Assessment of Copper Status in Patients with Paroxysmal Atrial Fibrillation

Background: Recent research has demonstrated disturbances of copper balance in the development of cardiovascular diseases. Copper status in patients with atrial fibrillation is still unknown. Serum or plasma copper and ceruloplasmin activity are widely used laboratory indicators of copper status. Purpose: То evaluate copper status in the early hours of paroxysmal atrial fibrillation and monitor its changes after sinus rhythm restoration. Methods: Serum copper levels and plasma oxidase activity of ceruloplasmin were measured in 33 patients with paroxysmal atrial fibrillation (17 males, 16 females, mean age 60.03±1.93). Indicators were measured upon hospital admission, on the 24th hour and on the 28th day after sinus rhythm restoration. Thirty-three control subjects were also enrolled in the study (17 males, 16 females, mean age 59.27±1.72) and their indicators were measured only once. Copper levels and ceruloplasmin activity were quantified by atomic absorption spectrometry and colorimetric enzymatic assay respectively. Results: Mean duration of atrial fibrillation episodes up to hospitalization was 8.64±1.03 hours (from 2 hours up to 24 hours). Upon admission, patients' copper levels and ceruloplasmin activity were decreased compared to controls (16.77±0.59 vs. 18.30±0.45 μmol/L, p<0.05; 0.03±0.01 vs. 0.07±0.01 A530/mg protein, p<0.001 respectively). 24 hours after rhythm conversion, copper was not substantially different (17.11±0.71 vs. 18.30±0.45 μmol/L, p>0.05), whereas ceruloplasmin activity was diminished (0.05±0.01 vs. 0.07±0.01 A530/mg protein, p<0.001). On 28th day we established significant difference in neither of the indicators (17.61±0.48 vs. 18.30±0.45 μmol/L, p>0.05; 0.06±0.01 vs. 0.07±0.01 A530/mg protein, p>0.05). Conclusion: Our results provide evidence for disturbances of copper homeostasis in patients with paroxysmal atrial fibrillation. Decreased copper levels and ceruloplasmin activity during the first hours of arrhythmia and their subsequent elevation following sinus rhythm restoration give us grounds to assume that these changes are closely related to the disease pathogenesis.