Impact of Pulmonary Vein Anatomy on Long-term Outcome of Cryoballoon Ablation for Atrial Fibrillation.

Variant pulmonary vein anatomy (PVA) has been reported to influence the recurrence of atrial fibrillation (AF) after radiofrequency ablation. However, the effects of PVA on AF in patients undergoing cryoballoon ablation (CBA) remain unknown. The present study aimed to examine the impact of PVA on the long-term outcome of CBA for AF. A total of 78 patients (mean age 60.7±10.9 years, 64.1% males) with symptomatic and drug-refractory paroxysmal AF were enrolled in the study. Left atrium (LA) and PVA acquired at computed tomography angiography (CTA) were reconstructed with CARTO® 3 SYSTEM. Patients were routinely evaluated by 24-hour Holter monitoring following CBA. Cox regression was used to detect the predictors of AF recurrence after CBA. The results showed abnormal PVA in 30 patients (38.5%) and 18 patients (23.1%) had left common PV (LCPV). Electrical pulmonary vein isolation was achieved in all patients. After a mean follow-up of 689.5±103.8 days, it was found that patients with abnormal PVA had similar AF recurrence rate to those with normal PVA (26.7% vs. 25.0%, P=0.54), and there was no significant difference in AF recurrence rate between LCPV patients and non-LCPV patients (33.7% vs. 23.3%, P=0.29). Cox regression analysis showed that AF duration (72.9±9.0 vs. 42.3±43.2 months, HR 1.001; 95%CI 1.003-1.014; P<0.001) and cryo-applications of right-side PVs (3.0±1.6 vs. 4.7±1.7, HR 0.661; 95% CI 0.473-0.925; P=0.016) were independent predictors of freedom from AF, but PVA was not identified as a predictor of long-term success. In conclusion, the variant PVA cannot significantly influence the long-term outcome of AF patients undergoing CBA; longer AF duration and less cryo-applications of right-side PVs are associated with higher AF recurrent rate.

Protective effect of carnosine on subcortical ischemic vascular dementia in mice.

AIMS: Recently, we found carnosine protects against N-Methyl-D-Aspartate (NMDA) induced excitotoxicity through a histaminergic pathway. The aim of this study was to determine whether the carnosine-histidine-histamine pathway also played a protective role in subcortical ischemic vascular dementia (SIVD). METHODS: Adult male mice (C57BL/6 strain) were subjected to right unilateral common carotid arteries occlusion (rUCCAO) and treated with carnosine or histidine. Object recognition test, passive avoidance task, Morris water maze, and immunohistochemical analyses were performed after rUCCAO. RESULTS: We found that carnosine (200, 500 mg/kg) ameliorated white matter lesion and cognitive impairment evaluated by object recognition test, passive avoidance task, and Morris water maze test after rUCCAO in both wide-type mice and histidine decarboxylase knockout mice, which are lack of endogenous histamine. However, administration of histidine did not show the same effect. The myelin basic protein in the corpus callosum decreased obviously at day 37 after rUCCAO, which was largely reversed by carnosine (200, 500 mg/kg). Carnosine (200, 500 mg/kg) suppressed the activation of microglia and astrocyte as attenuating the elevation of glial fibrillary acidic protein (GFAP) and Iba-1 fluorescent intensity. Moreover, carnosine (200, 500 mg/kg) significantly attenuated the increase in reactive oxygen species generation after rUCCAO. CONCLUSION: These data suggest that the neuroprotective effect of carnosine on rUCCAO in mice is not dependent on the histaminergic pathway, but may be due to a suppression of reactive oxygen species generation, glia activation, and myelin degeneration.