Objective. To investigate the risk factors of radial artery obstruction after repeated right radial coronary interventions. Methods. 497 patients who underwent repeated coronary intervention via the right radial artery in our hospital from January 2017 to January 2021 were selected and followed up for 28.07 ± 6.07 months. According to whether the right radial artery was obstructed or not, they were divided into radial artery occlusion group (n = 48) and nonradial artery occlusion group (n = 449). Results. The proportion of patients with diabetes mellitus, elevated D-dimer, and elevated LDL cholesterol was higher in the radial artery occlusion group than in the nonradial artery occlusion group (
p
<
0.05
). The radial artery occlusion group had more passage through the right radial artery often and had a longer cumulative sheath retention time than the radial artery occlusion group (
p
<
0.05
). Cumulative sheath retention time (hours) had a high predictive value for radial artery occlusion. The optimal diagnostic limit for radial artery occlusion was 2.75 h, with a sensitivity of 77.1% and a specificity of 79.5% (
p
<
0.05
). Conclusion. Diabetes mellitus, elevated D-dimer, elevated LDL cholesterol, and long retention sheath time predispose to radial artery occlusion. Cumulative duration of sheath retention is a predictor of radial artery occlusion.
Background. Although calcium channel blockers (CCBs) are recognized as clinical first-line agents for the treatment of hypertension, their use in combination with diuretics in cardiovascular disease caused by hypertension remains controversial. Methods. We searched the three major databases of the Cochrane Library, EMBASE, and PubMed for the terms “calcium channel blockers,” “thiazide diuretics,” “loop diuretics,” and “hypertension,” “randomized controlled trials” and “meta-analysis trials.” These terms were searched from January 1991 to October 2021. Results. For the primary outcome, in 5 studies including 35,057 patients, there was no statistically significant difference in all-cause mortality with calcium channel blockers compared with diuretics (RR = 0.98, 95% CI 0.92–1.04, I2 = 0). In four studies including 33,643 patients with major cardiovascular events, there was no statistically significant difference in major cardiovascular events with calcium channel blockers compared with diuretics (RR = 1.00, 95% CI 1.04–1.09, I2 = 0). Conclusion. There is no statistically significant difference between calcium channel blockers and diuretics in terms of cardiovascular clinical prognosis in hypertensive patients, but there are positive implications for clinical guidance, which need to be fully validated in new large randomized controlled trials.
The stick–slip piezoelectric actuator is a promising type for precision positioning with large stroke and high resolution; however, it is still challenging to achieve high motion speed at a relatively low driving frequency. To solve this problem, a novel two-stage amplification mechanism (TSAM) was designed, and correspondingly, a stick–slip piezoelectric actuator was developed. The structure, two-stage amplification principle, and motion processes of the designed actuator were addressed in detail, followed by analyzing the displacement amplification ratio and stress of TSAM via the elastic beam method and finite element method, respectively. Then, the actuator prototype was fabricated, and its output performances were tested under various experimental parameters. By comparative analysis with the actuator that only used the first-stage amplification hinge, the significant improvement in stepping displacement was verified when employing the TSAM. The resultant maximum motion speed was 20.05 mm/s, achieved under the locking force of 2 N, the input voltage of 100 V, and the driving frequency of 700 Hz. In addition, the developed actuator still maintained competitive motion resolution and loading capacity. The comparative analysis with some previous studies further indicated that the developed actuator with the TSAM had successfully achieved a relatively high motion speed at a relatively low driving frequency, which would be beneficial to the practical application.
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