Atrial Fibrillation Management in the ED. J Fisher May 2014"

Transcription

1 Atrial Fibrillation Management in the ED J Fisher May 2014"

2 A 48 yr old man presents with palpitations. He had a big night last night with old mates. ECG How will you manage him?

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4 Why important? Common Impairs quality of life: palpitations, fatigue, SOB Increases risk: stroke, heart failure, death

5 AF increases mortality AF is an independent risk factor for mortality AFFIRM trial SR associated with decrease in mortality (hazard ratio 0.53) Retrospective observational study 272,186 pts with incidental AF at time of hospitalisation, compared to 544,344 matched controls in SR RR death (varied with age, sex) Framingham Heart Study AF associated with increased mortality Deaths mostly heart failure, stroke, coronary disease Insufficient evidence to blame AF as cause vs association

6 Classification New onset Paroxysmal self-terminating episodes <48hrs frequently asymptomatic Persistent episodes last longer 7 days, or require cardioversion Longstanding, persistent >1 year Permanent refractory to cardioversion, or attempts to restore SR abandoned Lone AF <60 yrs, normal heart, low risk stroke (CHADS 0)

7 Assessment History Triggers: exercise, alcohol, emotional stress Co-morbidities associated with AF: HT, DM, Risk factors for stroke Consider secondary causes: Ischaemic heart disease Hypertension Valvular heart disease (esp. mitral stenosis / regurgitation) Acute infections Electrolyte disturbance (hypokalaemia, hypomagnesaemia) Thyrotoxicosis Drugs (e.g. sympathomimetics) Pulmonary embolus Pericardial disease Pre-excitation syndromes Cardiomyopathies: dilated, hypertrophic. Obesity/sleep apnoea

8 Assessment Examination Investigations ECG FBE, UEC, glucose consider TSH

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10 AF in the ED New onset Rate vs rhythm control Is DC cardioversion indicated? What method of rate control? Anticoagulation? Disposition? Rapid AF in patient with known AF

11 Rhythm vs Rate control Does it matter?? AFFIRM no difference in mortality Cochrane review - no difference in mortality Meta-analysis 2012 no significant difference between rate and rhythm control for all-cause mortality, cardiovascular mortality or ischaemic stroke in patients with AF. Caldeira, David, Sampaio. Rate v rhythm control in AF and clinical outcomes: updated systematic review and meta-analysis of RCTs. Arch Cardiovasc Dis 2012;105:

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13 Rhythm vs Rate control Does it matter?? AFFIRM no difference in mortality Cochrane review - no difference in mortality Meta-analysis 2012 no significant difference between rate and rhythm control for all-cause mortality, cardiovascular mortality or ischaemic stroke in patients with AF. Caldeira, David, Sampaio. Rate v rhythm control in AF and clinical outcomes: updated systematic review and meta-analysis of RCTs. Arch Cardiovasc Dis 2012;105: Rate control is an appropriate primary strategy Not well represented new onset AF, age <65

14 Rhythm vs Rate control Factors favouring rhythm control Younger age First presentation Frequent episodes with significant symptoms No significant structural heart disease/la enlargement Heart failure triggered by AF Factors favouring rate control Older Longstanding, persistent AF Severe LA enlargement Previous failed attempts at rhythm control Minimal symptoms

15 Rhythm control DC cardioversion Drugs

16 Rhythm control DC cardioversion Risks STROKE sedation, arrhythmia, post reversion APO failure to revert SR Patient selection

17 DC reversion risk stroke Conversion to SR risk of thrombo-embolism both electrical and pharm cardioversion LA thrombus pre-existing de-novo atrial stunning

18 DC reversion risk stroke Extremely high risk valvular heart disease/ prosthetic heart valves High risk AF > 48 hrs 1-5% during 1 month post cardioversion (w/out anticoag) need anticoagulation for 1 month before and after cardioversion

19 AF < 48 hours Embolic risk very low Excluding valve disease, severe LV dysfunction, PHx thrombo-embolism, stroke RFs Assumes onset can be definitely determined Recommendations re anticoagulation vary Relying on expert opinion only Peri-procedural heparin Longer term anticoagulation only if CHADS 2 > 1

20 AF < 48 hours Finnish Cardioversion Study AF < 48 hours. Embolic complications in 30 days after 5,116 successful cardioversions in 2,481 patients with AF <48 h without anticoagulation. 38 (0.7%) thromboembolic events (31 strokes) within 30 days (median 2 days) after cardioversion. Age, female, heart failure, diabetes - independent predictors of definite embolic events. Patients with no heart failure and age<60 years had the lowest risk of thromboembolism (0.2%). Airaksinen KE, Grönberg T, Nuotio I et al. Thromboembolic complications after cardioversion of acute atrial fibrillation: the FinCV (Finnish CardioVersion) study. J Am Coll Cardiol. 2013;62(13):1187.

21 AF < 48 hours Careful patient selection Age < 60, no heart failure, no PHx stroke CHADS 2 = 0

22 AF < 48 hours > 60% chance spontaneous reversion within 72 hours 1,822 consecutive adults admitted with AF* 356 patients with atrial fibrillation of <72-h duration. Spontaneous conversion to sinus rhythm occurred in 68% of the study group Within 24 h in 159 (66%), 24 to 48 h in 42 (17%) *Danias PG, Caulfield TA, Weigner MJ et al. Likelihood of spontaneous conversion of atrial fibrillation to sinus rhythm. J Am Coll Cardiol. 1998;31(3):588.

23 My approach AF < 48 hrs with clear onset Assess co-morbidities (CHADS 2 = 0) Rate control Discharge home Return next day fasted Electrical cardioversion if still in AF Duration of AF > 48 hours or not clear Risk factors for thromboembolism/chads>0 rate control assess need for anticoagulation refer outpatient cardiology follow-up

24 Rhythm control Electrical cardioversion Drugs Flecainide LV dysfunction, CAD! ventr arrythymias Sotalol QT prolongation/torsades women >70yrs, renal dysfunction, LV dysfunction Amiodarone thyrotoxicosis, sleep disturbance, photosensitivity, tremor, pulm fibrosis (rare) avoid in younger patients Catheter ablation

25 Rate control in the ED Beta-blockers resting HR and blunts HR response to exercise atenolol=metoprolol metoprolol oral or IV (2.5-5mg over 2 min, rpt 5 minutely up to 15mg) Calcium channel blockers verapamil, diltiazem oral or IV negative inotrope caution in heart failure, C/I if hypotensive Digoxin less effective for rate control, espec during exercise LV dysfunction Amiodarone side effects, 2 nd line only

26 Magnesium? Slows cardiac conduction, increases refractoriness Accepted role in torsades?benefit in AF Measuring serum Mg concentration represents 1% of total body Mg no correlation between se Mg and intra-cellular Mg (atrial tissue) no relationship between hypomg and atrial tachycardia

27 Magnesium Davey, Teubner. A RCT of magnesium sulfate, in addition to usual care, for rate control in AF. Ann Emerg Med 2005;45: patients rapid AF (mean rate 142) Usual therapy (mostly digoxin) + IV MgSO4 (2.5g +2.5g) OR placebo Mg increased likelihood of achieving a ventricular rate < 100 bpm (65 v 34 %) Difference in mean ventricular rate never exceeded 12 bpm Benefit of magnesium was modest Preferred usual Rx (BB, CCB) used in only % of patients Side effects hypotension Chu, K., et al. Magnesium Sulfate Versus Placebo For Paroxysmal Atrial Fibrillation: A Randomized Clinical Trial. Acad Emerg Med (4): patients rapid AF <48 hrs Randomized to Mg vs placebo No difference after 2 hours (HR 116 vs 114)

28 Rate control in the ED Advanced heart failure? yes no Digoxin Beta-blocker contra-indicated? yes no CCB Metoprolol oral or IV inadequate response Add Digoxin

29 Target heart rate? < 110 bpm RACE II Rate Control Efficacy in Permanent AF: a comparison between lenient versus strict rate control no increased adverse outcomes with HR <110 vs HR < 80

30 Stroke prevention Anti-coagulation must be considered in ALL patients Stroke occurs in 5% of patients with non-valvular AF annually Stroke is bad Warfarin (INR 2-3) reduces risk of stroke by 64% Hart, Pearce, Aguilar. Meta-analysis:anti-thrombotic therapy to prevent stroke in patients who have non-valvular AF. Ann Intern Med 2007; 146: Dabigatran, rivaroxiban equivalent efficacy Warfarin vs Aspirin RR reduction 38% Warfarin vs Aspirin + Clopidogrel RR reduction 42%

31 NNT NNT = 25 to prevent a stroke NNH = 384 to cause an ICH Should we anticoagulate everyone then? Which patients with AF are at increased risk of stroke?

32 CHADS 2 score Clinical feature Score C Congestive heart failure 1 H Hypertension: (140/90 mmhg or treated) 1 A Age 75 years 1 D Diabetes mellitus 1 S Prior Stroke or TIA or Thromboembolism 2 CHADS2 score Annual stroke risk % Expert recommendations Score 0 no anticoagulation Score 1 consider anticoagulation Score > 1 - anticoagulate

33 What about the NOACs? rivaroxiban, apixaban and dabigatran at least as effective in reducing stroke risk, lower rates of ICH age, weight, renal function increased bleeding likely to be used more frequently

34 Follow-up Outpatient TTE structural heart disease Cardiology (especially if <65yrs)

35 Back to our case

36 My approach AF < 48 hrs with clear onset Assess co-morbidities (CHADS 2 = 0) Rate control Clexane Discharge home Return next day fasted Electrical cardioversion if still in AF Duration of AF > 48 hours or not clear Risk factors for thromboembolism/chads>0 rate control assess need for anticoagulation refer outpatient cardiology follow-up

37 Paroxysmal/permanent AF Look for precipitants Rate control Assess need for anti-coagulation

38 Take home points Common Do you really need that TSH? Rate vs rhythm control DC cardioversion for select patients Rate < 110 adequate ANTICOAGULATE