Relationship between success of atrial fibrillation catheter ablation and left atrial strain echocardiography and cardiac MRI left atrial T1 mapping

Atrial fibrillation is a common arrithymia which is caracterized with atrial fibrosis in all aged population. Success rate of atrial fibrillation treatment is lower in patients have high atrial fibrosis. In this trial, we aimed to evaluate atrial fibrosis burden with some clinical parameters. In this prospective clinical study, 30 patients which are planned for atrial fibrillation catheter ablation with cryo-energy in Hacettepe University Adult Hospital Cardiology Clinic were enrolled. In addition to rutine clinical examination, patients were examined with cardiac MRI and transthoracic echocardiography. Blood sampling was done from left atrial cavity and peripheral vessels during the procedure. It was aimed that atrial disease level of patients were evaluated with cardiac MRI T1 relaxation time and transthoracic echocardiography parameters and blood levels of FGF-21 and FGF-23 which are fibrosis biomarkers. After the procedure, patients were followed for 12 months. Four of 30 patients had recurrences of atrial fibrillation during follow-up. We aimed to examine relationship between atrial fibrosis markers and the success of atrial fibrillation catheter ablation. Post contrast T1 relaxation time which was calculated in posterior left atrium was shorter in patients which had recurrences (325,75±27,11 ms; 431,41±52,59 ms; p=0,004). Blood levels of FGF-21 were not different neither santral nor peripheral between groups (patients without recurrences santral: 230,15±147,35 pg/ml, peripheral: 196,50±114,60 pg/ml; patients with recurrences santral:182,00±96,73 pg/ml, peripheral:128,25±76,36 pg/ml; p=0,625; p=0,300). Blood levels of FGF-23 were lower in patients without recurrences than patients with recurrences (patients without recurrences peripheral: 1946,54±302,95 pg/ml, santral:1848,20±286,05 pg/ml; patients with recurrences peripheral: 2392,53±199,00 pg/ml, santral:2367,93±162,86 pg/ml; p=0,009; p=0,002). Left atrial volüme index (56,00±13,04ml/2 - 27,31±11,41ml/m2; p=0,003) and left atrial passive empty fraction (%23,75±5,85 - %13,69±9,51; p=0,025) were higher in patients with recurrences. Left atrial active empty fraction (%14,50±4,20 - %29,65±11,46 p=0,008) and peak atrial reservoir strain (%14,00±4,51 - %21,64±7,02; p=0,019) were lower in patients with recurrences. Left atrial contraction strain index (%70,75±5,38 - %56,15±11,51 p=0,024) was higher in patients with recurrences. In conclusion, this study showed that cardiac MRI left atrial T1 relaxation time, blood levels of FGF-23, volumes of left atrium and left atrial strain could predict the success possibility of atrial fibrillation catheter ablation procedure. Large scaled, prospective, randomized trials and long-term outcome data are essential to understand the role of these parameters about atrial fibrillation catheter ablation success prediction and to use routinely in clinic approach.