over 75
D DM
S Previous stroke/TIA = 2 points
What does CHA2DS2VASc consider? Differences between CHADS?
When to use?
V Vascular disease
Age 65-74 = 1 point
Age 75+ = 2 points
Sex = 1 point (female)
Used if CHADS score is 0 (good for truly low risk patients)
In the HASBLED score
What is hypertension defined as?
CKD function?
Labile INR?
Drugs or alcohol?
What is hypertension defined as?
- SBP >160 mmhg
CKD function?
- Dialysis
- SCr 200+ mmol/L
Labile INR?
- <60% TIR
Drugs or alcohol?
- antiplatelet agents
- NSAIDs
- alcohol abuse
What are additional risk factors to assess bleeding risk? (6)
- Thrombocytopenia
- Active bleeding or recent surgery
- Prior severe bleeding (including ICH) while on OAC
- Suspected aortic dissection
- Malignant hyper tension
- use of antiplatelet agents
After 4 weeks of anticoagulation post-cardioversion
Which patients benefit from OAC?
65+
or CHADS2 score of 1+
After 4 weeks of anticoagulation post-cardioversion
Which patients should be ONLY ASA? (3)
<65 years
CHADS2 = 0
Vascular disease (CAD, PAD)
After 4 weeks of anticoagulation post-cardioversion
Which patients should not be on antithrombotic therapy? (3)
<65 years
CHADS2 = 0
NO Vascular disease (CAD, PAD)
How much do OAC reduce risk of stroke by in patients with Afib?
60%
When is warfarin indicated over DOACs? (3)
Mechanical prosthetic valve
Rheumatic mitral stenosis
eGFR 15-30 mL/min
What does the RE-LY trial say about dabigatran high dose (150mg) & low dose (110mg) vs Warfarin
Efficacy and safety?
- Dabigatran 110 mg BID was non-inferior to warfarin
- dabigatran 150 mg BID was superior to warfarin for [stroke or clot],
Safety
Warfarin had more major bleeding than dabigatran
What does the ROCKET AF trial say with rivaroxaban vs Warfarin
Efficacy
Safety:
Major and minor bleeding
Intracranial hemorrhage
Fatal bleeding
Rivaroxaban was non-inferior to warfarin for [stroke or clot]
Major and minor bleeding: No difference
Intracranial hemorrhage: Warfarin had more
Fatal bleeding: Warfarin had more
What does the Aristotle trial say with apixaban vs Warfarin
Efficacy
Safety:
Major bleed
All-cause mortality
Hemorrhagic stroke
Efficacy
Apixaban was non-inferior to warfarin
Safety:
Major bleed
All-cause mortality
Hemorrhagic stroke
- Warfarin worse for all
What does the ENGAGE AF-TIMI trial say with Edoxaban high (60mg) and low dose (30mg) vs Warfarin in CHADS = 2+
Efficacy
Safety
Efficacy
Edoxaban (both high- and low dose) was non-inferior to warfarin
Safety
Warfarin had more major bleed than both high- and low-dose edoxaban
What did systematic reviews say about DOACs vs Warfarin in:
Total death
CV death
Stroke or clot
Major bleed
Brain bleed
Ischemic stroke
Total death
CV death
Stroke or clot
Major bleed
Brain bleed
- DOACs are better
Ischemic stroke
- no difference
What do trials say about risks concerning with dabigatran?
Increase MI risk
Dabigatran vs Warfarin safety observational study
Dabigatran increased all bleed risks, except ICH - it decreased it (this was observational!!, but still concerning)
OAC + ASA vs OAC in afib patients
Efficacy
Safety
ASA + OAC resulted in less arterial clots but only in mechanical heart valve patients but not A fib patients.
More major bleed with ASA + OAC.
When can warfarin + ASA be indicated
May be indicated and for MI prevention
What is the renal dosing for stroke prevention in AF for rivaroxaban and apixiban
15-30 mL/min
<15 mL/min
Rivaroxaban
15-30mL/min 15mg approved
<15 avoid
Apixaban
15-24 mL/min 5mg (no dose approvement)
<15 avoid
What do guidelines say for interrupting OAC for:
Low bleed risk surgery
Intermediate bleed risk surgery
High bleed risk surgery
Low bleed risk surgery: no need to interrupt
Intermediate bleed risk surgery: interrupt
High bleed risk surgery: interrupt
What are examples of low bleed risk surgeries?
Laparoscopic chole
Laparoscopic inguinal hernia repair
Dental
Ophthalmologic procedures
Colonoscopy
Cardiac implantable surgery
Biopsy
When to stop
ASA or clopidogrel
Warfarin before surgery?
ASA or clopidogrel
- 5-7 days
- 7-10 days for high risk of major bleeding
Warfarin
- 5 days
When to consider bridging? (3)
CHADS2 3+
Stroke/TIA last 3 months
Heart valve
What did the PERIOP trial say for mechanical valve patients bridging with dalteparin
Efficacy
Safety
No difference in clot, all death,
No difference in major bleed risk.
What did the BRIDGE trial say for afib patients bridging with dalteparin
Efficacy
Safety
Efficacy
No difference in [arterial clot = stroke + TIA + clot], [death], [MI], [DVT], or [PE]
Safety
but more major bleed
Contrast between ventricular rate control and rhythm control
Rate control:
- accept that patients may remain in irregular heart rhythm, just focus on controlling ventricular rate
- BB, NDHPs, digoxin
Rhythm control
- try to restore and maintain sinus rhythm
- Antiarrythmic meds, catheter ablation and/or surgical procedure
Which strategy is better when done early? Rate/rhythm control
AFNET-4
rhythm control
In patients with newly diagnosed Afib (within a year), which strategy is used first
Rhythm control
AFFIRM trial rhythm (class Ia, Ic, III) vs rate control for HR <80 and 6-min walk
All cause death
Composite (death + stroke + major bleed + cardiac arrest)
Hospitalization
All cause death
- no difference
Composite (death + stroke + major bleed + cardiac arrest)
- no difference
Hospitalization
- lower in RATE control group
Rate-control arm vs rhythm control arm in the AFFIRM trial
Which patients achieved more sinus rhythm?
which patients used radiofrequency ablation more?
Which patients achieved more sinus rhythm?
- Rhythm control
which patients used radiofrequency ablation more?
- Rate control
What were issues with the affirm trial?
- mean age was 70
- crossover: many switched fro rhythm to rate but less switched from rate to rhythm
- most patients had 1 episode/month (little symptomatic relief expected from baseline if baseline is already so mild)
- Catheter ablation was not very available at this time, radiofrequency ablation was used
What does the subgroup of AFFIRM show for digoxin?
increase in all-cause mortality ASSOCIATED with patients always or never on digoxin in the study AND patients on digoxin at baseline
What is the general appropriate first step with patients recently diagnosed with symptomatic AF to keep the heart rate <100 bpm?
Rate control
What did EAST-AFNET 4 trial tell us about treatment?
Early rhythm control is better for patients with early
What is the inclusion criteria for EAST-AFNET 4 trial
2 options (2) (8)
75+ and had a previous TIA or stroke
OR
any of the 2:
- 65+
- female
- HF
- HTN
- DM
- Severe CAD
- CKD <60 mL/min
- Left ventricular hypertrophy 15+mm
When is rhythm control preferred over rate-control in persistent AF?
- Recently diagnosed AF (within 1 year)
- Highly symptomatic or sig QOL impairment
- Multiple recurrences
- Difficulty to achieve rate control
- Arrhythmia-induced cardiomyopathy
What is the target ventricular rate for rate control therapy?
<100 bpm
What did the RACE II trial say when compared <80 bpm to <110 bpm for resting heart rate
No difference
What did AFFIRM trial show for digoxin use?
What refused this?
AFFIRM trial:
- showed increase in all-cause mortality ASSOCIATED with patients always or never on digoxin in the study AND patients on digoxin at baseline
Refuted:
However, propensity-matching and statistical “trimming” refuted this. Still a worrisome result - (don’t use digoxin first line in rate control of AF)
Is it safe to combine BB and NDHP in Afib for suboptimal response
Yes
When is amiodarone used in Afib
Antiarrhythmic drug
- added as last option
If patient has HF (LVEF <40%) and afib, what drugs do we use? Avoid?
BB and digoxin
- avoid NDHP
What is the last line if unable to get rate control
Catheter Ablation for AF
- (surgically removing (killing) the AV node + inserting a pacemaker to create pulses and send them to atrium AND ventricle)
Goals of rate control (2) vs rhythm control (2)
Rate control
- reduce symptoms (palpitations, dizziness)
- Reduce cardiomyopathy risk
Rhythm control
- to enhance quality of life
- to enhance the ability to perform physical acivity
What to do if patient is high risk for rhythm control and TEE is:
Positive?
Negative?
TEE positive:
- OAC for 3+ weeks before cardioversion
TEE negative:
- proceed with cardioversion
What are the most common drugs used to maintain sinus rhythm in Afib?
1C
- flecainide
- propafenone
Class III
- Amiodarone
- Dronedarone
- Sotalol
If choosing Flecainide and propafenone, what should it be combined with? Why?
When are these drugs contraindicated?
Contraindicated
- CAD (ACS) (can use in “minimal structural heart disease)
- HF
Combined with:
- AV nodal blocking agent (BB or NDHP)
- If we reduce SA node firing (through Class 1 antiarrhythmics), the refractory time in the AV node is reduced (due to “concealment effect”) -> MORE impulses will actually make it through the AV node (paradoxical) (can lead to Ventricular fibrilation)-> need AV blocking agent (Class 2 or 4)
When should dronedarone be avoided according to the PALLAS trial (2)
- Not used in HF
- Not used in permanent Afib
When should sotalol be avoided? (2)
- In patients at high risk of torsade de pointes
- HF (EF <40%)
What did the CAST trial tell us about antiarrythmic drugs (flecainide) in MI patients
Increased deaths in ACS
What did the PROBE trial tell us in short term (4 weeks) vs long term (6 months) flecainide (post successful cardioversion)
Use Cardioversion + 4 weeks of post-cardioversion flecainide to help maintain sinus rhythm (not reduce mortality)
When is pill in the pocket anti-arrhytmic strategy used?
What is it?
Paraxosymal afib lasting several hours with low reccurence burden
What
- 1 dose of Flecainide or proapfenone
- must also use AV nodal blocker
What are some factors that predispose to drug-induced pro-arrhythmia
- Long QT interval
- Structural heart disease
- LV dysfunction
- Hypokalemia/hypomagnesemia
- female
- renal dysfunction
- bradycardia
- rapid dose increase
- high dose of class III drugs
- previous proarrhythmia
Differentiate between QT and QTc
QTc is corrected for HR
What is the Cellular mechanisms of Acquired Long QT Syndrome (ALQTS)
Other mechanisms? (3)
- inhibition of hERG channel preventing Ikr entry (through rapid potassium current which is what blocks it)
Other mechanisms
- inhibition of Iks
- upregulation of depolarizing INa current
- impaired ion channel trafficking
What are some symptoms of Acquired Long QT Syndrome (ALQTS) (6)
- Heart palpitations
- Tachycardia
- Syncope/fainting
- Dizziness/light-headedness
- SOB
- Convulsions
What are some QT prolonging drugs associated with Torsade de pointes
Antiarrhythmic durgs (class I and III)
Non-cardiac
- antihistamines (terfendadine, astemizole)
- Antipsychotic and antidepressent (amitriptyline, fluoxetine, -ine)
- Haloperidol
- atypical antipsychotics (risperidone, citalopram)
Antibiotics
- quinolone (levofloxacin, all -floxacins)
- Macrolide (erythromycin, clarithryomycin)
Antimalarials (quinine, halofantrine)
Antifungals
Antimotality agents
Methadone
Tachy/Brady
which is the risk factor
Which is the sx of QT and
Risk factor:
Brady
Sx:
Tachy
In the TISDALE risk score, what is the most points given to (4)
What is considered low, moderate, high total score
Highest risk scores (=3)
- 2+ QTc prolonging drugs
- sepsis
- HF
- 1 QTc prolonging drug
Low: 0-6
Mod: 7-10
High: 11-21
What to do if given a known QT prolonger
recommend ECG pre and post initiation + monitor for symptoms (fatigue, palpitations, etc…)
