Background:
HSP and anti-HSP antibodies have been associated with AF development and progression. This study investigated the possible association between circulating heat shock protein 70 (HSP70) and anti-HSP70 antibodies as well their changes and rhythm outcome after atrial fibrillation (AF) catheter ablation.
Methods:
In 67 patients with AF (59±11 years, 66 % male, 66 % lone AF) undergoing catheter ablation, circulating HSP70 and anti-HSP70 antibodies levels were quantified 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. 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=.035). Using multivariable regression analysis, AF type was the only variable associated with anti-HSP70 antibodies (Beta=.342, p=.008). At 6 months, HSP70 was present in 27 patients (41 %, p<.001 vs. baseline) with an overall increase (median 0, IQR 0 - 0 vs. 0, 0 - 0.09 ng/ml, p=.029). Similarly, there was an increase of anti-HSP70 antibodies (48, 36 - 72 vs. 57, 43 - 87 µg/ml, p<.001). AF recurrence rates were higher in patients with HSP70 increase >0.025 ng/ml (32 vs. 11 %, p=.038) or anti-HSP70 antibodies increase >2.5 µg/ml (26 vs. 4 %, p=.033).
Conclusion:
HSP70 and anti-HSP70 antibodies may be involved in the progression of AF and AF recurrence after catheter ablation.