SHA24/006001

Atrial FibrillationHow to Manage Safely in the Emergency Room

Joseph G Akar, MD, PhD Associate Professor of Medicine

Director, Cardiac Electrophysiology Laboratory

The Mechanics •Deep sedation •Direct current cardioversion (DCCV)

•Synchronized shock •200-360 j •Safest and most effective procedure in all of medicine…as long as you take into account the risk of stroke

Clinical Case 1 67 year old female with HTN developed AF during routine stress test.

HR 130 bpm. Sent to ED for management.

Decisions: •Cardiovert or Rate-control?

•Perform a TEE or not?

•Anticoagulate or not?

•How long to anticoagulate

Clinical Case 2 28 year old male with Crohn’s disease found to be in asymptomatic AF at time of colonoscopy for GI bleeding. HR 130 bpm. Sent to ED for management.

Decisions:

•Cardiovert or Rate-control?

•Perform a TEE or not?

•Anticoagulate or not?

•How long to anticoagulate

The Big Question in the Emergency Room What is the difference between the long-term risk of stroke in AF versus the risk of stroke after cardioversion?

“Virchow’s Triad”

Circa 1856 Interrupted blood flow

Modern interpretation Vessel damage

Blood stasis

Endothelial damage

Thrombosis

Thrombosis

Abnormal coagulation

Hypercoagulability

Comorbid •↑ D-Dimer •  TAT and PF1.2 Conditions •  vWF ↓ Shear Stress

Blood Stasis Inflammation •  CRP •  TNF-a •  IL-1b •  IL-6

Atrial Fibrillation

Platelet Activation •  P-selectin •  platelet factor 4 •  b thromboglobulin •  platelet microparticle

Cross-Linked Fibrin Clot

 PAI-1

Endothelial Dysfunction

↓ NO

Extrinsic and Intrinsic Pathway Activation Prothrombin → Thrombin

Fibrinogen

Endothelial Damage •  VEGF

•  TF •↓ NO •  vWF

Long-Term Risk of Stroke in Patients With AF The CHADS2 Score Stroke Risk Factors

Score

Congestive heart failure Hypertension Age >75 yrs Diabetes mellitus Stroke/TIA

1 1 1 1 2

Patients (N=1733)

Adjusted Stroke Rate (%/y) (95% CI)

120 463 523 337 220 65 5

1.9 (1.2 to 3.0) 2.8 (2.0 to 3.8) 4.0 (3.1 to 5.1) 5.9 (4.6 to 7.3) 8.5 (6.3 to 11.3) 12.5 (8.2 to 17.5) 18.2 (10/5 to 27.4)

*Mitral stenosis: warfarin

Modified from Fuster, V. et al.

J Am Coll Cardiol 2006;48:e149-e246

CHADS2 Score 0 1 2 3 4 5 6

Treatment ASA alone ASA or Anticoag Anticoagulant Anticoagulant Anticoagulant Anticoagulant Anticoagulant

*Mechanical prosthetic valve: warfarin, INR>2.5

Long-Term Risk of Stroke in Patients With AF The CHA2DS2 –VASc Score Stroke Risk Factors Congestive heart failure/LV dysfunction Hypertension Age ≥75 yrs Diabetes mellitus Stroke/TIA/TE Vascular disease (prior MI, PAD, or aortic plaque) Age 65–74 years Sex category (i.e., female sex)

Score 1 1 2 1 2 1 1 1

For a score >1: oral anticoagulation (e.g., warfarin) For a score = 1: either as oral anticoagulation or aspirin 75 to 325 mg daily (oral anticoagulation is preferred ) For a score = 0: either aspirin 75 to 325 mg daily or no antithrombotic therapy can be used (no antithrombotic therapy may be preferred) From Lip GY et al. Chest 2010;137:263–72 and Marinigh R et al. J Am Coll Cardiol 2010; 56:827–37

Short-Term Risk of Stroke After Cardioversion ↓ Shear Stress

Endothelial Dysfunction

Blood Stasis

Cross-Linked Fibrin Clot

 PAI-1 ↓ NO

 Prothrombin F1.2

Extrinsic Pathway Prothrombin → Thrombin  TAT

Fibrinogen

Stasis

Left Atrial Stunning Electro-mechanical dissociation following cardioversion

Atrial Flutter

Sparks PB et al.

J Am Coll Cardiol.

1998;32(2):468475

Immediately after restoration of NSR

3 weeks after restoration of NSR

Sinus Rhythm

3 months AF

Akar et al, J Cardiovasc Electrophysiol 2002; 1027-1034

1 week after NSR

AF < 2 weeks

AF 2-6 weeks

Manning WJ et al. J Am Coll Cardiol. 1994;23(7):1535-1540.

AF > 6 weeks

Berger M et al. Am J Cardiol. 1998;82(12):1545-1547

Conclusions •Risk of stroke after DCCV is completely different from long-term risk of stroke •Risk of stroke after DCCV is primarily related to duration of AF •For AF duration < 48 hrs •DCCV can be performed without a TEE

•No need for anticoagulation after DCCV •If AF duration is > 48 hrs (or unknown) •TEE needed if patient not on therapeutic antocoagulation x 3 weeks

•Anticoagulation is absolutely needed x 4 weeks

Common Myths

•Atrial flutter carries less stroke risk that AF •Pharmacological cardioversion carries less stroke risk than electrical cardioversion

•Spontaneous conversion carries less stroke than cardioversion

Common Myth: Low Intensity Anticoagulation is OK â&#x20AC;˘Target INR is 2.0-3.0 â&#x20AC;˘Strokes in patients with sub-therapeutic INR are more likely to result in disability and death

Fuster, V. et al. J Am Coll Cardiol 2006;48:e149-e246

Hylek EM et al. N Engl J Med 2003; 349:1024

Unanswered Questions

•Do you need a TEE before cardioversion of a patient on novel anticoagulant (Dabigatran, Rivaroxaban, Apixaban)?

•Do you need a TEE before cardioversion of a patient who had undergone surgical left atrial appendage closure/removal?

•Do you need a TEE before cardioversion of a patient who had undergone left atrial appendage occluder?

Clinical Case 1 67 year old female with HTN and palpitations developed AF during routine stress test. HR 130 bpm. Sent to ED for management.

Decisions: •Cardiovert or Rate-control?

Cardiovert

•Perform a TEE or not?

No TEE

•Anticoagulate or not?

Anticoagulate

•How long to anticoagulate

Indefinitely

Clinical Case 2 28 year old male with Crohn’s disease found to be in asymptomatic AF at time of colonoscopy for GI bleeding. HR 130 bpm. Sent to ED for management.

Decisions:

•Cardiovert or Rate-control?

Rate control

•Perform a TEE or not?

No

•Anticoagulate or not?

No

•How long to anticoagulate

ECASA when acceptable