ABSTRACT
Background: Transcatheter aortic valve implantation (TAVI) has recently become more common as a treatment for severe, symptomatic aortic stenosis (AS). Cognitive impairment (CI) is strongly associated with the prognosis of TAVI patients. However, some cognitive assessments currently in use are difficult to perform routinely in the clinical setting. To easier CI evaluation, we investigated whether CI using the clock-drawing test (CDT), one part of the Mini-Cog, affects the postoperative prognosis of TAVI patients with AS. Methods: The present study enrolled 52 patients (median age, 85 years; 28.8% male) who underwent TAVI and were discharged between 2019 and 2021. The outcome was readmission for all causes within one year of discharge and patients were grouped according to whether they were readmitted or not. Cognitive function was assessed using the Mini-Cog which combines verbal playback and CDT. Results: Of the 52, 11 patients (21.2%) comprised readmission group, including 4 (36.4%) each for fracture and infection, and 1 (9.1%) each for heart failure, subdural hematoma, and pneumothorax. Median Mini-Cog score was lower in the readmission group than in the non-readmission group (4 vs. 5; P < 0.05). The frequency of Mini-Cog score < 3 (indicative of CI) and CDT failure were significantly higher in the readmission group than in the non-readmission group, respectively (46% vs. 7%, P < 0.01) (46% vs. 12%, P < 0.05). Both of Mini-Cog score < 3 and CDT failure were independently associated with readmission. The areas under the curve showed CDT was an indicator of readmission with similar accuracy to the Mini-Cog score < 3. Kaplan-Meier curves showed significant differences in readmission after 1 year between the 2 Mini-Cog groups with scores of < 3 or ≥ 3 points and CDT failure and success. Conclusion: The CDT may be a very easy and simple screening assessment of preoperative CI with readmission within one year after TAVI.
ABSTRACT
It is very important to observe the concentrations and flow patterns of blood through a dialyzer to evaluate its function and to obtain the most appropriate design. We established a visualization method for the blood flow pattern in a dialyzer using X-ray computed tomography, and investigated the so-called internal filtration phenomenon. The results obtained were as follows: (1). The influence of 5% BaSO(4), which was added to the blood as a contrast medium, on the filtration rate of the dialyzer was minimal. (2). The relationship between the concentration of BaSO(4) and the Hounsfield unit value was expressed by linear regression. (3). Hounsfield unit values increased massively just after blood entered the dialyzer and peak values increased with dialysate perfusion under the following conditions: the dialyzer (BS-1.6UL, polysulfone hollow fibers) was used, and bovine blood with 5% BaSO(4) added was used at a blood flow rate of 200 ml/min. The dialysate flow rate was 500 ml/min and the slice thickness of X-ray computed tomography was 1-10 mm. (4). It was observed that blood flowed slightly faster in the center than the peripheral portion of the dialyzer, when the flow pattern was followed after pulse injection of blood containing 20% BaSO(4) into the dialyzer. It was concluded that this method could possibly be utilized not only qualitatively but also quantitatively for observation of the real state of blood flow and in designing dialyzers.
