On-X Valve: The Next Generation Aortic Valve.

The On-X valve is a newer generation mechanical bileaflet valve. Its key features include the use of pure pyrolytic carbon (devoid of silicon), a length-to-diameter ratio similar to a native valve, an inlet flared orifice, a leaflet opening up to 90 degrees, a shorter leaflet closing angle, a 2-point leaflet contact, and an actuated pivot. These features have translated into increased strength, improved valve hemodynamics, reduced hemolysis, and thrombogenicity. The 2014 American Heart Association/American College of Cardiology guidelines for the management of patients with valvular heart disease recommend an international normalized ratio (INR) of 2.5 (range, 2-3) in patients with a mechanical valve at the aortic position. However, based on the results of the Prospective Randomized On-X Anticoagulation Clinical Trial (PROACT), the Food and Drug Administration approved this valve in April 2015 in the aortic position with a lower INR goal of 1.5-2.0. This reduction in INR goals led to a statistically significant reduction in the combined endpoint of clots, bleeding events, and stroke rates with 9/patient-years for the lower INR group compared with 12/patient-years in the standard INR group. This review compares the currently available literature on the On-X valve with that of other contemporary valves.

Safety And Efficacy Of Uninterrupted Periprocedural Apixaban In Patients Undergoing Atrial Fibrillation Catheter Ablation: A Metaanalysis Of 1,057 Patients.

Apixaban (factor Xa inhibitor) is a novel anticoagulant and may be beneficial during atrial fibrillation (AF) ablation for prevention of thromboembolic events. However, the adverse effects of periprocedural apixaban therapy have not been thoroughly evaluated. A meta-analysis was performed to evaluate the safety of apixaban for anticoagulation in AF ablation. We searched the online databases till October 2015 for studies comparing Apixaban with Vitamin K antagonists in atrial fibrillation patients undergoing catheter ablation. Primary outcome of our study was composite of thromboembolic event and bleeding (includes major and minor bleeding). A total of 1,057 atrial fibrillation patients in 3 studies undergoing catheter ablation were included in this analysis. Zero thromboembolic events were reported in the apixaban group and 1 in the VKA group with no statistical difference (OR 0.75; 95% CI 0.03-18.49). No major differences were observed for the primary outcome (OR 0.92; 95% CI 0.54-1.55), risk of overall bleeding (OR 0.94, 95% CI 0.55- 1.58), major bleeding (OR1.37; 95% CI 0.33-5.67), minor bleeding (OR 0.89; 95% CI 0.50-1.55), pericardial effusion (OR 0.50; 95% CI 0.18-1.38) and groin hematoma (OR 1.36; 95% CI 0.70-2.65). Uninterrupted apixaban administration in patients undergoing AF catheter ablation was non-inferior to VKA without increasing the risk of major and minor bleeding.

Cryoballoon versus Radiofrequency Ablation for Atrial Fibrillation: A Meta-analysis of 16 Clinical Trials.

Introduction: We aimed to study the procedural characteristics, efficacy and safety of cryoballoon ablation (CBA) versus radiofrequency ablation (RFA) for catheter ablation of paroxysmal atrial fibrillation (AF). Methods: A systematic literature search was performed using PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to clinical trials comparing CBA and RFA for AF. Outcomes were evaluated for efficacy, procedure characteristics and safety. For each study, odd ratio (OR) and 95% confidence intervals (CIs) were calculated for endpoints for both approaches. Results: We analyzed a total of 9,957 participants (3,369 in the CBA and 6,588 in RFA group) enrolled in 16 clinical trials. No significant difference was observed between CBA and RFA with regards to freedom from atrial arrhythmia at 12-months, recurrent atrial arrhythmias or repeat catheter ablation. CBA group had a significantly higher transient phrenic nerve injury (OR 14.19, 95% CI: 6.92-29.10; p<0.001) and persistent phrenic nerve injury (OR 4.62, 95% CI: 1.97-10.81; p<0.001); and a significantly lower pericardial effusion/cardiac tamponade (OR 0.43, 95% CI: 0.26-0.72; p=0.001), and groin site complications (OR 0.60, 95% CI: 0.38-0.93; p=0.02). No significant difference was observed in overall complications, stroke/thromboembolic events, major bleeding, and minor bleeding. Conclusion: CBA was non-inferior to RFA for catheter ablation of paroxysmal AF. RF ablation was associated with a higher groin complications and pericardial effusion/cardiac tamponade, whereas CBA was associated with higher rates of transient and persistent phrenic nerve injury.