ABSTRACT
Objective Perioperative myocardial infarction remains a severe complication in non-cardiac surgery and is one of the major causes of death.Cardiac troponin (cTn) Ⅰ elevation is associated with short-term and long-term mortality.The aim of the study was to assess the proportion rate of cTnⅠ elevation and its clinical characteristics among patients admitted for orthopaedic surgery with or without cardiovascular events.Methods This is a retrospective study including 27 744 patients aged 50 years or older who admitted for orthopaedic surgery from 2009-2015 in Beijing Jishuitan Hospital.Results Two hundred and sixty-five patients [age (71.7±9.9) years] had cTnⅠ level＞ 0.04 μg/L with 66％ (175 patients) of them being female.Among them,59 patients were isolated troponin rise (ITR) (n=59),13 were preoperative acute myocardial infarction (AMI),and 193 were postoperative AMI.The proportion of postoperative AMI was 0.69％.Those patients were more likely to have a history of coronary artery disease or hypertension.Non-ST-segment elevation myocardial infarction (NSTEMI) was more common (93.3％) than ST-segment elevation myocardial infarction in these patients.Most of them did not experience ischemic symptoms.Totally 76.7％ of the AMI occurred within 3 days of surgery;and the in-hospital mortality rate was 10.4％.Conclusions Perioperative elevation of troponin is common in patients undergoing orthopaedic surgery.Most postoperative AMI were NSTEMI and with absent or atypical ischemia symptoms.Monitoring troponin levels and electrocardiograph in at-risk patients is needed to find most of the AMI.
ABSTRACT
Objective To investigate the levels of serum chemerin in the acute myocardial infarction (AMI) patients and explore the clinical significance.Methods A total of 76 AMI patients from January 2013 to December 2013 were inrolled and 30 healthy patients were included as normal control(NC) group.Chemerin, tumor necrosis factor α(TNF-α), adiponectin were asessed by enzyme linked immunosorbent assay(ELlSA).The clinical data of high sensitivity C reactive protein (hs-CRP), body mass index (BMI), blood lipids, underlying diseases et al were collected.Results Serum levels of chemerin in AMI patients was higher than the NC group significantly((12.97±4.17) μg/L vs.(30.96± 17.16) μg/L, t =5.642, P＜0.001).The Serum levels of Chemerin in single vessel disease group, two vessel disease group and triple vessel disease group were (22.25 ± ±6.93) μg/L, (28.57 ± 15.92) μg/L, (37.95 ± 16.52) μg/L respectively and was linearly increasing relationship with increasing AMI severity (P＜0.001, F =22.84, r2 =0.397).Serum levels of Chemerin positively correlated with TNF-α, hs-CRP level(r2=0.347,0.455 ,P＜0.001) and negative correlated with adiponectin(r2 =0.396,P＜0.001).Logistic regression analysis showed that chemerin was an independent risk factor for AMI (OR =4.822,95％ CI 4.422-7.141, P =0.032).Conclusion The results showed that serum chemerin levels were significantly elevated in AMI patients,and chemerin may be involved in the development process of AMI.
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Objective To study the changes and clinical significance of heart rate turbulence(HRT)in patients with diabetic cardiomyopathy.Methods 24h Holter ECG recordings were examined in 33 patients with diabetic cardiomyopathy(DC)and 30 patients in the control group.Turbulence onset(TO)and turbulence slope (TS)were calculated from Holter recordings.The mean value of TO,TS between the two groups were compared,the relativity among TO,TS,SDNN and LEVDD were analyzed as well.Results TO was significantly higher in the DC group compared with the control group[(-0.38 ± 0.12)％ vs(-1.88 ± 0.13)％,t =7.38,P =0.01)].TS in the DC group was significantly lower than that in the control group[(2.02 ± 0.82)ms/R-R vs (9.72 ± 1.18)ms/R-R,t =18.69,P =0.02)].TO was significantly related to SDNN(r =-0.35,P =0.02)and LEVDD(r =0.68,P =0.01),TS was also significantly related to SDNN(r =0.45,P =0.01)and LEVDD (r =-0.39,P =0.03).Conclusion The manifest of heart rate turbulence is significantly impaired in patients with diabetic cardiomyopathy.
ABSTRACT
Biodegradable magnesium-alloy stents have been employed in animal experiments and clinical researches in recent years. Magnesium-alloy stents have been reported to be biocompatible, and degradable due to corrosion after being implanted into blood vessel. However, magnesium alloy is brittle compared with stainless steel. This may cause strut break under large deformation. In this paper, a finite element model of magnesium-alloy stent was set up, with reference to pictures from Biotronik Corporation, to simulate the expanding and bending processes. The results of analysis show that the maximum strain during expanding reaches 20%, being greater than the elongation limit of the commercially available magnesium alloys. Therefore, to avoid strut breakage during expanding, the magnesium alloys should be custom-made. The plasticity of the material should be improved by grain refinement processes before practicable magnesium-alloy stents could be developed.