目的:明确肌钙蛋白Ⅰ(cTnI)在心源性呼吸困难的鉴别诊断中有无应用价值。方法:比较急性心衰与急性肺源性呼吸困难时cTnI的变化情况,并观察一定的cTnI临界值辅助诊断心衰的敏感性和特异性。结果:总共156例患者,最后确诊为急性心衰的患者69例,而肺源性呼吸困难患者87例。急性心衰组的平均cTnI值为076±085ng/dL,而肺源性呼吸困难组为025±032ng/dL,两组间有显著性差异(Plt;0001)。根据ROC曲线计算肌钙蛋白Ⅰ的临界值(截点值)为042ng/dL,其鉴别心衰的敏感度为7153%,特异度为9036%,准确度为8014%。结论:检测肌钙蛋白Ⅰ水平并与其它临床信息相结合,有助于快速准确地诊断充血性心力衰竭。
In order to construct and express human cardiac troponin C-linker-troponin I(P) fusion protein, detect its activity and prepare lyophilized protein, we searched the CDs of human cTnC and cTnI from GenBank, synthesized cTnC and cTnI(30-110aa) into cloning vector by a short DNA sequence coding for 15 neutral amino acid residues. pColdⅠ-cTnC-linker-TnI(P) was constructed and transformed into E. coli BL21(DE3). Then, cTnC-linker-TnI(P) fusion protein was induced by isopropyl-β-D-thiogalactopyranoside (IPTG). Soluable expression of cTnC-linker-TnI(P) in prokaryotic system was successfully obtained. The fusion protein was purified by Ni2+ Sepharose 6 Fast Flow affinity chromatography with over 95% purity and prepared into lyophilized protein. The activity of purified cTnC-linker-TnI(P) and its lyophilized protein were detected by Wondfo FinecareTM cTnI Test. Lyophilized protein of cTnC-linker-TnI(P) was stable for 10 or more days at 37℃and 4 or more months at 25℃and 4℃. The expression system established in this research is feasible and efficient. Lyophilized protein is stable enough to be provided as biological raw materials for further research.
The objective of this study is to combine troponin and indicators of cardiac acoustics for synthetically evaluating cardiac fatigue of rabbits, analyzing exercise-induced cardiac fatigue (EICF) and exercise-induced cardiac damage (EICD). New Zealand white rabbits were used to conduct a multi-step swimming experiments with load, reaching an exhaustive state for evaluating if the amplitude ratio of the first to second heart sound (S1/S2) and heart rate (HR) during the exhaustive exercise would decrease or not and if they would be recovered 24-48 h after exhaustive exercise. The experimental end point was to complete 3 times of exhaustions or death from exhaustion. Circulating troponin I (cTnI) were detected from all of the experimental rabbits at rest [(0.02±0.01) ng/mL], which, in general, indicated that there existed a physiological release of troponin. After the first exhaustive swim, cTnI of the rabbits increased. However, with 24-hour rest, S1/S2, HR, and cTnI of the tested rabbits all returned toward baseline levels, which meant that the experimental rabbits experienced a cardiac fatigue process. After repeated exhaustion, overloading phenomena were observed, which led to death in 3 out of 11 rabbits, indicating their cardiac damage; the troponin elevation under this condition could be interpreted by pathological release. Evaluation of myocardial damage can not be based on the troponin levels alone, but can only be based on a comprehensive analysis.
Objective To measure the rate of changes of the cardiac troponin T (cTnT) and serum urea nitrogen (N), serum creatinine (Cr), estimated glomerular filtration rate (eGFR) of acute type A aortic dissection (AAAD) patients before and after surgery, and to explore the prognostic significance of the rate of changes. Methods We retrospectively analyzed 77 AAAD patients' clinical data between August 2015 and March 2016 from the department of the cardiothoracic surgery in Nanjing Drum Tower Hospital. There were 57 males and 20 females with an average age of 51.1±13.1 years. The test results of cTnT, N, Cr, eGFR were recorded. Patients were divided into three groups based on the duration of ventilation: less than 48 hours, 48 hours to 7 days, longer than 7 days, and divided into two groups based on whether postoperative dialysis was performed: dialysis group and non-dialysis group. Results In the groups with different duration of ventilation, the rate of cTnT change differed significantly. The rate of Cr and eGFR change in the group with the duration of ventilation longer than 7 days showed significantly different compared to other two groups. We found that the rate of Cr and eGFR change were statistically significant between the dialysis group and the non-dialysis group. In the receiver operating characteristic curve (ROC), the optimal cut-off value of the Cr growth rate for predicting postoperative dialysis therapy was 58.1%, and the optimal cut-off value of the eGFR decline rate was 45.5%. Conclusion The rate of changes in cTnT, N, Cr and eGFR can be used as a reliable mean to evaluate respiratory and renal function for AAAD patients in the early stage, which will facilitate an early assessment of the prognosis of AAAD patients.
ObjectiveTo evaluate the predictive value of the high-sensitivity cardiac troponin I (hs-cTnI) in patients with acute pulmonary embolism (APE). MethodsIn a retrospective cohort study,272 consecutive patients with APE were reviewed and the 30-days death and in-hospital adverse events were evaluated. The patients were classified according to hs-cTnI value into a high hs-cTnI group and a low hs-cTnI group. The simple pulmonary embolism severity index (sPESI) was used for clinical risk determination. The adverse event was defined as intravenous thrombolytic therapy,noninvasive ventilator support to maintain oxygen saturation >90% and suffered with severe complications. The correlations of hs-cTnI with sPESI score,30-days adverse events and mortality were analyzed. The Kaplan-Meier curves and the log-rank test were used to compare time-to-event survival. Stepwise multivariate logistic regression analysis models were used to determine the incremental prognostic value of sPESI score and hs-cTnI. ResultsThe incidence of 30-day death (6.1%),renal failure (14.6%),bleeding (13.4%) and thrombolytic therapy (7.9%) were higher in the high hs-cTnI group than those in the low hs-cTnI group (P values were 0.009,<0.001,0.018 and 0.003,respectively). The patients with sPESI ≥1 and low hs-cTnI had greater free adverse events survival (P=0.005). hs-cTnI provided incremental predictive value for in-hospital adverse events,beyond the sPESI score (P<0.001). Conclusionhs-cTnI has excellent negative predictive value of APE prognosis,especially when used combined with sPESI score.
Objective To investigate the changes of serum cardiac-specific troponin I (cTnI) level in patients after lung transplantation. Methods Clinical data of patients undergoing lung transplantation in our hospital from December 2016 to December 2022 were retrospectively analyzed. The relationship between postoperative serum cTnI level and clinical characteristics were explored. Results Finally 20 patients were collected, including 15 males and 5 females with an average age of (51.65±12.79) years. The serum cTnI level was significantly increased after lung transplantation. The serum cTnI reached the highest level on the first day after transplantation, and significantly decreased from the third day after transplantation. The serum cTnI levels in patients with obstructive pulmonary disease and bilateral lung transplantation were significantly higher than those in patients with restrictive pulmonary disease and unilateral lung transplantation on the day after surgery and on the first day after transplantation. Conclusion Transient myocardial injury can occur after lung transplantation, which is characterized by an abnormal increase in serum cTnI level.
Objective To identify clinical significance of high level cardiac troponin I （cTnI） in the early postoperative period of off-pump coronary artery bypass grafting （OPCAB） and its predictive value for early clinical outcomes. Methods A total of 240 patients undergoing isolated OPCAB in the Department of Cardiac Surgery of People’s Hospitalof Peking University during 2011 were recruited in the study. There were 164 males and 76 females with their age of 36-83（62.07±8.24） years. Serum cTnI levels in 4-6 hours and 12-18 hours after OPCAB were monitored. Influential factors and its predictive value for early clinical outcomes of OPCAB were analyzed. Binary logistic regression analysis，correlation analysis and receiver operating characteristic （ROC） curve were performed for statistic analysis. Results Serum cTnI level in 4-6 hours after OPCAB （TNI0） was 1.28±0.40 ng/ml，and serum cTnI level in 12-18 hours after OPCAB （TNI1） was 3.60±0.74 ng/ml. Binary logistic regression analysis revealed that graft number was significant influential factors of TNI0 （P=0.000） and TNI1 （P=0.010）. Serum cTnI level in 12-18 hours after OPCAB was significantly correlated with early clinicaloutcomes of OPCAB （P＜0.05），but the correlational relationship was not b （correlation coefficient＜0.5）. ROC curveanalysis showed that serum cTnI level in 12-18 h after OPCAB had higher predictive value for patient prognosis （P＜0.05）. Serum cTnI level higher than 1.49 ng/ml in 12-18 h after OPCAB had good predictive value for postoperative ECG changes，use of intra-aortic balloon pump （IABP） and in-hospital mortality. Conclusions Serum cTnI level increases in varying degrees in the early postoperative period of OPCAB. Together with ECG changes，serum cTnI level can be used for early diagnosis of perioperative myocardial infarction with significant predictive value for early clinical outcomes of OPCAB.
Objective To investigate the perioperative change and the predictive value of myoglobin, creatine kinase-MB (CK-MB), and cardiac troponin I (cTnI) in non-coronary cardiac surgery. Methods The clinical data of 77 patients undergoing cardiac surgery for non-coronary lesions in the Shanghai Xinhua Hospital from March 2016 to November 2016 were retrospectively reviewed, including 37 males and 40 females with a median age of 2 years. There were simple congenital heart diseases in 45 patients, complicated congenital heart diseases in 10, and heart valve diseases in 22. The levels of myoglobin, CK-MB and cTnI were collected at the first postoperative day. The ventilation duration and the length of ICU stay were recorded. The recovery condition was accessed by senior surgeons. Results The myoglobin, CK-MB and cTnI concentrations increased at the first postoperative day, and cTnI increased most significantly. The multivariate linear regression analysis indicated that these changes were only related to cardiopulmonary bypass time and aortic cross-clamping time (P<0.001). The high cTnI level was associated with prolonged ventilation duration and length of ICU stay. Fourteen patients (18.2%) did not recovered well, and their cTnI level was significantly higher than that of well-recovered patients (16.8±16.7 ng/mlvs. 5.1±4.4 ng/ml,P<0.001). The cTnI cutoff value of 5.33 ng/ml could predict whether patients had good postoperative recovery (area under the receiver operating characteristic curve=0.862,P<0.001), and the predictive value of cTnI was superior to that of myoglobin and CK-MB. Conclusion The increase levels of myoglobin, CK-MB and cTnI post non-coronary cardiac surgery are associated with prolonged cardiopulmonary bypass time and aortic cross-clamping time. cTnI on postoperative 24 h may predict good recovery, and it is a useful biomarker.