Incidence,timing, and predictors of valve dislodgment during TAVI with the medtronic corevalve system

Objectives : To determine the incidence, timing and predictors of periprocedural valve dislodgment with the Medtronic Corevalve System (MCS). Background : Periprocedural valve dislodgment may occur during transcatheter aortic valve implantation (TAVI). Methods : Ninety‐eight consecutive patients underwent TAVI with the MCS after a comprehensive baseline assessment including invasive angiography, echocardiography, and Multi‐Slice Computed Tomography (MSCT). The invasive monitoring charts and angiographic studies of all TAVI procedures were reviewed to determine the incidence and timing of valve dislodgment. Results : Valve dislodgment occurred in 18 patients. Patients with valve dislodgment had a larger Aortic Valve Area (0.76 ± 0.25 cm² vs. 0.61 ± 0.19 cm², P = 0.007), lower mean transaortic gradient (37.65 ± 14.62 mm Hg vs. 47.11 ± 16.08 mm Hg, P = 0.03) and significantly less aortic root calcification (Agatston score median 1951 AU (IQR, 799–3103) vs. 3289 AU (IQR 2097–4481), P = 0.016). A lower aortic root calcium score (Agatston score < 2359 AU) was the single independent predictor for valve dislodgment (OR 3.10, 1.09–8.84). After valve dislodgment, the valve could be successfully retrieved and implanted in the proper anatomic location in all cases. Valve dislodgment was associated with a lower incidence of post‐procedural AR ≥ 2 (11.1% vs. 34.6%, P = 0.05). There were no relevant procedural or clinical implications to valve dislodgment. Conclusions : The incidence of periprocedural valve dislodgment was 18% in these series. Less aortic root calcification appeared the single independent predictor. © 2011 Wiley Periodicals, Inc.     

Locomotor Training and Muscle Function After Incomplete Spinal Cord Injury: Case Series

Abstract

Background/Objective: To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). Study Design: Longitudinal prospective case series.

Methods: Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque₂₀₀), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle crosssectional area (CSA) was measured prior to and after LT.

Results: Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% ± 20.0%), followed by the more-involved KE (21.1% ± 12.3%). Even larger improvements were realized in Torque200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles.

Conclusion: Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.