The Prognostic Value of the Results of 123 I-metaiodobenzylguanidine Myocardial Scintigraphy in the Examination of Patients with Atrial Fibrillation Referred for Its Interventional Treatment

Objective. To identify the scintigraphic predictors of the efficiency of interventional treatment for atrial fibrillation (AF) by cardiac 123 I-metaiodobenzylguanidine ( 123 I-MIBG) radionuclide scanning. Material and methods. The investigation enrolled 35 patients with AF concurrent with hypertensive disease (HD): 17 persons with persistent AF (PAF) and 18 patients with long-standing PAF (LPAF). In addition, 10 patients with HD without arrhythmia signs were examined as a comparison group. All the patients with AF before radiofrequency ablation (RFA) and those with sinus rhythm underwent 123 I-MIBG myocardial scintigraphy to assess the sympathetic innervation of the heart. The efficiency of RFA was evaluated after 12 months by 24-hour ECG monitoring. Results. The patients of both groups were divided into subgroups according to the presence of recurrent arrhythmia one year after interventional treatment. ROC analysis could determine the main scintigraphic predictors of the efficiency of RFA. The preoperative indicators, in which the subgroups with and without recurrent AF showed significant differences, were studied. In the patients with PAF, the delayed Heart/ Mediastinum (H/M) ratio cutoff was ≥1.55 (the area under the ROC curve was 0.929; 100% sensitivity and 57% specificity), and the threshold value of 123 I-MIBG washout rate was ≤22.3% (the area under ROC curve was 0.957; 100% sensitivity and 43% specificity) may suggest that RFA is effective. In the patients with LPAF, the threshold values of early H/M ratio were ≥1.69 (the area under the ROC curve was 0.849; 100% sensitivity and 62% specificity) and those of delayed H/M ratio were ≥1.66 (the area under the ROC curve was 0.938; 94% sensitivity and 23% specificity) allow the prediction of a risk for postoperative recurrent AF. Conclusion. The findings suggest that 123 I-MIBG scintigraphy can be used to predict a high risk for recurrent AF after RFA of the pathological pathways of a pulse in the myocardium.