Abstract
BACKGROUND: Obesity paradox addressing all-cause mortality has been described in several chronic total occlusion (CTO) studies. However, the impact of aging on long-term cardiac events in patients with overweight and obesity with CTO recanalization were less studied. METHODS: A total of 458 patients (64.4 ± 11.3 years, 403 male) with CTO interventions were enrolled. The overweight/obesity group included 311 patients with body mass index (BMI) ≧24 kg/m(2) and the non-obesity group included 147. With a median follow-up of 40.0 (17.9-61.4) months, 422 patients with successful true-lumen recanalization were further assessed for target lesion failure [TLF: cardiac death, target vessel myocardial infarction (TVMI), target lesion revascularization (TLR)]. RESULTS: At follow-up, the rates of cardiac death, TVMI, TLR, TLF, and stent thrombosis were 1.9%, 1.9%, 9.2%, 10.7%, and 0.5%, respectively. The TVMI-free survival was borderline better (p = 0.067 by log-rank test) in overweight/obesity than non-obesity group. Among patients <65 years of age, the TVMI-free survival was significantly better in the overweight/obesity group (p = 0.013 compared to non-obesity group by log-rank test). In multivariate Cox regression model, the non-obesity patients younger than 65 years were at a higher risk of TVMI, not only among those <65 years of age (hazard ratio = 11.0, 95% CI = 1.1-106.0) but also among the whole patients (hazard ratio=6.9, 95% CI = 1.4-35.1) with successful CTO recanalization. CONCLUSIONS: For those with true-lumen recanalized CTO, the higher risk of TVMI after successful recanalization was rather evident in patients <65 years of age and without overweight/obesity, suggesting that aging might attenuate prognostic significance of "obesity paradox" for CTO interventions.