Early Experience of Novel Oral Anticoagulants in Catheter Ablation for Atrial Fibrillation: Efficacy and Safety Comparison to Warfarin

PURPOSE: Compared with warfarin, novel oral anticoagulants (NOACs) are convenient to use, although they require a blanking period immediately before radiofrequency catheter ablation for atrial fibrillation (AF). We compared NOACs and uninterrupted warfarin in the peri-procedural period of AF ablation. MATERIALS AND METHODS: We compared 141 patients treated with peri-procedural NOACs (72% men; 58+/-11 years old; 71% with paroxysmal AF) and 281 age-, sex-, AF type-, and history of stroke-matched patients treated with uninterrupted warfarin. NOACs were stopped 24 hours before the procedure and restarted on the same procedure day after hemostasis was achieved. RESULTS: We found no difference in the CHA2DS2-VASc (p=0.376) and HAS-BLED scores (p=0.175) between the groups. The preprocedural anticoagulation duration was significantly shorter in the NOAC group (76.3+/-110.7 days) than in the warfarin group (274.7+/-582.7 days, p<0.001). The intra-procedural total heparin requirement was higher (p<0.001), although mean activated clotting time was shorter (350.0+/-25.0 s vs. 367.4+/-42.9 s, p<0.001), in the NOAC group than in the warfarin group. There was no significant difference in thromboembolic events (1.4% vs. 0%, p=0.111) or major bleeding (1.4% vs. 3.9%, p=0.235) between the NOAC and warfarin groups. Minor stroke occurred in two cases within 10 hours of the procedure (underlying CHA2DS2-VASc scores 0 and 1) in the NOAC group. CONCLUSION: Pre-procedural anticoagulation duration was shorter and intra-procedural heparin requirement was higher with NOAC than with uninterrupted warfarin during AF ablation. Although the peri-procedural thromboembolism and bleeding incidences did not differ, minor stroke occurred in two cases in the NOAC group.

Mechanisms of Paroxysmal Supraventricular Tachycardias according to Age and Gender

BACKGROUND AND OBJECTIVES: Age and gender are known to influence the mechanisms of paroxysmal supraventricular tachycardia (PSVT), but large scale data regarding this subject is limited. In addition, data regarding the mechanisms of PSVT in the Korean population is limited. In this study, we sought to investigate the different mechanisms of PSVT according to age and gender in Korean patients. SUBJECTS AND METHODS: Database of 3,176 patients diagnosed with PSVT excluded atrial flutter or atrial fibrillation and referred for electrophysiologic study from 1986 to 2004 was retrospectively analyzed. The mechanisms of PSVT were classified as: WPW syndrome (WPW), atrioventricular reentrant tachycardia (AVRT) due to a concealed bypass tract (CBT), atrioventricular nodal reentrant tachycardia (AVNRT), atrial tachycardia (AT). RESULTS: The mean age was 40.7+/-16.0 (1-90) and 53.3% of the patients were male. The mean age of females was significantly higher than males. (43.0+/-16.1 vs. 38.6+/-15.6, p<0.001) Overall, the dominant mechanism of tachycardia was AVRT at 62.6% (WPW: 31.1%, CBT: 31.5%), compared to AVNRT at 34.1 and AT at 3.1%. This was mainly due to the predominance of AVRT (74.2%; WPW: 38.1%, CBT: 361%) in male. The mechanisms of PSVT differed according to gender with 63.2% (1257/1988) of AVRT patients being males where as 64.6% (700/1084) of the AVNRT patients were females. The distribution of PSVT mechanisms differed according to gender. In males, the proportions of AVNRT : CBT : WPW were 22.7 : 36.1 : 38.1%, whereas in females the proportion was 47.2 : 26.3 : 23.0%. Age had a significant influence upon the mechanism of PSVT in both genders with an increasing proportion of AVNRT and a decreasing proportion of AVRT in the older age groups. AVRT was the dominant mechanism of PSVT in all age groups for males, where as AVNRT was the dominant mechanism of PSVT for females over 50 years of age. CONCLUSION: The mechanism of PSVT differs significantly according to age and gender. This may be due to the increased degeneration of accessory pathway with age and difference in the conduction properties of the accessory pathway according to gender. In Koreans, the overall dominant mechanism of PSVT was AVRT mainly due to it a greater male population.