Pulmonary vein isolation (PVI) with radio-frequency catheter ablation (RFCA) is effective therapy for the patients with paroxysmal atrial fibrillation (pAF). However, it is not easy to predict relapse of pAF. Approximately 70% pAF patients were maintained sinus rhythm for 1 year after PVI in Japan. In this study, all of the cases were underwent chest computed tomography (CT) to check for the morphology and positional relationship of the left atrium. We detected relapse cases that exhibited spur formation in the thoracic vertebrae. Therefore, we conducted an investigation based on the hypothesis that, "Because hyperostosis involves proliferative changes in the synovium or pia mater cells with an inflammatory basis, it is related to the onset of atrial fibrillation." The study sample consisted of 24 sequential cases (males: 20, mean age: 66.2 ± 6.9 years) of drug-resistant pAF that underwent PVI at our hospital between January and May, 2015. When subjects were divided into a relapse group and a non-relapse group and 21 background factors were compared, it was found that the relapse group subjects were older than the non-relapse group subjects (70.3 ± 7.2 vs 64.1 ± 5.7, p = 0.04). The proportion of cases with thoracic vertebra hyperplasia was markedly high in the relapse group (6 cases [75%] vs. 3 cases [18%], p = 0.007). No statistically significant differences were observed between the two groups for any other background factors. Our results suggested that thoracic vertebra hyperplasia could be a marker for predicting relapse after PVI in pAF patients.