This study investigated the association between heat shock protein 70 (HSP70) and anti-HSP70 antibodies as well their changes and rhythm outcome after atrial fibrillation (AF) catheter ablation.Methods
We studied 67 patients with AF (59 ± 11 years, 66 % male, 66 % lone AF) undergoing catheter ablation. Circulating HSP70 and anti-HSP70 antibody levels were quantified using commercially available assays before and 6 months after catheter ablation. Serial 7-day Holter ECGs were used to detect AF recurrences.Results
At baseline, HSP70 was detectable in 14 patients (21 %), but there was no correlation between clinical or echocardiographic variables and the presence or the level of HSP70. In contrast, patients with paroxysmal AF (n = 39) showed lower anti-HSP70 antibodies (median 43, IQR 28 – 62 μg/ml) than patients with persistent AF (n = 28; 53, 41 – 85 μg/ml, p=0.035). Using multivariable regression analysis, AF type was the only variable associated with anti-HSP70 antibodies (Beta=0.342, p=0.008). At 6 months, HSP70 was present in 27 patients (41 %, p < 0.001 vs. baseline) with an overall increase (median 0, IQR 0 – 0 vs. 0, 0 – 0.09 ng/ml, p=0.029). Similarly, there was an increase of anti-HSP70 antibodies (48, 36 – 72 vs. 57, 43 – 87 μg/ml, p < 0.001). AF recurrence rates were higher in patients with HSP70 increase ≥0.025 ng/ml (32 vs. 11 %, p=0.038) or anti-HSP70 increase ≥2.5 μg/ml (26 vs. 4 %, p=0.033).Conclusion
HSP70 and anti-HSP70 antibodies may be involved in the progression of AF and AF recurrence after catheter ablation.