Activation of coagulation occurs after electrical cardioversion in patients with chronic atrial fibrillation despite optimal anticoagulation with warfarin

• Published in: International journal of cardiology Vol. 95; no. 1; pp. 83 - 88
• Main Authors: Jacob, Koshy, Talwar, Suneel, Copplestone, Adrian, Gilbert, Timothy J, Haywood, Guy A
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-05-2004; Elsevier Science
• Subjects: Adult; Aged; Anticoagulants - therapeutic use; Antithrombin III - drug effects; Antithrombin III - metabolism; Atrial Fibrillation - blood; Atrial Fibrillation - therapy; Biological and medical sciences; Biomarkers - blood; Blood Coagulation - drug effects; Cardiac dysrhythmias; Cardiology. Vascular system; Chronic atrial fibrillation; Chronic Disease; Coagulation; Electric Countershock; Electrical cardioversion; Female; Fibrin Fibrinogen Degradation Products - drug effects; Fibrin Fibrinogen Degradation Products - metabolism; Fibrinogen - drug effects; Fibrinogen - metabolism; Heart; Humans; Male; Medical sciences; Middle Aged; Oral anticoagulation; Protein C - drug effects; Protein C - metabolism; Treatment Outcome; United Kingdom; Warfarin - therapeutic use; Electrical cardioversion; Oral anticoagulation; Chronic atrial fibrillation; Coagulation; Human; Intensive cardiocirculatory care; Warfarin; Arrhythmia; Atrial fibrillation; Instrumentation therapy; Cardiovascular disease; Cardioversion; Activation; Excitability disorder; Oral cavity; Chronic; Heart disease
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2003.05.019

Background: There is evidence for the activation of the coagulation system and a hypercoagulable state following cardioversion. The aim of the study was to determine whether electrical cardioversion in patients with chronic atrial fibrillation induced a prothrombotic state despite optimal anticoagulation. We studied the effects of electrical cardioversion on plasma levels of fibrinogen, antithrombin III, protein C and D-dimers.
Methods: We studied 24 patients with chronic atrial fibrillation who were on optimal anticoagulation and were referred for electrical cardioversion. Samples of venous blood were taken 2 h pre and post cardioversion and 1 month later.
Results: Plasma median concentrations of fibrinogen decreased significantly from 3.8 g/l (interquartile range 3.1–4.2 g/l) before cardioversion to 3.5 g/l (interquartile range 2.9–3.9 g/l) 2 h after cardioversion levels (
P=0.004). The fibrinogen levels at 1 month post cardioversion (3.45 g/l, interquartile range 3.1–3.9 g/l) were also significantly lower than baseline (
P=0.02). Plasma median levels of antithrombin III fell from 93.5 U/dl (interquartile range 89.3–97.0 U/dl) pre cardioversion to 89.5 U/dl (interquartile range 83.0–93.0 U/dl) 2 h after cardioversion (
P=0.001) and returned to normal by 1 month (94.0 U/dl; interquartile range 89.3–98.5 U/dl;
P=0.0001). There were no significant changes in plasma median D-dimer or protein C levels at any time.
Conclusions: We have demonstrated a significant fall in the plasma fibrinogen and antithrombin III levels in patients with chronic atrial fibrillation early after electrical cardioversion, indicating thrombin generation. This study suggests that there are haemostatic changes of thrombogenesis induced by cardioversion despite optimal anticoagulation with warfarin.